01_FM:IP_Clewell
9/17/07
11:00 AM
Page i
01_FM:IP_Clewell
9/17/07
11:00 AM
Page ii
about island press Island Press is the only nonprofit organization in the United States whose principal purpose is the publication of books on environmental issues and natural resource management. We provide solutionsoriented information to professionals, public officials, business and community leaders, and concerned citizens who are shaping responses to environmental problems. Since 1984, Island Press has been the leading provider of timely and practical books that take a multidisciplinary approach to critical environmental concerns. Our growing list of titles reflects our commitment to bringing the best of an expanding body of literature to the environmental community throughout North America and the world. Support for Island Press is provided by the Agua Fund, The Geraldine R. Dodge Foundation, Doris Duke Charitable Foundation, The Ford Foundation, The William and Flora Hewlett Foundation, The Joyce Foundation, Kendeda Sustainability Fund of the Tides Foundation, The Forrest & Frances Lattner Foundation, The Henry Luce Foundation, The John D. and Catherine T. MacArthur Foundation, The Marisla Foundation, The Andrew W. Mellon Foundation, Gordon and Betty Moore Foundation, The Curtis and Edith Munson Foundation, Oak Foundation, The Overbrook Foundation, The David and Lucile Packard Foundation, Wallace Global Fund, The Winslow Foundation, and other generous donors. The opinions expressed in this book are those of the authors and do not necessarily reflect the views of these foundations.
about the society for ecological restoration international The Society for Ecological Restoration International (SER) is an international nonprofit organization comprising members who are actively engaged in ecologically sensitive repair and management of ecosystems through an unusually broad array of experience, knowledge sets, and cultural perspectives. The mission of SER is to promote ecological restoration as a means of sustaining the diversity of life on Earth and reestablishing an ecologically healthy relationship between nature and culture. The opinions expressed in this book are those of the authors and are not necessarily the same as those of SER International. SER, 285 W. 18th Street, #1, Tucson, AZ 85701. Tel. (520)622-5485, Fax (270)626-5485, e-mail
[email protected], www.ser.org.
01_FM:IP_Clewell
9/17/07
11:00 AM
Page iii
ecological restoration
01_FM:IP_Clewell
9/17/07
11:00 AM
Page iv
Society for Ecological Restoration International The Science and Practice of Ecological Restoration James Aronson, editor Donald A. Falk, associate editor Wildlife Restoration: Techniques for Habitat Analysis and Animal Monitoring, by Michael L. Morrison Ecological Restoration of Southwestern Ponderosa Pine Forests, edited by Peter Friederici, Ecological Restoration Institute at Northern Arizona University Ex Situ Plant Conservation: Supporting the Survival of Wild Populations, edited by Edward O. Guerrant Jr., Kayri Havens, and Mike Maunder Great Basin Riparian Ecosystems: Ecology, Management, and Restoration, edited by Jeanne C. Chambers and Jerry R. Miller Assembly Rules and Restoration Ecology: Bridging the Gap Between Theory and Practice, edited by Vicky M. Temperton, Richard J. Hobbs, Tim Nuttle, and Stefan Halle The Tallgrass Restoration Handbook: For Prairies, Savannas, and Woodlands, edited by Stephen Packard and Cornelia F. Mutel The Historical Ecology Handbook: A Restorationist’s Guide to Reference Ecosystems, edited by Dave Egan and Evelyn A. Howell Foundations of Restoration Ecology, edited by Donald A. Falk, Margaret A. Palmer, and Joy B. Zedler Restoring the Pacific Northwest: The Art and Science of Ecological Restoration in Cascadia, edited by Dean Apostol and Marcia Sinclair A Guide for Desert and Dryland Restoration: New Hope for Arid Lands, by David A. Bainbridge Restoring Natural Capital: Science, Business, and Practice, edited by James Aronson, Suzanne J. Milton, and James N. Blignaut Old Fields: Dynamics and Restoration of Abandoned Farmland, edited by Viki A. Cramer and Richard J. Hobbs Ecological Restoration: Principles, Values, and Structure of an Emerging Profession, by Andre F. Clewell and James Aronson
01_FM:IP_Clewell
9/17/07
11:00 AM
Page v
Ecological Restoration Principles, Values, and Structure of an Emerging Profession
Andre F. Clewell and James Aronson
Society for Ecological Restoration International
Washington • Covelo • London
01_FM:IP_Clewell
9/17/07
11:00 AM
Page vi
Copyright © 2007 Andre F. Clewell and James Aronson All rights reserved under International and Pan-American Copyright Conventions. No part of this book may be reproduced in any form or by any means without permission in writing from the publisher: Island Press, 1718 Connecticut Ave., NW, Suite 300, Washington, D.C. 20009. ISLAND PRESS
is a trademark of The Center for Resource Economics.
Grateful appreciation is acknowledged for permission to reprint Guidelines for Developing and Managing Ecological Restoration Projects, 2d edition, by Andre Clewell, John Rieger, and John Munro. Copyright 2005 by the Society for Ecological Restoration International. Library of Congress Cataloging-in-Publication data. Clewell, Andre F. Ecological restoration : principles, values, and structure of an emerging profession / Andre F. Clewell and James Aronson. p. cm. Includes bibliographical references and index. ISBN 978-1-59726-168-5 (hardcover : alk. paper) — ISBN 978-1-59726-169-2 (pbk. : alk. paper) 1. Restoration ecology. I. Title. QH541.15.R45C54 2007 639.9—dc22 2007025912 British Cataloguing-in-Publication data available. Printed on recycled, acid-free paper Design by Karen Wenk Manufactured in the United States of America 10 9 8 7 6 5 4 3 2 1
01_FM:IP_Clewell
9/17/07
11:00 AM
Page vii
contents
contents
vii
dedication
ix
preface
xi
Introduction
PART I. Introduction and Essential Background Chapter 1. Essence of Restoration
1
5 7
Virtual Field Trip 1. Restoring Desertified Vegetation in Australia David Tongway and John Ludwig
14
Chapter 2. Ecological Impairment and Recovery
19
Virtual Field Trip 2. Restoring Cultural Landscapes in Central Chile Carlos Ovalle and James Aronson
33
Chapter 3. Cultural Ecosystems, Fire, and Alternative States
38
PART II. Elements of Restoration Projects
53
Chapter 4. Ecological Attributes of Restored Ecosystems
55
Virtual Field Trip 3. Restoring Wet Prairie in Mississippi, USA George Ramseur Jr. and Andre F. Clewell
70
Chapter 5. Reference Models and Developmental Trajectories
75
Chapter 6. Project Planning and Evaluation
88
PART III. Values That Restoration Addresses
97
Virtual Field Trip 4. Restoring a Communal Savanna in South Africa James Blignaut and Rudi van Aarde
99
Chapter 7. Values and Ecological Restoration
104
Virtual Field Trip 5. Restoring Forests and People’s Well-Being in Southern India Narayanan Krishnakumar and T. S. Srinivasa Murthy
112
vii
01_FM:IP_Clewell
viii
9/17/07
11:00 AM
Page viii
Contents
Chapter 8. A Four-Quadrant Model for Holistic Ecological Restoration
PART IV. Structure of an Emerging Profession
116
123
Virtual Field Trip 6. Restoring Drained Peatlands for Sustainable Use in Germany Achim Schäfer and Wendelin Wichtmann
125
Chapter 9. Relationship of Restoration to Related Fields
130
Virtual Field Trip 7. Restoring Dogleg Branch in Florida, USA Andre F. Clewell
141
Chapter 10. Project Roles and Contexts
147
Virtual Field Trip 8. Setting Up a Long-Term Restoration Ecology Research Site in Southern France James Aronson and Edouard Le Floc’h
158
Chapter 11. Recognizing the Profession and the Professional
163
PART V. Holistic Ecological Restoration Chapter 12. The Concept of Holistic Ecological Restoration: A Synthesis
167 169
appendix: guidelines for developing and managing ecological restoration projects Andre Clewell, John Rieger, and John Munro
173
glossary
191
references
199
about the authors and collaborators
209
index
211
01_FM:IP_Clewell
9/17/07
11:00 AM
Page ix
We dedicate this book to our colleague the late Keith Winterhalder.
01_FM:IP_Clewell
9/17/07
11:00 AM
Page x
01_FM:IP_Clewell
9/17/07
11:00 AM
Page xi
preface
The Science and Practice of Ecological Restoration Book Series is intended to serve a broad audience of people who are active in the field of ecological restoration or who have special interests in it. Of the twelve previously issued volumes in the series, most have emphasized restoration science and its applications but not the process of doing ecological restoration projects. These volumes were intended largely for teachers, students, and researchers. Other volumes are more practical but address practitioners, trainees, and students who work in specific bioclimatic regions, such as Cascadia, in western North America, or very specific contexts such as old fields (abandoned agricultural lands). The present book attempts to provide a more comprehensive treatment of the field for all those who are associated with restoration practice, both the programs and specific projects. We treat concepts, principles, and values that are applicable to restoration practice anywhere in the world and describe the emerging profession and the professionals of ecological restoration.
Acknowledgments We would like to thank our wives, Judith Snow-Clewell and Joëlle Fischer, for their patience and support and for their insights when we became stymied in the writing process. James thanks Thibaud and Perrine for graciously tolerating their father’s frequent absences during the preparation of this book. We offer heartfelt thanks to Dean Apostol, James Blignaut, Keith Bowers, Barbara Dean, Bev Devincat, Narayanan Krishnakumar, Liz McPhee, Sue Milton, John Munro, John Rieger, John Stanley, and Paddy Woodworth for their reviews of much or all of the manuscript at short notice and for their suggestions, which led to many improvements. In addition, we thank Don Falk, William Jordan III, John Ludwig, and Dave Tongway, who read parts of the book and gave us many useful comments. We acknowledge the substantial effort of John Rieger and John Munro, coauthors of the guidelines reproduced in the Appendix. We thank all our collaborators who kindly provided or helped prepare Virtual Field Trips, including David Tongway and John Ludwig, Carlos Ovalle, George Ramseur Jr., James Blignaut and Rudi van Aarde, Narayanan Krishnakumar and T. S. Srinivasa Murthy, Achim Schäfer and Wendelin Wichtmann, and Edouard Le Floc’h. xi
01_FM:IP_Clewell
xii
9/17/07
11:00 AM
Page xii
Preface
During the year in which we prepared this book, Christelle Fontaine (Centre d’Ecologie Fonctionnelle et Evolutive, Centre National de la Recherche Scientifique) provided invaluable services by chasing down and checking references, helping to prepare illustrations, copyediting, and maintaining our copious files and correspondence. Jérôme Bertho kindly drew Figure 8.6 in three dimensions and rendered all the figures in publishable format. Over the intense period of review and final revision of the book, we continued to marvel at the expertise, professionalism, and interpersonal skills of Barbara Dean and her associates, Erin Johnson, Barbara Youngblood, Jessica Heise, Kat Macdonald, and others at Island Press. A very special thanks to you, Barbara Dean. Andre F. Clewell Ellenton, Florida, USA James Aronson Montpellier, France May 2007
02_Intro:IP_Clewell
9/17/07
11:01 AM
Page 1
Introduction
In this book we attempt to provide a comprehensive and coherent account of the field of ecological restoration to its practitioners, to others who are concerned with aspects or consequences of restoration project work, and to those who have a more general interest in this young discipline. We identify fundamental concepts on which restoration is based, including those of ecosystems and their degradation. We address the principles of restoration practice, such as the selection of a reference model and the integration of people as inhabitants and ecological influences in the restoration of socioecological landscapes. The book also explores the diverse values that are fulfilled with the restoration of ecosystems. We review the structure of restoration practice in terms of the various contexts for restoration work, the professional development of its practitioners, and the relationships of restoration with allied fields and activities. Throughout the book, ecological restoration is conceived as a holistic endeavor. Holistic restoration was the term used by Pandey (2002) to address issues of ecological degradation, biodiversity loss, and sustainability science simultaneously and to draw on cultural resources and local knowledge and skills in restoration work. We adopt this point of view, as opposed to the application of independent and incremental solutions to specific and more narrowly conceived problems. We wrote this book specifically for practitioners who are directly engaged in the restoration of ecosystems at project sites somewhere, anywhere, in the world. We also wrote it for people who participate in the conception, planning, management, administration, and financial underwriting of ecological restoration projects. We recognize and include among the ranks of restorationists those who dedicate time and effort to project work without compensation as well as those who earn their living by restoring ecosystems. Others who may find interest in this book are ecological engineers, conservationists, and environmental resource professionals whose work approaches that of ecological restoration; people in supporting industries such as native plant nurseries; professionals engaged in nature conservation efforts such as managers of parks and protected areas; and people engaged in programs in sustainable local economic development and the restoration of natural capital, a subject that is considered briefly in Part IV and in much greater detail in a recent volume in this book series. We also address technical college and university students who intend to pursue careers in ecological restoration and their instructors, the environmentally 1
02_Intro:IP_Clewell
2
9/17/07
11:01 AM
Page 2
in t r o d u c t i o n
concerned public, and stakeholders who are directly affected by restoration projects. Finally, we hope to count among our readers public policymakers whose decisions affect restoration programs, environmental philosophers, and journalists and writers who have a bent for environmental issues and have noticed the rapid increase in public interest in ecological restoration in recent years. We want to reach this diverse audience because their understanding of restoration is crucial if our field is to realize its full potential. Indeed, ecological restoration is emerging as a meeting ground for many different fields and interest groups in all strata of society and in all cultures around the world. A common understanding of its precepts and practice is essential for effective dialogue and collaboration, and we attempt to facilitate that understanding in this book. Academically inclined restoration ecologists, who provide much of the ongoing scientific dialogue and theoretical underpinnings for the ways in which we plan, conduct, and evaluate ecological restoration projects, will also find interest in this book. However, we remind them that this book is intended for a broad audience and does not provide an exhaustive literature review, nor do we pretend to be neutral and entirely objective on certain academic subjects under debate. We prepared a glossary of the perplexing array of terms that apply to an understanding of ecological restoration and its theoretical and technical underpinnings. Definitions are tailored to the way we use these terms in this book.
Virtual Field Trips The sequence of chapters in this book is interrupted in eight places by what we call Virtual Field Trips. These are short photo-essays of project sites that illustrate various points we make in the chapters. Each Virtual Field Trip was prepared by those who were intimately involved in the restoration or research project described therein. Our intention is to allow the reader to take breaks from the book’s regular chapters and visit these various project sites, which illustrate ideas and arguments presented in the main text. They are intended to provide an extra layer or dimension to the book and thereby add to its interest, provocativeness, and usefulness. The Virtual Field Trips and other examples of project work that are cited in the main chapters come from around the world because the intended readership—reflecting current activity in ecological restoration project work—is truly global. We also wrote this book with a particular group of students in mind: those who are enrolled in the master’s program in eco-restoration at Dimoria College in Kehtri, Assam, India, where we both have lectured. Located in rural northeastern India, the college is surrounded by landscapes with great potential—and need—for ecological restoration. Our book is offered in support of students in that program and in similar programs now being formed in Asia, Africa, Latin America, and elsewhere in the developing world. We hope students, teachers, and practitioners in Australia, New Zealand, Europe, North America, and elsewhere in the so-called developed world will find it equally pertinent and stimulating.
SER Foundation Documents and Terminology The Society for Ecological Restoration International (SER) has issued several foundation documents on its Web site (www.ser.org/), most notably The SER Primer on Ecological Resto-
02_Intro:IP_Clewell
9/17/07
11:01 AM
Page 3
Introduction
3
ration (SER 2002). This book elaborates on the succinct discussions of topics that make up the SER Primer, and we adhere to the definitions of terms therein. Our book presents much material that is not included in the SER Primer and SER’s other foundation documents. However, where we overlap with these documents, the reader will find amplifications rather than substantive departures. Given that we, together with the late and much-missed Keith Winterhalder, were the principal authors of the SER Primer, we felt free to clarify points and nuances and to suggest updates. Indeed, this book was originally conceived as an expanded version of the SER Primer, although it turned out to be more than that. We discussed the idea in the spring of 2002 with Keith Winterhalder and had hoped to prepare it with him. We find it difficult not to think of this as a three-author book. One last introductory note: The contents of this book are our own and are not intended to represent official policy of SER. We are grateful to Keith Bowers, current chairperson of SER, and to the SER Executive Board for permission to include as an appendix another SER foundation document, the “Guidelines for Developing and Managing Ecological Restoration Projects,” which heretofore has been available only electronically. Throughout this book, restoration is used consistently as an abbreviation for the term ecological restoration and not for any other meaning of that word.
Layout of Sections and Chapters The book is not a how-to manual that instructs the reader in particular strategies and methods for performing ecological restoration at a given project site. Instead, it attempts to cover all the other topics relevant to restoration practice. The book consists of twelve chapters, arranged in five parts. Part I, “Introduction and Essential Background,” lays the groundwork for the field of ecological restoration from ecological and cultural perspectives. An overarching thesis is that humans and ecosystems are inseparable and that it is not possible to restore ecosystems satisfactorily without devoting serious attention to the relationship of people to nature. Part II, “Elements of Restoration Projects,” addresses essential issues in the conceptualization and planning of restoration projects. Of particular interest is an explanation of restoration trajectories, their relationships to reference models, and the application of both to project planning in a world where environmental change is becoming the norm. Part III, “Values That Restoration Addresses,” emphasizes that restoration projects are conducted because they satisfy people’s needs and values. We explore values in terms of our varied personal and cultural relationships to nature and our socioeconomic dependencies on nature with respect to the natural goods and services that ecosystems provide. Implications of values for ecological restoration are explored and synthesized in a four-quadrant model to clarify the multifaceted aspects of restoration project work. We propose this four-quadrant model as something new and, we hope, valuable for the science and the practice of ecological restoration. Part IV, “Structure of an Emerging Profession,” distinguishes ecological restoration from allied fields. It discusses the roles, contexts, and institutional structures of project work and lays out the rationale for recognizing ecological restoration as an emerging profession. Part V, “Holistic Ecological Restoration,” ends the book with a succinct summary of holistic ecological restoration that incorporates the concepts developed in the various chapters of this book. This summary is intended as a standalone document that could be useful in other settings.
02_Intro:IP_Clewell
4
9/17/07
11:01 AM
Page 4
in t r o d u c t i o n
How to Use This Book Different readers will want different kinds of information from this book. Many will want to read it in sequence. Others may want to read the Virtual Field Trips first as general background before tackling the text—a bit like reading the comics before the editorial page of a newspaper. In fact, the book is organized like a newspaper article, with the topics of most interest to most readers addressed in the first several chapters. Later chapters are more specialized and may mean more to those who are already experienced restorationists. Most chapters are independent essays and can be read in any order, particularly by those with experience in the field. We advise those who do so to skim previous chapters first to grasp the context. We wrote this book to solidify definitions, clarify concepts, illuminate current trends, encourage interdisciplinary alliances, and stimulate readers to develop new visions. We recognize that this book is only a small contribution to a rapidly developing discipline. We trust that our writings will contribute to a global dialogue that pushes ecological restoration forward, in synergy with the related activities of ecological engineering, ecological economics, and sustainability science. We are ready to participate in this dialogue, and to that end we invite your e-mails, addressed to us at
[email protected] and
[email protected].
03_ch01 (pt1):IP_Clewell
9/17/07
11:04 AM
Page 5
pa r t i
Introduction and Essential Background
More than a century ago, the term restoration of mountain lands was already being used by foresters and engineers in southern Europe, but the meaning was quite different from what we think of today as ecological restoration (Vallauri et al. 2002). People then were referring more to what we would call today silviculture and erosion control. Although restoration was bandied about as a notion for recovering the ecological past, until very recently there was no discipline called ecological restoration. In an earlier generation, Aldo Leopold had used the terms restoration and restoring with reference to his attempts to reconstruct habitat and to admonish his contemporaries to become land doctors (Zedler 1999). By the mid-1970s there was a dawning realization that restoration—or whatever it was to be called—was a potential new approach to stemming the ominous trends toward losses of habitat, biological diversity, and natural areas (Bradshaw and Chadwick 1980). By the time of the first annual conference of the Society for Ecological Restoration and Management (now the Society for Ecological Restoration International), held in Oakland, California in 1989, the term ecological restoration and the emerging discipline that this term signified had already jelled. Restoration then meant the recovery of a prior state, and it still does. However, as we became increasingly experienced with restoration work, and as Europeans and others from around the world became engaged in the restoration effort, we began to assume a broader view as to what constituted ecological restoration. As we were trying to figure out what we meant by restoration, our firm theoretical foundation was trembling beneath our feet. Ecology was undergoing a revolution of sorts as patch dynamics and nonequilibrium theory were being formulated and were replacing the older paradigms of succession, climax, and balance of nature. Added to this milieu was the clamor for environmental preservation, which had been simmering for a century and had erupted into a cultural war in North America between environmental and economic development interests. Among the otherwise solid ranks of the preservationists was a schism that divided those who recognized humans as indistinguishable from nature and those who pursued the ideal of pristine nature in which people could only leave footprints. These crosscurrents swirled as ecological restoration began to take shape. The choppy seas are subsiding but are still not calm as we continue to debate what we mean when we say that we restore ecosystems. A powerful new driver in the debate is the recognition of restoration as an elixir to 5
03_ch01 (pt1):IP_Clewell
6
9/17/07
11:04 AM
Page 6
in t r o d u c t i o n a n d e sse n ti a l b a ckground
resolve socioeconomic problems and to institute sustainable economic development, particularly in less affluent regions of the world, and to preserve biodiversity. This, then, is the backdrop for Part I of this book. Our intention is to identify and assemble the various concepts, contexts, and principles of ecological restoration in a coherent fashion that reflects a global vision for our field. By doing so, we attempt a holistic and realistic overview of ecological restoration that will encourage readers to explore more deeply what ecological restoration really means, how and why we go about accomplishing it, and the promises it offers. We shall also take the reader on the first two of the eight Virtual Field Trips in this book, to Australia and to Chile, in order to illustrate ideas presented in the text.
03_ch01 (pt1):IP_Clewell
9/17/07
11:04 AM
Page 7
Chapter 1
Essence of Restoration
Ecological restoration is the process of assisting the recovery of an ecosystem that has been degraded, damaged, or destroyed (SER 2002). From an ecological perspective, it is an intentional activity that initiates or accelerates ecosystem recovery with respect to species composition, community structure, ecological function, suitability of the physical environment to support the biota, and connectivity with the surrounding landscape. From a socioeconomic perspective, ecological restoration recovers flows of natural goods and services of economic consequence that functional ecosystems provide to society. From the perspective of personal and cultural values, ecological restoration renews our relationship with nature in the realms of aesthetics, personal fulfillment, and shared experience and meaning. A restored ecosystem represents a long-term commitment of land and resources with potential benefits for communities and cultures and for the practitioners who conduct the work. The people who are affected by an ecological restoration project should understand its intent and appreciate its potential value. Otherwise, they may not respect—or protect—the restored ecosystem. For that reason, the decision to restore should enjoy the consensus of stakeholders, financiers, and, to the extent possible, the broader community. Stakeholders should have ample opportunity to contribute to project planning, implementation, and later to the stewardship of the restored ecosystem. The benefits of restoration should be intergenerational and should sustain or improve people’s well-being—whether individual, cultural, or socioeconomic—and their ecological security into the indefinite future. Ecological restoration returns an ecosystem to a prior state to the extent that the state can be ascertained and then approximated through restoration practice. In this manner, ecological restoration satisfies a profound human desire to recover something of value that was lost. Ecosystems that have suffered only minor degradation or disturbance sometimes can be restored quickly to their apparent former states, perhaps in only a few years. For many other ecosystems, full recovery to an intended target condition may take decades or centuries. For systems that need longer recovery time, the ideal of recovering an ecosystem with historic fidelity must be reconciled with the reality that ecosystems are dynamic and subject to alteration on account of environmental flux and longer-term changes in environmental conditions, and in response to random occurrences in their own dynamic processes. Restored ecosystems can never be static replicas of the past, as if they were paintings, monuments, or 7
03_ch01 (pt1):IP_Clewell
8
9/17/07
11:04 AM
Page 8
in t r o d u c t i o n a n d e sse n ti a l b a ckground
dioramic exhibits in a museum. Instead, they respond continuously in biotic expression to their own internal processes and to ever-varying conditions in the external environment. The role of the restoration practitioner is to reinitiate ecosystem development. The restoration practitioner assists ecosystem recovery much as a physician assists the recovery of a patient. The patient heals himself or herself under the supervision, care, interventions, and encouragement of the physician. Similarly, the ecosystem recovers spontaneously with minimal intervention by a restoration practitioner. The physician cannot guarantee the final disposition of the patient, because healing is ultimately accomplished by the patient. Likewise, the restoration practitioner cannot guarantee the state of the recovered ecosystem, because recovery is ultimately accomplished by the ecosystem. Ecological restoration necessarily produces a future state of an ecosystem. In Virtual Field Trip 3 and in many other instances, that state may seem like a faithful representation of a prior ecosystem, but to believe it can ever return to that former state—as if time were reversible—is wishful thinking and counterproductive. We invariably restore ecosystems “to the future” within the context and constraints of the present. Because we cannot restore ecosystems to the past, ecological restoration is a metaphorical concept that should not be taken literally. Nonetheless, it is a powerful metaphor that has captured the imagination of people globally. Once an ecosystem has undergone ecological restoration, it should be self-organizing, self-sustaining, and capable of maintaining itself to the same degree as would be expected of an undisturbed ecosystem of the same kind in a similar position in the local landscape. It may seem reasonable that a restored ecosystem should be fully self-organizing and capable of selfdevelopment, but that is not necessarily the case, for two reasons. First, human-mediated environmental impacts have become so pervasive globally, and so severe locally, that all ecosystems are threatened by transformation if not degradation. These impacts include releases of greenhouse gases that induce global warming, oceanic and atmospheric pollution, acid rain, increases in atmospheric nitrogen, fragmentation of natural landscapes, and colonization by invasive species. Ecosystem management activities must be applied in compensation for these impacts if ecosystem transformations are unacceptable. Second, many seemingly natural ecosystems coevolved with human inhabitants, whose traditional cultural practices were among the normal ecosystem processes that shaped and maintained those ecosystems. Among cultural ecosystems, intentional burning was the most prevalent traditional practice, and others were important, such as manipulations of community structure associated with harvests of wild plants and animals. Many traditional cultures have been absorbed by modern civilization. The cultural ecosystems that they shaped and tended have suffered consequent degradation. Such ecosystems are candidates for ecological restoration. Once they are restored to their previous condition, traditional cultural practices must be renewed or surrogate practices substituted as ecosystem management. A cultural ecosystem can be self-sustaining only insofar as traditional cultural practices are counted among normal ecosystem functions. In other words, humans belong to ecosystems and participate in ecosystem processes. Not all traditional cultural practices are ecologically benign. In the long history of our species, we have commonly exploited ecosystems to their ecological detriment in attempts to ensure our own survival and comfort (Diamond 2005). Human-mediated exploitation and abuse of the natural environment have amplified and deflected ecosystem trajectories. Often,
03_ch01 (pt1):IP_Clewell
9/17/07
11:04 AM
Page 9
Essence of Restoration
9
ecosystems cannot recover spontaneously and need intensive ecological restoration. In other words, they have crossed one or more thresholds of irreversibility. These thresholds sometimes prevent practitioners from returning an impaired ecosystem to its former state and require that restoration be modeled for new conditions. However, the future state of the restored ecosystem will not be a novel or synthetic assemblage of organisms that are haphazardly selected. Instead, it will be conceived and organized on the basis of how that ecosystem probably would have evolved on its own in response to contemporary environmental conditions, assuming no impairment. An ecosystem has a developmental trajectory that consists of the chronological sequence of its prior dynamic states. This trajectory can be projected into the future in a predictive manner. The accuracy of that prediction depends on two contingencies. One is the accuracy with which future environmental conditions can be construed. The other is the latitude of expression in ecosystem composition and structure that may result from random events that influence ecosystem development. The projection of a trajectory into the future is necessarily a probability rather than a certainty, but it improves the likelihood that the restored ecosystem will be resilient and sustainable relative to an entirely synthetic or novel ecosystem that was assembled without a reference model. The projected trajectory serves as the basis for project goals and for the development of a reference model on which project plans are based. This model accepts contemporary realities and anticipates future directions in the developmental trajectory of the historic ecosystem. In this regard, ecological restoration is a holistic endeavor that strives to embrace realities and trends in both culture and the environment from an ecological— rather than a purely engineering or landscaping—perspective. This vision broadens the conventional meaning of restoration. It recognizes the openended nature of ecosystem development throughout time. It acknowledges the magnitude of environmental change that has occurred throughout the world in the last two centuries and, especially, in recent decades. It gives hope that we can continue to enjoy the personal, cultural, and economic benefits of fully functional ecosystems and their biotic grandeur. It suggests that we can undo at least some of the ecological and environmental damage people have done in the past and that despite our ongoing demographic explosion we can clear new paths for cultural and sustainable economic development.
Some Basic Terms and Concepts Before continuing, we offer background on recurring concepts in this book. This will be essential reading for those who are not familiar with ecology, and it indicates to others our particular points of view in regard to notions that are subject to variable interpretation.
States and Processes In this book, we distinguish between ecological states and ecological processes (or functions, as processes are alternatively called). A state is the expression or manifestation of an ecosystem in terms of how it appears, as determined by its species composition, community structure, and the sizes and life forms of its prominent species and their spatial configurations. Ecological processes, by contrast, are the dynamic aspects of an ecosystem, many of which
03_ch01 (pt1):IP_Clewell
10
9/17/07
11:04 AM
Page 10
in tr o d u c t i o n a n d e sse n ti a l b a ckground
can be appreciated only over an ecologically significant period of time. These processes pertain, for example, to the capture and transformation of energy through food webs; the absorption, sequestration, and recycling of nutrients and water; carbon uptake and storage; the differentiation of soils and habitats; the demographic dynamics of species populations; and the myriad interspecific interactions, including competition for resources and symbiotic or mutualistic relationships such as pollination, mycorrhizal associations, and seed dispersal by animals. States and processes are related concepts, though, because an ecological state is necessarily the expression, manifestation, or product of ecological processes.
Ecosystems The basic unit of ecology, and thus of ecological restoration, is an ecosystem. An ecosystem is a functioning unit of the biosphere of any defined magnitude in space in time, consisting of populations of living organisms that interact with each other and with the physical environment that sustains them. A. G. Tansley (1935:299), who first coined the term, described it as “the whole system, including not only the organism complex, but also the whole complex of physical factors forming what we call the environment.” The living organisms in an ecosystem—plants, animals, and microbial forms of life—collectively make up its biota. The physical environment, which is also called the abiotic (nonliving) environment, consists of the soil or substrate, moisture regime, climatic factors, nutrients, fire cycles, water bodies and their ionic salt content in aquatic environments, and any other physical features and processes that sustain the biota. An ecosystem is thus any predefined unit of the biosphere that occupies a particular place or geographic location during a particular period of time. Its appearance is the combined expression of various underlying, ongoing processes. It generally displays a measure of internal consistency in terms of its species composition, community structure, and a common physical environment. Species with shared attributes within an ecosystem may be recognized as communities, such as the plant community, the soil microorganismal community, or the zooplankton community. Ecosystem is sometimes used in a collective sense to designate a particular kind of ecosystem that occurs repeatedly, such as riparian forest, alpine tundra, or tidal marsh. Ecosystems are complex, and no two of the same kind are ever alike, particularly at smaller spatial scales. This complexity results from heterogeneity in the physical environment, stochastic (random) variations in ecological processes, and the differential effects of stresses and disturbances on an ecosystem. Furthermore, ecosystems do not exist apart, as if they were separate, isolated islands. They interact with each other and cannot be nicely distinguished from each other or from the rest of the biosphere. Mobile organisms move regularly between ecosystems, causing ongoing change in the biota at different levels of organization from the genome to populations and communities. Water and nutrients move from one ecosystem to the next. Ecosystems exchange chemical energy and biological information when organisms, water, nutrients, and detritus move from one to another. In effect, an ecosystem is a unit of nature designated for convenience by an ecologist or another professional to demarcate an area of interest or study. An ecosystem also may be designated for a more practical reason, such as to set boundaries for an ecological restoration project. The spatial and functional connectivity between adjacent ecosystems is a crucial consideration in restoration, and the ecotones or ecoclines in
03_ch01 (pt1):IP_Clewell
9/17/07
11:04 AM
Page 11
Essence of Restoration
11
which it occurs are a major horizon for both fundamental and applied research and experimentation. An ecological restoration project cannot be successful unless the surrounding terrain and ecotones are suitable for effective exchanges of organisms, materials, and energy that sustain ecological processes. Four key qualities are relevant here: integrity, health, resistance, and resilience. The SER Primer on Ecological Restoration (SER 2002:7) defined integrity as the state of an ecosystem that displays characteristic biodiversity in its species composition and community structure “and is fully capable of sustaining normal ecosystem functioning.” The SER Primer (SER 2002:7) defined health as the “condition of an ecosystem in which its dynamic attributes are expressed within ‘normal’ ranges of activity relative to its ecological stage of development.” Integrity and health are both handy descriptors; however, they are generalizations that resist satisfactory empirical validation. In this book we refer to ecosystems as being intact if they display normal integrity and health. Resistance is the capacity of an ecosystem to maintain its structural and functional attributes in the face of stress and disturbance (Westman 1978; SER 2002). Resilience is the measure of the rate of recovery of an ecosystem from disturbance and, by inference, the capacity for recovery (Holling 1973; Gunderson 2000).
Production Systems A production ecosystem, as opposed to a natural ecosystem, is a unit of land or water that is managed to produce commodities with market value, which may also be consumed or used for subsistence. In the process, the site normally is manipulated in an engineering sense and receives subsidies of energy and materials. Sources of energy may include the work of domestic animals and the use of fossil fuels to operate equipment. Material subsidies may include lime, manure, compost, or applications of other natural products or of synthesized agrochemicals such as mineral fertilizers, pesticides, and herbicides. Examples of production ecosystems (or production systems, for short) include agricultural lands dedicated to row crops, vineyards and orchards, tree plantations, biofuel plantations, impoundments for the production of fish and other seafood by aquaculture, intentionally managed meadows and pastures for domestic livestock, and food plots that are prepared and sown in game reserves. Nonnative species are commonly introduced into production systems for their commercial values. Many agroforests are production systems for that reason. Relative to the natural ecosystems that formerly occupied production sites, production systems are characterized by net reductions in species composition, less complex community structure, and lower capacity to provide a broad array of environmental services for people. These qualities are sacrificed for the production of one or more commodities. The management of production lands sometimes causes adverse environmental impacts, such as the runoff of agrochemicals that contaminate streams. Most production systems are not self-organizing and need intentional management to maintain their integrity, such as periodic harrowing or plowing, competitive weed control, mowing, thinning, fertilizing, and chemical pest control. They may rely on civil engineering, such the excavation of canals or ditches, the installation of drainage tiles, weirs and culverts, pumps, and the construction of levees or dikes, all of which need periodic operation, maintenance, or replacement. Permanent engineering features are used at times to stabilize substrates, such as riprap and gabions.
03_ch01 (pt1):IP_Clewell
12
9/17/07
11:04 AM
Page 12
in tr o d u c t i o n a n d e sse n ti a l b a ckground
Scope of Restoration Projects The definition cited in the first sentence of this chapter (SER 2002) infers and contributes to what we call holistic restoration. In other words, an ecosystem is repaired or restored in its entirety to a state of wholeness. When restored, an ecosystem displays integrity and health, selforganization, and the potential for self-sustainability, even as it remains dynamic. Holistic ecological restoration addresses issues of ecological degradation, biodiversity loss, and sustainability science simultaneously and draws on cultural resources and local knowledge and skills to do so. Not all aspects of an impaired ecosystem need attention. Most ecosystem recovery takes place spontaneously, without intentional interventions or manipulations. Restoration practitioners need only concern themselves with making the interventions that are necessary to attain ecosystem wholeness. We do not recognize as ecological restoration any partial measures that do not lead to ecosystem wholeness. The reintroduction of an extirpated species, for example, cannot be called ecological restoration unless that happens to be the only intervention needed to achieve wholeness. Instead, it should be designated by some other term, such as species restoration. Some authors consider partial measures as qualifying as ecological restoration as long as they compensate in some measure for ecological impairment (Cairns 1988; Jordan 2003). Although we applaud any partial efforts that may be undertaken, we reject definitions of ecological restoration that are not holistic. We designate partial measures with other terms, such as ecological enhancement. If partial measures were recognized as ecological restoration, it would allow numerous activities in many diverse fields to be so designated, including ecosystem management, agronomy, silviculture, and even civil engineering, which would render ecological restoration a vague and nearly meaningless term. To be clear, in this book we use the holistic definition of ecological restoration.
Spatial Scales Although the basic unit for ecological restoration is an ecosystem, the spatial scale can be expanded to that of a landscape (or seascape, riverscape, or other “scape,” as determined by geomorphology). The intent of landscape restoration is to recover a mosaic of interacting ecosystems that occupy a given space, such as a catchment (watershed), a mountain range, or any other geomorphological unit regardless of size. Virtual Field Trip 7 describes such a mosaic, which consists of a restored stream, a restored forested wetland, and a restored mesic forest. These ecosystems interact with each other in ways, composing “a cluster . . . that is repeated in similar form throughout” (Forman and Gordon 1986:11). This landscape concept, which is the one emphasized in The SER Primer (SER 2002), allows quantitative measurement and analysis of ecosystems and the frontier zones between them. The important point here is that the member ecosystems of the landscape mosaic are restored simultaneously in the same project. Under these circumstances, the landscape mosaic is treated as if it were a single, albeit heterogeneous ecosystem for restoration purposes. The reintegration of landscapes that have become fragmented, or artificially disconnected, is a fundamental corollary to the effort to restore an assemblage of ecosystems (see Virtual Field Trip 8). We will refer to the restoration of so-called socioecological landscapes, in which natural or semicultural ecosystems are interspersed with production systems and even some devel-
03_ch01 (pt1):IP_Clewell
9/17/07
11:04 AM
Page 13
Essence of Restoration
13
oped lands (see Chapter 3). Strictly speaking, ecological restoration refers only to the restoration of natural and semicultural ecosystems in those landscapes. However, we extend the meaning of restoration to include production systems, if needed to restore an entire landscape to its former state. A production system by itself cannot undergo ecological restoration because there would be no purpose in restoring, for example, an agricultural field or rowplanted trees in a commercial forest. However, a landscape can be restored in an ecological sense if it includes both a production system and an ecologically interactive natural or semicultural ecosystem. This usage of ecological restoration seems a little messy, but in our opinion, it is both logical and unavoidable, particularly when the production system represents a distinctive and discontinued land use from the past. In any event, the restoration of a socioecological landscape assumes that its component production systems will continue to be used for production or maintained in their former states for other reasons, as exemplified in Virtual Field Trip 2.
04_VFT1:IP_Clewell
9/17/07
11:05 AM
Page 14
VIRTUAL FIELD TRIP 1
Restoring Desertified Vegetation in Australia David Tongway and John Ludwig
The natural vegetation across large areas of arid and semiarid outback Australia consists of bands of vegetation, where strips of woody or grassy zones are separated by bare soil (VFT Figure 1.1). Similar banding occurs in West Africa, called brousse tigre, or tiger bush. We have studied areas of western New South Wales, Australia (Ludwig and Tongway 1996; Tongway and Ludwig 1996; Tongway et al. 2001), where a three-phase mosaic is common and consists of a bare soil zone, a perennial grass zone (Eragrostis eriopoda, Monachathera paradoxa, Thyridolepis mitchelliana), and a mulga (Acacia aneura) woodland zone (VFT Figure 1.2). Soils in the bare soil zone lack obvious plant cover but contain a rich and biologically active cryptogamic flora that forms a protective crust against the erosive forces of rainfall runoff. This landscape is maintained in response to patterns in the spatial concentrations of resources, mainly soil moisture, topsoil, and plant litter, carried by the runoff–runon of rainfall. Rainfall is both low and highly irregular in amount and seasonality. Bare soil areas experience high runoff, whereas both the grassy and woody zones absorb and use runoff and other resources that flow into them from the bare soil zone upslope. A number of studies have confirmed theoretical predictions that this redistribution of resources leads to more productive landscapes than if resources were uniformly spread over the landscape. These landscapes tend to be stable over time because few resources escape. These naturally banded landscapes are damaged when domestic stock graze and trample without periods of relief for recovery. Typically, this happens close to artificially supplied watering points, where livestock traverse, trample, and graze the land every day. With time, the perennial grasses and biological crusts die. The soil is compacted or churned into powder, and this powdered soil is washed or blown away. Consequently, infiltration rates and nutrient concentrations are very low in surface soils, and runoff water sometimes flows rapidly around mulga bands without depositing the resources it contains. Much less water is stored in the soil over time, and the landscape undergoes desertification. Eventually the trees die (VFT Figure 1.3). The pasture becomes dominated by ephemeral species of low palatability, growing briefly in response to rain. A damaged banded landscape is susceptible to continued degradation from erosion because natural recovery processes are retarded by arid conditions. We considered the possibility of ecological restoration to accelerate succession, but we had to develop a restoration 14
04_VFT1:IP_Clewell
9/17/07
11:05 AM
Page 15
Restoring Desertified Vegetation in Australia
15
VFT Figure 1.1. Aerial view of banded mulga woodland, central Australia.
VFT Figure 1.2. A natural banded (three-phase mosaic) mulga woodland.
strategy that could be applied readily and inexpensively over large areas by commercial graziers of livestock. For that reason, we decided against reseeding or other costly agricultural practices and instead built on basic landscape function principles and ecological and hydrologic processes using undamaged banded mulga as a reference model. We piled small bands of mulga
04_VFT1:IP_Clewell
16
9/17/07
11:05 AM
Page 16
in tr o d u c t i o n a n d e sse n ti a l b a ckground
VFT Figure 1.3. A damaged banded landscape.
VFT Figure 1.4. A new grass plant (Eragrostis eriopoda) protected from grazing by woody twigs.
branches across slope contours to retard overland flows of water and to sieve out materials carried in this runoff. These piles of branches, about 40 centimeters high, also trapped windblown materials. The fine, springy twig structure of mulga discouraged grazing, allowing emergent palatable plants to establish (VFT Figure 1.4). We sampled the soil for chemical and physical properties before treatment and, at 3-month intervals, assessed the germination
04_VFT1:IP_Clewell
9/17/07
11:05 AM
Page 17
Restoring Desertified Vegetation in Australia
17
and establishment of perennial plants, using a gridded quadrat to follow individual plants over time. After the first rains, the effectiveness of the branch mounds in trapping materials was evident from sediment and plant litter that accumulated on the upslope edge of the mounds. Within 6 months, perennial palatable grass plants and subshrubs had self-established, as is typical of undamaged landscapes. Weed species establishment was minimal. Sheep and kangaroo at stocking rates higher than the district average were maintained throughout because our stakeholder investigations had shown that total destocking was an economically and socially unacceptable option. Establishing pasture plants were grazed, but because of the twig structure, grazing down to ground level, typical of sheep, goat, and kangaroo grazing, was not possible. Plants were able to maintain photosynthetic tissue and thrived with the continuing accumulation of trapped resources. After 10 years, the treated plots had a dense perennial plant cover, and the soil properties had markedly improved. VFT Figure 1.5 shows the development of robust colony of characteristic vegetation in response to our restoration strategy. Such establishment demonstrated that the soil seed pool was not limiting but that poor resource retention and overgrazing of plants were the major factors that impaired landscape function. In particular, water infiltration had improved fifteenfold because of an opening up of compacted soil by fauna such as termites that create a system of storage galleries and tunnels. Nutrient concentration had increased, notably that of organic carbon, which increased significantly at the 5- to 10-centimeter layer, attributed to the death and decomposition of plant roots. Our work demonstrated that ecological restoration was effective and could be applied widely. Our success interested local graziers, who had previously lopped mulga to feed their livestock during droughts. They can now easily lop mulga in a more structured way, by felling
VFT Figure 1.5. Dense perennial, palatable species growing on soil with improved chemical, physical, and biological properties after 10 years.
04_VFT1:IP_Clewell
18
9/17/07
11:05 AM
Page 18
in tr o d u c t i o n a n d e sse n ti a l b a ckground
VFT Figure 1.6. A landscape on a commercial property with mulga felled by chaining in strips along contours.
the mulga so that branches were aligned along landscape contours to form effective resource traps as patches in bands across the landscape. This easily implemented and disarmingly simple land management practice initiates perennial plant establishment and ultimately the ecological restoration of the landscape, providing livestock graziers increased forage and improving biodiversity and nature conservation. Moreover, our experimental work clearly shows that the process of desertification is not only halted but reversed. In the course of their management practices, graziers sometimes fell mulga by dragging a chain between two tractors in the hope of reducing competition and improving pasture production. However, this chaining often is done up and down slopes, which typically leads to increased runoff and erosion down new rills and gullies. Building on our experimental principles, we have advised that chaining mulga in strips, rather than continuously, across landscape contours can lead to effective resource capture and repair of damaged country (VFT Figure 1.6).
05_ch02:IP_Clewell
9/17/07
11:07 AM
Page 19
Chapter 2
Ecological Impairment and Recovery
We humans are adept at manipulating our environment and at adapting to it as it changes. Our early ancestors had no choice but to do so in order to eke out subsistence and secure their survival. In this regard, they were no different from other species. Beavers impound streams and dramatically alter the environments of catchments. Forest corridors used by Asian elephants are recognizable by characteristic bamboo-dominated ecosystems that develop in response to the mechanical damage caused as these large beasts move about. Termites construct complex edifices with intricate thermodynamic properties and strong impact on soils. Even fungi and bacteria modify their environments proportionately to their small size by exuding enzymes that digest enveloping organic matter. Ancient humans were transforming ecosystems to survive, as do many other species of all sizes. At present, vast numbers of people from poverty-stricken and less affluent regions remain in a subsistence mode that can be environmentally damaging, whereas others of us have exploited ecosystems to the point that they may no longer be able to sustain our boom-or-bust economies, agriscapes, urban migrations, and rampant consumerism. Over the past half century or so, a heightened sense of global precariousness has emerged and with it an ecumenical, international environmental code of ethics to guide our actions responsibly. Ethics are predicated on the availability of choices and on making the right choice. There can be no choice—and no environmental ethic—in the survival mode that currently grips substantial segments of the world’s poor. Tribal taboos that may have once discouraged overexploitation and environmental damage are under assault by increasing demographic pressures and pervasive influences of modernization. When everyone enjoys at least a basic level of self-sufficiency, appropriate technology, and opportunities for livelihood, only then can all citizens of this planet participate in making sound environmental choices. Ideally, these choices will lead to sustainable development that meets the needs of the present without compromising the ability of future generations to meet their own needs, as specified in the Brundtland Report to United Nations General Assembly on August 4, 1987. We find ourselves far from this ideal. Instead, we are faced with environmental destruction of our own making that impairs our economies, threatens social order in much of the world and enforces a life of poverty for many, and offends the sensibilities of the few of us who enjoy a bountiful existence (MA 2005). Most terrestrial ecosystems have been co-opted 19
05_ch02:IP_Clewell
20
9/17/07
11:07 AM
Page 20
in tr o d u c t i o n a n d e sse n ti a l b a ckground
for agriculture, resource extraction, infrastructure, and other economic uses. These ecosystems have been impaired to the point that they cannot recover promptly or adequately, if at all, to meet our desire for unabated economic growth (Balmford et al. 2002; Blignaut et al. 2007). Conservation measures have retarded but not prevented the continuing demise of the remaining natural systems on which we depend, and conservation alone is inadequate. Many of these ecosystems will need restoration to return them to states of sustainability. The alternative to ecosystem restoration is an increase in the economic and social chaos that now plagues much of the world. As citizens of the world, we can no longer allow large parts of nations such as Bangladesh to be flooded repeatedly because we have stripped forests from the Himalayas and allowed their high-mountain glaciers to melt from global warming that is accelerated by human endeavors elsewhere. We can no longer abuse wetlands of the Mississippi River system without destroying suburbs of St. Louis, Missouri, as occurred in 1993, and the city of New Orleans in 2005 (Hey and Philippi 1995, 1999; Day et al. 2005).
Reallocation and Impairment Many ecosystems have been sacrificed for economic development, such as for agricultural and other production systems, for urbanization, industrialization, and resource extraction, and for transportation and other infrastructure. The rededication of ecosystems for such new uses is called reallocation (Aronson et al. 1993a; SER 2002). Reallocation should not be equated with the gradual transformation of ecosystems to alternative states, whereby gross species substitutions occur without net losses in desirable biodiversity and ecosystem function. Many “natural” ecosystems are really alternative states of other kinds of ecosystems, as will be discussed in the next chapter. Many other ecosystems have been subjected to various forms of ecological impairment, whereby a natural ecosystem is degraded incrementally and cumulatively over time or acutely damaged in a single event. With regard to degradation, certain ecosystems tolerate individual incidents of mild or moderate disturbance to biodiversity and ecosystem function but not a series of incidents that preclude intervening recovery time. The specific designation as degraded, damaged, or disturbed thus depends on the natural disturbance regime for the ecosystem. However, some broad distinctions are possible and worthwhile. The relationships between degraded, damaged, and destroyed ecosystems can be illustrated as follows. A forest can be degraded by the occasional removal of mature individual trees at a frequency that exceeds their rate of replacement, and the site gradually becomes scrubland. That same forest can be damaged if all the trees are harvested at the same time. Although it is true that this damage might mimic natural disturbances such as fire, hurricane, or elephant population peaks, the origin and difference in regime between a natural and an anthropogenic disturbance justifies the use of the term damaged. Finally, the forest can be entirely destroyed, by people, if all vegetation is cleared and soil removed in order to access a seam of coal through opencast strip mining. Ecosystem impairment is not to be equated with normal and continuing environmental stress or with punctuated incidents of disturbance (also called perturbation). All ecosystems are subjected to stress and disturbances in some degree. Stress conditions or stressors may be climate related, such as alternating hot and cold seasons or wet and dry seasons (Lugo 1978).
05_ch02:IP_Clewell
9/17/07
11:07 AM
Page 21
Ecological Impairment and Recovery
21
In coastal areas, the stressors may be related to variable salinity from periodic tidal inundation, seasonal evaporation in estuaries, or the effects of saline aerosols carried inland by wind. Stressors may include seasonal deficiency in oxygen (hypoxia) or oxygen depletion (anoxia), which is commonly caused by soil saturation resulting from inundation (flooding). Other stressors include permafrost, hardpans, excessively acidic soils, hypersaline waters, and chronic nutrient deficiency. Disturbances include lightning-set or other naturally ignited fires in fire-driven ecosystems. Ignition by lightning may cause surface fires that burn through grasses or other ground cover, whereas human-set fires, particularly in dry seasons, could cause underground peat fires or crown fires in treetops. Disturbance can cause mechanical damage to vegetation from wind, ice storms, and the movements of large animals. Other disturbance can be caused by plagues of voracious herbivorous insects and outbreaks of plant pathogens. Species composition, and thus the kind of ecosystem that occurs at a given location, is regulated by the stressors associated with that place. For example, tidal marshes are stressed by diurnal variability in salinity, which plays havoc with osmotic regulation, and by frequent soil saturation that interferes with aeration of belowground tissues, which must be sufficiently massive and extensive to prevent being uprooted by storm-driven waves. Few species can tolerate such stresses, and these few persist and become characteristic or dominant in tidal marsh ecosystems. On slightly elevated terrain, stress from salinity and soil saturation is less intense, and tidal marsh dominants may be competitively excluded by other species. Nearly all ecosystems are maintained by combinations of stressors in this manner. Periodic stress events therefore do not cause an ecosystem to be impaired. On the contrary, they are responsible for maintaining the integrity of ecosystems. In this context, stressors are sometimes called drivers. Restoration practitioners must ensure that appropriate stress conditions exist and that periodic stress events can occur when impaired ecosystems are restored.
Ecological Consequences of Impairment Impairment is the consequence of a more serious disturbance that is usually caused or intensified by humans. For example, the forests in the vicinity of Sudbury, Canada were subjected to toxic aerial emissions from nickel smelters. The local ecosystems became degraded as individual plants succumbed. Forests located near the smelters were entirely destroyed. Keith Winterhalder developed restoration methods and restored these forests, including the one shown in the photograph on page ix. Similarly, wet prairies inland from the Gulf of Mexico were reallocated as silvicultural production systems (commercial pine forests). As the pines grew and once-prevalent surface fires were suppressed, the wet prairie grasses, sedges, and forbs gradually succumbed to competition from woody plants. The restoration of this ecosystem is described in Virtual Field Trip 3. Numerous examples abound of disturbances to ecosystems that were intentionally caused by changes to the hydrologic regime. These include impounding, diverting, or channelizing streams; impeding overland flows at flood stage or at high tide by constructing dikes and levees; lowering groundwater tables by excessive pumping; and accelerating runoff over impervious or compacted surfaces. What happens to an ecosystem that has been degraded, damaged, or undesirably transformed? The answer is site dependent; however, some commonly expected consequences are described as follows.
05_ch02:IP_Clewell
22
9/17/07
11:07 AM
Page 22
in tr o d u c t i o n a n d e sse n ti a l b a ckground
Losses of Specialized Species and Relative or Actual Gains of Generalist Species Species that need specialized or well-differentiated habitat are more susceptible to becoming scarce or lost after impairment. Ecologists call these species K-strategists, meaning that their life history revolves around the population carrying capacity (K) of a given environment. Correspondingly, generalist species—ruderal species or weeds—opportunistically colonize impaired sites, commonly in abundance. These are called r-strategists, relying on rapid growth (MacArthur and Wilson 1967). The role of the practitioner is not to eliminate r-strategists, because they are essential to ecosystem dynamics. Instead, the goal should be to promote the establishment and increase the numbers of K-strategists present. Grime (1974, 1977, 1979) recognized three basic strategies for plant species—disturbance tolerators, stress tolerators, and competitors—with most species displaying combinations of these strategies to varying degrees. Competition is defined as the tendency of neighboring plants to use the same volume of space and the same resources (water, nutrients, solar radiation). Stress is defined as the external constraints that limit dry matter production of plants (e.g., extreme temperatures, deficiencies of water and nutrients, osmotic tensions from salinity, anoxia, shade). Disturbance (e.g., mechanical damage from storms and floods, burning, herbivory, pathogens, mowing, trampling) reduces or destroys plant biomass. Plants that adopt the disturbance strategy occupy highly disturbed, ruderal sites and qualify as r-strategists. These ruderal species tend to be short-lived herbs that dedicate much of their photosynthate to reproduction rather than to the development of vegetative structures. Plants that adopt strategies for competition and stress tend to be K-strategists, including both herbs and woody plants, which sparingly dedicate their photosynthate to reproduction and instead develop vegetative adaptations to resist stress or competition.
Colonization by Invasive Species Invasive species are those that abnormally proliferate at the expense of other, more characteristic species and co-opt space and habitat that would otherwise be occupied or recaptured by them. Such proliferation causes impairment in more mature ecosystems and, in less mature or already impaired ecosystems, causes succession to be arrested. Invasive species generally are nonnative, and current usage of the term invasive is commonly limited to nonnative species. However, native species can become invasive by arresting succession, at least temporarily. Such native species are sometimes called nuisance species (Clewell and Lea 1990), and they may consist of vines and sprawling shrubs such as species of Vitis (grapes), Smilax (greenbriers), and Rubus (blackberries) in North America. Restoration practitioners often are obliged to remove them or reduce the tenacity of invasive and nuisance species.
Simplification of Community Structure Structure is determined by the sizes, life forms, and abundance of sedentary species, principally rooted plants. In aquatic environments structure can be determined by rooted aquatic macrophytes such as kelps or sea grasses, by corals or oyster shells, and by the inert substrate organisms colonize or burrow into. Changes in structure may be expressed as proportional differences in life form, as when fire suppression allows shrubs and trees to replace grasses. The change may simplify vertical stratification in terms of the presence and prevalence of
05_ch02:IP_Clewell
9/17/07
11:07 AM
Page 23
Ecological Impairment and Recovery
23
Figure 2.1. Forest restoration on the floodplain of the Pascagoula River, Mississippi, USA, to accelerate recovery of forest structure from wind damage caused by Hurricane Katrina in 2005 and to improve the abundance of some kinds of trees. Natural regeneration after successive timber harvests in the past had disfavored reestablishment by the tree species that were being planted.
layers of vegetation (e.g., ground cover, shrub cover, midstory trees, overstory trees). Change in community structure may reduce the size distribution of organisms when, for example, trees of a given size class are removed. Other changes in structure may occur, depending on site-specific properties (Figure 2.1).
Changes in Microclimate A microclimate consists of small-scale meteorological variations that occur within an ecosystem or because of a natural topographic exposure, in contrast to the macroclimate, as would be determined by an official weather station. Microclimatic control is largely a function of community structure, such as the shade that is afforded by a forest or the reduction in wind immediately above ground level in grasslands. Microclimate is also influenced by plant transpiration, which increases humidity and sometimes cloud formation.
Changes in the Frequency Distribution of Plant Life Forms Plant structures vary dramatically. Palm fronds, fern fronds, pine needles, and grass blades are all leaves, but they display very different ecological properties. For example, we are aware of an instance in the Himalayas where pine forest replaced oak forest. Leaf litter consisting of
05_ch02:IP_Clewell
24
9/17/07
11:07 AM
Page 24
in tr o d u c t i o n a n d e sse n ti a l b a ckground
pine needles accumulated to such a thickness and density that rainfall failed to penetrate the litter and percolate into the soil. Instead, rainwater cascaded over, or wicked through, the litter to the stream below, leaving the mountain soil desiccated much of the year. In another example, if fire is suppressed so that oaks colonize grassland, the grasses are reduced by shade, by competition from oak roots, and by accumulations of the less flammable litter produced by oak leaves. The total amount of carbon fixation may not change because of these transformations, but ecological properties are radically altered.
Losses in Beneficial Soil Properties Soils are complex and can be adversely affected in a number of ways, including compaction, erosion, excessive introductions of nutrients and contaminants, and variations in electrical conductivity and moisture availability. Soil compaction can be induced by equipment used in extractive processes or by the hooves of domestic livestock. Machinery and livestock can compress macropores created by tunneling shrews, annelids, and insect larvae. Precipitation is prevented from percolating into compacted soil and becoming captured in macropores; the excess runs off, causing greater amplitudes in the volume of discharge and a consequent depression in the water table between rainfall events. Compaction retards root penetration. Soil aeration is reduced, which, in turn, reduces the metabolism of aerobic soil organisms including plant roots, numerous kinds of soil animals, fungi, and most bacteria. Other impacts on the soil can set off similar chain reactions that disrupt ecosystem function. Such impacts include erosion, sedimentation, leaching of nutrients, oxidization of organic matter, accumulation of salt, and the introduction of excessive nutrients from agricultural operations and pollutants from industrial discharge and urban runoff.
Reduction in Capacity for Mineral Nutrient Retention A common attribute of resilient, complex ecosystems is their ability to sequester (capture) and recycle mineral nutrients. Soluble nutrients in the soil can be lost to the ecosystem by excessive percolation or runoff of rainfall and soil moisture. Such loss has been called leakage by ecologists. Leakage has at least two negative consequences for otherwise stable ecosystems. First, nutrient loss reduces the productivity of plants that are K-strategists. Such plants tend to sequester and accumulate mineral nutrients in their biomass and in the slowly decomposing litter that they produce. These nutrients are released and are exposed to leakage for brief periods under normal conditions. If soils are damaged, exposure to leakage can become prolonged, soluble nutrients are lost, and the competitive ability of K-strategists to sequester nutrients is forfeited. Second, leakage makes nutrients available to opportunistic r-strategist plants that typically need ample and readily available sources of mineral nutrients. Sometimes damage to soils directly affects soil fungi, some of which form mycorrhizal associations with the roots of vascular plants and translocate nutrients to them in a mutual exchange for carbohydrate. If these fungi are harmed and their extensive networks of nutrient-absorbing hyphae reduced, their vascular plant symbionts will suffer from a corresponding reduction in nutrient supply. It should also be noted that excess nutrients, especially nitrogen, can also be a severe stressor to ecosystems that are naturally nutrient poor.
05_ch02:IP_Clewell
9/17/07
11:07 AM
Page 25
Ecological Impairment and Recovery
25
Alteration in the Moisture Regime Through self-organization, ecosystems commonly assert tight control of their water budgets and the inputs and outputs of water (Descheemaeker et al. 2006). For example, trees are efficient conductors of soil water and will lower water tables through transpiration by a meter or more in growing seasons (Trousdell and Hoover 1955; Sikka et al. 2003). In addition, tree crowns intercept much precipitation that evaporates before reaching the ground. For these reasons, tree felling may profoundly change the soil moisture regime. Most stable terrestrial ecosystems develop mechanisms to sequester moisture. This can be accomplished by maintaining a favorable microclimate that moderates temperatures and reduces evaporation. It can also come about by the production of plant structures that capture precipitation and dew, by growth forms that retard percolation and runoff, by accumulations of humus and other detritus that absorbs moisture, and by the activities of soil organisms that loosen soil particles and create passages for retaining moisture. In other ecosystems the opposite problem occurs: the need to discharge excess water. For example, plants in tidal marshes may produce dense mats of surficial roots and rhizomes that resist penetration of water from tidal inundation. The water runs off as surface flow, and the mineral soil and plant roots beneath remain aerated (Kurz and Wagner 1957). External impacts to ecosystems can reduce the effectiveness of moisture regulation and thereby reduce their productivity and stability. Restoration practitioners should be aware of these and other, site-specific consequences in order to determine the causes and extent of ecosystem impairment and to prescribe appropriate restoration strategies and protocols.
Restoring Systems After Natural Disasters Ecological restoration generally addresses and attempts to rectify ecosystem impairment that is attributable to impacts from human activity, whether intentional or inadvertent. Should restoration be attempted to recover ecosystems that were harmed by entirely natural phenomena? A hurricane or tsunami can remove coastal ecosystems. Mountainsides can fail and bury forests beneath debris. Volcanic activity can bury ecosystems beneath ash or magma. Some would argue that restoration under these circumstances amounts to environmental meddling and another instance of human artifice that despoils nature. Aside from such objections, there is no reason why such ecosystems could not be restored. The only compelling reason to restore after natural devastation would be to protect values. For example, artificial dune reconstruction after a hurricane and the restoration of a dune ecosystem could be justified as affording protection to adjacent commercial developments or popular recreational areas. Alternatively, it would be difficult to identify wholly natural instances of ecosystem impairment or destruction. A mountainside may fail after the harvest of timber and thus the removal of the vegetation that bound the soil. A tsunami may be caused by entirely natural geological phenomena, but the extent of its damage to coastal ecosystems may be related to the removal of protective mangrove forests that once occupied much of the shoreline. Property damage in New Orleans caused by hurricane Katrina has been attributed partially to the prior destruction of tidal marshes (Costanza et al. 2006).
05_ch02:IP_Clewell
26
9/17/07
11:07 AM
Page 26
in tr o d u c t i o n a n d e sse n ti a l b a ckground
Desertification and Salinization Many landscapes, especially in less affluent regions, have been mismanaged or exploited for agriculture beyond their capacity for self-renewal and sometimes human repair. A common consequence has been the loss of organic matter from soil, which reduces cation exchange capacity, facilitates nutrient leaching, and reduces soil moisture retention. Soil compaction or erosion follows and increases rates of surface runoff through precipitation. In response, such landscapes become drier and less productive, a process called desertification. The process creates an environment that is more arid than before but not necessarily a desert. This trend is generally irreversible unless intensive, expensive long-term effort is undertaken (Figure 2.2). Desertified regions may receive less rainfall and dew because of a reduction in water vapor that was previously generated from evapotranspiration (although global circulation effects may override local effects). Aquatic ecosystems also suffer from desertification occurring off site. Precipitation is no longer retained on the land and instead moves rapidly into streams via surface runoff. The amplitude of stream discharge increases, with surges or spikes of discharge in wet seasons followed by prolonged periods of low water flow. Discharge is
Figure 2.2. Mina Jansen collecting seeds of Mesembryanthemaceae for the project RenuKaroo, run by ecologists Sue Milton and Richard Dean. The project’s mission is to make ecological restoration with locally indigenous plants a sought-after service in the Central Karoo, South Africa, thereby sustaining ecological services and creating sustainable livelihoods.
05_ch02:IP_Clewell
9/17/07
11:07 AM
Page 27
Ecological Impairment and Recovery
27
more likely to be turbid from suspended particulates that erode off the land. The discharge will carry more nutrients from the land, which causes eutrophication in receiving waters. Another form of desertification is salinization, which has occurred on a vast scale in overexploited landscapes of Australia, China, India, the Middle East, North Africa, and western North America. Salinization occurs when croplands are flooded by irrigation water, some of which evaporates from the soil surface and leaves a residue of dissolved salts. Repeated irrigation can cause salt to increase and become toxic for plants. In addition, salinization commonly develops in arid areas where salts are dissolved in groundwater, which lies below the rooting zone of plants. If there were sufficient rainfall, the soil would become moistened to a depth that reached the saline groundwater, and the salt would diffuse upward to the soil surface. Ordinarily, low rainfall, in combination with high rates of transpiration of soil moisture by forest trees, precludes rainwater from penetrating deep enough in the soil to reach saline groundwater. If forests are clear-cut, rainfall may continue to percolate downward until it reaches the saline groundwater. The dissolved salts are then able to diffuse gradually to the surface, where the water evaporates and leaves a saline residue. The process continues until the salt content at the surface becomes toxic to plants. Deposits of these salts are highly mobile in surface runoff and can spread their toxicity to lower-elevation lands. This salt may reach streams, where it raises electrical conductivity and affects aquatic ecosystems. Many people have fled landscapes that became desertified, salinized, or otherwise degraded and have taken up lives as ecological refugees in urban slums of cities such as Lagos, Nigeria; Mumbai, India; and Mexico City, among many others. Those remaining fight a losing battle to maintain former levels of socioeconomic and cultural well-being. Ecological restoration or a related measure to restore natural capital (see Chapter 9) may be the only way to prevent and reverse degradation.
Ecosystem Recovery Ecological recovery is sometimes portrayed as degradation in reverse (Bradshaw 1987). With whatever assistance may be needed from a restoration practitioner, a degraded ecosystem undergoes natural succession that returns it to its original state. In doing so, it regains its community structure and composition, and its ecological functions and processes return to normal. In this model, restoration practitioners assist with interventions—also called manipulations—that ensure a direct return to the former ecosystem state. Bradshaw (1987) warned that natural succession involves “probabilistic obstacles” that could retard or prevent the return of the ecosystem to the original state. For example, the soil may be compacted or seeds of appropriate plant species may be unavailable, and it is the practitioner’s role to address such problems and thereby accelerate succession. The practitioner is seen as a problem solver in an engineering sense. Bradshaw (1987:72) wrote, “Ecologists . . . are in the construction business and, like their engineering colleagues, can soon discover whether . . . the bridge collapses or the ecosystem fails to flourish.” Luken (1990) called this process “directing ecological succession.” Degradation in reverse has been the predominant model for restoration for the past two decades. It is easy to comprehend and embraces the ideal of ecologists to return an impaired
05_ch02:IP_Clewell
28
9/17/07
11:07 AM
Page 28
in tr o d u c t i o n a n d e sse n ti a l b a ckground
ecosystem to its previous and preferred condition. The fact that the “degradation in reverse” model is not universally applicable is gradually being recognized. Its underlying assumptions have been challenged, and new models are emerging. In the following paragraphs, we will briefly discuss natural succession theory and relate it to the tasks and challenges of ecosystem restoration. Natural succession, also called biological succession, ecological succession, or simply succession, has been defined in many ways (Hobbs and Walker 2007), ranging from the simple and inclusive “process of vegetation change” to “a hypothetically orderly sequence of changes in plant communities leading to a stable climax community” (Dodson et al. 1998:50). According to this latter definition, succession returns an impaired ecosystem to a complex and stable state. The term succession in this commonly used sense infers an endpoint that will be attained and that will mark the termination of the successional process. Traditionally, ecologists have designated this hypothetical endpoint as the climax, at which point the biotic communities on site reach stability and equilibrium with their environment. Restorationists commonly select a climax or other stable state as a target for restoration and also as a reference model that the restored ecosystem is intended to emulate (see Chapter 4). The target is alternatively called an outcome or endpoint by some authors. However, there are problems with this approach. The notion of ecological equilibrium corresponds to the simplistic, naive, and still very popular concept of balance of nature. The endpoint of succession is thus considered to be a predictable biological expression, as characterized by the composition of the dominant species and by the structure of the community. At that advanced stage in successional development, the eight environmental consequences of ecological impairment described earlier in this chapter have been reversed. K-strategists prevail, community structure has reached its ultimate expression, microclimatic conditions are favorable for protection of the biological and ecological status quo, production is limited but efficient, soils are well developed, nutrients are tightly recycled, and moisture is favorably regulated. In short, in this view there is a happy end to succession. The entire sequence of successional stages that leads to a climax or endpoint is called a sere, and an intermediate stage within a sere can be called a seral community. A basic tenet of traditional succession theory has been that the plant species that occurred early in a sere will modify, or ameliorate, the harsh and open site conditions of the initial conditions by their shade, leaf litter, or other traits to the point that other species that are better adapted to these improved conditions will replace them. In other words, one group of species facilitates its own replacement by another group of species. Facilitation is a fundamental tenet of succession theory. The facilitation process is repeated until a climax state is reached in which the species present can reproduce themselves indefinitely despite competition. Egler (1954) called sequence of replacements “relay floristics,” whereby entire plant communities are replaced in sequence until a climax is reached. Recovery of forest after abandonment of cropland has commonly been cited as an example of such a sere (Drury and Nisbet 1973). In more recent ecological parlance, the result of natural succession as classically conceived is a single equilibrium endpoint. In other words, only a single kind of ecosystem is predicted as the climax at a particular location, and that climax community persists indefinitely in equilibrium with its environment. Succession theory tacitly assumes that environmental conditions remain stable throughout the development of a sere, which could take centuries to complete because of the long generation time of many kinds of trees or even dominant
05_ch02:IP_Clewell
9/17/07
11:07 AM
Page 29
Ecological Impairment and Recovery
29
grasses (Clewell 1989). A major argument against the concept of a single equilibrium endpoint, or climax, is that environmental conditions commonly change more rapidly than it takes for equilibrium to develop. The generation time of the dominant species is too long, as in many kinds of forest. The importance of generation time becomes obvious from palynological data (mainly from pollen preserved in sediments) that generally reveal climatic conditions at study sites since the last glacial advance about 10,000–19,000 years ago, depending on the region considered. The problem is one of perception. Old-growth trees live longer than people. Therefore, people tend to identify a generation of trees as “climax” when that forest may represent only a seral stage of development. If we lived longer, we would better appreciate the sere. Succession theory also assumes the existence of strong internal regulation and feedback of ecosystem processes, in which one process reinforces another in synchronous fashion. Regulation can be imposed by harsh climatic conditions, such as prolonged below-freezing winter weather. These areas have limited numbers of plant species, particularly of those that assume dominance, relative to warmer bioregions. The significance of this observation is that classic succession theory—and the application of the “degradation in reverse” model for ecological restoration—seems to be most applicable in regions where the number of plant species is limited to those that can tolerate harsh climates and where the climate exerts extensive control over ecosystem processes. Succession theory is also applicable in environments that favor what Grime (1979) called competition-tolerant species. The great temperate deciduous forests of eastern North America, eastern Asia, and much of Europe are representative of ecosystems where competitiontolerant species prevail and the facilitation principle of succession theory is much in evidence. In many other environments, stressors are so severe, or there are so many of them in concurrent operation, that seral development is completed in only the few years that are needed for K-strategists to become prevalent. Thereafter, the K-strategists that initially colonize a denuded site persist indefinitely. In contrast to succession theory, Egler (1954) called this the theory of initial floristic composition. Species that predominate in such areas are what Grime (1979) called stress-tolerant species. The Florida Everglades are an excellent example of an entire series of landscapes that developed in accord with initial floristic composition theory and that are dominated by stress-tolerant species. Five thousand years of peat accumulation reveals a remarkably consistent species composition by species that must cope with low availability of nutrients, fluctuations in oxygen availability, frequent fires, frequent hurricane-driven wind storms, and occasional salinity shocks. Another assault on natural succession theory is the realization that disturbance within an ecosystem is normal and expected and that lack of disturbance is abnormal. Different places within an ecosystem can be disturbed at different times. Some may suffer wind damage, lightning strikes, or fires of varying frequency and intensity. Others may be plagued by local depredations by insects, outbreaks of plant diseases, or localized erosion or sedimentation. Each of these disturbances occurs at different times and affects areas of different size within an ecosystem. Therefore, an ecosystem is really a patchwork or mosaic, with each patch undergoing its own, unique micro-sere. One area may suffer additional disturbance before it fully recovers from the previous disturbance. The consequence of these dynamics is ecosystem heterogeneity. In other words, an ecosystem that may seem uniform on first impression may prove to be quite heterogeneous.
05_ch02:IP_Clewell
30
9/17/07
11:07 AM
Page 30
in tr o d u c t i o n a n d e sse n ti a l b a ckground
For example, if a large tree falls after a lightning strike, a sere is initiated beneath the resulting gap in the canopy. That sere may last for decades while young trees compete with one another to determine which of them will eventually fill the canopy gap. When we walk through a forest, our eyes tend to see the largest trees, and we ignore—or look right through—these canopy gaps without registering the seral dynamics that are occurring before our eyes. Likewise, anyone who has done ecological sampling of plants in a grassland, shrubland, or savanna probably has been surprised at the irregularity in the distribution of many species and their shifting patterns of dominance, despite the apparent uniformity of the environment as one casually walks through it. The collective process that leads to ecosystem heterogeneity in response to multiple disturbances in an ecosystem is called patch dynamics and is often referred to as flux (Pickett and White 1985). Patch dynamics also occurs because of random and unpredictable ecosystem processes that drive succession. For example, whether a particular species of nut-bearing tree becomes dominant in the future canopy of a forest may depend on the density of predators of squirrels that distribute the nuts at the time when conditions are favorable for tree seedling establishment. The concept of patch dynamics is another major argument against classic succession theory. At best, natural succession may seem to be operating at a very large scale at a landscape or bioregional level. As the scale decreases, this uniformity disappears. Similarly, when we view the moon without magnification, it appears uniform. As viewed by telescope, the moon’s surface really consists of one crater after another, often overlapping, each of a different size and, as we are told, a different age. Flux and resulting patch dynamics are recognized as the primary characteristics of nonequilibrium theory (Suding and Gross 2006), which stand in direct contrast to the single equilibrium theory of classic natural succession theory. Nonequilibrium theory posits that a stable state or steady state cannot be reached as predicted by succession theory because ecosystems undergo essentially continuous flux. According to this theory, the attainment of a persistent balance of nature is more easily described on paper than can be demonstrated in the field. The theory of multiple equilibrium states asserts that more than one stable state or “climax” can occur at a given site (Hobbs and Norton 1996; Hobbs and Suding 2007). From the standpoint of restoration, this theory is applicable in cases of alternative states of ecosystems because of traditional cultural practices, as will be described in Chapter 3.
Recovery and Restoration Practice What do all of these conflicting and competing ways of conceptualizing ecosystems and ecosystem dynamics mean to restoration practitioners? We offer three scenarios, each with a different response to our question. First, certain ecosystems can be restored in accordance with the single equilibrium theory of succession and the “degradation in reverse” model of restoration. Those that can be restored represent one of two situations. One is that the degree of impairment is modest and probably requires little or no repair of abiotic conditions on site. Restoration can be accomplished simply through manipulations of the biotic community, such as replenishing biotic diversity that was reduced for whatever reason. The other situation occurs in particularly
05_ch02:IP_Clewell
9/17/07
11:07 AM
Page 31
Ecological Impairment and Recovery
31
harsh environments, where plant diversity—particularly of potential dominant species—is already low and ecosystem processes are restricted by the environment. Examples include high montane ecosystems in temperate latitudes. In such circumstances, the potential for flux and patch dynamics is reduced (except at very small spatial scales), and attainment of the former state is probable. Most other ecosystems cannot be restored in this manner. Second, certain ecosystems can be restored directly, in accordance with the theory of initial floristic composition (Egler 1954). Marshes (emergent herbaceous wetlands) often can be restored in only a few years if a suitable hydroperiod and water quality are present and all the component species are introduced. There may be a brief initial stage of development as species populations adjust to environmental conditions, but such adjustment may also occur after extreme fluctuations in the natural environment, such as prolonged drought. Third, all other ecosystems undergo a long process of seral development between the time that they are restored to an initial condition of self-organization and the time that they attain the ecologically mature stage of their target system. During this protracted interim, which takes decades or centuries, the developing ecosystem may experience flux in response to patch dynamics. The ecosystem will also be exposed to possible alteration from changing environmental conditions, such as global warming or sea level rise, or from human impact. The outcome of development is difficult to predict with precision and may or may not resemble a target that was selected at the time of restoration planning. Consequently, the restoration could be perceived as a dismal failure for not attaining a preconceived target but would otherwise be hailed as a resounding success for attaining another state of high ecological value. For these reasons, selection of the target should be ecologically realistic. The target can be described in very general terms to accommodate flux, or it can be described more specifically as a range of potential endpoints, any one of which would be acceptable. Flux in the development of ecosystems is a major reason that we were careful in Chapter 1 to describe restoration as the assisted return of an impaired ecosystem to a condition of self-organization rather than to extend it to the time when the target condition is attained. Because of flux, ecosystems are constantly in a state of becoming, and they can never reach a stable equilibrium as an endpoint. Theoretically, the ecological restoration of such an ecosystem can never end, and the restoration process must continue indefinitely, which we find absurd and unacceptable from a practical standpoint. In all three of these scenarios, we return to Bradshaw (1987), who recognized ecological complexity as a principal feature of a restored ecosystem in the “reverse of degradation” model. This model assumes a direct relationship between the degree of ecological complexity (structure and differentiation of habitat in response to biotic activity) and the degree of ecological function. We contend that the responsibility of practitioners is to restore appropriate ecological complexity with the intent of reinitiating ecosystem processes. The precise meaning of ecological complexity, as we use that term in this book, varies widely between ecosystems. In some ecosystems it means a great diversity of plant species and functional groups of plants. In others it may mean few species or few function groups of plants but well-developed detrital organic matter in terms of downed trees, deep humus, or peat or muck accumulation, or at least the potential for detritus to develop. In yet others, particularly aquatic environments, it means a large diversity of animal species and functional groups of animals. It is the responsibility of practitioners and others who conceive and plan
05_ch02:IP_Clewell
32
9/17/07
11:07 AM
Page 32
in tr o d u c t i o n a n d e sse n ti a l b a ckground
restoration projects to understand ecological complexity with reference to the kinds of ecosystems they intend to restore. In this chapter we have emphasized the more exploitive and destructive tendencies by people in their interactions with ecosystems and landscapes. In the next chapter, we view culture as a positive influence in nature, which profoundly challenges us in the way we perceive nature and how we go about restoring ecosystems.
06_VFT2:IP_Clewell
9/17/07
11:08 AM
Page 33
VIRTUAL FIELD TRIP 2
Restoring Cultural Landscapes in Central Chile Carlos Ovalle and James Aronson
When Diego de Almagro and his companions arrived in central Chile more than five centuries ago, native people were numerous, but their ecological footprint was small. From the time of the Spanish colonization onward, a dryland farming system based on rainfed crops and livestock was developed, and landscape dynamics were profoundly and irreversibly transformed. Instead of sclerophyll woodlands and other ecosystems typical of Mediterranean-type climate regions that predominated at the time of European contact, the region is blanketed with an anthropogenic pseudo-savanna called espinales, as shown in VFT Figure 2.1. The term espinales alludes to the dominant tree, Acacia caven, a spiny legume that recovers rapidly after cutting, grazing, and fire (Ovalle et al. 1990; Aronson et al. 1993b). Water shortages threaten the agricultural productivity of the region. Five to six months of absolute drought each summer inhibit plant and root nodule establishment, and much of the mean annual rainfall of 500–800 millimeters is lost as surface runoff. The most productive lands in the Central Valley have undergone irrigation and intensive crop production. In the unirrigated areas where we conduct our work, traditional farming practices have depleted soils and reduced productivity and diversity. From a socioeconomic perspective, the Chilean espinales are a battered vestige of a silvopastoral farming system that was introduced from Spain and that had great merit in the past when it was managed as a multipurpose, multiuser system (Ovalle et al. 1999). At that time, espino was cut to the ground every 10–15 years, after which wheat was sown for a year or two. Currently, the only activity on most farms is livestock grazing, with characteristically low productivity (VFT Figure 2.2). Increasingly, landowners are abandoning the traditional agrosilvopastoral land use system and planting Eucalyptus globulus and Pinus radiata (Monterrey pine) for export to paper and lumber mills, causing soils to degrade further and more jobs and livelihoods to be lost. These degraded espinales are in urgent need of ecological and economic restoration. Since the 1970s, we have been developing strategies and methods to restore, ecologically and economically, the unirrigated, interior drylands (secano interior) of Chile. In particular, we are researching the potential to restore the anthropogenic silvopastoral landscapes of the seventeenth to early twentieth century, consisting of mixed espinales with high productivity, diversity, and resilience. This effort intends to recover well-designed cultural landscapes at the farmholding scale, combining ecologically and economically interactive landscape units. 33
06_VFT2:IP_Clewell
34
9/17/07
11:08 AM
Page 34
in tr o d u c t i o n a n d e sse n ti a l b a ckground
VFT Figure 2.1. Native sclerophyll woodland fragment, surrounded by anthropogenic espinales. Both the stump-sprouting shrubs in the foreground and the single-stemmed trees in the open fields are Acacia caven. Taller trees on the ridgetop are Eucalyptus globulus.
VFT Figure 2.2. Very degraded Chilean espinales in which very few espino or other trees grow. In the background, the leafless shrubs are espino and green shrubs are weedy Baccharis sp.
06_VFT2:IP_Clewell
9/17/07
11:08 AM
Page 35
Restoring Cultural Landscapes in Central Chile
35
VFT Figures 2.3 and 2.4. Reference system of mature, intensively grazed espinal at La Estrella, a private farm near Cauquenes, Chile. Tall, long-lived trees of Acacia caven are managed to optimize their multipurpose value.
Our reference model consists of the unirrigated farmlands that remain economically sustainable and that occupy about 2 percent of the region (VFT Figures 2.3 and 2.4). Our research combines agronomy, agroforestry, forestry, and landscape ecology and is conducted in collaboration with many local farmers who have expressed interest in our work. Among our investigations, we have tested annual and perennial legumes that were sown as forage plants (VFT Figure 2.5), sometimes in association with native leguminous trees including Acacia caven. These herbaceous legumes doubled and in some cases tripled the biomass of forage for livestock (Ovalle et al. 1996, 1999; Aronson et al. 2002b), thanks to improvements in the content of soil organic matter and nitrogen. Our approach also includes introducing new cash crops, planting vineyards, installing water retention tanks, increasing tree cover as shade for livestock, and reforesting water
06_VFT2:IP_Clewell
36
9/17/07
11:08 AM
Page 36
in tr o d u c t i o n a n d e sse n ti a l b a ckground
VFT Figure 2.5. Experimental trial of annual and herbaceous perennial legumes on typically degraded soils. Like some legume trees, these plants can fix large amounts of atmospheric nitrogen to jump-start restorative processes in degraded soils.
courses (Aronson et al. 2002b). The latter effort is aimed at retarding or retaining surface runoff from rainfall and prevents its immediate loss as stream flow. At the landscape scale, we have shown it is possible to diversify the arboreal vegetation and to generally increase the heterogeneity of the vegetation in pastures. We advise landowners and farm managers on stocking rates, water management practices, and the establishment of trees and forage plants in a topographically appropriate manner. We explain how diversification of the landscape increases the delivery of natural goods and services and improves agricultural profitability. In addition, we advise and encourage ecologists and foresters to conduct restoration to provide connectivity between the many fragmented forest patches scattered within the espinal-transformed agriscape. Our long-term goal is to transform landscapes to a more stable, diverse, and productive condition relative to the extant of espinales and commercial forest plantations. As much as possible, we encourage traditional land use practices with which farmers are comfortable and then incorporate innovations as needed to address degradation problems and reverse the spiral of degradation that has characterized the region’s trajectory in recent decades. Partly as a result of the research program carried out in the espinales of central Chile since the late 1980s, a series of interrelated policy changes and practical tools for combating desertification have been achieved in recent years. Through a program of recuperation of degraded areas, the Chilean government has begun helping farmers to restore and rehabilitate espinales on their lands (VFT Figure 2.6). Funds have been made available to help underwrite the costs of managing espinal formation in new ways so as to achieve and maintain
06_VFT2:IP_Clewell
9/17/07
11:08 AM
Page 37
Restoring Cultural Landscapes in Central Chile
37
VFT Figure 2.6. Socioecological landscape with forest preserves and agricultural usage.
a higher, denser tree cover, approaching or exceeding 50 percent. Simultaneously, the problem of degraded pastures is being addressed directly: Government support can now be obtained for the initial sowing of mixtures of annual fodder legumes that can increase species diversity and improve soil fertility through greater biological fixation of nitrogen. This is an example of using plants as beneficial ecological engineers (Jones et al. 1994; Rosemund and Anderson 2003).
07_ch03:IP_Clewell
9/17/07
11:09 AM
Page 38
Chapter 3
Cultural Ecosystems, Fire, and Alternative States
The SER Primer on Ecological Restoration (SER 2002:5) defined cultural ecosystems and landscapes as those that have “developed under the joint influence of natural processes and human-imposed organization.” In this chapter we will develop the concept of cultural ecosystems. There is general agreement among scholars that cultural ecosystems exist. These ecosystems coevolved in tandem with human culture. In the absence of traditional or local cultural practices, they would lose their integrity and transform to a contrasting state, perhaps irreversibly. There is also firm agreement that no ecosystem on Earth has escaped direct or indirect human impact and that the concept of an entirely pristine ecosystem or “wilderness” that has escaped any influence whatsoever by humans is out of date, to say the least. For example, even the endolithic lichen ecosystems of Antarctica are subject to increased solar radiation from human-mediated ozone depletion. Similarly, mercury content in the blood systems of birds and fish is alarmingly high all over the world, including those found at the North and South Poles. Indeed, from a certain perspective, the entire world can be seen as “a mosaic of coevolving social and ecological systems,” as noticed by Norgaard (1987:109). Cultural ecosystems differ from ecosystems that are only affected by human exploitation or misuse, and we limit our consideration to cultural ecosystems in this chapter. However, the distinction between cultural and other ecosystems that have only been affected is not always easily determined, particularly in places where people visit periodically and cause recurring impacts but do not reside. Scholars are sharply divided, and debates can get quite heated between those who agree that conclusive evidence exists to designate few ecosystems as “cultural” and those who assume from indirect evidence that all ecosystems are “cultural” unless compelling evidence exists to the contrary. The debate is sometimes a matter of degree. In other words, did a particular ecosystem evolve on account of cultural practices, or had it already evolved to its present state, and humans only embellished it with a little ecological “house cleaning”? The distinction is relevant to restoration planning. Should an ecosystem be restored with the assumption that it will henceforth need a resumption of cultural practices or equivalent management? Will such practices or management materialize, or should restoration plans be modified or canceled before they are implemented? Or can the ecosystem be restored without regard to cultural concerns? 38
07_ch03:IP_Clewell
9/17/07
11:09 AM
Page 39
Cultural Ecosystems, Fire, and Alternative States
39
In regions of the world that have been densely and continuously populated by people for many millennia, and where traditional land and resource uses and practices are reasonably well known, local ecosystems can be safely described as cultural. Such areas include much or most of the African and Eurasian continents, and certainly the Middle East. In the Western Hemisphere, particularly, the question of cultural ecosystems remains quite contentious because of the assumption by European colonists and their contemporary descendants that the hemisphere was largely unpopulated at the time of colonization and that most indigenous peoples and cultures were not technically advanced or politically organized to the point that they could do much more than fine-tune or moderately expand preexisting ecosystems. However, anthropological and historical evidence to the contrary keeps surfacing and has amassed to the point that many ecologists accept that cultural ecosystems were pervasive in pre-Colombian times. Studies on Incan agroforestry and other land use systems in the Andean highlands are a good case in point (Chepstow-Lusty and Winfield 2000; ChepstowLusty et al. 2005). We are both persuaded that cultural ecosystems are much more widespread than our professors assumed when we were graduate students. Our views on this point have been reinforced by our experiences with tribal peoples in various parts of the world and their intensive and inventive uses of natural resources. We advise those involved in restoration project work that they may have to make controversial assumptions about cultural ecosystems. We will proceed by elaborating on some of the evidence and propositions that presume that cultural ecosystems are a widespread phenomenon. We will follow with a discussion on fire, which apparently has been the most effective mode of the cultural transformation of ecosystems (Pyne 1995; Vale 2002) and is a vitally important aspect in many restoration projects. We then discuss the concept of cultural ecosystems as alternative ecosystem states and their significance in cultural landscapes.
Evidence for Cultural Ecosystems and Landscapes A recent assessment of cultural ecosystems in California, USA by ethnobotanist Kat Anderson (2005) revealed that cultural ecosystems and landscapes are much more prevalent than has been previously suspected or recognized. California is large, is dramatically varied topographically and climatically, and supports a wide range of ecosystems. Anderson’s work showed that most of these ecosystems were culturally altered and that the only entirely wild ecosystems in the state of California were subalpine forest, deserts, salt marsh, beach and dune ecosystems, alkali flats, and serpentine balds and outcroppings. Anderson (2005:8) claimed that “much of what we consider wilderness today was in fact shaped by Indian burning, harvesting, tilling, pruning, sowing, and tending.” She argued eloquently that “much of the landscape in California that so impressed early writers, photographers, and landscape painters was in fact a cultural landscape, not the wilderness they imagined. The wildflower displays they depicted were edible plant gardens” (2005:158). For example, open and grassy oak savannas of California’s valleys and foothills were entirely shaped by intentional burning and by the tending of oaks (Quercus lobata) for the food value of their acorns and a variety of other uses. Supporting evidence for this was provided by McCarthy (1993), who showed that in the absence of fire, coniferous trees encroached into these savannas at the expense of oaks. Extensive coastal prairies were largely coniferous forests in the past that were transformed by
07_ch03:IP_Clewell
40
9/17/07
11:09 AM
Page 40
in tr o d u c t i o n a n d e sse n ti a l b a ckground
Indian burning and subsequently fire-maintained by them as both a source of food from wild plants and as a hunting ground for native animals (Anderson 2005). The prevalence of cultural ecosystems in California should not come as a surprise. Day (1953) documented a similar ecological importance of American Indians in the northeastern United States half a century earlier. University of Wisconsin geographer William Denevan (1992) presented compelling arguments to dispel what he called the “pristine myth” of virgin landscape in the Americas at the time of the first voyage by Columbus in 1492. That myth, which he claimed had been woven by nineteenth-century romanticists and “primitive” writers such as Cooper, Longfellow, and Thoreau, came to be accepted as undisputed fact until very recently. Denevan (1992) estimated a substantial indigenous human population in the Western Hemisphere of 40–100 million people in 1492. He claimed that this population was reduced by European-borne diseases by 89 percent a mere 158 years later, in 1650. By that time, however, through secondary biological succession, the indigenous biota had sufficiently recovered from the sustained cultural impacts of the formerly large and active indigenous population so as to suggest a wilderness condition to residents of permanent colonies that were being established by Europeans. Denevan (1992:370) emphasized that American “Indian impact was neither benign nor localized and ephemeral, nor were resources always used in a sound ecological way.” Over several millennia, Native American Indians had developed socioecological landscapes that contained production systems and wild and seminatural ecosystems by the time of Columbus’s arrival. Agricultural clearing and burning had converted much forest into fallow growth and into semipermanent meadows, glades, savannas, and prairies. Denevan (1992:372) surmised and somewhat overstated that “the longleaf, slash pine, and scrub oak forests of the Southeast are almost certainly an anthropogenic subclimax created originally by Indian burning.” He cited biogeographer Carl Sauer, who argued that the great grasslands of the New World at the time of contact were of anthropogenic origin. Sauer reasoned that rainfall was generally sufficient to support trees and that the eastern prairies would have become forested without frequent, nearly annual burning by Indians. Such opinion is fairly surprising, if not shocking, for some people, and many scholars are not at all in agreement. Baker (2002) and others, remain skeptical of the extent to which Indian-induced fire has shaped New World ecosystems. We fully understand these reservations and readily acknowledge that there are many ecosystems that were modified by other means. However, on a global, historical scale, we feel justified in giving fire a very prominent place in this book. With regard to intentional fire and other major modifications of environments, North America is far from being an isolated case (Ponting 1991; Diamond 1992). Some of the earliest and strongest evidence of intentional, prehistoric burning comes from Australia. Among many other scholars, Bowman (1998) asserted that humans colonized that island continent at least 40,000 years ago and perhaps much earlier. Palynological data from lake sediments showed abrupt increases in the frequencies of fine charcoal particles and of pollen from Eucalyptus and other fire-tolerant trees that were more easily explained on the basis of aboriginalset fires than by climate change and ignition by lightning. Bowman wrote that there was little doubt that aboriginal burning was central to the maintenance of many or most Australian landscapes long before the time of European contact. This burning caused substantial changes in
07_ch03:IP_Clewell
9/17/07
11:09 AM
Page 41
Cultural Ecosystems, Fire, and Alternative States
41
the geographic range and demographic structure of much vegetation, not to mention the extinction of many kinds of plants and animals. The fires favored the expansion of grasslands and other structurally open vegetation, and they allowed Eucalyptus to colonize rainforest. Aboriginal fires were used for driving game, smoking animals from burrows, asphyxiating bats in caves, cooking, clearing thick vegetation, regenerating senescent vegetation, felling trees, clearing camps, facilitating travel, controlling insects and vermin, creating warmth and illumination, performing ritualistic ceremonies, signaling, and waging war. Moving to a third continent, Asia, Wharton (1966, 1969) argued that the savannas of southeast Asia apparently originated from human activity and that tribal people in what is now Cambodia and indigenous wild cattle had apparently achieved a cooperative and mutually beneficial way of life. Similarly, tropical dry forests throughout south Asia are thought to have originated from anthropogenic fires (Hiremath and Sundaram 2005). Several similar situations have been studied in Africa and elsewhere in recent colonial times (Bond and Van Wilgen 1996; Bond et al. 2003). Contrary to popular opinion, truly pristine environments in the Amazon Basin—considered by many as the epitome of vast, boundless wilderness—probably were rare at the time of European contact. Clement (2006) estimated a population of 4–5 million people in Amazonia at that time. In 1542, Spanish explorer Gaspar de Carvajal described the banks of a 180mile stretch of river as being densely inhabited with essentially contiguous villages (Mann 2005). Balée (2000) described forests growing on enormous mounds of potsherds in the Amazon. Clement (1999) identified 138 plant species that were cultivated or managed by tribal peoples. Many of these species were trees bearing fruits or other edible parts, which were interplanted or seeded throughout the Amazon, thereby converting it into a vast agroforest or “fruiting forest,” to borrow a phrase from the relevant French literature. The significance of these observations can hardly be overestimated. Humans have substantially reshaped most ecosystems with which they are associated. In this respect, they are a very influential—if not dominant or keystone—species. People are integral biological components of the biosphere and therefore of most terrestrial and some aquatic ecosystems. We cannot be distinguished as something different from nature when we ourselves are among the most significant expressions of nature. Our conscious awareness, memory, and deductive logic do not set us apart from nature; they only add to our capability as a dominant species in nature. Our special abilities as highly conscious beings give us the capacity to understand our position in nature and the understanding, which is becoming more evident every day, that we must provide stewardship for the rest of nature if it is to continue to sustain us.
Fire and Restoration The ecological restoration of many impaired cultural ecosystems consists primarily of reestablishing former burning regimes (Arno and Fiedler 2006). Much prescribed burning is conducted in North America by skilled specialists whose primary motivation is fuel reduction. This approach responds to the very serious problem that has developed since the early twentieth century in response to fire suppression, both intentional and inadvertent. The absence of fire has converted whole regions that were formerly covered by open ecosystems into scrublands, thickets, and multistory forests with dense undergrowth and much leaf litter. In
07_ch03:IP_Clewell
42
9/17/07
11:09 AM
Page 42
in tr o d u c t i o n a n d e sse n ti a l b a ckground
semiarid regions particularly, and elsewhere during periods of drought, these woody formations are susceptible to catastrophic wildfires, particularly those that contain coniferous trees or other plants producing volatile oils. An effective remedy is to conduct prescribed burning in the cool season to reduce the fuel load (quantity of combustible materials) of flammable litter and undergrowth, thereby reducing the opportunity for the ignition of wildfire that threatens life, property, and the structure of forest ecosystems themselves. In Europe, in earlier days, this practice was common in wooded and agricultural areas and was called by such names as “little fires of winter.” Fuel reduction is commonly an important use of fire for restoration purposes. However, it is not the only one, and practitioners need to be aware of how fire affects ecosystems and how it can be used effectively in restoration projects. Issues of particular concern to practitioners with regard to the properties of fire are described in this section.
Attainment of Lethal Temperatures A principal reason to burn is to kill unwanted shrubs, woody vines, and small trees. Thin, tight bark of some species transmits heat quickly to the cambium, which girdles the bark and kills the plant. Thick, flaky bark of other species retards heat penetration and protects the cambium. Unwanted woody stems must be exposed to lethal temperatures long enough to reach the cambium. Various forms of plant life respond differently to fire. For example, in South Africa, fire at short intervals generally promotes grass, whereas fires at longer intervals (decades) allow fire-adapted woody plants to mature and build up a seed bank (S. J. Milton, personal communication, 2007). Decadal fires are much hotter than annual fires because fuel loads are greater. They may destroy grass bases, thereby making way for seedlings of pines and other woody plants that germinate on bare soil after a high-intensity fire, which we have observed repeatedly in North and Central America, South Asia, and elsewhere.
Residence Time, or How Quickly a Fire Moves Through an Area The longer it takes a fire to burn, the longer plant tissues may be exposed to lethal temperatures. In wind-driven or other fast-moving fires, the duration of potentially lethal temperatures may not be long enough to kill woody plants.
Evenness or Spottiness of the Burn Many or most areas in a site that was burned may avoid lethal temperatures. Some areas are spared because of heterogeneity in the distribution of fuel or its flammability. Other areas are spared by erratic winds, which cause flames to part and burn around, rather than through, these areas. Topographic relief also causes uneven burns, especially in mountainous terrain. Unevenly burning fires may allow much vegetation to survive unscathed. This in turn promotes spatial heterogeneity, providing refuges for fire-intolerant species of plants and animals. Depending on the intent of burning, such refuges can foster the survival of desirable species or prevent the elimination of unwanted species.
07_ch03:IP_Clewell
9/17/07
11:09 AM
Page 43
Cultural Ecosystems, Fire, and Alternative States
43
Season of Burning During the dormant season (typically in winter in extratropical regions of the Northern Hemisphere), carbohydrate reserves that were produced by photosynthesis have been translocated below ground into roots and rootstocks. Most kinds of woody plants can resprout from their belowground parts. Dormant season fires may kill aerial portions of woody plants, which resprout at the onset of the next growing season. Fire that is ignited during the growing season can kill those same plants because their carbohydrate reserves are concentrated in aboveground tissues, and insufficient quantities remain below ground to resprout. Two or more growing-season fires in rapid sequence can kill belowground tissues (see Virtual Field Trip 3). Most fuel reduction fires are conducted in the dormant season and are ineffective in removing woody plants. Early growing season fires may also stimulate prolific seed production on regrowth of herbs and shrubs later in the same year. This may be another reason why a practitioner would ignite fires in growing seasons.
Effects on Germination Fires remove competing vegetation, expose mineral soil, and provide a flush of soluble nutrients from ash, all of which promote plant establishment. Heat from fire sometimes stimulates seed germination, as in Chamaecrista fasciculata (partridge pea) in the eastern United States (Martin and Cushwa 1966). Smoke from fires initiates germination in a whole suite of Australian woodland species (Rokich et al. 2002). An understanding of seedling establishment that can be expected after fire is an important consideration in prescribing fire for restoration. The timing of burning will influence the survival of seedlings that germinate in response to fire, in accord with seasonal climatic conditions. Grasses and sedges are particularly flammable because of the density at which they grow and the splintlike growth form of their leaves. Leaves of conifers also are quite flammable because of their high content of volatile substances. Other plant structures resist ignition, such as the leaves of oaks and many other broadleaved hardwood trees. A log that lies in a grassy field will not ignite in a grass fire unless it is dry and partially decomposed, just as a green log will not burn in a fireplace without a glowing bed of embers. Therefore, a practitioner should have knowledge of fuels and their flammability before using fire as a restoration technique.
Pyrogenic Ecosystems Pyrogenic ecosystems are commonly characterized by the frequency of fire, which is expressed as the return interval or average number of years between successive fires. However, it would be more accurate to express the return interval in ecological terms, such as the quantity and quality of the fuels, which, in turn, may reflect recent weather conditions. Most pyrogenic ecosystems are maintained by surface fires, in which grasses and other fine fuels burn quickly and lethal temperatures reach only a short distance above ground level. In open pinelands and other kinds of savannas, the trees generally are adapted to survive such fires. In other ecosystems, the return interval may extend for decades, and the fires are crown fires that burn through generally dense, tall shrubby undergrowth and ignite the crowns of trees, sometimes killing them. Examples are pocosin (evergreen shrub-bogs) and bay swamps in
07_ch03:IP_Clewell
44
9/17/07
11:09 AM
Page 44
in tr o d u c t i o n a n d e sse n ti a l b a ckground
southeastern North America, jack pine (Pinus banksiana) forest in the Great Lakes region, lodgepole pine (Pinus contorta) forests in western North America, Eucalyptus forests in Australia, and various Mediterranean-type woodlands in south Australia, South Africa, and elsewhere. At a different level of resolution it has been shown that in pyrogenic ecosystems, some of the keystone perennial plant species have clearly evolved physiological, reproductive, and phenological adaptations to fire. The cork oak (Quercus suber) of the western Mediterranean region is an excellent example (Pausas 1997), which supports the growing evidence of community- and ecosystem-level adaptations to fire (Pausas et al. 2004; Bond and Keeley 2005). Exceptions are known, but ecological mechanisms are generally operating to ensure that the same or similar kinds of vegetation recover after such crown fires. Forest type conversions may also occur. For example, acid, headwater swamps on the southeastern coastal plain of the United States are dominated by broadleaved evergreen hardwood trees (esp. Magnolia virginiana) that are infrequently destroyed by crown fires and replaced by pines (Pinus elliottii). The pines are short-lived (80–125 years) and are eventually replaced by the slowly recovering broadleaved evergreen hardwoods (Hebb and Clewell 1976). Restoration practitioners need to know whether an impaired ecosystem is pyrogenic, what the return interval is, and what kind of fire behavior is normal for it. This kind of information is incorporated into the restoration plan and into recommendations for postrestoration management that practitioners may be required to prepare. The substitution of mowing (including bush-hogging, mowing coarse herbs and brush with a heavy, horizontally pivoting blade) or herbicidal application is commonly suggested as a substitute for prescribed fire in restoration projects. This expedient may avoid the hassles of obtaining burning permits or the costs and risks of liability posed by prescribed burning. However, mowing without subsequent burning is ecologically unacceptable if mowing causes a litter layer to form, which suppresses fire-adapted species. Herbicides, or at least those with longer residence times in the soil before degradation, may find their way into groundwater and contribute to environmental pollution. By contrast, burning removes litter and releases mineral nutrients quickly in soluble ash that is absorbed by shallow root mats of the fire-adapted grasses and forbs and is expressed shortly after the next rainfall by a flush of verdant new growth. This fire-adapted vegetation is efficient in absorbing nutrients and in preventing their leakage (see Chapter 2). In addition, the dense vegetation and its root mat are effective in absorbing rain, detaining surface runoff, and stabilizing soils. In other words, the ecological stability and complexity of fire-adapted systems depend on the qualities that fire—and fire alone—brings. Practitioners are commonly challenged by preemptive constraints (Manning et al. 2006) of high costs, liability issues, and permitting difficulties that induce them to search for substitutes for burning. These challenges should be overcome, as they were at the restoration project site in Virtual Field Trip 3, despite the fact that a freeway bisected it. Culture is by no means the only important cause of fire in ecosystems. Many fires are ignited by lightning or, much less often, by other natural causes. Some pyrogenic ecosystems may have originated on account of cultural burning and have been enhanced and expanded by lightning-set fires. Other pyrogenic ecosystems originated from ignition by lightning and have been enhanced and expanded by cultural fires. One consequence of fires is that they clean up fire-adapted communities by ridding them of less fire-tolerant vegetation and associated fauna and by attracting fire-adapted biota. Burn-
07_ch03:IP_Clewell
9/17/07
11:09 AM
Page 45
Cultural Ecosystems, Fire, and Alternative States
45
ing practices in prehistoric times probably had the same cleansing effect and would have spurred the refinement of distinctive, fire-adapted communities. Much prescribed burning is conducted in parks and other public lands in North America expressly for that purpose. A similar situation occurs in Australia, where national park managers and private ranchers have reestablished the regular burning regimes used over millennia by various aboriginal groups throughout the continent (Bradstock et al. 2002).
Alternative Ecosystem States in Cultural Landscapes At evolutionary time scales, all ecosystems have undergone transformations in response to changes in climate and geomorphology and to the evolution, dispersal, adaptation, and extinction of species. This topic is being elaborated by theoretical ecologists under the rubric of multi-equilibrium theory, as mentioned in Chapter 2 (see Suding et al. 2004; Suding and Gross 2006; Falk 2006; Hobbs and Suding 2007). Here we are concerned with the relevance of this perspective to ecological restoration in cultural ecosystems and landscapes. The recognition of a cultural ecosystem assumes that it was derived from an alternative “wild” state from which it was transformed by intentional burning, clearing, plowing, grazing, terracing, other cultural practices, and combinations thereof (see Virtual Field Trip 8). In other words, an ecosystem that occupies a particular site or location can assume at different times two or more states that can be very different from each other and very different in terms of their composition, structure, and other ecological attributes. In many instances, the wild state of a cultural ecosystem exists nearby, or some semblance of it can be induced through biological succession upon the cessation of all cultural practices. This indeed has happened globally, as traditional rural societies assume new socioeconomic structures or are enticed or coerced into uprooting and moving elsewhere. Many ecological restoration projects have been conducted to reverse this process and to cause the return of a former cultural ecosystem that can provide sound, sustainable support systems for people with a range of needs and livelihoods. Sometimes more than one cultural ecosystem has evolved from its “wild” state, reflecting different cultural practices or different intensities of these practices. Consequently, the practitioner is faced with more than one alternative state to which a transformed or impaired ecosystem could be restored. For example, the tallgrass prairie of the North American Midwest is maintained by frequent fires. At the time of European contact, that ecosystem may have owed its widespread occurrence to annual burning by American Indians. In addition, some areas were prairie-like but were interspersed with occasional large individuals of bur oak (Quercus macrocarpa) and several herbaceous species that occurred nowhere else (Packard 1988, 1993). These were bur oak savannas and are recognizable as an alternative state that was presumably the product of a fire regime that was more irregular than it was in tallgrass prairies. In the greater Chicago region, which extends into Wisconsin and other nearby states, fire suppression has allowed deciduous forest to replace tallgrass prairie and bur oak savanna. Deciduous forest may be the “wild” state in this triage; however, we may never know with certainty, and the role of post-Pleistocene climate change cannot be discounted as a consideration. For restoration practitioners, all alternative states are valid references, and determining the original “wild” state is irrelevant. However, restoration of prairies and bur oak savannas in the greater Chicago region not only has been spectacularly successful but has
07_ch03:IP_Clewell
46
9/17/07
11:09 AM
Page 46
in tr o d u c t i o n a n d e sse n ti a l b a ckground
sparked great interest among citizen-volunteers throughout North America to contribute their labor to local restoration initiatives. In another example, in the Mediterranean region, alternative ecosystem states reflect variation in the cultural fire regime, the intensity and frequency of wood extraction through coppicing or pollarding of trees, and the intensity of domestic livestock grazing. Plant species composition is similar in every alternative state, but the relative abundance of the species and thus the community structure varies markedly between them. The least cultural activity allows oak forest to develop, which may represent the “wild” state. However, the duration and intensity of human occupancy in this region cast doubt on any purely natural state ever being identified with certainty. Fire and fire-related activities can transform oak forest either to pine woodland or to an oak-dominated shrubland known from one region to another as garrigue, maquis, or matorral (for synthesis of a large literature, see Blondel and Aronson 1999). Garrigue is further transformed in structure by coppicing, which is a local cultural practice. Frequent burning, often coupled with livestock grazing and fuelwood collection, transforms garrigue to shrubland dominated by Ulex or into sward (grassland community). Restoration could, in principle, be modeled after any of these alternative states (Figure 3.1). The potential for alternative ecosystem states to occupy the same location at different times raises the question of desirability. Is one alternative state more desirable than another? After initial adjustment, will the transformed ecosystem perform ecologically just as well as it did in its former state before transformation, if not better? Could it instead perform less well? This, of course, would depend on the measures of performance that are used (e.g., net productivity, biodiversity, stability). Therefore, the question of desirability is reduced to one of human values. Do we prefer the original or the transformed ecosystem? Which version favors our ecological values, our economic well-being, our cultural fulfillment, and our aesthetic preferences? This question
Figure 3.1. Alternative successional pathways between five different, observable ecosystem states in a single environmental and socioeconomic setting in northeastern Spain. Dashed lines represent slow or rare pathways (Vallejo et al. 2006). Arrows that loop back to the same state represent direct pathways of recovery after disturbance. Photographs and further discussion of some of these alternatives appear in Virtual Field Trip 8.
07_ch03:IP_Clewell
9/17/07
11:09 AM
Page 47
Cultural Ecosystems, Fire, and Alternative States
47
has profound significance to the field of ecological restoration in light of great increases in the rate and severity of ecosystem transformations worldwide that have occurred in the last two centuries in response to human endeavor. Not all transformations are desirable, and many are the consequence of unsustainable resource exploitation that causes ecosystems to become degraded or otherwise impaired. The selection of the preferred alternative state in restoration planning is critical because stakeholders and members of the broader community will have to live with the results. We recommend these guidelines for the selection of which alternative state to choose as a reference or metric for restoration if several exist. First, be practical. Preference should be given to states for which subsequent ecosystem management can be provided as needed after the completion of restoration. For example, if an alternative state requires frequent prescribed fire and burning permits will not be issued at any time in the near future, then that alternative state should not receive consideration as a restoration target. Second, if the restored ecosystem will be used in some way, including for recreation or aesthetic improvement, only alternative states should be considered that are conducive to that purpose. Third, an alternative should be selected in which a high diversity of K-strategists prevails. We may ask what are the ecological consequences of ecosystem transformation to alternative states—or metastable states, as they are sometimes called—by traditional cultural practices? The most common consequence is that parts of forests or other closed communities are converted to more open states, such as a woodland, savanna, or grassland. Ecologists have ignored or discounted cultural practices as equivalent to entirely natural ecological drivers, particularly those associated with climate. Indeed, the traditional assumption in ecology has been that these more open states represent earlier stages in biotic succession that were caused by human-mediated disturbance. The value that ecologists have traditionally placed on endpoints in succession does not address the fact that these more open states resulting from intermittent human disturbances, and above all the more varied landscape mosaic they contribute to, often contain greater species richness, and therefore greater biodiversity, than the so-called climax states that were conceived without recognition of cultural influence. They also contribute to landscape systems of more direct value to more people than the completely unmanaged systems from which they were derived. The issue then arises as to how they can be managed sustainably and “from the inside out” (Waltner-Toews et al. 2003), in other words, through local, grassroots initiatives with the assistance of the public or nongovernment sectors. The complexity of the issue is compounded by changing climate and other global changes (Harris et al. 2006). There are obvious tradeoffs in relation to biodiversity. The species composition and structure of a coastal prairie that was described by Anderson (2005) in California contrast greatly with the coniferous forests that once occupied many of these sites before their conversion to grassland by cultural fires. Existing coniferous forests nearby display intricate and impressive structure but comprise very few plant species. In contrast, prairies display little structure and remarkable species richness. (Actually, grasslands have much structure and microclimatic differentiation that is simply not evident to creatures that stand more than a few centimeters tall.) Seral stages in ecosystem development can be considered alternative states with implications for restoration. One reason is that the presumed climax state can be less diverse than earlier seral stages. For example, the presumed climax forest in the southern Great Lakes region of the United States is dominated by American beech (Fagus grandifolia) and sugar
07_ch03:IP_Clewell
48
9/17/07
11:09 AM
Page 48
in tr o d u c t i o n a n d e sse n ti a l b a ckground
maple (Acer saccharum). The preceding seral stage is a more diverse forest codominated by white oak (Quercus alba) and several species of hickory (Carya). Cultural burning by Indians apparently played a role in maintaining this oak forest. Karl Smith conducted a prescribed fire in beech–maple forest to restore this seral or alternative state and discovered that burning stimulated a profusion of spring wildflowers, whereas these same herbaceous plants had previously persisted as dormant rootstocks beneath the formerly dense cover of beech and maple (Smith 1994). Restoration of this type was conducted in southern Illinois (Stritch 1990) and Missouri (McCarty 1998), with small fires that created patches of varying species composition and structure. The so-called climax or old-growth stages of development are preferably included in such landscapes and should be large enough to accommodate the ecological and territorial needs of their characteristic species. Practitioners who are engaged to restore larger natural landscapes have the opportunity to incorporate all of these alternative states into their plans. Some restored parcels of land could even be intentionally restored to early seral states that harbor mainly r-strategists, such as on riverbanks, where r-strategists make up the characteristic vegetation. These are “leaky” ecosystems with regard to nutrient loss, moisture retention, and substrate stability. Their habitats lack the differentiation needed by specialized species. The ecological value of these communities of r-strategists becomes apparent in ecological emergencies after a destructive wildfire or other “creative destruction,” in the terminology of adaptive cycles described by Gunderson and Holling (2002). Populations of their species can spread quickly to provide temporary cover until K-strategists recover. As such, they are the ecological equivalents of first aid kits for healthy, adaptive ecological landscape mosaics. To what do they need to adapt? We address this question in the next section.
Range of Landscape Types In this chapter, and in Chapter 5 when we discuss cultural ecosystems whose species composition, dynamics, and structure were appreciably shaped by traditional cultural practices, we accept and indeed affirm that the ecological value of these cultural ecosystems may be equivalent to or even greater than that of “natural” or pristine ecosystems. Ecosystems with cultural influence very often are interspersed with natural landscape units to form landscape mosaics of high ecological and conservation value. They represent a part of a vast array of landscapes for which we present a simple typology in Figure 3.2. As shown, landscapes can be either pristine or cultural. Pristine is used here in a relative sense—for lack of a better term—to designate ecosystems that reveal no apparent cultural influence in their development and current state. They are natural and lack any human handiwork, and at least in North America they would be called wilderness. All other ecosystems and the landscapes that comprise them are cultural, as defined by the SER Primer (SER 2002). Cultural landscapes cover the gamut from wild and seminatural lands that many people would find indistinguishable from wilderness all the way to the most highly developed urban ecosystems consisting of flower boxes, pigeons, and concrete. In most contexts, including this book, cultural ecosystems generally connotes those that are seminatural and gardenified rather than those consisting of intensely managed production systems, as described in Chapter 1. Agroforests should be included here that contain nonnative crops or commercially pro-
07_ch03:IP_Clewell
9/17/07
11:09 AM
Page 49
Cultural Ecosystems, Fire, and Alternative States
49
Figure 3.2. Landscape terms for use in a restoration perspective.
duced cultivars. Highly developed landscapes include residential and industrial areas, wind farms, waste disposal sites, abandoned extraction sites such as surface-mined and unreclaimed land, abandoned industrial areas such as brownfields, and sites that are dedicated to infrastructure, such as transportation corridors, other corridors for power lines and pipelines, human-made dikes and levees, and shipping channels. Gardenified landscapes are widespread, and their recognition by practitioners is essential for planning and implementing projects. A gardenified ecosystem is one whose former natural state was modified noticeably by human activity but that nonetheless retains an essentially natural character and is self-sustainable, assuming a continuation of present levels of traditional cultural practice. In other words, human activity that transformed them does not threaten their survival, and they are expected to persist indefinitely. A gardenified landscape, in turn, consists in part or in whole of gardenified ecosystems. At high altitudes in the European Alps can be found a series of gardenified landscapes where, after several centuries of livestock grazing, tree harvesting, and other local cultural practices, the native ecosystems have become notably transformed to altered states with regard to species composition and structure (Hall 2005). However, they retain their naturalness and their functional aspects. For example, forests lost much of their undergrowth and many trees lost their lower branches because of grazing. Some forest was converted to meadow, and meadows were transformed by additions to their species composition and by differential grazing by livestock among plant species. In addition, in the twentieth century dozens of ski resorts were created in the Alps and in a few other mountain ranges in Europe and North America, and this has changed landscape dynamics and local economies quite dramatically. (Given global warming and its prominent impact on the Alps, many ski stations there are seriously at risk of closing in the coming years. What an opportunity this will provide for restoration as people discover other ways to enjoy montane landscapes without skis and snowmobiles!) Human activities that cause gardenification are commonly called traditional cultural practices. We prefer to identify them as local cultural practices if they are still occurring and
07_ch03:IP_Clewell
50
9/17/07
11:09 AM
Page 50
in tr o d u c t i o n a n d e sse n ti a l b a ckground
are sustainable. We therefore support a clear-eyed approach of local ecological knowledge (LEK) as a complement to the more widely used term traditional ecological knowledge (TEK). Traditional cultural practices and knowledge are those that were known to occur in the past and therefore are historical. Local cultural practices and knowledge are those that will continue into the future and will evolve and undergo modification in response to new technology and cultural development in a manner that respects and maintains biodiversity and ecosystem quality. A gardenified ecosystem probably will undergo additional transformation accordingly in the future, but it will remain gardenified as long as it retains a character of naturalness and remains self-organizing. As in natural ecosystems, self-organizing is dynamic, and changes in state can result from natural causes and also changes in local cultural practices. For example, a closed forest may become open grassy woodland in response to periodic burning. A former ski station may be restored to forest, woodland, meadow, or some combination of them. The gardenified ecosystem retains its sustainability, despite changes in state, because it does not suffer from decreases in the quality or levels of biodiversity and ecosystem function. Seminatural ecosystems and landscapes that comprise them are those that cannot be clearly identified as being gardenified, yet they display at least subtle evidences of land use. Perhaps the most critical distinction is whether land usage will be continuing, as in a gardenified state, or whether the ecosystem will have time to recover from human disturbance. Seminatural and gardenified ecosystems occur along a continuum of land use, and a precise distinction between them may not be possible or even necessary. In Chapter 1 we introduced the concept of socioecological ecosystems, a term that is gaining increasingly wide currency, especially through the work of the Resilience Alliance (see Carpenter et al. 2001 and issues of the free online journal Ecology and Society). The key of this approach is to stop seeing people as somehow outside ecosystems but rather as part and parcel of nature and therefore of ecosystems. This leads to the notion of local management of the ecosystems on which we depend from the inside out rather than by government edict. Socioecological landscapes are those that combine production systems with gardenified or seminatural ecosystems, generally with some residential or even some light industrial lands. An example would be agricultural cropland and a meadow used as pasturage for livestock (both managed production systems), some forested land along a stream (gardenified or seminatural ecosystems), and several residences and barns. Light industrial usage could be a grain mill or small saw mill. Collectively, they represent a landscape unit that provides ecological services of use to people (see Chapter 7). Socioecological systems make up most rural regions of the world, with the notable exception of landscapes that consist of production systems almost in their entirety, such as large corporate farms, stockyards, and commercial forests, as are particularly common in many parts of North America, western Europe, Australia, and increasingly large parts of Brazil, Argentina, Malaysia, and elsewhere. Socioecological landscapes that consist largely or entirely of both forests and pastures for domestic livestock are called silvopastoral landscapes. A test for distinguishing managed production lands from gardenified lands is the manner or intensity of land use (Figure 3.2, middle). Production systems are managed in a top-down, administrative manner, usually by an authority that resides elsewhere and only visits the land. Land managers generally depend on outside sources of energy (mainly fossil fuels), materials (inorganic fertilizers, herbicides, pesticides), and planting stocks (commercially produced
07_ch03:IP_Clewell
9/17/07
11:09 AM
Page 51
Cultural Ecosystems, Fire, and Alternative States
51
seeds). Gardenified systems are managed from within, and people act as stewards or caretakers of the land and its resources in an interactive manner. They generally live on or near the land and use external sources of energy, materials, and stocks in moderation, if at all. This test is not always easy to apply. For example, an otherwise natural wildlife management area may be interspersed with production units in the form of food plots and may contain other gardenified lands. Some silvicultural land only marginally qualifies, if at all, as a production system. Other forests are better recognized as production systems, such as row-planted tree farms and silvicultural areas that are managed with herbicides to eliminate competing native undergrowth. We have now come to the end of the first part of this book. We began by describing ecosystems in ecological terms: biota, biosphere, the physical environment. In the second chapter we shifted gears and spoke about people and their negative impacts on ecosystems that lead to decline and the need for ecological recovery and restoration. In the present chapter, and in contrast to Chapter 2, people were portrayed as champions and guardians of numerous ecosystems with which they had coevolved. Two themes emerged that will appear repeatedly as this book progresses. One is that ecosystems, and thus ecological restoration, are inextricably related to people. The other is that the relationship between people and their ecosystems is exceedingly complex. The background that was presented in Chapters 2 and 3 was intended to inscribe those two themes indelibly on those interested in restoration project work—not so much because people–ecosystem interactions are unavoidable but because they add dimensions to our endeavors that make ecological restoration fascinating.
07_ch03:IP_Clewell
9/17/07
11:09 AM
Page 52
08_ch04 (pt2):IP_Clewell
9/17/07
11:17 AM
Page 53
pa r t i i
Elements of Restoration Projects
In Part I, we provided an introduction and essential background for the emerging field of ecological restoration. The three chapters in Part II address more practical issues in conceiving and evaluating restoration projects. In Chapter 4 we discuss ecological attributes of restored ecosystems, which ensure quality in restoration projects. These attributes are listed in The SER Primer on Ecological Restoration (SER 2002) and are expanded at some length here. We then take a Virtual Field Trip to a restoration project site in Mississippi to illustrate some of the ideas in that chapter. In Chapter 5 we address the principles of reference models and developmental trajectories, including previously unpublished material that is intended to clarify these basic but not universally understood topics. Finally, in Chapter 6 we revisit ecological attributes, reference models, developmental trajectories, and related issues in terms of their application in project planning and evaluation.
53
08_ch04 (pt2):IP_Clewell
9/17/07
11:17 AM
Page 54
08_ch04 (pt2):IP_Clewell
9/17/07
11:17 AM
Page 55
Chapter 4
Ecological Attributes of Restored Ecosystems
Once an impaired ecosystem has been restored, it should exhibit ecological attributes that demonstrate its recovery. The SER Primer on Ecological Restoration (SER 2002) suggested nine ecological attributes. Three attributes pertained to species composition. The first required that the restored ecosystem contain an assemblage of species that were representative of the reference model and that would provide appropriate community structure. The second required that the restored ecosystem consist of indigenous species to the greatest practicable extent. The third required that all functional groups necessary for continuing development and stability be present or at least be able to colonize spontaneously. The fourth attribute stated that the physical environment should be suitable for sustaining reproducing populations of species necessary for continued ecosystem stability and development. The fifth attribute required that the ecosystem be functioning normally with regard to its developmental stage or that signs of dysfunction be absent. Two attributes pertained to landscape issues. The sixth attribute required suitable integration of the restored ecosystem with its landscape so that it could exchange organisms and materials. The seventh attribute asked that any threats in the surrounding landscape to the integrity or health of the restored ecosystem be reduced or removed, if possible. The final two attributes pertained to sustainability. The eighth attribute asked that the restored ecosystem be resilient to expected sources of stress and disturbance. The ninth attribute required that the restored ecosystem have the potential to be self-sustaining in a dynamic sense. In other words, it would remain intact, even though it will change in response to its own self-organization and to flux and longer-term changes in environmental conditions. We will now examine each of those attributes in more depth.
Species Composition The fundamental aspect of any ecosystem is its species composition, which determines ecosystem structure and function. Ensuring appropriate species composition therefore is the principal obligation of a restoration practitioner. Appropriateness is a measure of the consistency with which the biota of the restored ecosystem reflects that of the reference model on which restoration planning was developed, as will be described in Chapter 5. At some project sites, practitioners may not have to do anything directly to fulfill this responsibility because 55
08_ch04 (pt2):IP_Clewell
56
9/17/07
11:17 AM
Page 56
elements of restoration projects
appropriate species already occupy the site. However, practitioners must make that determination at every project site. In the restoration of terrestrial ecosystems, including wetlands and some shallow aquatic systems, the plant species composition is of foremost importance because it is the plant community that gives an ecosystem its structure and provides habitat. Only in aquatic systems, where planktonic algae predominate, does the plant community assume less importance as the focus of restoration concern. A restored ecosystem should have a full complement of species, or if it does not it should have the potential to attract any that are missing. Not every species—plant or animal—must be present at the time restoration is completed. Animal species generally appear spontaneously without assistance from a practitioner if the habitat is suitable, because of their high mobility. The wind-blown spores of fungi, mosses, and ferns can travel great distances to colonize available sites spontaneously as long as habitat conditions are suitable. The minute seeds of epiphytic orchids and bromeliads have this same capacity. There may be instances when practitioners have to introduce animals, such as rare species for which the restoration was expressly conducted. Mycorrhizal fungi are commonly introduced, not for their own sake but as an aid to the establishment and growth of trees and other rooted plants. Aldo Leopold (1887–1948), whom many credit as the first modern exponent of what later became known as ecological restoration, wrote passionately on the importance of species composition. In Round River, a book compiled from Leopold’s journals by his son, Luna (Leopold 1993:146–47), Leopold wrote, The last word in ignorance is the man who says of an animal or plant: “What good is it?” If the land mechanism as a whole is good, then every part is good, whether we understand it or not. If the biota, in the course of eons, has built something we like but do not understand, then who but a fool would discard seemingly useless parts? Leopold continued with the metaphor of repairing a pocket watch: “To keep every cog and wheel is the first precaution of intelligent tinkering.” Leopold’s message is clear: When we restore an ecosystem, we must ensure that all species will be represented. Otherwise, the restored ecosystem may not regain its former structure and may not function as well as it once did. At project sites that need reintroductions of numerous kinds of plants, it may be sufficient—and certainly less costly—to introduce a few individuals of many plant species rather than to plant large numbers of each. If site conditions are suitable for a species, and several individuals are planted with care, they will grow with vigor, reproduce, and increase their abundance without assistance. This was demonstrated during headwater wetland forest restoration on surface-mined and physically reclaimed land (Clewell 1999). Several plants each of about thirty species of undergrowth herbs and a few shrubs were removed from natural forest and transplanted to a thicket of previously planted saplings on reclaimed land. After 2 years, many transplants representing most of these species had increased their numbers dramatically. Some were dominant in the undergrowth in the young forest. However, transplants of a few of the species evidently were poorly suited for the restored environment and eventually succumbed. It would not matter how many individuals of these unadapted species were planted if none would survive; therefore, the introduction of only a few individuals is justified. The preferred strategy is to overintroduce species rather than to overplant individuals of a given species. As a note of caution, more individuals should be introduced on larger and more hetero-
08_ch04 (pt2):IP_Clewell
9/17/07
11:17 AM
Page 57
Ecological Attributes of Restored Ecosystems
57
geneous project sites so as to ensure multiple genotypes and thus genetic flexibility. This admonition becomes even more important where project sites are isolated and unlikely to exchange organisms of the same species from elsewhere in their surrounding landscape. A full complement of species can be estimated from one or more reference ecosystems that are selected as models for restoration planning (see Chapter 5). The estimate consists of the median number of species within reference systems in areas of the same size and physical heterogeneity as exist at the project site. The determination of what constitutes a full complement of plant species requires some sophistication in the practitioner’s familiarity with the vegetation. Species that are characteristic of mature stages in ecosystem development (K-strategists) deserve particular attention in order to ensure that ecosystem recovery will lead to ecological maturity. Ruderal species that colonize recently disturbed sites and that do not persist can be discounted. Overintroduction occurs when the practitioner introduces more than the median number of species. Overintroduction compensates for losses of species that fail to become established at the project site for any reason. If all species that are overintroduced become established, the restored ecosystem is enriched by that much more diversity. Well-developed soils generally contain a wealth of species—fungi, bacteria, algae, insects, other arthropods, protozoa, nematodes, annelids, and so on—most of which are not inventoried by restorationists for lack of taxonomic expertise, laboratory facilities, time, and cost. Yet these species are important ecologically for their roles in decomposing organic matter, recycling nutrients, maintaining soil texture and aeration, and other crucial processes. In sites where soils were damaged or recently reclaimed, these species can be introduced by salvaging soils from donor sites scheduled for development and spreading them on restoration project sites. This technique has been called topsoiling or mulching and is commonly followed by disking or another mechanical manipulation to incorporate the transferred soil into the substrate at the project site. If the supply of donor soil is limited, small quantities can be transferred to a project site and incorporated into the substrate in small locations, where desirable biota in the transferred soil can radiate into surrounding soil. This activity is predicated on the expectation that the soil biota will eventually disperse throughout the project site. With the same technique, sediments can be transferred from an aquatic donor site to inoculate benthic macroinvertebrates into a stream or wetland that is undergoing restoration. Donor materials sometimes are scarce and are a precious resource for practitioners. The project site must be suitably prepared to receive them. For example, there is no benefit from transferring donor soil from a mesic or wetland habitat to an arid restoration site, where its organic matter content will oxidize from desiccation (Clewell et al. 2000). Because of its scarcity, an explicit goal of restoration can be to establish a source of donor soil for use as inoculum at future project sites. One of the great problems in conducting wetland restoration in the United States, particularly when prescribed by specific permit conditions or contract stipulations, is that only a few plant species are required to be planted. These are generally species that are commercially available and that are characteristic and conspicuous. In forested wetland restoration, they are commonly limited to a few species of commercially valuable trees, even though most plant species in forests consists of herbs, shrubs, and vines of the undergrowth and of smaller trees of the midstory. In emergent herbaceous marshes, perhaps six plant species are designated when that kind of ecosystem normally contains dozens of species. Clearly, this practice ignores Aldo Leopold’s dictum on intelligent tinkering.
08_ch04 (pt2):IP_Clewell
58
9/17/07
11:17 AM
Page 58
elements of restoration projects
The most effective strategy to attract a wide array of species that belong to higher trophic levels may be to establish a full complement of plant species at project sites. Preferences of animal species, such as insects and other arthropods, for particular species of plants strongly suggest that animal species diversity is directly correlated with plant species diversity. This principle is central to the field of biological control, whereby assemblages of other plant species are maintained with crops to attract entomophagous (insect-eating) arthropods (e.g., predacious beetles and spiders) that consume crop pests (Altieri and Whitcomb 1980). This principle is equally applicable to restoration. The more plant species that can be established, the greater the diversity of animals that will be attracted to them. Some ecologists have raised the issue of species redundancy (Walker 1992). They subscribe to the proposition that many ecosystems contain far more species than are necessary to carry out particular ecological processes in an ecosystem. In other words, an ecosystem may contain superfluous species in terms of function as a kind of insurance policy to increase ecosystem “reliability.” This line of reasoning can be extended to argue that restoration practitioners need not be concerned with overintroducing species and that intelligent tinkering does not entail saving all the cogs and wheels. The precautionary approach in ecological restoration would be to introduce as many of the original species as possible regardless of whether they are redundant. One reason for precaution was proposed by Naeem and Li (1997) and Wellnitz and Poff (2001), who suggested that the capacity of a given species to perform a function may vary within a heterogeneous environment. If redundant species were present, one species may be better able to perform a role under one set of conditions, and another species under another set. Therefore, it would be beneficial for several species to perform the same ecological role collectively to ensure efficiency under all conditions. Another reason is that a species that readily fulfills a particular ecological function in an intact ecosystem may not do so in an impaired ecosystem. For that reason, redundant species may be needed to ensure proper functioning during the process of ecosystem recovery. Finally, the capacity of a functional, intact ecosystem to respond to changes in the environment may depend on redundant species that are better adapted to new environmental conditions. In other words, an ecosystem can be preadapted to novel environmental conditions by carrying redundant species that may function effectively in an altered environment (Naeem 1998). Practitioners facilitate that eventuality by introducing a full complement of species. Not all restoration projects demand this amount of attention to species composition. For example, the introduction of a full complement of undergrowth species during forest restoration on an alluvial floodplain may be accomplished passively from the deposition of waterdispersed seeds of numerous species that are carried from upstream in flood events. However, the practitioner must be vigilant and intentionally introduce species that fail to appear.
Indigenous Species Ordinarily, practitioners should introduce only native species in restoration project sites. There may be instances when nonnative cover crops or nurse species can be introduced, as long as they will not persist at the project site beyond a finite time or ecological stage of development. There may also be instances when nonnative species are integral components of certain cultural ecosystems and should be reintroduced. Examples are segetal species—
08_ch04 (pt2):IP_Clewell
9/17/07
11:17 AM
Page 59
Ecological Attributes of Restored Ecosystems
59
weeds that have coevolved with domesticated crop plants—and the crop plants themselves. The question of whether to control or eliminate nonnative species that were present before project work began—or that may appear in the midst of restoration—may be more difficult to decide. The SER Primer (SER 2002) advises that restored ecosystems should consist of indigenous species to the greatest practicable extent. The onus remains on the practitioner and stakeholders to determine what is practicable. A species is designated as nonnative, alien, or exotic if it only recently appeared in a given location, usually through human agency. The determination of what recently means is a matter of judgment. Most nonnative plant species consist of ruderals and other r-strategists that are limited to open and disturbed habitats. Most are unable to compete in mature, intact ecosystems. They prefer beaches, riverbanks, talus, and places disturbed by human activity such as roadsides and cultivated fields, where they pose little or no ecological threat to the integrity of native ecosystems. Nonnative K-strategists are less likely to survive, especially those that need habitats that are unavailable in the new environment because they do not exist or because they are already filled by native species. However, some nonnative K-strategists do survive, and they are the most problematic and difficult to eradicate of all invasive species. Numerous species of plants and animals have been transported to remote regions by humans, intentionally or inadvertently. Many were carried by accident in the ballast of sailing vessels and others as packing materials for transported goods. Yet others were purposely transported for their economic or ornamental value or as curiosities. More arrived as weed seeds that contaminated shipments of grain. The numbers of nonnative species have become quite large. For example, more than 30 percent of the vascular plant species in Florida are nonnative (Wunderlin and Hansen 2003). The rampant transport of species through human agency in recent times is unlike any mass migration that has ever occurred in nature since terrestrial life evolved. This transport is causing a homogenization of the world’s biota. For example, European and American biologists on their first visit to India are shocked as they gaze on vast stands of the New World shrub Lantana camara and the Neotropical eupatorium Chromolaena odorata. Their counterparts from India may be just as surprised by dense monocultures in the southeastern United States of cogongrass (Imperata cylindrica), native to India, where it is consumed and under the biological control of elephants and rhinoceros. In South Africa the fire-driven fynbos shrublands usually are replaced by K-selected Australian species of Acacia and Hakea or by various Mediterranean pines when disturbed. After mining in semiarid savannas, Prosopis hybrids from the Americas often dominate the damaged site before native acacias return. Similar problems occur in Australia, where South African acacias, Asian Ziziphus, and others replace indigenous K-selected species on damaged landscapes (S. J. Milton, personal communication, 2007). Some nonnative species do not persist and form permanent reproductive populations. If they are plants, they are called adventives. If they are birds that stray off course, they are called accidentals. Nonnatives that form persistent, reproductive populations are called naturalized species. Some naturalized species soon come under the control of herbivores or predators, pathogens, and other control agents. They blend in unobtrusively with the native biota and function as if they had evolved locally. They generally pose no threat to ecosystem integrity. Nearly all occur in open or semidisturbed environments and not in closed or well-integrated ecosystems.
08_ch04 (pt2):IP_Clewell
60
9/17/07
11:17 AM
Page 60
elements of restoration projects
Other naturalized species that lack controls to their growth and reproduction may increase in abundance and become invasive species. A common demographic pattern is for such a nonnative species to increase in abundance slowly and essentially without notice over a period of years or decades, until it reaches a threshold population size. Then its numbers increase rapidly (D’Antonio and Chambers 2006). For example, cogongrass was rare, a mere botanical curiosity in Florida in the early 1980s. Before that decade came to a close, however, cogongrass was the predominant vegetative cover on vast areas of disturbed land. At that time the species became recognized as being invasive. Invasive plant and animal species commonly must be controlled with biocides, mowing, or trapping. Otherwise, they threaten the integrity of native ecosystems by their colonization or by competing successfully and causing the demise of native species and by altering ecosystem dynamics in profound ways. The designation of a species as nonnative raises several issues. The geographic range of distribution of any species may expand or contract in response to cyclic changes in environmental conditions and sometimes expands dramatically through natural long-distance dispersal. For example, many species of tropical ferns and epiphytic orchids occur as disjunct populations in Florida, presumably because of tropical storms that carry their spores and minute seeds to naturally available habitats, including rock outcrops and tree branches. Species that expand their ranges through entirely natural causes can scarcely be called nonnative. Some species arrived in a new location on their own, such as cattle egrets (Bubulcus ibis ibis) that came from Africa (via South America) to North America in about 1950 (Stevenson 1976). Although they had been recorded as accidentals previously, they survived and formed metapopulations shortly after the passage of the “fence law” in 1949 in Florida, which closed the open range and required cattle ranchers to fence their livestock (Akerman 1976). Native pine savannas that made up the open range were converted into improved pastures, the preferred habitat of cattle egrets. Should cattle egrets be considered native because they arrived on their own? Or should their habitat—improved pastures—be considered nonnative and the cattle egret native because they simply expanded their range of distribution into a new location for their preferred habitat? Cattle egrets have greatly increased their numbers and therefore behave as an invasive species. The example of the cattle egret demonstrates the difficulty in determining what constitutes a nonnative species and an invasive species. The practice in North America has been to consider any plant species as being native that was present on that continent before colonization by Europeans, beginning with the arrival of Columbus in 1492. Plants were listed as native if they were recorded by early naturalists or if specimens were collected during or not long after the colonial period. Many other species that appeared as specimens collected well into the postcolonial period were commonly considered to be nonnative, although such evidence was indirect, and the possibility that they had simply been overlooked by botanists cannot be discounted. There are instances of plant species that were known to have been intentionally introduced from elsewhere by American Indians before European colonization (Anderson 2005). In Australia, fossil remains of the dingo (Canis lupis dingo) date back only 3,500 years, and the species was thought to have been introduced by people from Asia, perhaps multiple times. Is the dingo native because of its residence time in Australia or nonnative because it may have been introduced intentionally? Who should decide and by what criteria? Concern about nonnative species has spread to Europe and elsewhere. However, the discovery of the New World can scarcely be invoked
08_ch04 (pt2):IP_Clewell
9/17/07
11:17 AM
Page 61
Ecological Attributes of Restored Ecosystems
61
as the time threshold for determining whether a species is native in Europe, and another threshold date is needed, except perhaps for American species that were transported there. Ambiguities such as these will continue to pester practitioners. Botanists commonly disagree about the status of a species. Some presumed nonnative species are the product of slovenly taxonomic circumscription. For example, the spade-leaf of wet prairies in the southeastern United States has long been considered a nonnative species from the Old World, known as Centella asiatica. However, plants in the United States differ notably from Asiatic plants of that species in both their vegetative and reproductive structures and readily warrant recognition as the separate and decidedly American species C. erecta. At this point, we might pause and consider what constitutes a native species. Perhaps the most conservative definition would be a species that evolved in situ, unless, of course, it evolved from nonnative ancestral species, which we may never know for sure. Human agency is commonly invoked as a criterion for deciding whether a recent arrival is native. However, that criterion presupposes that humans are distinct from nature, which would mean that cultural ecosystems should be considered artifacts that are unworthy of restoration. To avoid that conundrum, a more functional definition could be used, recognizing a species as native if it is functionally integrated and demographically stable in local ecosystems, irrespective of its place of origin and time of arrival. Such a species would be better called a noninvasive species. Our point is that both native and nonnative species defy strict definition. In the past two or three decades, conservation biologists have expressed grave concerns about the increasingly large numbers of nonnative species—both plants and animals—that are appearing around the world and especially about their threats to the ecological integrity of native ecosystems. This concern expresses a cultural value judgment that native species are good and nonnative species are bad. This judgment has become public policy. New regulations have been promulgated to discourage the introduction and spread of nonnative species. Government programs have been instituted and funded to extirpate certain nonnative species, although not without criticism with regard to their efficacy (Simberloff et al. 2005). An alternative value has been expressed that the movement of species by humans is simply another instance of ecosystem dynamics and that our only concern should be to learn how to adapt to these new circumstances. Particularly in nonaffluent regions of the world, there are many instances in which invasive species have become so entrenched—and socioeconomic circumstances for their control so impossible—that practitioners must accept that inevitability. Nonnative species are a huge concern to practitioners who try to restore ecosystems to a former state that usually occurred before recent onslaughts of invasive species (Figure 4.1). Little land is left in the world that is not occupied by nonnative species. Much of the time— and the budget—of practitioners is spent in removing exotic species so that they can establish desirable native species. The task would be easier if only invasive species were targeted for removal. However, noninvasive species remain a concern for fear that some may eventually become invasive and threaten the integrity of the restored ecosystem. The invasive species problem is likely to worsen because of global increases in disturbed habitat, the availability of human-mediated transport of organisms, and the potential for expansions of populations of resident, nonnative species. The problem is sometimes compounded by good intentions. We are aware of attempts to remove nonnative species from wetland restoration project sites by labor crews that
08_ch04 (pt2):IP_Clewell
62
9/17/07
11:17 AM
Page 62
elements of restoration projects
Figure 4.1. Wild elephant in southern India, unable to graze the surrounding undergrowth of invasive Lantana camara and Chromolaena odorata.
trampled and destroyed many desirable plants while mechanically removing naturalized species. In other sites, nonnatives were treated with herbicides that also killed vigorous plants of desirable species with which they grew. In these instances, public agencies with regulatory powers demanded eradication of naturalized species just because they were nonnative. These species cannot possibly be eradicated and undoubtedly would reestablish themselves after eradication efforts were no longer required, upon completion of other project work. These naturalized species may as well have been ignored as targets for eradication. Instead, the natural environment was assaulted with chemical poisons by government edict without a demonstrable ecological benefit. Mandates of this sort are overreactions to satisfy agency policy rather than to facilitate ecological restoration. We advise restorationists to remain focused on combating invasive species that pose the greatest threat and not to deplete budgets by trying to eradicate the nonnative species that pose no immediate threat. Among the latter are large numbers of generalist species that appear in abundance only in early seral stages of ecosystem development. These will disappear without assistance from a practitioner, and their humus will be a welcome addition to soil organic matter content. Furthermore, some introduced species can be useful for land management or specific restoration goals (Smith et al. 1997; D’Antonio and Meyerson 2002; Ewel and Putz 2004). This decrease in concern does not mean that we can relax our vigilance. Newly arrived species that are known to be invasive elsewhere should be monitored closely and eliminated before they can become invasive locally.
08_ch04 (pt2):IP_Clewell
9/17/07
11:17 AM
Page 63
Ecological Attributes of Restored Ecosystems
63
Functional Groups A functional group consists of the species that perform a particular role in an ecosystem or respond to a given stressor or driver in an adaptive manner (Lavorel et al. 1997; Gondard et al. 2003; Rosenfeld 2002). We have already mentioned functional groups in relation to functional redundancy and treat them here in more general terms. Examples of functional roles are carbon fixation through photosynthesis, nitrogen sequestration, reduction of dead plant materials into humus, herbivory, soil stabilization, and microclimatic control. One species can play multiple roles. For example, a leguminous tree can fix carbon, contribute the raw materials for humus production from its fallen leaves, and harbor nitrogen-fixing bacteria in its roots. Obviously, many essential roles must be fulfilled if ecological restoration is to recover a fully functional ecosystem. The restoration practitioner is responsible for making that happen. The organisms that play a particular role may have persisted despite ecosystem impairment and are not of concern to the practitioner. If they are absent, they may have the capacity to recolonize the project site spontaneously. For example, certain pollinating insects may be prevalent throughout the region and will be attracted to the project site once certain plant species begin to bloom. Organisms that play other roles may not return, at least not promptly, such as annelid worms in mine soils, which play several roles in soil development, humus formation, and nutrient cycling. The practitioner can intentionally introduce annelids, preferably of native species, on newly prepared mineral substrates at physically reclaimed mine sites. The practitioner need not ensure the presence of all functional groups when restoration is otherwise complete. For example, wide-ranging top predators may not discover a project site until long after it has been restored and has matured to the point that it attracts suitable prey. The practitioner’s concern is limited to recovering an ecosystem that has the capacity to continue its development to the point at which it can attract and support consumers belonging to higher trophic levels. Ecological restoration projects that are conducted in urban and periurban areas may not be capable of recovering all their former ecological roles because of contemporary conditions and constraints in the environment. For example, the proximity of residences may prove to be a deterrent to top predators. Consequently, populations of herbivores such as deer commonly increase to the point that they threaten newly restored ecosystems with degradation from overgrazing and pose a nuisance to residents whose ornamental plantings are damaged. In such instances, a program of ecosystem management would have to supplant ecosystem roles that could not be performed. Deer populations would have to be reduced in a manner that would substitute for the missing top predators (Sauer 1998). The conduct of ecosystem management is not the concern of the restoration practice. Instead, it becomes the responsibility of an ecosystem manager. However, it is incumbent on the practitioner to foresee the need for ecosystem management and develop a strategy to accommodate it before implementing a restoration project. Potentially affected stakeholders may then decide whether to implement restoration as planned and, if so, to arrange for subsequent management. Ecologists tend to consider structural units of vegetation as a functional role, even though this stretches the definition of function. These elements were conceived by previous generations of ecologists as life forms. Plant species that belonged to a given life form all shared the same habit (general appearance). For example, the classification of life forms by Raunkaier
08_ch04 (pt2):IP_Clewell
64
9/17/07
11:17 AM
Page 64
elements of restoration projects
(1934) was based on the position of dormant buds during winter or the dry season. Two extremes were phanerophytes (trees with elevated buds) and geophytes (herbs with their buds located in buried rootstocks). Contemporary ecologists recognize plants with a common life form to share a common functional role. For example, all needle-leaved evergreen trees in an ecosystem are considered to be functionally equivalent. In this manner, purely structural aspects of the vegetation are conscripted as surrogates for function.
Physical Environment The physical environment should be capable of supporting the biota. Otherwise, the desired species composition and community structure cannot be sustained. Impairment of the physical environment in terrestrial systems largely concerns alterations in hydrology and soils. Ditching and drainage—or impoundment and flooding—may alter the water table, the seasonal availability of moisture, the amount of soil saturation or inundation, and other aspects of hydrology. Impacts on hydrology commonly reduce the residence time of water in catchments, increase peak discharges in streams, and prolong intervening periods of low discharge. All such changes can degrade ecosystems. Plants and animals become stressed by altered schedules of moisture availability. If soils become desiccated, their organic matter can oxidize and cause profound degradation. If soils become saturated or inundated more than briefly, they may become anoxic and unable to support organisms that need the normally aerated soils of mesic habitats. Soil can suffer from other impacts, such as erosion and the compaction and mechanical damage from overgrazing by livestock or trafficking by heavy equipment. Sources of degradation and damage to aquatic systems include hydrologic alteration that affects water quantity and seasonal changes in water volume such as stream discharge, alterations to water quality such as increased turbidity, increased pollution, altered water chemistry, altered temperature regimes, or a change to the substrate such as scouring, dredging, or sedimentation. The degradation is commonly ascribed to impacts occurring in terrestrial systems in the catchment. Timber removal, for example, can cause accelerated surface runoff, pulsed discharge into receiving waters, elevated water temperature, increased turbidity, and the deposition of eroded sediments in stream channels. Discharge of animal wastes and fertilizers in agricultural runoff is a common cause of accelerated eutrophication. In estuaries, aquatic systems can be degraded or damaged by changes in salinity, which, in turn, can be caused by water usage inland that alters the volume or seasonality of river discharge. Hydrologic alteration can be corrected by repairing the physical environment, so that the hydroperiod recovers, or by restoring another kind of ecosystem that is suited to the new hydroperiod. The latter may be the only option when, for example, an impoundment or other public works project has permanently altered the hydrology of an ecosystem. In such instances, impoundment would constitute a contemporary condition that crosses a threshold of irreversibility. Repair of the physical environment must be attempted with great care. Otherwise, subsequent manipulations to the biota, such as the intentional reestablishment of vegetation, could fail. Retrofitting the physical environment at that stage of project work can prolong a project’s duration and inflate project costs to an amount that far exceeds that which would
08_ch04 (pt2):IP_Clewell
9/17/07
11:17 AM
Page 65
Ecological Attributes of Restored Ecosystems
65
have been needed to do the job correctly in the first place. The ultimate test of the suitability of the physical environment is its capacity to sustain reproductive species populations of an appropriate biota for a self-sustaining ecosystem of a designated type. In other words, the biota serves as a bioassay for the physical environment.
Normal Ecosystem Function A restored ecosystem should be functional. Restoration practitioners manipulate the environment and the biota in ways that promote biotic interactions and ecosystem function. The role of the practitioner is analogous to turning on a light. You throw a switch to complete an electrical circuit, and then you allow the electricity to flow to a bulb, where it is converted into light. Similarly, the practitioner throws the switch to turn on ecosystem processes. The practitioner’s role is not to pollinate the flowers but to ensure that habitat exists for the pollinating insects. The direct measurement of function generally entails detailed planning, sophisticated equipment, ample budget, and scientific expertise to interpret data. These requirements lie well beyond the scope of most ecological restoration projects and exceed the capacity of most practitioners. For that reason, indirect evidence of function must be substituted. Indirect evidence can include determinations of growth and reproduction by measurement of plant size, vegetation cover, seed production, and vegetative reproduction. Normal growth rates of this sort indicate normal functioning. Another kind of evidence is the documentation of an increase in soil organic matter, which indicates primary production and ensuing biological activity by detritivores. A third kind of evidence is obtained from an evaluation of plant vigor, which is inferred from an absence of stress indicators. Plants are stressed if their leaves appear chlorotic, anthocyanic, or necrotic. Stressed trees may defoliate early or exhibit dieback among the branches. In animals, abnormal behavior can signal stress. If such symptoms are detected, the practitioner should search for causes and apply remedies. Several direct measurements of function can be made rapidly by practitioners with modest training and outlays for equipment. For example, metabolic rates of soil microorganisms can be measured periodically, and upward trends can be interpreted as evidence of improving soil function. Increase in the sporulation of mycorrhizal fungi is another indication of function. A return to normal conditions in the physical environment generally indicates proper ecosystem functioning. For example, clearly flowing streams can indicate that emergent vegetation is filtering suspended particulates in surface runoff, as measured in turbidity units. Diurnal measurements of dissolved oxygen can indicate recovery from eutrophication in an aquatic system. Temperature, pH, and electrical conductivity are easily measured with inexpensive equipment. Water table elevation can be measured in piezometer wells, and stream discharge can be estimated from water depth data recorded on a staff gauge.
Landscape Context During the planning phase of a restoration project, careful consideration must be given to the landscape context of a project site. If the landscape is impaired, the restoration effort may not attain its full potential. In such instances, part of the project site may have to be dedicated as
08_ch04 (pt2):IP_Clewell
66
9/17/07
11:17 AM
Page 66
elements of restoration projects
a buffer to a cleared landscape, thereby reducing the size of the restored ecosystem. A buffer of shrubs and small trees, for example, may be needed to maintain the microclimate in a newly restored forest. Consider for a moment that the landscape surrounding a restoration project site has been cleared of its vegetation for some permanent land use. Animals may not be able to move in and out of the project site because the cleared landscape makes them susceptible to predation. In other words, the quality of a restoration project depends in part on the quality of the landscape. The restoration practitioner must integrate the landscape with the project site to the greatest possible extent. Stakeholders should be informed of landscape restrictions—existing and potential—before deciding to implement a restoration project. Practitioners should be thoroughly familiar with the immediate landscape that surrounds a project site. Floodplains along alluvial rivers are dramatic examples of landscape influence. A floodplain receives deposition of alluvial materials that were transported from upstream during flooding. The alluvium contains mineral nutrients, organic matter, organisms of all kinds— from bacteria to seeds or whole plants and from protozoa to fish and other vertebrates—and the materials and energy they contain, and water itself and its ionic content. In turn, floods remove materials, organisms, and energy from the site and transport them to other floodplain sites downstream and eventually to an estuary or other receiving water, where they contribute to those ecosystems. Larger animals—larger insects, fish, birds, reptiles, and mammals—use the entire river corridor as they move independently from one place to another. The landscape of an estuary may include the entire floodplain of a large river system. Filter feeders in estuaries such as oysters may consume bacteria that were decomposing leaves that fell into the river dozens of kilometers upstream of the estuary. If levees are constructed along riverbanks that prevent flooding, the entire floodplain and its component ecosystems suffer in terms of reduced function and productivity. Impoundments and excavated channels cause similar impacts that can be felt along the entire length of a river, across an estuary, and beyond into marine ecosystems. Restoration practitioners whose projects occur within floodplains must be aware of the magnitude of the surrounding landscape.
External Threats Practitioners should address threats in the surrounding landscape that may affect the quality of a project to the greatest practicable extent. For example, surface runoff from the cleared landscape could move rapidly onto the project site, causing erosion or depositing sediment. A crucial task for the practitioner may be to arrange for the clearing to be planted. Alternatively, if nearby colonies of invasive plant species on this cleared land pose a risk of invasion, the practitioner could negotiate with adjacent property owners or managers to eradicate them as one of the restoration tasks. The cost of doing so probably would be much less than treating invasive species on site that repeatedly colonized from the surrounding landscape. One of the most contentious issues is controlled burning, primarily because of liability concerns. If a project site needs intentional fire, then an offer can be made to burn an adjacent property concurrently on the basis that it would be beneficial to that property owner in terms of fuel load reduction or habitat improvement. Otherwise, an adjacent land owner could take legal or other action to prevent needed burns.
08_ch04 (pt2):IP_Clewell
9/17/07
11:17 AM
Page 67
Ecological Attributes of Restored Ecosystems
67
Resilience A restored ecosystem should be able to resist normal stress events and recover from disturbance. The ability to avoid damage altogether is called resistance. The ability to recover from damage caused by stress or disturbance is called resilience. There are two kinds of resilience (Holling and Gunderson 2002). In stable ecosystems, resilience is the speed of return to a state of equilibrium after disturbance. In dynamic ecosystems, it is the magnitude of disturbance that can be absorbed before a system switches to an alternative state. Periodic stress events include drought, inundation, freezing temperatures, mechanical damage from wind storms and flooding, fires, and fluctuating salinity. Observations of resilience in restored ecosystems are nearly absent because of the recency of most project work and the lack of follow-up studies at completed project sites. Resilience has been observed at project sites on mines and reclaimed land in the central Florida phosphate mining district. The Hall Branch restoration project, begun in 1985, was documented shortly after it was completed and the project site had been donated to the State of Florida for incorporation into a state park (Clewell 1999). A headwater wetland forest was restored in a manner that closely resembled that of the Dogleg Restoration project at the same mine, described in Virtual Field Trip 7. Shortly after the state acquired the property, mining began on an adjacent property, which caused the water table to become substantially depressed beneath restored Hall Branch for 2 years, until the new mine pit was backfilled. Unusually severe drought occurred in those 2 years, in which time the soils dried out, became fissured, and may have lost most of their organic matter content from desiccation. By the time that normal wetland hydrology returned, only a few trees had succumbed, and the forest remained intact. Populations of some herbaceous species were reduced in their coverage. Several nonnative species had colonized and could become problematic if they are not removed by ecosystem management, whose implementation has been delayed for several years. Reconnaissance suggested that the young restored forested wetland ecosystem was resilient to stress from inadequate hydration and was able to recover quickly and that lingering problems with invasive species could be resolved with ecosystem management. Examples of resistance are equally rare at former project sites. The Dogleg Restoration project (Virtual Field Trip 7) displayed resistance to fire. State Park officials had conducted fire in Year 17 after restoration began in the grassy upland surrounding the project site, which raged out of control and burned into the edge of the project site. Most trees were killed in one small area (about 0.5 hectares) at elevations where mesic conditions prevailed. However, the restored wetland resisted fire because of its structure, which offered unfavorable fuels, detritus that was too moist, and probably a microclimate that was too humid to carry fire into the hydric forest. It is not yet clear whether the mesic forest that burned is resilient and will recover or whether it will transform to another state.
Self-Sustainability A restored ecosystem should be autonomous (self-organizing and self-sustaining) without further need for assistance by a restoration practitioner. The restored ecosystem may need periodic management, particularly if it is a cultural ecosystem or if it is severed from its normal landscape context by human development and infrastructure or by land use activities. This
08_ch04 (pt2):IP_Clewell
68
9/17/07
11:17 AM
Page 68
elements of restoration projects
need for management should be similar in kind and extent to that which would be needed by the same ecosystem if it had not been impaired and restored, with allowance for differences in seral stage. In most projects, if the eight previously described attributes of restored ecosystems are satisfactorily recovered, this attribute is attained concomitantly. There is a large and growing ecological literature on this topic, where it is generally called self-organization (PahlWostl 1995; cf. Perry 1995; Yates and Hobbs 1997; Temperton et al. 2004). Few bridges are available between theory and practice. In Chapter 5, we begin to address this gap.
Ecological Attributes as Project Standards These nine desirable attributes of restored ecosystems can be adopted as goals or standards for any ecological restoration project. No other ecological goals are needed, although others can be added, such as the recovery of habitat for a particular species. Project plans can be prepared so that each of these attributes is likely to be realized in completed projects. Monitoring protocols and performance standards (also called success criteria) can be drafted that provide reasonable assurance that these goals will be achieved and that their attainment will be documented with monitoring information (see Chapter 6). Project plans can be evaluated on the basis of how well they address each of the nine attributes. Projects that have been implemented but await completion can be evaluated on the basis of their plans and of the skill that has been applied in the performance of project tasks. Any ecological evaluations that are conducted in addition to specified project monitoring can be structured to demonstrate the degree to which each of these attributes was satisfied. The application of these attributes as project standards is particularly relevant in projects where historical fidelity cannot be attained and where the reference model is based at least in part on projections of the historic trajectory on the basis of contemporary conditions and constraints (see Chapter 5). In such situations, we cannot depend on historical knowledge of ecosystems to ensure that the restored ecosystems will contain all the aspects that guarantee sustainability and resilience. Instead, practitioners are faced with a greater degree of uncertainty. However, if these nine attributes are satisfied during the course of restoration, then it is more likely that the restored ecosystem will continue its development to ecological maturity and persist and sustain itself in response to stress and disturbance. Evaluation by an academic research program should not be necessary. Instead, an experienced practitioner or other competent professional should be able to examine a restored project site on foot and reasonably judge whether the species composition is representative and adequate, whether there are threats from invasive species, whether requisite functional groups are present, whether the physical environmental conditions are sustaining the biota, whether the vegetation is vigorous and free of stress indicators, whether the landscape context is free of abnormalities and potential threats, whether the ecosystem is likely to be resilient, and whether there is any question that the restored ecosystem will continue its self-development. In some environments, this examination may have to be repeated until the examiner gains confidence. In other systems, a single visit will suffice. This is admittedly a broad-brush approach that will not satisfy everyone. However, we all make these same ecological judgments every time we go into the field and examine ecosystems, whether disturbed or intact, that have never undergone ecological restoration. There will be some restored ecosystems for which a more critical inventory cannot be avoided, but
08_ch04 (pt2):IP_Clewell
9/17/07
11:17 AM
Page 69
Ecological Attributes of Restored Ecosystems
69
these are the minority. An academic research project can do little other than document more thoroughly what a competent professional can determine from reconnaissance. The only valid test is time, which cannot be abbreviated by a thorough research project. If a restoration project was completed and begins to fail shortly thereafter, the potential remains for the project to be reopened and midcourse corrections implemented. This is no different from a patient returning to the physician for additional treatment when it was thought that the patient had been cured.
09_VFT3:IP_Clewell
9/17/07
11:18 AM
Page 70
VIRTUAL FIELD TRIP 3
Restoring Wet Prairie in Mississippi, USA George Ramseur Jr. and Andre F. Clewell
Lowlands near the northern coast of the Gulf of Mexico once supported extensive wet prairies dominated by grasses and sedges, interspersed by forbs—including four genera of insectivorous plants—and low-growing shrubs (VFT Figure 3.1). Copious rainfall and hydrophilic clays maintain soil saturation in the root zone for most of each year. Tree establishment is discouraged by soil saturation and near-annual surface fires, which were once ignited by lightning and American Indians and later by sheep herders and land managers. Hydrophytic trees, mainly pond cypress (Taxodium ascendens), formed open savannas near streams. These cypress savannas differ inconsequentially from wet prairies in the composition and structure of ground cover vegetation. Wet prairies support uncommon vertebrates, notably the narrowly endemic and federally endangered Mississippi sandhill crane (Grus canadensis pulla). More than 250 species of vascular plants inhabit wet prairies in the area where VFT Figure 3.1 was taken. Plants belonging to a mean of 7.2 species were rooted per 200 square centimeters at that photo location (Clewell et al. 1998). In the 1940s and 1950s, many wet prairies were reallocated as pine plantations. Slash pines (Pinus elliottii) were row-planted on elevated planting beds. Fires were suppressed, allowing shrubs and small trees (mainly Ilex spp.) to replace wet prairie herbs. Planted pines grew and reproduced, but their growth was too slow for commercial purposes. Many plantations were abandoned. Those that were harvested contained remnants of wet prairie herbs, suggesting the persistence of propagule banks that had remained viable for approximately 50 years. VFT Figure 3.2 shows a typical pine plantation, its dense shrub cover, and, in the lower right corner, a patch of persisting wet prairie herbs. In 1997 The Nature Conservancy (TNC, an international nongovernment organization), purchased the 753-hectare Old Fort Bayou tract, consisting largely of abandoned pine plantations, adjoining the Mississippi Sandhill Crane National Wildlife Refuge (Crane Refuge) near Ocean Springs, Mississippi. The intent was to restore the ecosystems on that property to their prior state in 1942, as determined at a small spatial scale from historical aerial photography and at a larger scale by ecological inventories on site and in undisturbed areas in the wildlife refuge. Data from inventories at the refuge became the reference model. Andre Clewell was contracted to prepare a restoration plan. Restoration was conducted jointly under Clewell’s direction and that of the project director for TNC, George Ramseur Jr. 70
09_VFT3:IP_Clewell
9/17/07
11:18 AM
Page 71
Restoring Wet Prairie in Mississippi, USA
71
VFT Figure 3.1. Wet prairie (foreground) and cypress savanna (mid-background) at the Mississippi Sandhill Crane National Wildlife Refuge.
VFT Figure 3.2. Former wet prairie that was reallocated as pine plantation.
Most trees and larger shrubs and saplings were cut manually. Merchantable logs were largely removed by draft horses to prevent ruts from being formed by mechanical harvesting equipment (VFT Figure 3.3). Shrubs were burned in the growing season when vigorous shoot growth was occurring and, consequently, when food reserves were reduced in their roots (VFT Figure 3.4). Shrubs resprouted, expending scarce food reserves in their roots. This regrowth was burned in subsequent growing seasons or whenever fuel loads were adequate and burning permits could be obtained. Shrub regrowth was weak, and some were killed by starvation of their roots. Grasses and forbs were favored by fire and flourished. In some sites, young planted pines had been harvested well before TNC purchased the property, which allowed the dormant rootstocks of surviving wet prairie plants to recover
09_VFT3:IP_Clewell
72
9/17/07
11:18 AM
Page 72
elements of restoration projects
VFT Figure 3.3. Draft horse removes pine logs.
VFT Figure 3.4. Shrub cover is burned.
briefly before they were suppressed again by shrub regrowth. After two successive fires in the restoration program, this wet prairie vegetation returned in profusion on those sites (VFT Figure 3.5). Shrubs that resprouted did not replace the regrowth of grasses and forbs. Herbaceous cover in cypress savannas was also restored after brush removal and fire (VFT Figure 3.6). In large areas where the pines had not been commercially harvested before 1997, wet prairie plants did not recover after two fires. Contingency plans were made to harvest seeds of wet prairie species and directly plant them on these sites. However, after the third fire, wet prairie vegetation recovered in profusion from the seed bank. Direct seeding was not needed, and contingency plans were canceled.
09_VFT3:IP_Clewell
9/17/07
11:18 AM
Page 73
Restoring Wet Prairie in Mississippi, USA
73
VFT Figure 3.5. Restored wet prairie after tree and brush cutting and fires.
VFT Figure 3.6. Restored pond cypress savanna.
Elevated tree planting beds, which had formerly scarred the land, had largely subsided from several decades of pelting rainfall and were not removed during restoration. Their removal would have ruined much of the seed bank and would have facilitated colonization by invasive species. Several especially tall beds have been identified for possible removal later, after the restored vegetation has stabilized. One goal of restoration was to provide habitat for Mississippi sandhill cranes. Cranes were observed foraging shortly after restoration efforts began, and a nest with an egg was reported on site by Crane Refuge biologist S. G. Hereford (personal communication, 2007). Another goal was to return the landscape to its appearance in 1942 aerial photographs, when prairies
09_VFT3:IP_Clewell
74
9/17/07
11:18 AM
Page 74
elements of restoration projects
VFT Figure 3.7. Detail of a restored pond cypress savanna with a pitcher plant (Sarracenia alata) to the left of a flowering shrub (Hypericum suffruticosum).
were prevalent and trees were nearly absent. An unmistakable trend in this direction was evident in a comparison of images in a 2001 aerial photo with one taken just before restoration began in 1997. Community structure goals have nearly been satisfied for reducing the cover of undesirable shrubs and increasing that of characteristic vegetation for wet prairies (VFT Figure 3.7). The total number of species relative to the reference model has been approached but not demonstrably attained. All functional plant groups have recovered. Undesirable invasive species (e.g., Panicum repens, Imperata cylindrica) colonized roadsides and a few disturbed areas. These were vigorously and—for the most part—effectively treated with herbicides. This project is significant because it shows that wet prairies can be restored to their reference state with historical fidelity. Restoration project work is nearly complete, although some areas still need attention. The project site will need ecosystem management such as frequent prescribed fires indefinitely. TNC financed this restoration project by establishing the property as the Old Fort Bayou Mitigation Bank. Credits in the mitigation bank were purchased by other parties to satisfy their obligations to perform mitigation in order to compensate for permitted development in wetlands elsewhere in the region. TNC applied proceeds from credit sales to purchase the property, to pay the costs of ecological restoration and overhead, and to establish a trust fund to pay for ecological management of the restored land in perpetuity. An interagency Mitigation Bank Review Team, consisting of six state and federal agencies, oversees mitigation and determines the ecological improvement or “lift” obtained by restoration. The amount of lift determines the value of mitigation credits, which are sold on the open market.
10_ch05:IP_Clewell
9/17/07
11:19 AM
Page 75
Chapter 5
Reference Models and Developmental Trajectories
An ecological restoration project begins with a vision of how an impaired ecosystem or landscape would appear if it were restored. This model is called the reference model or simply the reference. The reference may consist of one or more intact ecosystems that the impaired ecosystem is expected to emulate when it is restored. Alternatively, the reference may consist of descriptions of such ecosystems or of the salient ecological expressions that are desired in the restored ecosystem. The mental image that the reference projects may recall is the way the ecosystem looked and functioned at some period of time before it was degraded, damaged, or destroyed. It could also be intended to look like other ecosystems of the same kind that currently exist nearby. If recent environmental change or land use constraints prevent restoration to a former condition, the reference model may incorporate novel features that reflect current realities. In locales that have suffered extensively from human activity, little reference information may be available that describes previously existing natural areas, and the reference model will necessarily be skeletal. However imperfect it may be, a reference is a valuable tool to guide restoration (Aronson et al. 1995; Swetnam et al. 1999; Egan and Howell 2001). Without a reference as a target, a project lacks direction and probably should not even qualify as ecological restoration. A restored ecosystem displays a suite of ecological attributes, as described in Chapter 4. Each of these attributes is tailored to a specific restoration project from a description of the reference model. It is the reference model that distinguishes the products of ecological restoration in a holistic sense from other kinds of environmental activities. Such activities are valuable in their own right, including mine reclamation, range management (in America), bush regeneration (in Australia), reintroductions of favored species, ecological enhancements, installations of “designer” ecosystems, and management actions associated with commodity production. All of these are occasionally designated as restoration (see Chapter 9) but none really qualify as such without a reference model. Upon project completion, the reference serves as a basis for project evaluation.
Reference Types White and Walker (1997) classified the sources of reference information into four categories: same place, same time; different place, same time; same place, different time; and different place, different time. In the first case (same place, same time), the ecosystem to be restored 75
10_ch05:IP_Clewell
76
9/17/07
11:19 AM
Page 76
elements of restoration projects
contains sufficient evidence of its prior, intact condition to serve as its own reference, and it is called an auto-reference. In the second case (different place, same time), the primary reference site is called a refuge, indicating that a portion of the ecosystem remains intact and can serve as a reference for other portions that need restoration. In instances where an auto-reference or refuge is available, the reference sometimes serves almost as a template for ecosystem recovery, particularly if the degraded ecosystem needs little intervention to return it to its former, intact state. Consider a grassland or savanna that has been degraded by colonization of woody plants after an extended period of fire suppression. Its original plant species composition may persist for an extended period in dormant condition as a seed bank or propagule bank. All that would be needed is to ignite several fires with short return intervals during growing seasons to kill invasive shrubs and young trees and to remove an accumulation of leaf litter and coarse detritus. Thereafter, the degraded ecosystem will restore itself to a condition that cannot be distinguished from its former self. Virtual Field Trip 3 illustrates this kind of project. An auto-reference may also serve as a template in more severely damaged ecosystems that consist of only a few species and a predictable structure, such as extratropical mangrove forest. More commonly, a reference is not a template but rather a target to be approximated. This circumstance applies to the third and fourth reference types of White and Walker (1997). In the third type—different time, same place—reference information is available that characterizes the ecosystem before its decline or demise. For instance, photographs may exist, reports may be available, or historical documents may describe the natural history of the locale. In contrast, in the fourth type—different time, different place—essentially no information is available on prior ecosystem conditions at the project site, but such information is available for one or more regional ecosystems of the same kind that occupy a similar landscape position with similar physical site conditions. Sometimes reference information of any kind is lacking. Almost all extant ecosystems in much of Europe, the Mediterranean region, and many parts India and Asia have undergone extreme modification in response to extensive and extended land use activities, to the point that historic documentation of former natural or semicultural ecosystems is fragmentary, if it exists at all. In such instances, the reference model can be fashioned at a small spatial scale such as that of a biome or ecoregion. Details can be supplied from whatever information is discovered, such as lists of native species (with emphasis on K-strategists) from published floras and faunas and from herbarium and museum specimens. Patient detective work can provide scraps of evidence from examinations of historical documents, visits to local botanical gardens and to vestiges of seminatural vegetation, and even to art museums to examine old landscape paintings. The palynological and archaeological records can be accessed if used with caution. Much pollen can be identified only to genus or family, and its relevance is limited. Windborne pollen did not necessarily originate in the site where it was deposited, and insect-pollinated species may be underrepresented or entirely absent from fossil pollen samples. Nonetheless, paleoecological sources can provide a surprising wealth of information in some circumstances (Egan and Howell 2001).
Contingencies Ecologically and culturally important species from the past may have been intentionally or accidentally extirpated by people and cannot be included in restoration, such as American
10_ch05:IP_Clewell
9/17/07
11:19 AM
Page 77
Reference Models and Developmental Trajectories
77
chestnut (Castanea dentata) and many of the larger animals from the Holocene that were driven to extinction by prehistoric hunters. Overkill and, in many cases, local extinction of top predators and large herbivores (e.g., tigers, lions, elephants, wolves, and bears) represent irreversible threshold crossings that limit the potential for restoration. In any case, it is rare that people accept the idea of reintroducing such animals, yet without them restoration to a prior state may not be possible. Indeed, precise replication of a former state in terrestrial ecosystems is inconceivable, as Hilderbrand et al. (2005) noted, calling this “the myth of the carbon copy.” Even if a former ecosystem state could be precisely achieved, it would be fleeting because of ongoing ecosystem dynamics and inevitable changes in state. The subtleties of gradients, frontier zones, and microsites are particularly difficult to recreate with precision and must be allowed to redevelop on their own. Ecological development is further shaped by numerous stochastic (random) events that occur sequentially, with the results of one influencing the next. These developmental variations commonly reflect the timing and severity of stress events with respect to stages in the life histories of species. For example, the species composition of trees that colonize a forest canopy gap may be influenced by weather conditions that differentially affect pollination and seed production among potential colonizing species. Seed dispersal can also be haphazard and cause great variations in species composition from one place to another despite uniform site conditions. In addition to historical contingencies, ecosystem development is influenced by factors elsewhere in the landscape off site, such as human actions that affect hydrologic input or extreme fluctuations in the populations of wide-ranging herbivores relative to their predators. To the extent possible, reference models should be selected that reflect the gamut of potential variability in biotic expression in terms of species composition and community structure. A single reference site can represent only a fraction of the potential expression that led to its own development. A restoration cannot be considered unsatisfactory because it expressed another state that its reference could have expressed but did not, because of chance occurrences. Instead, a restoration project should be considered successful if biotic expression falls within a range of variability that was determined from multiple reference sites. This procedure was advocated by Clewell and Lea (1990) and has been widely practiced, for example, by Baird and Rieger (1989). Landscape position can be contingent on the proper selection of a reference. For example, in Florida the forest cover is continuous and structurally similar between first-order and second-order streams. However, species composition and the physical environment differ substantially, as indicated by the relative contributions of colluvial and alluvial inputs (Clewell et al. 1982). Therefore, the selection of a reference for the restoration of forest in headwaters, as in Virtual Field Trip 7, should be limited to those occurring along first-order streams. The degree to which the reference can serve as a model for a restoration project and for its evaluation depends on its specificity and its appropriateness, and both can vary widely between projects. In some projects, as mentioned earlier, the reference can serve almost as a template. In others, it can only hint at the desirable direction, or trajectory, of development. Project goals determine the degree of specificity to which the reference is emulated. If the goals are general, as would often be the case for large-scale projects, the degree of specificity would be small.
10_ch05:IP_Clewell
78
9/17/07
11:19 AM
Page 78
elements of restoration projects
Interpretation of Reference Data Most reference sites are selected because they represent mature biotic expressions of the kind of ecosystem designated for restoration. However, a recently restored ecosystem represents a young stage in ecosystem development. A comparison between systems of contrasting ecological ages must be interpreted to overcome age discrepancy. Early seral species may dominate a recently completed project site. Most of these species may be absent at reference sites. Species abundance will certainly change as a system matures. The comparison would be much more valid if the reference sites were at the same ecological stage of succession as was the restored ecosystem, as will be addressed later in this chapter. However, there would be no assurance that young reference sites would eventually develop the mature biotic expression that was desired in project plans. The use of reference data entails interpretation. For example, forest along a free-flowing river can serve as a reference for a forest being restored along a reach of river that is influenced by water impounded behind a dam only if accommodations are made to account for the altered conditions. With rare exception, reference sites contain evidence of disturbance or impact that should not be emulated at a restoration project site. Nonnative species probably will occur at reference sites and should not be intentionally introduced at project sites. Conversely, desirable native species may spontaneously colonize a project site that were absent at reference sites. Evaluators should praise and not penalize a restoration project for containing these additional species.
Selection of the Reference in Changing Environments Climate change may prevent the historic ecosystem from being restored or from persisting if it is restored (Harris et al. 2006) (Figure 5.1). If so, a different ecosystem that will be suitable
Figure 5.1. Global warming accelerates melting of glaciers in Alaska and contributes to sea level rise.
10_ch05:IP_Clewell
9/17/07
11:19 AM
Page 79
Reference Models and Developmental Trajectories
79
for future conditions should be selected along with an appropriate reference model. For example, forests in the eastern United States in which hemlock (Tsuga canadensis) is a dominant tree are largely restricted to cool and moist locations in the Appalachian Mountains and border regions with Canada. However, numerous small forests of mature hemlock trees exist as geographically isolated relics of a formerly much broader range of distribution dating to times of cooler climate after the retreat of the Wisconsin glaciation. Hemlock reproduction is sparse in many of these relic stands because of increasingly warm and seasonally dry climatic conditions. Large hemlock trees that are already well established may persist indefinitely because of their longevity and massiveness, despite rapidly changing climate. A reasonable goal of restoration in such a site would be the establishment of a forest consisting of other species that grow with hemlock but not hemlock itself. Hemlock trees could be planted anyway, with hopes that some would survive. However, project success should not be contingent on their establishment, particularly in light of recent depredations by the hemlock woolly adelgid, a deadly invasive insect. Sea level change constitutes another risk for selecting the kind of ecosystem of the future that can be restored. Coastal locations such as tidal marshes, mangrove swamps, dunes, and deltas are obviously at risk. The effects of sea level rise in river valleys far from the coast may be subtle but should not be discounted. These effects can extend upstream as far as mountainous terrain, in terms of reduced gradients, slower flows, accretion of sediments on floodplains, and corresponding rises in the surrounding water table. Uncertainty as to the extent of climate change and sea level rise may stimulate practitioners to introduce some plants of species more representative of another kind of ecosystem into all or a portion of a restoration site. Then, if environmental conditions change, the plants of the second ecosystem would be favored and would stimulate the restored ecosystem to transform itself into another kind that was better suited. For example, assume that a cypress–blackgum swamp (Taxodium ascendens and Nyssa biflora) was being restored but that a reasonable possibility existed that the water table would fall significantly in the foreseeable future. The practitioner could plant a few oaks, maples, and sweetgum trees (species of Quercus, Acer, Liquidambar) on the most elevated terrain, where they could persist and eventually serve as seed trees to replace cypress and blackgum if conditions became drier. The introduction of species for their potential value under future conditions should be attempted after a careful projection of the historic trajectory of ecosystem development is determined, as will be described later in this chapter. The species selected for introduction should be those that would be expected to colonize independently of restoration, assuming that the trajectory changed as predicted.
Temporal References Significant and inescapable subjectivity is introduced into project evaluation when a newly restored ecosystem of a decidedly immature seral stage is compared with a mature reference model. To negate this inherent problem, several restorationists have suggested comparisons between restoration project sites and unrestored sites bearing equivalently immature ecosystems of the same kind that are undergoing unassisted biological succession. The first such attempt was reported by Feiertag et al. (1989) with respect to the restoration of sand pine scrub (Pinus clausa) and ecologically similar scrubby pine flatwoods in central
10_ch05:IP_Clewell
80
9/17/07
11:19 AM
Page 80
elements of restoration projects
Florida, USA. Both communities are fire maintained and occupy internally well-drained crests of low, sandy ridges. They are sometimes restored on land that was physically reclaimed by backfilling after opencast mining for phosphate ore. Restoration commonly includes mechanically salvaging topsoil that contains rootstocks and seed from a site about to be mined and spreading it on mined and physically reclaimed land nearby. Feiertag et al. (1989) prepared a reference site by removing topsoil from a previously undisturbed site and immediately respreading it on the same site. Unlike mined and reclaimed land, the reference site had suffered no disruption to its deep soil structure and hydrologic regime from mining and was allowed to recover by unassisted biological succession. Recovering vegetation was monitored 2 years later at both restoration and reference sites. Similarities in composition suggested recovery along the same ecological trajectory for both reference and mined sites. Grant (2006) applied a different variation of this approach to evaluate the restoration of jarrah (Eucalyptus marginata) forests whose vegetation had been planted on lands that were backfilled and physically reclaimed after opencast mining for bauxite in Western Australia. Elaborate monitoring of both vegetation and physical parameters had been conducted regularly on restored lands of various ages since restoration began. Restored jarrah forests on the oldest reclaimed sites had developed sufficiently to indicate that this restoration strategy was indeed satisfactory for recovery of the premining ecosystem. Therefore, monitoring data representing earlier stages of restoration were used as sequential reference models, called stateand-transition successional models, for newly restored sites on more recently mined and reclaimed lands. For example, a new, 2-year-old restoration site would be compared with former 2-year-old restoration sites. If monitoring values for important parameters at the new site fell within the range of values for those same parameters at former, ultimately successful restoration sites, then the new restoration was considered satisfactory. If those values fell outside this range, then midcourse corrections were conducted. In this example, previously restored project sites would become sequential reference models for newly restored project sites. Similarly, reference states in various degrees of degradation can be used as reference models for an ecosystem in sequential states of recovery, as illustrated in Figure 5.2. The main message of this figure is that as ecosystems become overexploited or degraded, various bits, species, or functions drop off (left, top to bottom), and their health, integrity, and resilience decline. The flow of goods they provide to people may increase in the short term, but the services they provide will inevitably decline (see Chapter 7). The distortion and diminution of the circles representing an ecosystem within its matrices is further indication of transformation that represents damage and degradation. When the restorationist attempts repair, which takes some time, some of the ecosystem’s parts and processes may not fully emulate the reference system because of irreparable damage to the environment or intensive land use. In such instances, multiple references in different stages of a restoration project provide a reasonable way to measure restoration progress.
Trajectories An ecological trajectory is the sequence of biotic expressions of an individual ecosystem over time. It could be conceived as a moving picture of an ecosystem that covered several centuries or millennia and that is speeded up so that its development can be viewed in a few minutes. The movie shows the continuous self-adjustments that a dynamic ecosystem undergoes,
10_ch05:IP_Clewell
9/17/07
11:19 AM
Page 81
Reference Models and Developmental Trajectories
81
Figure 5.2. Sequential references in ecological restoration. Dashed lines represent degraded or fragmented conditions as compared to a whole system and integrated landscapes. The inner circles represent the ecosystem. The one or two outer concentric circles represent the landscape and the socioeconomic matrix in which the restored ecosystem is embedded. The triangular appendages represent various natural goods and services that accrue from an ecosystem.
such as the growth of the dominant and more conspicuous plants, demographic changes in species populations, and other internal processes. The state of the ecosystem would differ from one time to the next; however, the ecosystem would always be identifiable as one kind, such as tundra, river swamp, or tropical savanna. However, a change in environmental conditions could produce a dramatic and apparently unidirectional change in the state and kind of ecosystem. Such a change could reflect natural circumstances, such as climate change, sea level change, or alterations in geomorphology. The change could also be cultural, such as burning. The changes could be caused by the persistent effects of socioeconomic exploitation of natural resources or of other development, such as building a dam upstream or farmers irrigating croplands and drawing down the regional water table. Furthermore, it can be the result of extreme events in internal community dynamics, within or between populations. Examples include epidemic disease leading to extensive dieback or, conversely, extensive proliferation of a given species’ local populations. Unlike an ecosystem, a trajectory is not real or tangible. Instead, it is a progressive historical record of what an ecosystem was like in the past. A trajectory can be projected into the future as a prediction, as long as future environmental conditions can be ascertained with a reasonable degree of confidence. For example, if no changes in future environmental conditions are anticipated, then the ecosystem would not be expected to change much in the future. If impaired, that ecosystem could be restored with historic fidelity to a former state. Figure 5.3 illustrates this situation by portraying ecosystems as railroad trains and their trajectories as the tracks. However, it must be remembered that the ecosystems remain
10_ch05:IP_Clewell
82
9/17/07
11:19 AM
Page 82
elements of restoration projects
stationary and that the train tracks merely indicate the passage of time. Two parallel sets of train tracks are shown that represent the trajectories of two sections of the same ecosystem. One section becomes degraded or otherwise impaired, as portrayed by the train derailment on Line B at one point, shown as Time 1. The other section on Line A suffers no impairment, and the train is not derailed. The restoration practitioner’s job is to put the train back on its tracks, so to speak, which happens when the restoration project has been completed. Restoration does not occur instantaneously. The practitioner cannot put the train back on its track where the derailment occurred. Instead, the train goes back on track further down the line, in the future at Time 2. Thereafter, the two ecosystems on Line A and Line B are again very similar, except the one on Line B is ecologically younger and will have to go further down the track before it reaches the stage of ecological maturity of the unimpaired ecosystem on Line A. Figure 5.3 illustrates our contention from Chapter 1 that you can restore only to the future and not to the past. However, the restoration was accomplished with historic fidelity that resembles a prior state. This type of restoration is illustrated by Virtual Field Trip 3. Figure 5.3 assumes that there were no changes in external environmental conditions and consequently no changes in the state of the unimpaired section of the ecosystem. However, if environmental changes did occur, the unimpaired section of the ecosystem would be transformed, and its historic trajectory would be deflected accordingly. The impaired section of the ecosystem could not be restored to its prior historic state. Figure 5.4 illustrates how the trajectory responds to environmental change. On Line A, the intact ecosystem undergoes a
Figure 5.3. Relationship between trajectories and ecosystems. Two identical ecosystems (trains) travel in time on parallel tracks (trajectories). The train on Line A travels through time without interruption as an intact, self-organizing ecosystem. The train on Line B is derailed at Time 1 and is restored later, at Time 2, with historic fidelity.
10_ch05:IP_Clewell
9/17/07
11:19 AM
Page 83
Reference Models and Developmental Trajectories
83
Figure 5.4. Relationship between trajectories and ecosystems, assuming a change in environmental conditions and a corresponding deflection in the historical trajectory. Two identical ecosystems (trains) travel in time on parallel tracks (trajectories) (as in Figure 5.3). The train on Line A travels through time unperturbed as an intact ecosystem, even though it transforms itself continually to successive states in response to changes in environmental or internal conditions and dynamics. The train on Line B is derailed at Time 1 and is restored at Time 2 to another state corresponding to the change in environmental conditions. The projected trajectories at Time 1 are indicated but were not realized.
significant change in state from what it was in the past. The section of ecosystem on Line B that underwent impairment cannot be restored to its state at Time 1 because of this change in conditions. It must be “restored” to a new state that reflects contemporary conditions and constraints. This new state is that of the section of ecosystem of Line A at Time 2. If it were restored to the trajectory that was projected at Time 1, as happened in Figure 5.3, the restoration would either fail or undergo transformation to the new environmental conditions. Figure 5.4 raises a serious question for practitioners who restore an ecosystem when environmental change is pending or has recently transpired. What is the historic trajectory of the ecosystem? Line A provides the answer. An ecological trajectory consists of the sequence of biotic expressions of an ecosystem over time. The train (ecosystem) on Line A has already curved (changed in response to changing environmental conditions). Therefore, the historic trajectory is that of Line A in Figure 5.4. It is not the historic trajectory of Line A in Figure 5.3, where no environmental changes occurred. The restoration shown at Time 2 on Line B of Figure 5.4 is conducted with historic fidelity because you can restore only to the future, and that future is determined by Line A. Conversely, an attempt to restore the ecosystem on Line B to its projected trajectory at Time 1 would return it to a state that formerly existed but
10_ch05:IP_Clewell
84
9/17/07
11:19 AM
Page 84
elements of restoration projects
not to the historic trajectory. This proposition may seem counterintuitive, but it is the only logical conclusion that can be drawn if you recognize that you can restore a dynamic system only to the future. As Cairns (1995) suggested, the damaged portion or elements of a landscape might best be “restored” to the condition it would have been in if no damage had occurred. Part of the problem in comprehending the concept of an ecological trajectory is that the term trajectory in ecological usage, like the term ecological restoration itself, is metaphorical. Trajectory is a term that ecologists borrowed from physics to describe sequential changes in the biotic expression of an ecosystem in response to its dynamics. This application of the term differs from its meaning in physics, where a trajectory is the path of an inert object as it moves through space. The term itself suggests that a trajectory is real, that it somehow molds the future of an ecosystem, and that it extends into the future. A trajectory is not real in the same sense that the image on a movie screen is not real. A trajectory does not shape an ecosystem. Instead, it reflects that ecosystem as if in a mirror. A trajectory does not extend into the future. Instead, a trajectory is more like the wake of a boat or a vapor trail behind a jet-propelled aircraft. The wake of a boat soon dissipates, but while it lasts it gives you a good idea of where you have been and where you came from. You can project the vapor trail into the future, based on the assumption that the aircraft will follow a particular course, but that projection is only a prediction. Restoration planning is founded on the anticipated projection of the historic trajectory into the future. Figure 5.4 portrays a single change in environmental conditions. There can be multiple changes, as were shown for altered states in Figure 5.2, each caused by different kinds of traditional cultural practices. Those altered states could be portrayed in Figure 5.4 but would necessitate the insertion of a switching station to accommodate several curving tracks and the possibility of a straight track as shown in Figure 5.3. In other words, when a practitioner conceives a new restoration project, several alternatives may exist, all of which may be acceptable. The problem is how to know what system B was like before derailment and what system A was like a while ago so as to be able to roughly match them starting from Time 2. This may entail detective work, as described by Egan and Howell (2001), to determine and assemble appropriate and compelling reference states. The projection of the trajectory does not have to extend indefinitely when a restoration project is conceived. It should be long enough for the restored ecosystem to attain its full ecological maturity or target condition. This may take several centuries for some kinds of forest or only one or two decades for some herbaceous wetlands. Thereafter, the restored ecosystem would be thoroughly established and capable of adapting to changing environmental conditions, should they occur. Options for restoring to various alternative states are illustrated in Figure 5.5. In ecological restoration, there are several problems with applying the notion of trajectory too strictly. First, the predisturbance or original ecosystem is not necessarily the reference model. Instead, another reference is commonly substituted or constructed for lack of adequate descriptions of the predisturbance state (White and Walker 1997). In those cases there is always a certain degree of ambiguity and arbitrariness (Aronson et al. 1995). Second, environmental stability cannot be guaranteed and indeed should not be expected. In other words, the track in Figure 5.4 curves shortly after a restoration project begins. Third, an ecological trajectory is many orders of magnitude more complex than the trajectory of a single
10_ch05:IP_Clewell
9/17/07
11:19 AM
Page 85
Reference Models and Developmental Trajectories
85
Figure 5.5. Schematic portrayal of ecosystem trajectories through time. Five possible future states, A through E, are shown on the right-hand side of figure, each with a different shape. The trajectory of the original state could lead to no change, as in State A, or to a transformed State B, assuming a change in environmental conditions (as in Figure 5.4, Line A). Without restoration, the trajectory of the impaired state would lead to no change in State E. Restoration allows the impaired ecosystem to surmount a threshold of irreversibility and become intact and self-sustaining, although at an early stage of ecosystem development. Thereafter, biological succession, perhaps supplemented by ecosystem management, allows development to any of several ecologically mature target states. These would be either State A or State B (whichever is applicable) and also alternative States C or D (both cultural ecosystems), assuming the resumption of traditional cultural practices (or contemporary local cultural practices or surrogate ecosystem management). Also, something could go wrong, such as unexpectedly intense land use on or near the site or a discontinuation of management or cultural practices, and the ecosystem could once again slip beneath the threshold of irreversibility.
object moving through space. The continuous process of self-adjustment to disturbance in an ecosystem is a consequence of this complexity and can cause fluctuations in the state of an ecosystem across time under constant environmental conditions. The value of the ecological trajectory concept thus depends on these three questions: Does the reference model faithfully represent the predisturbance ecosystem? Is the natural environment, including that of the surrounding landscape, likely to remain sufficiently stable during the course of restoration to ensure the preferred outcome? Are the intrinsic processes of an ecosystem likely to contribute to achieving the preferred outcome? The answers probably are affirmative for ecosystems that develop rapidly under uniform conditions, such as those of benthic marine environments. However, such ecosystems are not prone to disturbance and rarely are considered as being in need of ecological restoration. Other ecosystems that are candidates for an affirmative answer to those questions are those consisting of few
10_ch05:IP_Clewell
86
9/17/07
11:19 AM
Page 86
elements of restoration projects
species or those that typically occur in highly stressed environments, such as mangrove forests in subtropical regions. For most other kinds of ecosystems, the outcome is less certain. A restoration practitioner initiates ecosystem processes but does not control subsequent ecosystem dynamics. Planting certain species at particular densities may nudge a recovering ecosystem toward a desired biotic expression but does not guarantee its attainment. Spontaneous colonization by other species and their competitive exclusion of planted species can radically change a trajectory. The option remains to continue manipulating species populations indefinitely. However, such a practice can no longer be called ecological restoration. Instead, it is a form of management, whereby an intentional design is imposed on a natural system. The result is human artifice rather than a recovery of nature. In such instances, endpoints in terms of target states are valued more than ecological processes. Dynamic disequilibrium is rejected as an underlying theory. This point of contention has divided landscape architects and also ecological engineers, whose work occasionally extends into ecological restoration. Some (e.g., Jones et al. 1994) argue for acceptance of disequilibrium theory, and others opt for endpoints that may be more defensible with regard to client expectations. The term trajectory has metaphorical value but lacks precision when used in an ecological sense. The concept holds interest for restoration ecologists, who may use it to measure the ecological distance between the predicted and the actual outcomes of restoration. They may use the concept as a prolonged bioassay of environmental conditions. The trajectory concept has educational value in explaining the intent of ecological restoration in a gross manner. However, at finer levels of pedagogic application, it can cause misunderstanding and unattainable expectations. Above all, a trajectory should not be used as a method for evaluating the success of an ecological restoration project, except in very broad terms. Too many environmental variables exist for a trajectory to have rigorous predictive value. The same admonition applies to the reference model. Both the reference model and its anticipated trajectory are points of departure rather than endpoints that must be attained. Many ecosystems exhibit open-ended development, and endpoints cannot be predicted with precision. Thus, an ecological restoration project cannot be judged unsuccessful if it fails to emulate a reference model in full detail (e.g., community structure, inventory, functional dynamics) or if it fails to follow an expected trajectory. However, the restored system should bear some similarity to the reference system at least in terms of the anticipated future land use capability, which may include biodiversity conservation and socioeconomic services. Our concern here is to emphasize that the evaluation of a restoration project should not be held hostage to theoretical expectations and models that defy rigorous application or to technocratic criteria that disregard biocomplexity at population, community, and, a fortiori, ecosystem and landscape scales. An agreed-upon trajectory and its projection as embodied in reference model serve above all as signposts, yardsticks, beacons, and, where needed, foghorns to indicate that the ecologically young system has self-sustaining and self-organizing characteristics and that the shared goals of the people who have agreed to work together to achieve holistic restoration are being followed and respected. An agreed-upon trajectory and reference can greatly aid in the process of galvanizing support and consensus among participants and stakeholders at the outset and during implementation of a restoration project. The anticipated trajectory serves most importantly as part of the vision that drives restoration. It is ultimately unimportant whether
10_ch05:IP_Clewell
9/17/07
11:19 AM
Page 87
Reference Models and Developmental Trajectories
87
the vision is entirely attained. What is important is that the vision leads to the development of a fully functional, resilient, self-organizing, sustainable ecosystem that complements contemporary environmental conditions and imparts enduring service and value to people. This view recognizes that the value of restoration lies more in the process of redeeming a mindset of environmental sanctity than in reassembling a rigidly prescribed target.
11_ch06:IP_Clewell
9/17/07
11:20 AM
Page 88
Chapter 6
Project Planning and Evaluation
Ecological restoration projects are surprisingly complex. Restoration is not akin to civil engineering, where each task has a highly predictable outcome, nor is it like gardening or farming, where local conditions can be tightly controlled until crops are harvested. Instead, conducting ecological restoration is more like raising children. Projects, like children, need a great deal of attention, and unexpected circumstances often arise that necessitate prompt resolution using ingenuity and assertiveness. Many project tasks are not difficult to perform, but omitting one inadvertently can cause delays, run up costs, and threaten project quality. The scheduling of interrelated tasks can be harrowing, particularly for tasks that must be completed seasonally and sequentially. The most meticulous planning can be unraveled by unanticipated labor and equipment problems, unexpected weather conditions, temporary funding restraints, or delayed authorizations to conduct work. For these reasons and others, planning and project management to oversee the implementation of plans are crucial to complete projects in a satisfactory manner. The tasks that make up an ecological restoration project are identified and summarized in fifty-one guidelines that encompass project work from initial feasibility studies to the preparation of the final report for a completed project (Clewell et al. 2005). These guidelines were adopted by SER International and are posted on the SER Web page (www.ser.org), where they are available without charge to anyone with Internet access. They have also been included verbatim in the Appendix of this volume. The Guidelines for Developing and Managing Ecological Restoration Projects are not the only source of guidance; Whisenant (1999) and Hobbs (2002), among others, have provided useful contributions. The guidelines serve as a checklist for practitioners and project managers to ensure that they make no errors of omission. The guidelines also serve as a filing system for project information. A computer file can be made for each guideline. Project activities can be noted in the appropriate file as if in a diary. Descriptions, data, digital photographs, and digitized maps can be entered as they become available, as can other documentation and pertinent bibliographic references. These files become the project database that facilitates the preparation of progress reports, midterm funding proposals, public and professional presentations, and publications. If new personnel join the project, the database allows rapid familiarization with the project and its current status. 88
11_ch06:IP_Clewell
9/17/07
11:20 AM
Page 89
Project Planning and Evaluation
89
Because the SER Guidelines appear in the Appendix, we will only review the principal points in this chapter. The guidelines are categorized in seven groups: conceptual planning, preliminary tasks, implementation planning, implementation tasks, postimplementation tasks, and evaluation and publicity.
Conceptual Planning Tasks in this group collectively represent a feasibility study to determine whether restoration should be conducted. The geographic location of the potential project site, its boundaries, and its ownership are identified. The potential need for ecological restoration is described, along with a succinct characterization of the ecosystem or landscape. Each of the potential restoration goals is designated. At a minimum, ecological goals should emphasize that the restored ecosystem will meet the nine attributes identified in Chapter 4. The goals should specify whether ecological recovery is anticipated to a prior state, to an existing alternative state, or to a projected future condition. Conservation goals can be added, for example, to provide habitat for particular species. Socioeconomic goals can be included, such as to retain surface runoff on site to reduce flood risk elsewhere or to provide fuelwood or fodder for a local village. Cultural goals may also be added, such as to provide a venue for nature study where students can raise their environmental awareness. The scope of the project must be determined in terms of the kinds of interventions that may be needed to repair the physical environment and to recover a desirable expression of the biota. Legal and logistical requirements and constraints must be identified, such as environmental permitting needs and zoning restrictions. The surrounding landscape must be evaluated to determine whether existing or proposed land usage and development might threaten the restoration process or the ecosystem after it is restored. A strategy is needed to ensure long-term protection and management of the restored ecosystem. Sources must be identified for project funding, labor, equipment, and biotic resources such as seeds and planting stocks. Once all this information is available, project administrators can decide whether to proceed with the restoration project.
Preliminary Tasks Before project planning begins, important administrative and technical decisions must be made and crucial background information gathered. Personnel must be engaged, beginning with the restoration practitioners and also a project manager and technical experts if they are needed. The ecological condition of the project site should be inventoried empirically (Aronson et al. 1993a, 1993b) and many photos taken. Otherwise, no record will exist with which to compare the completed project and evaluate its effectiveness. Monitoring data may be needed to establish a baseline before restoration, especially with regard to water budgets, water quality, and nutrient availability. The reference model must be identified, and if it includes actual reference sites, they will have to be photographed and inventoried biologically and ecologically for purposes of preparing restoration plans. Pilot projects may be necessary to test new methods. Other studies may be needed to refine propagation techniques. Project goals must be finalized and perhaps modified, should that be warranted from the project site inventory or other information gained during the preliminary tasks. Goals
11_ch06:IP_Clewell
90
9/17/07
11:20 AM
Page 90
elements of restoration projects
embody the ideal state or conditions that the restoration project attempts to achieve. These goals should be reflected in concrete objectives so that project plans can be formulated (Wyant et al. 1995). For example, if the goal is to restore a particular kind of forested ecosystem, one objective could be to establish sapling trees of the designated species. This procedure is important and is discussed further in Guideline 27 in the Appendix. Applications for any required permits will have to be prepared and submitted. Stakeholders must be contacted and fully briefed on the proposed project. They will include adjacent property owners or managers, other local residents who will potentially use or benefit from the restored ecosystem, personnel from interested public agencies, and any other affected parties. Stakeholder input warrants careful consideration, and initial plans may have to be modified to accommodate stakeholder concerns. If stakeholders disapprove of the project, it should probably be abandoned. Access roads or other project infrastructure must be prepared. Additional personnel who will perform project work may have to be engaged and trained.
Implementation Planning Once the preliminary tasks have been completed, detailed plans can be prepared for conducting work on site to satisfy the objectives. Performance standards (also called design criteria or success criteria) are devised to determine when an objective has been attained. For example, sapling trees planted to establish a forest may have to grow to a minimum height, and they must exceed a minimal abundance, perhaps in terms of tree density or crown cover. Performance standards can also be devised for abiotic conditions, such as the length of the hydroperiod in a restored wetland. A monitoring protocol is then established to determine how performance will be determined, such as how sapling height and abundance will be monitored and how the monitoring data will be assessed. Likewise, criteria will be developed for determining the hydroperiod, along with instructions on how it will be measured in a monitoring program (e.g., use of staff gauges, piezometer wells, soil saturation measurements) and how the data will be assessed. Another responsibility of implementation planning is the preparation of schedules in terms of sequencing tasks in proper order and seasonality. For example, seed collection can be scheduled only in seasons when fruits are ripe, and planting is commonly a seasonally dependent task. Equipment, supplies, planting stocks, or other biotic resources will have to be ordered or secured. The budget for implementation must be finalized. Stakeholder input should be solicited throughout the planning process and accommodated to the extent possible.
Implementation Tasks The restoration plan is implemented. Boundaries are marked, and fencing or other needed protection is installed. Any permanent monitoring locations are marked.
Postimplementation Tasks The newly implemented restoration must be protected against vandals, herbivores, or other dangers. Maintenance is conducted as prescribed in project plans, such as irrigating newly planted nursery stock. Frequent reconnaissance is made to identify problems that necessitate
11_ch06:IP_Clewell
9/17/07
11:20 AM
Page 91
Project Planning and Evaluation
91
midcourse corrections. Such corrections or adaptive management procedures may have to be instituted, whereby the initial biotic response will determine what kinds of aftercare will be needed. Aftercare consists of any restoration activities that follow project implementation, and these activities may not become evident until after implementation. For example, native vines that are considered necessary components of the species composition may become abundant and smother young planted trees (Clewell 1999). Aftercare tasks will have to be imposed to remove these vines until the trees have grown sufficiently in height to overcome their competition. Some implementation tasks that were purposefully delayed are conducted, such as interplanting stocks of undergrowth species that cannot tolerate direct exposure to sunlight until young trees are established. Scheduled monitoring is conducted.
Evaluation and Publicity Monitoring data are evaluated to determine whether and when performance standards were attained. Other on-site evaluations may be made to compare the completed project with a reference model in order to obtain additional evidence concerning the achievement of project goals. A report is prepared that represents a comprehensive case history of the completed project. Technical presentations are made and articles prepared for publication so that other restoration professionals can learn from the achievements—and the mistakes—of the project. The news media are informed to announce project completion, and a public celebration can reinforce publicity and favorable public attitudes toward the completed project.
Project Strategies, Plans, and Designs Restorationists commonly speak of designing a project and of a project’s design. Design is a term that is appropriate for engineers and architects whose end products are exact and predictable. It is not as readily applicable a term when applied to ecological restoration, in which practitioners have only a few years to reengage ecosystem processes to the point of selforganization. Instead of engineering and architecture, ecological restoration is more closely related to pediatrics. The concerns of both fields are youths—young people and youthful ecosystems—that are just beginning their development in a manner that defies the precise prediction of final outcomes. Practitioners in both fields have targets at which they aim in terms of norms of physical development and role models of behavior for youths and reference models for impaired ecosystems. However, not all youths meet physical and behavioral norms as adults, and not all ecosystems meet their intended targets, for reasons that were described in the previous chapter. A design promises or at least suggests that a particular endpoint will be achieved. Ecological restoration is open ended and cannot make that promise with a high degree of certainty, except for ecosystems that need little intervention and will recover from impairment rapidly. Project design therefore is a somewhat misleading term in the context of ecological restoration, despite its convenience and its widespread use. We prefer to speak of a restoration project in terms of its approach or strategy. Here the inference is guidance rather than insistence. We are helping a young ecosystem toward a particular trajectory of ecological development. We really have no control over what will happen to it in the long term, just as we cannot control our children’s lives after they strike off on their own as young adults. We can
11_ch06:IP_Clewell
92
9/17/07
11:20 AM
Page 92
elements of restoration projects
inculcate our children with moral behavior and a good education, just as we can imbue degraded ecosystems with favorable hydrology and desirable species. But we cannot say for sure how either will ultimately turn out. Engineers and conventional architects are not concerned with living, open-ended systems. Their only interest is that the bridge does not collapse and that the building is both efficient and aesthetically pleasing. In other words, only end products count. Many restoration practitioners have been inspired by Ian McHarg’s (1967) concept of design with nature. This phrase has become the byword of an entire generation of landscape architects cum restoration practitioners (Orr 2002; Todd 2005; Apostol and Sinclair 2006; see also the writings of Richard Forman, e.g., Forman 1995). Nonetheless, we suggest that strategy is a more appropriate term. From the standpoint of accuracy and effective communication, we hope that it will be adopted. A strategy describes the manner in which a project is conceived with regard to the kinds of interventions needed to achieve project goals. For example, will restoration tasks address the physical environment, the biota, or both? If interventions will affect the biota, will they be limited to vascular plants, mycorrhizal fungi, annelids, or other kinds of organisms? If vascular plants are the primary concern, will the project tasks include eradicating invasive species and introducing desirable species as seeds carried in topsoil from a donor site that is spread on a restoration site? Or will nursery-grown trees and other plants be planted out at the site? Answers to such questions, collectively, make up the strategy for an ecological restoration project. Once the strategy has been determined, we can prepare specific project plans. We can list the unwanted invasive species, describe the methods for their removal, and state how these methods should be applied in terms of the season of the year and care that is taken to protect desirable species as we remove invasive plants. The donor site for topsoil is identified, its manner and conditions of extraction and transport are specified, the quantity to be applied per unit area is noted, and the way in which it is deposited, spread, and incorporated into the soil at the project site is described. The kinds of trees to be grown in a nursery and which nurseries are to be engaged are listed. The method of propagation and source of propagules are described. The size and condition of the seedlings are designated at the time they are to be delivered to the project site. Their density of planting is specified, and the techniques of outplanting are described. These are the kinds of information that is needed for the preparation of project plans. In other words, project plans are developed to carry out project strategy.
Genetic Provenance An important aspect of restoration planning is the genetic provenance—or place of origin— of seeds, other nursery stock, or other organisms that are introduced at a project site (Falk 2006; Maschinski and Wright 2006). The reason is that many species are wide ranging and occur in regions with a different climate, soils, or other environmental conditions. Consequently, organisms from another locality that are introduced in a restoration site may have low survival, poor growth, low vigor, low reproductive capacity, or low tolerance to extremes in weather. Most individuals of a species are well adapted to the place where they live because of pressures of natural selection for alleles that favor high survival and copious reproduction under local environmental conditions. Adaptation is expressed in terms of physiological response, such as cold hardiness, drought resistance, or the timing of phenological events such as the breaking of dormancy. These differences are rarely linked to phenotypic expressions that are detectable from morphological examination. For example, the presence
11_ch06:IP_Clewell
9/17/07
11:20 AM
Page 93
Project Planning and Evaluation
93
of a floral bud does not indicate when it will open. However, reciprocal garden studies and other techniques allow the detection of ecotypes, consisting of species populations that are adapted to a specific set of environmental conditions and that usually occur in a specific location or genetic provenance. Next to nothing is known about ecotypic differentiation in all but a few species. Little is known about the gene frequencies of adaptive alleles within a given ecotype and the number of generations needed for an ecotype to differentiate. This does not prevent restoration ecologists from assuming the existence of numerous ecotypes and regulatory agency personnel from insisting that planting stocks be obtained within an arbitrarily determined distance from a restoration project site. Introductions of unfavorable ecotypes can cause biological havoc, such as flowers being produced in the wrong season for local pollinators or plants breaking dormancy during the cold season or dry season. Furthermore, hybridization may occur among introduced ecotypes, leading to genetic erosion of the local populations. If the intent of a project is to restore with historical fidelity, then planting stocks should be obtained locally to ensure that all stocks represent local ecotypes. If the intent is to restore an ecosystem on mined and physically reclaimed land, where the soil structure, hydrology, and perhaps other conditions were altered relative to the premining environment, then it would be best to introduce multiple ecotypes. Selection pressures for the new, postmining environment would determine which ecotypes survived and could also initiate the development of a new ecotype from the variety of alleles that were present. If the climate is predicted to become warmer and drier, then planting stocks should be obtained from another region where the climate is already warmer and drier. If local ecotypes are desired in a restoration project, much care should be exercised with regard to the genetic provenance—or location—of where planting stocks are obtained (Krauss and Hua He 2006). For example, in mountainous regions, stocks should come from nearly the same elevation and from the sites where soils originated from the same kinds of rock. A difference of a few kilometers in distance could be critical. In large regions of uniform environmental conditions, ecotypic differentiation is much less likely to be pronounced, and one may safely obtain planting stocks from hundreds of kilometers away. Practitioners should be particularly cautious with growers in commercial plant nurseries to ensure a suitable genetic provenance. Growers commonly buy seeds from seed collectors, who obtain them from distant locations. As a general rule, planting stocks should not come from regions with a wetter, drier, or warmer climate than the one at the restoration site. Practitioners should also avoid purchasing native trees that have been genetically selected by plant breeders for timber production. Such trees may have had alleles bred out of them that are important for certain ecological functions, such as frequent mast production and deformities that produce hollow trees that animals need for nesting and denning.
Ecological Evaluation of Advanced or Completed Restoration Project Sites Monitoring to determine whether success criteria were attained is welcome, but additional studies may be needed for other reasons. Maturing ecological restoration project sites can be evaluated to provide: • Proof that the project was conducted • Evidence that project tasks have been completed satisfactorily • Accountability to satisfy project sponsors and financiers
11_ch06:IP_Clewell
94
9/17/07
11:20 AM
Page 94
elements of restoration projects
• Prescriptions for future ecosystem management • Information that would improve the craft and profession of ecological restoration • Information for teachers who would use a site for educational instruction • Documentation and data for use by restoration ecologists Evidence of project completion is derived from monitoring that is specified in project plans to determine when performance standards have been satisfied. Every standard was developed to ensure the attainment of the specific project objectives. Providing proof that a project was completed may seem like a frivolous exercise that merely restates the obvious. But a project is obvious only to those who were familiar with the project site before restoration began. Observers who first see the site after restoration has been completed may have no idea that the site was ever anything but a natural area. The most effective way to demonstrate that a project was completed is to make available a chronological sequence of dated photographs that begin shortly before the commencement of restoration activities and continue through project completion. These should include before-and-after photos taken at permanent photo reference points that show exactly the same views. Permanent features of the landscape should appear as reference in at least some sets of before-andafter photos. The photos should be made accessible on a Web site and permanently archived in a local library or museum. The first use of such information should be to provide the local news media with press releases so that stakeholders and the broader local community are apprised of the project, its completion, and its value to the community. Among the saddest moments in the careers of practitioners is when they realize—5 or 10 years into a project—that they cannot find good photographs of their project site before the work began. They will need many crisp, clear pictures—both close-up and wide angle— taken in different seasons and identified with the date taken at sites that can be relocated precisely in the future. Demonstrating accountability is important to assure sponsors and funding sources of project completion. This evaluation becomes especially important in securing sponsorship and funding for subsequent projects. Potential sponsors, financiers, and public policymakers need to know that restoration projects can be conducted successfully (Bernhardt et al. 2005). They need to have a realistic assessment of the costs for conceiving and planning future projects. For that reason, project costs should be summarized in the evaluation process. The basis for determining project costs must also be specified. For example, the person-hours of volunteer labor (if any) should be noted or estimated along with calculations of restoration costs per acre or hectare. Otherwise, cost estimates can be misleading and grossly misinterpreted. Once a restoration project has been completed to the point that the ecosystem has attained autonomy and self-sustainability, periodic ecosystem management may be needed to substitute for local cultural practices or to compensate for contemporary human impacts. Practitioners who have conducted the restoration know the project site intimately and are in the best position to prescribe the type of ecosystem management needed, its frequency, and the details of application. This kind of evaluation is particularly valuable to managers who are responsible for ensuring that a newly restored ecosystem at an early seral stage continues its development toward ecological maturity. This process may take a few years if that ecosystem is a subtropical marsh or several centuries for certain kinds of temperate and montane forest.
11_ch06:IP_Clewell
9/17/07
11:20 AM
Page 95
Project Planning and Evaluation
95
Project evaluations are crucial for the development of the profession of ecological restoration. Practitioners need to know what strategies and methods have worked well in the past and under what conditions. They also need to know what has not worked well and why, so that mistakes are not repeated. Practitioners need to share their experiences with their peers by providing evaluations of their projects in readily accessible places, such as Web sites and journals of professional associations. The preparation of a case history of the project is vital in this regard. Evaluations should provide information that will be useful to educators and park naturalists who may use the restored ecosystem as a venue for teaching. A case history of the project and the chronological sequence of project photographs will be particularly useful for this purpose. Restoration ecologists may want to continue tracking ecological development at the restored site, or they may want to explore questions of a theoretical nature, such as the so-called assembly rules of how ecosystems become organized. For such purposes, they will need monitoring data and a case history of the project as background information. The case history should include an ecological description of the project site before the commencement of restoration tasks and also as a chronological record of interventions made by practitioners. We have identified several elements so far that make up the evaluation of a project. They are an ecological description of the site before restoration, monitoring data that demonstrate the attainment of performance standards, photo documentation that includes chronological sequences, a chronological record of interventions by practitioners, and a summary of project costs. This information should also include an ecological and geographic description of the landscape, precise identification of the project location, the sponsors of the project, and other relevant background information that was gathered during the conceptual planning stage of ecological restoration. Collectively, this information makes up a case history of the project. If the performance standards and their monitoring protocols were developed carefully, the monitoring data will provide ample information to determine whether the nine attributes for restoration projects, as described in Chapter 4, were attained. If not, an additional investigation should be conducted to account for the missing information and included with other evaluation documents. The evaluation of restored ecosystems is becoming of increasing interest to university researchers for theoretical studies. It is also important to those in academic and research positions who are asked by policymakers to advise them on proposals to allocate large public expenditures for restoration projects. The academic community is generally skeptical of assessments made by practitioners from routine monitoring data, and they prefer to conduct more comprehensive studies themselves if research funds can be procured. Although such studies are very welcome, the conclusions they draw must be evaluated as carefully as their research, for two reasons. One is that there are innumerable criteria by which an ecosystem— restored or unimpaired—can be evaluated ecologically. The second is that not all ecological criteria are relevant in evaluations of ecological restoration. For example, Craft et al. (2002) evaluated tidal marsh restoration and determined that marsh grasses approached the stature and abundance of those in an undisturbed reference marsh in only a few years but that soil organic matter would take several more decades to be restored. Should the restoration be hailed as a success based on vegetation or deemed a failure on account of soils? The answer to that question depends on the goals of the restoration
11_ch06:IP_Clewell
96
9/17/07
11:20 AM
Page 96
elements of restoration projects
project. If the project goal was to provide primary production for estuarine food chains, the project was an immediate success because of the abundance of marsh grasses. If the goal of the project was to sequester carbon from the atmosphere to reduce global warming, the project is not yet successful because of the low content of organic matter in the soil. In another example, Zedler and Langis (1991) reported that tidal marsh restoration was inadequate because the grasses (Spartina foliosa) had not attained sufficient height to support nesting by clapper rails. Later, Boyer and Zedler (1999) explained that the reason for failure was that the site was constructed at an inappropriate elevation for S. foliosa to attain its maximum height. Was anyone at fault? Was it the engineers who graded to site to the wrong elevation before restoration activities began? Or was it the permitting agency for specifying the wrong elevation? Or was the restoration practitioner to blame for planting inappropriate species for that elevation? Or was the restoration really successful but site conditions were inappropriate for clapper rails, and they should not have been used as a criterion for success? Were other factors involved that were overlooked by the evaluation team? Was nobody at fault, because our knowledge at that time had not yet been calibrated by experience? Assuming that the project did allow calibration of our experience for restoring tidal marshes, the project deserves acclaim. In this instance, different investigators using the same data could come to diametrically opposed conclusions regarding the worth of ecological restoration. Reference models almost invariably represent a mature stage of ecological development, whereas a recently completed restoration is much less mature, as we explained in Chapter 5. This complicates comparisons. If the evaluation is delayed until the restored ecosystem has reached the same degree of ecological maturity as its reference model, then the comparison will be compromised by circumstances that affect ecosystem development after the completion of restoration activities. For example, if a grassland, 20 years after being restored, is compared with its reference model, the comparison may reflect the quality of postrestoration management much more than it would the quality of the restoration. Such a comparison would be valuable to chart the trajectory of a formerly restored ecosystem but not to evaluate the restoration per se. A valid evaluation of ecological restoration can be made only shortly after its completion. This is no different from assessing a patient’s state of health after he or she recovers from a disease. The rigor of the assessment diminishes as it is delayed. Additional studies could be directed at determining the value of the restored ecosystem as natural capital and its ability to provide natural services and products of economic worth. For example, is stormwater runoff retained on site and flooding reduced downstream? How many kilograms of fuelwood can be harvested per year by villagers? Do teachers bring students to the restored ecosystem for nature study? Does the restored ecosystem support populations of rare species that were specified for introduction in project goals? These are the assessment criteria that are meaningful to stakeholders and ultimately to policymakers and financiers who will decide whether future restoration projects will be authorized and underwritten. They must be documented rigorously. The degree to which a restored ecosystem resembles its reference cannot be discounted, but it is ultimately of secondary importance relative to the value of that ecosystem to people.
12_VFT4 (pt3):IP_Clewell
9/17/07
11:24 AM
Page 97
part iii
Values That Restoration Addresses
We begin this part with a Virtual Field Trip to South Africa, where restoration is conducted to improve people’s well-being. This excursion makes us reflect on the reasons why we perform ecological restoration in the first place. The two chapters in this short part occupy an important place in the book. They emphasize that restoration projects are conducted because they satisfy people’s values. When someone asks, “Why do you restore ecosystems?” do you have to pause to think about your response? Perhaps the first thing that comes to mind is, “Why, I’ve never thought about that before!” The value question is one of those intangibles that never seems to get answered except by “Well, it’s the right thing to do,” “It makes me feel good,” or “Because I want to do it.” We argue that the task of identifying and, ultimately, validating the values that motivate our work is important. We should know our motivations and thus our values. In Chapter 7 we explore values in terms of our varied personal and cultural relationships to nature and our socioeconomic dependencies on nature in terms of the goods and services that ecosystems provide. We then take a Virtual Field Trip to Tamil Nadu, India to see a community forestation and restoration project in action in a part of the world where many people from several co-occurring cultures live in intimate contact with highly degraded and damaged ecosystems, and where restoration has economic consequences. In Chapter 8 we return to a very broad plane of discussion because the four basic kinds of values that inspire and motivate ecological restoration are synthesized in a simple four-quadrant model that is borrowed from contemporary philosopher Ken Wilber. In a series of four schematic figures, we try to clarify the personal and cultural, and the ecological and socioeconomic values that are—or should be—simultaneously integrated in the course of restoration project work. During the external review of this book, some reviewers exclaimed that this chapter represented the “heart of the book.” For others, it was irrelevant or incomprehensible. We propose this four-quadrant model as something new and valuable for the science and practice of ecological restoration. For those who are not interested in detailed discussions of values, we invite you to skim through the chapters in this part quickly in order to return to more “practical” material such as that presented in Part IV. For all others, we offer you some new notions to consider in the two chapters that follow.
97
12_VFT4 (pt3):IP_Clewell
9/17/07
11:24 AM
Page 98
12_VFT4 (pt3):IP_Clewell
9/17/07
11:24 AM
Page 99
VIRTUAL FIELD TRIP 4
Restoring a Communal Savanna in South Africa James Blignaut and Rudi van Aarde
A human and ecological tragedy is unfolding in northeastern Limpopo Province, South Africa, in an area adjacent to one of the world’s conservation icons, Kruger National Park. This tragedy is prompted by human-induced environmental degradation. Much of it has resulted from decades of uncontrolled and intensive extraction of natural resources, which was encouraged by widespread absolute poverty, lack of services such as water provisioning, sanitation, and electricity, and lack of other basic infrastructures. The vicious cycle of poverty and environmental degradation is self-reinforcing. People living here often rely on insufficient amounts of ecosystem goods and services, such as fuelwood as their energy source, herbs and medicinal plants, and natural savannas for grazing their livestock. They are also likely to remain poor, economically vulnerable, socially and politically marginalized, and dependent on scant natural resources unless drastic efforts are undertaken. Alleviating poverty and mitigating environmental degradation will entail proper governance and concerted interventions. Here we describe a program of community-based interventions. Much of the degradation occurs near rivers (VFT Figures 4.1 and 4.2). Such degradation negatively affects water quantity and quality and soil fertility and poses immediate concerns for biodiversity conservation. Often, as in the case presented here, rivers supply water for both rural communities and conservation hubs, such as Kruger National Park, instigating conflicts over water rights. Tourism is important to this region and ensures that places such as Kruger are both conservation hubs and centers of economic activity. It follows that the reversal of degradation through the rehabilitation of catchments makes both ecological and economic sense. The local nongovernment initiative Africa’s Rural Initiatives for Sustainable Environments (ARISE) considers restoration of natural capital (RNC) an effective strategy for residents of rural communities to provide a range of vital ecosystem goods and services. These include soil restoration, carbon sequestration, water flow regulation for flood control, and water purification, all of which have an economic value for local rural people, the broader public, and the conservation community. RNC offers an economic incentive to heal the landscape and to provide alternative incomes for rural people. RNC enables local communities to participate in an economy from which they would be excluded otherwise. 99
12_VFT4 (pt3):IP_Clewell
100
9/17/07
11:24 AM
Page 100
values that restoration addresses
VFT Figure 4.1. Degradation in the catchment of the Klein Letaba River.
VFT Figure 4.2. Gully erosion.
ARISE projects are currently being implemented in the Klein Letaba River catchment (VFT Figure 4.1), where the town Gawula forms the center of activities. The South African government funds the enterprise through a poverty alleviation program. The government considers ecological restoration an investment, which provides natural infrastructure that benefits people, their economy, and their environment.
12_VFT4 (pt3):IP_Clewell
9/17/07
11:24 AM
Page 101
Restoring a Communal Savanna in South Africa
101
VFT Figure 4.3. Local people undergo training.
VFT Figure 4.4. Local people engaged in restoration.
Unemployed people from local communities are actively recruited and trained to perform specialized duties such as constructing fences to protect project sites, implementing erosion control and soil enrichment measures, removing invasive species, collecting and sowing seeds of indigenous plants, and propagating selected tree species for planting (VFT Figures 4.3 and 4.4). They are also educated in management, relevant fundamental ecological and
12_VFT4 (pt3):IP_Clewell
102
9/17/07
11:24 AM
Page 102
values that restoration addresses
conservation principles, and safety procedures. Appointment follows standard government procedures. Wages are paid monthly, and work clothes are provided, including safety boots, helmets, protective clothing, and protective glasses. Local leaders participate in making appointments in accord with agreed-upon protocols for rural societies. Currently about 650 formerly unemployed people are working in the program for a daily income of US$6, which is on par with minimum wages required by government. This is at least five times higher than the average income per person before the project. Given the magnitude of the challenge, the restoration of degraded areas and the production of ecosystem goods and services offer a sensible livelihood option that combats desertification and climate change while contributing to biodiversity conservation. Fieldwork commenced in May 2005. Fencing to control fuelwood collection and livestock grazing gave pioneer plants an opportunity to become established in the first year and to initiate processes of ecological succession. VFT Figures 4.5 and 4.6 are of the same site and were taken in May 2005 and May 2006, respectively, and provide an early chronosequence of regeneration in response to restoration. The return of vegetation cover already limits surface erosion and is allowing tree seedlings to become established spontaneously. Seedlings of many indigenous plant species being propagated in a local community-based nursery will be transplanted once they are mature enough to withstand the severe natural conditions. The South African government has renewed funding for the project for another three years until 2010. In addition, a complementary project was launched to replace the use of fuelwood with biogas produced from animal manure, which will reduce the need for planting and harvesting trees.
VFT Figure 4.5. Savanna in May 2005, showing initial colonization of pioneer plants.
12_VFT4 (pt3):IP_Clewell
9/17/07
11:24 AM
Page 103
Restoring a Communal Savanna in South Africa
103
VFT Figure 4.6. Savanna in May 2006, in same location as VFT Figure 4.5, showing dense grass cover.
ARISE and its sister biogas initiative have the credentials to be extended to other sites across South and southern Africa. Project success depends on community involvement, which must be ensured through continued funding and responsible governance. The program allows citizens to live in an environmentally intact landscape, to access its natural services—a right that is uniquely entrenched in the South African constitution—and to participate in the economy.
13_ch07:IP_Clewell
9/17/07
11:25 AM
Page 104
Chapter 7
Values and Ecological Restoration
Why do we restore ecosystems? Why are people attracted to restoration as a career or as a principal focus of their professional work? Restoration is risky, complex, and frustrating longterm work that requires almost infinite patience and dedication. Working conditions at project sites can be challenging. Other professions offer steadier work and better pay. It can even be difficult for restorationists to explain what they do when others ask because the phrase ecological restoration has not yet entered mainstream public discourse. And even when restorationists are able to explain what they do quite clearly, they may be hard put to explain coherently why exactly they do it and what it means to them. Behind the discomfort in addressing these questions lie our values. People choose to become restorationists for a variety of reasons. Most would say it is because of the urgency of the threat to ecosystems, whether locally or globally. Many would add that they find restoration work fulfills other deep-seated values, satisfies diverse aspirations, and gives additional meaning to their lives. We recently published a categorization or typology of the main motivations for conducting ecological restoration (Clewell and Aronson 2006). In this chapter we consider them in a somewhat different manner for their incorporation into a model to be presented in Chapter 8. We begin by reflecting on the levels of ecological organization that are addressed by ecological values and with which environmentalists and conservation biologists are deeply concerned. Then we address personal values of importance to restoration practitioners and others who are associated with project work. Next, we look at socioeconomic values that intact ecosystems provide for people, thereby improving their well-being. Finally, we consider cultural values that are of particular concern to stakeholders and the broader community. Appeals to these latter two groups of values should help to bring ecological restoration into the center of public debate until it becomes as familiar a concept as climate change.
Ecological Values The crucial ecological value of ecological restoration from an objective, scientific point of view is the recovery of an impaired ecosystem to an intact condition in terms of its integrity and health. This value generates a series of goals of restoration practice, such as renovation of dysfunctional aspects of the abiotic environment, the preparation of suitable habitat for particular species, and the recovery of a functionally integrated landscape. Achievement of these 104
13_ch07:IP_Clewell
9/17/07
11:25 AM
Page 105
Values and Ecological Restoration
105
goals contributes to the function or health of the entire biosphere. Lovelock (1991) used the metaphor of the goddess Gaia to indicate the interconnectedness of the biosphere, to which we fully subscribe, and to suggest that the earth itself is a self-regulating organism, which we accept as useful allegory. The interconnectedness, and thus Gaia, suffer increasing disruption from human impact. Ecosystem recovery may seem to be an unquestionably obvious goal to many readers. But we need to be scrupulous here and acknowledge that, like all goals, restoration is informed by a particular set of values. Davis and Slobodkin (2004a, 2004b) and Lackey (2004) assert that terms such as damage, repair, integrity, and health are all subjective, value-laden terms lacking in scientific objectivity. Lackey (2004:45) wrote, For example, one person’s “damaged” ecosystem is another person’s “improved” ecosystem. A “healthy” ecosystem can either be a malaria-infested swamp or the same land converted to an intensively managed cornfield. Neither condition can be considered “healthy” except through the lens of an individual’s values and preferences. We agree, unless the terms and conditions of ecological restoration are qualified, as we have done in this book. We specified eight consequences of impairment in Chapter 2 and nine attributes of intact ecosystems in Chapter 4. We also identified what we meant by ecosystem integrity and health in Chapter 1. These qualifiers provide a sound scientific context for understanding terms such as damage and recovery, but of course these terms can never be entirely value free, nor should they be.
Personal Values To introduce individual values, we pose the question to the reader: Why would you, on a profoundly individual and personal level, want to restore ecosystems? Three answers that we have often heard are summarized in this section. Each answer reflects a somewhat different value.
“Because Restoration Gives Me a Meaningful Way to Reconnect with Nature” This question addresses the reentry value, a term we borrow from Bill Jordan, who called restoration a vehicle for establishing a meaningful way to reconnect with—or reenter—nature. Jordan (1986) explained that there are many ways to come into contact with nature. Contact can be as a visitor in terms of hiking, backpacking, canoeing, mountain climbing, bird watching, or nature study. Contact can be more exploitive or interactive, involving hunting, fishing, agriculture, gardening, or gathering wild plants for food or dye making. Making contact with nature is not as profound or satisfying as reentering nature. Jordan (1986:2) wrote that none of these ways of contact with nature “offers complete immersion in nature through the exercise of the full range of our abilities as human beings,” that is, as makers, inhabitants, and bona fide members of the natural world. Restoration gives us that opportunity. In this regard, restoration affords the practitioner the opportunity to participate in natural processes from the inside out rather than as a technician who is called in from afar to fix a problem. Practitioners share a bond of kinship with their landscape. Reentry or reconnection lifts the practitioner beyond the despair that is understandably pervasive among preservationists because
13_ch07:IP_Clewell
106
9/17/07
11:25 AM
Page 106
values that restoration addresses
restoration aims to actively repair environmental damage. This effort imbues the practitioner with the satisfaction of doing something positive that reverses environmental destruction.
“Because We Have an Environmental Crisis on Our Hands, and I’m Going to Do Something About It” This may be the main personal reason why people become restoration practitioners. It is what journalist Paddy Woodworth (personal communication, 2007) called the environmental crisis response value (or enviro-crisis response, for short). This response is recognition that the world and its human population are in trouble environmentally and that we had better act now to ensure our future well-being. Ecological restoration is an especially attractive solution because it reverses environmental ruination (Jordan 1994; Higgs 1997).
“Because It Allows Me to Experience Personal Transcendence or Spiritual Renewal” Practitioners may suddenly realize that they are intimately meshed with, and ultimately indistinguishable from, the ecosystem on which they are working (Clewell 2001). This is a powerful intuition or unreasoned awareness that may occur unexpectedly in the midst of routine project work. It is a very personal, subjective experience that cannot be rationalized and is difficult to describe. We do not know how common or rare this experience is; however, we suspect it happens more than occasionally and that practitioners find it too personal to relate to others. Reentry, environmental crisis response, and personal transcendence are all powerful incentives that reach deep into our psyches. We may rationalize that we entered the field of restoration because we took a course in that subject in college or because we were offered a job with a firm or institution that was doing restoration. The chances are that we took that course or considered that job because it resonated with our yearnings to fulfill of one or more of these related values. Is it really necessary for someone to acknowledge these motivations before becoming a practitioner? Perhaps not, but we feel that anyone who enters a new discipline such as restoration should be consciously aware of his or her motivations and recognize the values that made restoration attractive. It is not only practitioners who benefit from this deeper understanding. It also helps anyone who is engaged in any way with restoration project work, including administrators, financiers, and officials who make public policy regarding natural resources. Everyone can gain from this same grounding in values if they are to appreciate the importance of restoring ecosystems and retain the patience and devotion needed to see it through.
Socioeconomic Values We depend on and value nature for the air we breathe, the water we drink, the food we consume, and the raw materials that supply our domestic well-being and our urban industrial bases. We also depend on and value nature to stabilize the soil and keep it from eroding, to detain surface runoff that would otherwise cause flooding, and to provide many other natural services. The degree to which we are aware of these values from nature depends on where we
13_ch07:IP_Clewell
9/17/07
11:25 AM
Page 107
Values and Ecological Restoration
107
live and what we do. Many urban dwellers are only vaguely familiar with them. Rural residents, particularly those from impoverished areas, are likely to be much more knowledgeable because they are directly dependent on natural goods and services for their survival and wellbeing (see Virtual Field Trip 4 to South Africa). Furthermore, as will be discussed in chapter 9, the true value of nature is not fully recognized in current market transactions and by public policy—far from it. However, given the growing awareness and concern about environmental problems, including the accelerating and irreversible loss of biodiversity and global climate change, it is clear that many people are reevaluating personal and societal values in this arena. Ecosystems provide a wide array of natural products and services that are useful to people and on which all economies depend. These goods and services are free to people and available without costs of production. In contrast, goods such as agricultural products and manufactured items must be purchased. Engineering services must also be purchased. The array and importance of natural goods that are generated by natural ecosystems are becoming better known on account of recent interdisciplinary works such as those of Westman (1977) and Daily (1997) and the monumental Millennium Ecosystem Assessment project (MA 2005). The more important and obvious ones include the following: • Wood for construction purposes such as lumber, poles, and cross ties • Thatch for roofing materials and matting, consisting of palm leaves and grasses • Fiber for textiles and rope • Firewood for domestic cooking and heating and for charcoal production • Forage for grazing by domestic livestock on meadows and other rangelands • Fodder and silage for domestic livestock • Medicinal plants and pharmaceuticals • Dyestuffs for use in textiles, foods, and cosmetics • Exudates such as gums, resins, and latex • Honey and oils • Vegetable foodstuffs such as roots, nuts, berries, and mushrooms • Miscellaneous natural products for use in rituals • Seafood including finfish, shellfish, macrophytic algae, and marine mammals (Figure 7.1) • Bushmeat and animal products from a wide range of vertebrate and some invertebrate animals consumed for food and used for hides, sinews, bones, tusks, blubber, and other materials It is true that synthetic or cultivated replacements exist for most of these natural goods, at least for affluent people who benefit from economic globalization. But for much of humanity, few or no substitutes are available locally. Furthermore, substitution incurs various global costs, demonstrable by cost–benefit analysis, and should be avoided where possible. This reflection is even more pertinent if we also consider the gamut of natural services provided by ecosystems. Ecosystem services of value to people include the following: • Protection of water recharge areas by vegetation that absorbs rainwater and snowmelt and that detains surface runoff and allows it to percolate into aquifers, from which water can later be extracted for use
13_ch07:IP_Clewell
108
9/17/07
11:25 AM
Page 108
values that restoration addresses
Figure 7.1. Harvesting fish, a natural product from Deepor Beel, a wetland ecosystem near the Brahmaputra River in northeastern India.
• Detention of potential floodwaters by organically rich soils that encourage water percolation and by emergent wetland vegetation that provides mechanical resistance against surface runoff • Reduction of soil erosion and consequent reduction of eroded sediments through the soil binding capacities of roots and the soil crusts formed by microorganisms • Transformation of excess nutrients, including denitrification and the storage of mineral nutrients in biomass and detritus • Immobilization of contaminants, such as heavy metals, agrochemicals, disease-causing organisms, and pollutants in stormwater and industrial discharge, by organic matter and other colloidal materials in soil to which these contaminants are adsorbed • Cleansing of particulates from the air by the filtering action of forests and other terrestrial vegetation • Cleansing of particulates in water by adsorption to organic surfaces and by the stilling of turbid water by aquatic and emergent vegetation and consequent settling of suspended solids • Reduction in noise pollution by the baffling effects of mainly arboreal vegetation • Renewal of topsoil through the incorporation of humus into mineral soil or the deposition of peat and muck • Conservation of germplasm (genetic material) such as the wild progenitors of cultivated plants and domesticated animals for use in overcoming inbreeding and for introductions of genes to induce disease resistance and to develop new economic varieties; also the conservation of alleles (genetic stocks) as an aspect of biodiversity • Provision of habitat for pollen vectors, particularly of domesticated crops, which commonly need natural habitat for completion of their life cycles • Provision of habitat for predaceous arthropods (e.g., insects, spiders) or other predators of crop pests, which also need natural habitat for completion of their life cycles
13_ch07:IP_Clewell
9/17/07
11:25 AM
Page 109
Values and Ecological Restoration
109
• Provision of habitat for valued wildlife, including rare, endangered, threatened, and red-listed species as well as game animals, including fish, in areas where hunting and fishing are practiced • Buffering of acidity in soil and water • Regulation of the quantities of atmospheric gases, including oxygen and carbon dioxide • Natural and seminatural landscapes that serve as the basis for ecotourism, agrotourism, and many kinds of recreational and educational activities • Offsetting or dampening extremes of climate by the dissipation of solar radiation as heat • Buffering coastlines and shores from wave action, tsunamis, and storm surges Some of these natural services are commonly called social services by those who manage and regulate natural resources. Our economic structure and our social structure both suffer when these goods and services are threatened. In Chapter 9 we will explore the use of ecological restoration to augment the array and magnitude of natural goods and services as a means to alleviate poverty, joblessness, and the growing problems of ecological refugees caused by local environmental degradation and scarcities of ecosystem goods and services.
Cultural Values We restore ecosystems to satisfy values that are shared collectively within a culture. For example, much restoration is dedicated to the recovery of impaired ecosystems in iconic places such as parks and preserves, where people gather to enjoy nature-oriented recreation and leisure, or in sacred places and sacred groves that have spiritual or religious significance (Figure 7.2). Some restoration is intended for aesthetics. Other restoration helps to repair public
Figure 7.2. Temple in a sacred grove leading to the Pale iron ore mines in Goa, India and senior manager S. B. Haldankar, who said that its gods protected the mines and the miners.
13_ch07:IP_Clewell
110
9/17/07
11:25 AM
Page 110
values that restoration addresses
lands that have been impaired by excessive visitation or intense recreational use, as happens on ski slopes or all-terrain vehicle trails on desert dunes. A major reason for restoring ecosystems is to provide places where biodiversity can be protected. Biodiversity is generally considered first and foremost for its scientific value and sometimes for its economic value as sources of germplasm and pharmaceuticals. We should also recognize it as a cultural value because it has broad popular appeal that is evidenced by numerous school and television programs that highlight biodiversity and cable networks that carry such programming regularly. The phrase biodiversity value is increasingly used in both popular and scientific media. Another cultural value that is fulfilled through restoration is the development of a sense of place and a sense of community that occurs when like-minded people join in a restoration project to improve their local landscape (Clewell 1995). Projects of this sort have led to civic celebrations and even to a wedding of practitioners (Holland 1994). A place-based movement that was fueled by community-based restoration efforts was under way in the United States in the early 1990s as a response to the post–World War II habit among Americans to change residences and geographic locations frequently. This migratory lifestyle disconnected people from their sense of place and their understanding of the natural landscapes that supported them. Environmental quality deteriorated as new residents were insufficiently grounded to make wise decisions on land use. This same approach is being used by environmental nongovernment organizations in tropical villages in South America, Madagascar, and elsewhere, in regions at the edge of primary forest where most people are new immigrants—ecological refugees—with few or no cultural roots or sustainable agricultural traditions. Education and the pursuit of knowledge—research—are deeply ingrained cultural values. Much restoration has been conducted in schoolyards and near college campuses for the purpose of raising ecological knowledge or ecoliteracy (Orr 1994). The celebrated Curtis Prairie at the University of Wisconsin Arboretum was restored in the 1930s to allow access to a prairie for study by university students in ecology at a time when transportation was limited (Jordan 2003). School children sometimes are engaged as practitioners on project sites to give them firsthand experience with restoration. Restoration project sites are valued for their research potential by restoration ecologists. Few projects are conducted exclusively for research purposes. However, some practitioners are also researchers who have conducted studies at their own project sites. Project monitoring data sometimes are published in scientific studies. The case for conducting ecological restoration to satisfy heuristic values is not strong, but growing interest among researchers in restoration suggests that this value may grow in importance. The contentions by Harper (1987) and Bradshaw (1987) that ecological restoration can be an acid test of ecological theory are frequently cited. This opinion is optimistic because restoration projects sites often are too heterogeneous and “messy” for the application of replicated experimental designs. In addition, the restoration process is sequential and cumulative, which limits the ability to test single variables. However, new research designs and statistical methods can help restorationists deal with these problems (Osenberg et al. 2006). At the same time, a recent multiauthor volume in this series (Falk et al. 2006a) amply demonstrates that there are many opportunities for the study and practice of restoration to help test basic elements of ecological theory and contribute to basic knowledge about ecosystems, communities, and organisms. For example,
13_ch07:IP_Clewell
9/17/07
11:25 AM
Page 111
Values and Ecological Restoration
111
much progress has been made in the development of the so-called assembly rules for ecosystem development (Temperton et al. 2004) and the study of the relationship between biodiversity and ecosystem functioning (Naeem 2006). As Falk et al. (2006b:341) pointed out, “although saving the parts (Leopold 1953) is often used as shorthand for restoration, restoration ecology shows that how the pieces are assembled, and how they work together, are at least as critical.” Finally, ecological restoration has been conducted to renew the nexus between nature and culture, particularly among displaced tribal people who become reunited with their traditional landscape and revive cultural traditions and bonds as they undertake its restoration (Anderson 2005). Rogers-Martinez (1992) asserted that the restoration of a cultural landscape requires the concurrent restoration of culture and that the two are inseparable. This theme has been treated in depth by Janzen (1988, 1992, 1998, 2002), Bonnicksen (1988), House (1996), Higgs (1997), Farina (2000), Naveh (2000), Harris and Van Diggelen (2006), and Moreira et al. (2006). Ecological restoration has been initiated in rural India to recover and expand sacred groves that are revered by tribal peoples of Hindu tradition as the dwelling places of deities (Ramakrishnan 1994; Desai 2003). In this context, ecological restoration becomes an extension of religious practice for tribal people who participate in restoration and an exercise in upholding religious tradition for other practitioners who facilitate these projects. The values that motivate restoration, then, are multiple and diverse. People in most cultures can relate to at least some of them. This is grounds for optimism that ecological restoration, once effectively communicated to the general public, will have a smooth passage to broad global acceptance as having a major role in coping with the daunting environmental challenges of the twenty-first century.
14_VFT5:IP_Clewell
9/17/07
11:26 AM
Page 112
VIRTUAL FIELD TRIP 5
Restoring Forests and People’s Well-Being in Southern India Narayanan Krishnakumar and T. S. Srinivasa Murthy
In the State of Tamil Nadu, 17.29 percent of the geographic area is covered by forests. Because of anthropogenic pressures that include grazing, forest fires, illicit felling, and the harvest of fuelwood, fodder, and small timber, the forests in many places have undergone tremendous degradation. In order to stem this degradation, the Tamil Nadu Forest Department intensified forest protection measures and assumed responsibility for the restoration of degraded forests with community participation, which involved long-term planning, afforestation, watershed development, and benefit sharing from the whole program with the community. From 1997–98 to 2004–05 (Phase I), through its Tamilnadu Afforestation Program (TAP), a joint forest management operation, the Forest Department has been restoring 480,000 hectares of degraded forests with the participation of local people through 1,367 village forest councils (VFT Figure 5.1). About 466,000 members from villages are involved in this effort. The project involves the active support of nearly 3,900 women’s self-help groups. Watershed development by the Forest Department included construction of nearly 23,500 checkdams and 2,200 percolation ponds (VFT Figure 5.2), mainly for agricultural use, and the implementation of water-harvesting measures. Water and forest products that were generated by the program are shared between communities for people’s benefit. Other government agencies have provided services in concert with the Forest Department efforts, such as providing credit for local businesses, improving schools and public health facilities, installing wells for potable water, and providing electricity connections for public needs. One village in the program is Santhanakottai. It occupies 300 hectares in the Kaniyambadi Reserved Forests. Elevation ranges from 30 to 610 meters above sea level. Annual rainfall is approximately 900 millimeters. The terrain is gentle to steep, with a number of small ravines and streams. Much of the soil is red gravel, with some hard rocky patches. Challenges that faced this village were impoverished soils and soil erosion, rapid runoff of rainwater and limited water recharge, unavailability of water for drinking and agricultural use except in the monsoon season, groundwater depletion at other seasons, limited livelihood options, and economic poverty caused by these problems. Beginning in December 2000, villagers were oriented toward problem awareness and skill development (VFT Figure 5.3). A village forest council of 167 residents was formed. The 112
14_VFT5:IP_Clewell
9/17/07
11:26 AM
Page 113
Restoring Forests and People’s Well-Being in Southern India
113
VFT Figure 5.1. Young forest of planted trees.
VFT Figure 5.2. Checkdam.
council conducted local planning in collaboration with forest officials and developed plans to provide new jobs in the afforestation and watershed improvement programs. Nine women’s self-help groups formed. One of their principal tasks was to account for finances, including small loans extended to villagers by the government, so that they could establish a dairy industry, grow vegetable crops, breed sheep, weave coconut leaves for roofing thatch, and make handicrafts from the leaves of the native palmyra palm (Borassus flabellifer) (VFT
14_VFT5:IP_Clewell
114
9/17/07
11:26 AM
Page 114
values that restoration addresses
VFT Figure 5.3. Awarding of a certificate for completion of an awareness skills workshop.
VFT Figure 5.4. Women’s self-help group making handicrafts for export from palmyra leaves.
Figure 5.4), candles, and other products. The women’s group initiative is a way to keep the usurious private money lenders at bay who had previously preyed on villagers. Afforestation consisted of planting native tree seedlings that were grown in a local nursery. These were gap-planted without site preparation at a rate of 500 trees per hectare; 102,000 seedlings were planted. Some were legumes, including Acacia leucophloea,
14_VFT5:IP_Clewell
9/17/07
11:26 AM
Page 115
Restoring Forests and People’s Well-Being in Southern India
115
Alangium salvifolium, Dalbergia sissoo (shisham), Pongamia pinnata, Pterocarpus santalinus (red sanders), and Tamarindus indicia (tamarind). Others were Azadirachta indica (neem), Dendrocalamus strictus (bamboo), Emblica officinalis (Indian gooseberry), Feronia elephantum (wood apple), Ficus religiosa (peepal tree), Ficus spp., Hardwickia binata, Madhuca latifolia, Syzygium cuminii, Terminalia arjuna, and Sapindus emarginatus. All of these species have multiple economic uses (e.g., nitrogen fixation, fodder, fruits, oils, wood), and nearly all are valued for their medicinal properties. Catchwater pits were dug next to each planted seedling to collect runoff and maintain soil moisture. Four percolation ponds and five checkdams were installed near the village, including the one shown in VFT Figure 5.2. Because of the program, grazing, fires, and illicit removal of fuelwood have ceased. Agricultural productivity has increased because of the greater availability of water. Similar experiences can be witnessed in some of the other TAP villages located on the forest fringe, and more are being initiated in Phase II (2005–06 to 2012–13) of the Tamilnadu Afforestation Project.
15_ch08:IP_Clewell
9/17/07
11:27 AM
Page 116
Chapter 8
A Four-Quadrant Model for Holistic Ecological Restoration
In Chapter 7 we asserted that restoration was conducted to satisfy a broad range of ecological, personal, cultural, and economic values. In this chapter we explore this idea with the help of a series of schematic figures based on the work of a contemporary philosopher, Ken Wilber. Wilber (2001) developed a generic model that seems especially suitable for expressing the values of ecological restoration in a clear and stimulating way. Wilber noted that human endeavors of every kind are multifaceted, in spheres ranging from economic development to public health, education, religion, technology, human relationships, and social movements. Wilber proposed that values can be nicely arranged into four categories according to whether they are objective or subjective and whether they are individual or collective. The four categories are individual–objective, individual–subjective, collective– objective, and collective–subjective. In Figure 8.1 and three other figures that follow, we have adapted Wilber’s model showing these four categories as quadrants into which the different motivations for ecological restoration can be sorted. It is our contention that the process of ecological restoration combines—or should combine—rationales contained in all four quadrants of this model. We call it the four-quadrant model of holistic ecological restoration. The individual hemisphere pertains to the values of the practitioner and, perhaps to a lesser degree, of others who conceive, authorize, plan, administer, manage, and finance restoration projects. The collective hemisphere pertains to the values of culture and society. The objective hemisphere refers to values that lend themselves to empirical confirmation by independent observers. The subjective hemisphere refers to values that cannot be assessed empirically and lend themselves to personal internal assessment or assessment in light of communal traditions. As described in Chapter 7, individual personal values represent the motivations for a practitioner to conduct restoration, such as reentry to nature, response to environmental crisis, aesthetics, and personal transcendence. The ecological values of the individual practitioner are directed toward the recovery of an impaired ecosystem to an intact condition that is sustained by an appropriate abiotic environment and that contributes to a functional landscape. Collective cultural values include appreciation of iconic landscapes, a sense of place, a sense of community, ecoliteracy, ecological science (in terms of cultural appreciation), cultural integrity (in terms of the nexus between nature and culture), and aesthetics. Collective socioeconomic values include all the qualities our societies regard as necessary or desirable for ma116
15_ch08:IP_Clewell
9/17/07
11:27 AM
Page 117
A Four-Quadrant Model for Holistic Ecological Restoration
117
Figure 8.1. Four-quadrant model of holistic ecological restoration.
terial well-being, ultimately derived from the many natural goods and services intact ecosystems provide. Figure 8.1 is drawn with double lines separating the four quadrants, indicating a degree of separation and independence. This separation is intentional and represents the analytical inclination of professionals to focus on the one quadrant that best represents their professional interest. Wilber (2001) cautioned that those who ignore the whole and concentrate on a single quadrant are unable to see how the pieces fit together. They wear self-imposed blinders. Wilber (2001) calls them flatlanders, referring to pre-Renaissance intellectuals who ignored mounting evidence that the earth was round. Instead, planet Earth, and ecological restoration, must be viewed and conceived in a holistic manner. Everyone involved in a restoration project naturally brings a personal perspective and with it a set of particular values. The essential point is for everyone involved in a restoration project to be aware of the implications of his or her own personal values and of the importance of the values from the other three quadrants. This broad-focused awareness greatly facilitates the fulfillment of the particular values that are relevant to a given project as that project is conceived, planned, and executed. Ecologists and conservationists are likely to be attracted to the quadrant of ecological values. For them, the intent of restoration is ecological repair and recovery for the sake of biodiversity and ecosystem function. The sight of a degraded ecosystem is distressing to them, and their primary inclination is the restoration of natural values. They are dismayed when they view ecosystems that display indicators of decline that were listed in Chapter 2. They feel satisfaction when an ecosystem displays the nine attributes of integrity that were identified in Chapter 4. In contrast, personnel in public agencies who are charged with the protection and management of natural resources are more interested in restoring an ecosystem because it provides services such as flood control and clean water, stabilizes soils and substrates, and provides habitat needed by species that have been officially designated for protection. They are
15_ch08:IP_Clewell
118
9/17/07
11:27 AM
Page 118
values that restoration addresses
not too concerned with the ecological details and instead are drawn to the quadrant of socioeconomic values. Ecological engineers whose careers are dedicated to expediting flows of natural services are likewise attracted to this quadrant. Ecological economists and social scientists are also attracted to the quadrant of socioeconomic values because the restoration of ecosystems can improve people’s incomes and well-being. So too are industrial and political leaders, whose responsibility it is to build strong, self-sufficient economies and societies. The fact that some key species are missing would not concern them, as it would an ecologist or a conservationist. Many people engage in restoration project work because it satisfies their inner personal needs to reconnect with nature or atone for the environmental ravages that were perpetrated by their culture. Many of these people are weekend restorationists who volunteer their services to local organizations that conduct restoration projects. Others are employed by nongovernment organizations or consulting firms that pursue restoration contracts. These people are attracted to the personal values quadrant. They would be gratified if one or more species were durably reintroduced to a project site not so much for reasons of biodiversity conservation as for knowing that they had done the right thing for nature. They would have to think a moment before replying to someone who asked them about the practical values of their restoration activities. A teacher whose students help restore a patch of ecosystem in a schoolyard is thrilled to know that their participation is raising their ecoliteracy to a degree that could never be attained in the classroom. Restoration for that teacher is not so much about biodiversity, flood control, or personal satisfaction. Instead, restoration is the perfect vehicle to inculcate ecological values into the culture, the community, or the next generation (Figure 8.2). The teacher approaches restoration as a champion of cultural values. This same approach may be
Figure 8.2. Youth group collects seeds from native species for planting at a restoration project in Mississippi, USA (see Virtual Field Trip 3).
15_ch08:IP_Clewell
9/17/07
11:27 AM
Page 119
A Four-Quadrant Model for Holistic Ecological Restoration
119
Figure 8.3. Some elements of the four quadrants.
expected from interpretive naturalists in public parks, natural history museum personnel, nature writers, and producers of documentary films and videos concerning nature. Some weekend restorationists who volunteer at local restoration projects may also participate primarily because of the cultural value of strengthening their bonds of community and developing a shared sense of place. The four quadrants of Figure 8.1 are redrawn in Figure 8.3, to which is added another feature borrowed from Ken Wilber. It consists of four axes, one for each quadrant, shown as dashed lines that extend outward from a central point of unity and contain characteristic elements along each one. Elements that make up each axis proceed from the center outward, in such a way that each successive element incorporates all preceding elements and adds to them something new. Other elements could also be included but are not shown here for lack of space. On the right-hand side of the figure, the axis in the quadrant for ecological values begins with the abiotic environment and continues with elements for intact ecosystems, functional landscapes, and Gaia. Each successive element incorporates the preceding element or properties of it. Gaia is used here in an ideal sense to conceive of the biosphere and indeed the entire planet as a fully interconnected whole. A more complete list of elements for this axis might include genes, organisms, populations, habitats, and biotic communities, between abiotic environment and ecosystems, and bioregions and the biosphere between landscapes and Gaia. The axis for socioeconomic values begins with natural goods and services” and proceeds to social capital, socioeconomic systems, and ultimately to an ideal future nation-state and civilization in which a healthy relationship has been achieved between humanity and the environment. We borrow the title of the novel Ecotopia (Callenbach 1975) to designate this ideal state, which is perceived as being imbued with ecological wisdom and populated with a sustainable civilization. Each of these elements could not exist without the previous
15_ch08:IP_Clewell
120
9/17/07
11:27 AM
Page 120
values that restoration addresses
elements on which they depend. Again, additional elements can be inserted by the reader according to country and context, including political jurisdictions and governance. Moving to the subjective side of Figure 8.3, the elements placed along the axis for personal values begin with reentry into nature and continue with enviro-crisis response, aesthetics, and transcendence. Aesthetics could have also been included on the axis for cultural values because it is both a personal and a cultural consideration. Elements along the axis for cultural values begin with iconic areas, such as public parks and sacred groves (Figure 8.4). Three additional elements are indicated: sense of community, ecoliteracy, and the ideal of world peace. A more complete list of elements might include biodiversity (or the appreciation thereof), sense of place, environmental ethics, intergenerational justice, and universal brotherhood. Environmental ethics develops after a culture has attained an appropriate level of ecoliteracy. A system of environmental ethics is, in turn, a prerequisite for a culture to become cognizant of the need for intergenerational justice, that is, the importance of environmental stewardship for the well-being of subsequent generations. A culture that accepts environmental ethics and intergenerational justice transcends the propensity for greed and has replaced it with an ethic of shared trust and caring as its underlying motivation. Another feature of the four-quadrant model is that each axis extends through realms of organization that are ordered in a logical sequence, as shown in Figure 8.5. These are the physical, biological, conceptual, and intuitive realms. These realms form concentric rings, which Wilber (2001) calls a “great nest.” The physical and biological realms pertain to elements
Figure 8.4. Three students and Andre Clewell, who holds the temple bell, in a sacred grove near the Sevadham Trust School for tribal children west of Pune, India. The bell is attached to the tree, and the two painted rocks below represent the gods. The school and its students intend to restore the sacred grove by planting trees in adjacent grassland and installing a fence to exclude livestock.
15_ch08:IP_Clewell
9/17/07
11:27 AM
Page 121
A Four-Quadrant Model for Holistic Ecological Restoration
121
Figure 8.5. Realms of organization for the elements on the axes in the four-quadrant model of ecological restoration.
that are largely physical and biological in nature. By the conceptual realm we refer to consciousness and especially to abstract thought. By the intuitional realm we refer to the bursts of realization or insight we occasionally experience that defy logical explanation. Thomas Kuhn, in his classic book The Structure of Scientific Revolutions (1996:122–123), claimed that all science depends on such insights for the development of hypotheses and the evaluation of data. We include in the intuitive realm ideal states (Ecotopia, world peace, the interconnectedness represented by Gaia, and experience that defies full explanation, characterized by some people in terms of aesthetics, by others as transcendent or spiritual) (Wilber 2001). The realms of organization are not as discrete as Figure 8.5 indicates. Instead, they represent a continuum of expression within indivisible existence and experience. For example, the biological realm could not exist without physical matter. The conceptual realm requires the physical and biological realms, or else there would be nothing to conceptualize. In turn, intuitive experience would be meaningless without the ability to conceptualize biological and physical phenomena. The placement of elements is not as easy as it may seem at first glance. For example, an ecosystem seems to be a biological element, but it is actually a conceptualization of nature and belongs in the conceptual realm. The center of the four-quadrant model is the point where the axes of the four quadrants originate. This point represents the initial idea that later manifests as the project itself and the values that were its motivation. The four-quadrant model has yet another feature that is not all apparent when it is portrayed in two dimensions, as in Figures 8.3 and 8.5. That feature is the unity that is approached in the intuitive realm. As suggested already, the quests for Ecotopia, world peace, personal transcendence, landscape aesthetics, and Gaia are all aspects of a search for wholeness or oneness. A true Ecotopia could scarcely arise without world peace and without a healthy biosphere—Gaia—to sustain it. World peace is surely related to the inner peace of
15_ch08:IP_Clewell
122
9/17/07
11:27 AM
Page 122
values that restoration addresses
Figure 8.6. Convergence of the four axes to emphasize the fundamental relationship of all quadrants and their elements in ecological restoration projects.
individuals, which in turn seems related to intuitive experience. In this manner, the four quadrants become one in the uppermost realm. Both figures begin at the base with unity, where the four axes diverge. The pertinent elements for a project are distinguishable, as shown on each axis. Ultimately they are rejoined in the intuitive realm. This unity is indicated when Figure 8.5 is redrafted in three dimensions, as shown in Figure 8.6. This depiction emphasizes that ecological restoration is not a one-dimensional exercise. It is a holistic endeavor in which elements on each axis of all four quadrants are ultimately inseparable, and even if unity is not yet achieved, none of the individual elements should be ignored or dismissed. The fundamental idea we are elaborating here, tentatively but with increasing confidence as our experiences grow, is that ecological restoration has an extraordinarily positive role to play in multiple areas of human life.
16_VFT6 (pt4):IP_Clewell
9/17/07
11:33 AM
Page 123
pa r t i v
Structure of an Emerging Profession
In Part IV we come back to Earth, so to speak, from a more philosophical treatment of values. We examine the structure of the emerging profession of ecological restoration and consider practitioners and others who are engaged in project work as the professionals who populate it. We begin, in Chapter 9, by distinguishing ecological restoration from related activities with which it is sometimes confused. To the extent possible, we avoid quibbling over academic turf, which we find unproductive when professionals in various fields should be united in their desire to improve the world’s environment. Instead, we prefer to emphasize the special roles that ecological restoration can best serve in this larger context, relative to allied fields. This exercise is important and should be undertaken regularly in all fields as environmental professions evolve in response to a changing world. If you cannot explain what you are doing and why it is different from other related activities, then you are unlikely to achieve your goals in a field as multifaceted as ecological restoration and in a world as complex as the one in which we live. Our contention is that the environment and all people on Earth, who depend on it daily for their very existence, need all the help we can muster. Ecological restoration is just one of many ways. What we have done in this chapter is to distinguish restoration and its contributions to environmental improvement in an effort to promote understanding and accurate communication. In Chapter 10 we examine the roles, contexts, and institutional structures of project work. In Chapter 11 we present a rationale for recognizing ecological restoration as an emerging profession, even if the actual procedures for doing so are still evolving. Our intent here is to show young professionals how their careers can be affected by different pathways of professionalism and what they should be aware of as they inaugurate their careers. The three chapters here are accompanied by three Virtual Field Trips, to Germany, Florida, and France, designed to illustrate important aspects of restoration work in the types of settings in which many practitioners begin their careers.
123
16_VFT6 (pt4):IP_Clewell
9/17/07
11:33 AM
Page 124
16_VFT6 (pt4):IP_Clewell
9/17/07
11:33 AM
Page 125
VIRTUAL FIELD TRIP 6
Restoring Drained Peatlands for Sustainable Use in Germany Achim Schäfer and Wendelin Wichtmann
In the north German lowlands, extensive fen peatlands occupy broad and shallow river valleys. The peats are formed mainly by sedges (Carex spp.) and brown mosses (Hypnidae) and are known as percolation mires because they are hydrated mainly by lateral groundwater supply. Under historical peat-forming conditions, some characteristic species included Carex appropinquata, C. diandra, C. lasiocarpa, C. nigra, C. panicea, C. rostrata, Menyantes trifoliate, Potentilla palustris, Valeriana dioica, and mosses such as Calliergonella cuspidata, Drepanocladus revolvens, and Scorpidium scorpioides. At their interior margins, percolation mires are joined by spring mires that are charged by groundwater, commonly under high artesic pressure. Spring mires support sedges, common reed (Phragmites australis), and sometimes black alder (Alnus glutinosa) forest. A narrow band of common reed grows densely on riverbanks inundated from overbank river flow. Most fen peatlands were drained deeply and converted to meadows and pastures (VFT Figure 6.1) containing numerous grasses and ruderal species typical of agricultural landscapes (Elytrigia repens, Poa trivialis, Agrostis stolonifera, and Lolium perenne). After a long period of agricultural use, the degradation of the peatlands led to substantial losses in biodiversity, water, nutrients, and carbon and to decreases in the quantity and quality of fodder production. Natural peat accretion changed to anthropogenic peat consumption. Silage production and grazing by cattle were the traditional uses of these grasslands, which have declined since 1989. The continuation of intensive management on approximately 80,000 hectares of these sites in the federal state of Mecklenburg-Vorpommern no longer meets the demands of sustainable land use and best management practice. If such grasslands are abandoned, they will undergo succession without addressing the continuing negative impacts from drainage. One such impact is the emission of carbon dioxide into the atmosphere as peat oxidizes. We have been researching the possibilities for restoring these peatlands by rewetting them and returning them to alternative uses. Some herbaceous species typical of percolation mires still persist. We believe that these species will be favored by rewetting and will replace existing weedy agricultural species through plant succession. The resultant vegetation will serve as pasturage for Heck cattle, a genetically reconstituted lineage (derived from selective breeding of modern stock) of the extinct European aurochs (Bos primigenius), which was the forerunner of domestic cattle. In addition, we are planting black alder trees to supply wood for 125
16_VFT6 (pt4):IP_Clewell
126
9/17/07
11:33 AM
Page 126
structure of an emerging profession
VFT Figure 6.1. Intensively grazed pasture on drained peatland, Biesenbrow, Germany.
VFT Figure 6.2. Preparation of ridges on which to plant black alder trees, Brudersdorf.
the manufacture of furniture and as a carbon sink and habitat for wildlife. We are also introducing common reed as a biomass crop to be used as biofuel for the generation of electricity. We anticipate that our efforts will lead to the accretion of new peat. Our experiments are conducted in 10-hectare pilot plots at the Brudersdorf and Biesenbrow polders, administered by Greifswald University. Black alder trees were planted in 2002 and successfully established at Brudersdorf in five configurations (on ridges 20 and 40 centimeters high, on mounds, at ground level, and in fur-
16_VFT6 (pt4):IP_Clewell
9/17/07
11:33 AM
Page 127
Restoring Drained Peatlands for Sustainable Use in Germany
127
VFT Figure 6.3. Inundated black alder planted on ridges, Brudersdorf.
VFT Figure 6.4. Monitoring black alder 1 year after planting, Brudersdorf.
rows) (VFT Figures 6.2 and 6.3). Tree survival was low unless competing herbaceous vegetation was mowed at the time of planting. Tree heights reached as much as 5 meters within 4 years on ridges and mounds (VFT Figure 6.4). Rewetting was accomplished after the abandonment of constructed earthen dikes in 2006 from along the shore of the nearby Trebel River. These dikes are already breached in places and will gradually erode, allowing river
16_VFT6 (pt4):IP_Clewell
128
9/17/07
11:33 AM
Page 128
structure of an emerging profession
overflow to extend across the peatlands during wet seasons, thereby returning natural hydrologic conditions. We expect that plantations of black alder will benefit from rising water tables and that agricultural meadows will be replaced by natural succession of native hydric sedge-dominated communities in open gaps between the trees. Wildlife species are expected to be attracted to the new habitats, such as storks (Ciconia nigra), cranes (Grus grus), otters (Lutra lutra), water rails (Rallus aquaticus), moor frogs (Rana arvalis), and woodcocks (Scolopax rusticola). These animals had nearly disappeared from these sites during the time of intensive agricultural grassland use. The region surrounding the Biesenbrow pilot plot had also been highly degraded by its intensive and continuous use as agricultural grassland since the 1960s. Water reservoirs, water distribution systems, and dikes were installed in 1998 to maintain water levels in our experimental plots to within 20 centimeters above and below the surface of the peat with electrical pumps (VFT Figure 6.5). These will be replaced soon with a windmill. We are determining what hydrologic conditions are appropriate for propagating Phragmites australis and Carex gracilis (VFT Figure 6.6). One aim is to reintroduce peat-forming vegetation on degraded soil to restore former fen plant communities. The other aim is to attempt sustainable reed production. Several uses of reed have been tested successfully, including the fabrication of mats, plaster porters, roof thatching (VFT Figure 6.7), insulation materials for house construction, and grid “stones” for stabilizing soils at construction sites. Ecological investigations showed that the Biesenbrow site was functioning as a sink for calcium carbonate dissolved in groundwater after less than 2 years of restoration, particularly in permanently inundated areas that were spontaneously colonized by Characeae. Ecotypes of Phragmites australis that we introduced competitively excluded remnants of former agricultural grassland species. The better-adapted ecotypes were those taken from comparable sites and spread much faster than others. Carex gracilis that had been planted was competing
VFT Figure 6.5. Preparation for common reed cultivation, Biesenbrow.
16_VFT6 (pt4):IP_Clewell
9/17/07
11:33 AM
Page 129
Restoring Drained Peatlands for Sustainable Use in Germany
129
VFT Figure 6.6. Newly planted Carex gracilis (foreground) and older common reed (background).
VFT Figure 6.7. Binding common reed for use in thatching roofs.
and dispersing within the area. Some threatened wetland birds such as bittern (Botaurus stellaris) and corn crake (Crex crex) could be heard from the second year on. Our work allows us to envision restored fen peatlands in northern Germany that will support sustainable agriculture, forestry, and biofuel production. These landscapes will sustain normal hydrologic function and viable populations of native plants and animals. They will allow the accretion of new peat and will thereby serve as carbon sinks.
17_ch09:IP_Clewell
9/17/07
11:35 AM
Page 130
Chapter 9
Relationship of Restoration to Related Fields
In this chapter we explore the differences between ecological restoration and other activities that include restoration ecology, ecosystem management, rehabilitation, reclamation, revegetation, mitigation, creation, landscape architecture and design, ecological engineering, restoration of natural capital (RNC), and sustainability science.
Restoration Ecology The SER Primer on Ecological Restoration stated that “ecological restoration is the practice of restoring ecosystems as performed by practitioners at specific project sites, whereas restoration ecology is the science upon which the practice is based. Restoration ecology ideally provides clear concepts, models, methodologies and tools for practitioners in support of their practice” (SER 2002:11; italics added). This distinction between ecological restoration and restoration ecology is straightforward and quite clear. However, it is disconcerting how much confusion persists. The distinction between the two fields is logical, particularly to a grammarian, who would note that ecology is the study of the relationships of organisms to each other and their environment. Therefore, restoration ecology is the study of the relationships of organisms to each other and to their environment, with particular reference to restoration. It would make no sense to use restoration ecology to signify the conduct of a project, which is not a study of anything per se but rather the pragmatic application of ecological knowledge and related skills and experience to real-world situations where restoration is required or desired. Ecological restoration is urgently needed to help bridge the gaps and provide the necessary links between nature conservation and sustainable local economic development (Aronson et al. 2006a, 2006b, 2006c). Restoration ecology is likewise needed in support of this effort. If authors and practitioners continue to confuse these terms and the activities they describe they will also confuse policymakers, financiers, and others who need to understand the distinction between these fields as they make decisions that will promote efforts in support of nature and of culture as supported by nature. We encourage all concerned to respect the distinction between ecological restoration and restoration ecology. 130
17_ch09:IP_Clewell
9/17/07
11:35 AM
Page 131
Relationship of Restoration to Related Fields
131
Ecosystem Management According to Edward Grumbine (1994), ecosystem management attempts to maintain ecological integrity at various levels of organization (e.g., species, populations, communities, ecosystems) and evolutionary and ecological processes. Maintenance connotes any intentional activities that are intended to repair or compensate for human impacts that harm or threaten ecological integrity. In Chapter 1 and elsewhere, we proposed to make a clear distinction between ecological restoration and ecosystem management. Our position is that restoration assists the recovery of an ecosystem to the point that it becomes self-organizing and self-sustaining, even though it may be represented by an early stage of ecological development, and that postrestoration management is anticipated. One of two kinds of postrestoration activities may be needed. One is the resumption of traditional cultural practices that shaped and maintained cultural ecosystems in the past and could be conducted in future—albeit in updated fashion—by people who live on the land and seek to build and nurture mutually beneficial relationships with ecosystems. The other is ecosystem management, which is generally imposed externally by technical managers. These ecosystem managers can play either or both of two important roles. One is to manipulate cultural ecosystems and landscapes in a way that substitutes for traditional cultural practices in locations where local residents are absent or unable to perform them. This, of course, applies only to cultural ecosystems in what we have alluded to in earlier chapters as surrogate ecosystem management. The other is applicable to any ecosystem and consists of manipulations that compensate for modern human impacts on the environment that, if not addressed, will degrade ecosystems to the point that they will eventually need restoration. These impacts include various forms of pollution, restrictions on flows and exchanges of organisms and materials from the surrounding landscape caused by economic development of any sort, and other externally imposed problems of human origin. The kinds of manipulations that were needed to restore an ecosystem may have to be continued as ecosystem management after that ecosystem has been restored. Prescribed fire is a prime example, whereby several fires may be needed to remove woody growth and accumulated litter to restore an ecosystem, and more fires are needed in the future as ecosystem management to prevent the woody growth and litter from recurring and building up to undesirable levels. Controlled grazing by ruminants, or another appropriate proxy treatment in certain contexts, is another example of worldwide significance with myriad potential local applications. Ecosystem management can be conducted to manipulate the ecosystem—restored or undisturbed—in a manner that emulates a prior state (i.e., with historic fidelity). In other words, an impaired ecosystem is restored to a potentially self-sustainable state and thereafter is managed in a manner intended to achieve a predetermined target or to maintain a desired trajectory. Achievement of that target or trajectory is a function of ecosystem management; it is not ecological restoration. Instead, it is the imposition of planned and intentional active management on an ecosystem that has already undergone restoration. During this postrestoration phase, ecosystem management can and should help the ecosystem to respond to current environmental conditions and to its own internal processes within the evolving landscape and socioeconomic matrix (see Figure 5.5).
17_ch09:IP_Clewell
132
9/17/07
11:35 AM
Page 132
structure of an emerging profession
Rehabilitation, Reclamation, and Revegetation The SER Primer stated that “rehabilitation emphasizes the reparation of ecosystem processes, productivity and services, whereas the goals of restoration also include the re-establishment of the pre-existing biotic integrity in terms of species composition and community structure” (SER 2002:12). Rehabilitation has been the favored term in Europe and Australia for intentional ecological improvements to landscapes and remains in common use, despite recent acceptance of restoration in the North American sense. Rehabilitation resembles restoration in that both generally take a predisturbance ecosystem or landscape as a reference for the orientation of interventions to halt degradation (Aronson et al. 1993a). However, the European approach tends to rely less on a historical and ecologically mature reference system than in North America (Moreira et al. 2006). The reason is that Europe has no “original,” predisturbance ecosystems available for reference purposes because all ecosystems and landscapes have been altered substantially and repeatedly by human activities. Rehabilitation has also been the term of preference for many studies of grasslands, arid rangelands, and grassy woodlands that are prevalent in Australia (Noble et al. 1997) and elsewhere, particularly for those who apply a regeneration model to land management as opposed to a historic reconstruction model (McDonald 2005). The regeneration model uses different grazing regimes and fire to encourage native range grasses and discourage encroachment by undesirable shrubs and exotic plant species, thereby improving function (Prober and Thiele 2005). Historic reconstruction is hampered by a lack of reference sites that have escaped two centuries of livestock grazing by ranchers whose ancestors emigrated from Europe. Evidently, the original grassland environment was quite heterogeneous (Noble et al. 1997). The intentional return of habitat heterogeneity, coupled with control of nonnative species, judicious use of fire, and modest grazing pressure, might be a reasonable strategy for accomplishing ecological restoration. In other words, much rehabilitation in Australia readily qualifies as holistic ecological restoration. Rehabilitation has also been a favored term everywhere by those who work on aquatic ecosystems, probably because the composition and structure of submerged ecosystems ordinarily are obscured from view. The definition of ecological restoration adopted by SER (2002) and restated at the beginning of Chapter 1 encompasses much project work that has been called rehabilitation (see Lamb and Gilmour 2003). This book adopts and further clarifies that position; however, some projects remain that fail to qualify as restoration because of their disconnection from a historic trajectory—real or assumed—and from a reference model that is based on an extension of that trajectory in a manner that may accommodate contemporary conditions and presumed constraints of the future. Such work improves ecological processes and services and therefore should be considered rehabilitation. Notably, in both Spanish-speaking and Portuguese-speaking countries, especially in Latin America, a very common term for the kinds of projects discussed here is recuperation. The meaning in Spanish and Portuguese is very similar to rehabilitation in the sense we use. Reclamation is an older term to designate the conversion of lands perceived as being useless to a productive condition, commonly for agriculture and silviculture. Recovery of productivity is the main goal. However, the original sense of the word, re-claim-ation, implies recuperating or taking back something, generally land, from nature. This is done by and for the use of people. In the Netherlands, for example, where seawalls were built along the entire
17_ch09:IP_Clewell
9/17/07
11:35 AM
Page 133
Relationship of Restoration to Related Fields
133
coastline in the thirteenth century, the goal was to protect former salt marshes and other tidal lands that were “reclaimed” from the sea starting in the seventh century BC (Bakker and Piersma 2006). There and elsewhere, natural tidelands and freshwater wetlands were reclaimed by drainage or filling and the establishment of temporary dikes and embankments to halt or reduce tidal impacts and increase agricultural land and pastures for livestock. Notably, this process is being reversed in the Netherlands, England, and elsewhere in order to restore natural wetlands for “nature development” and to reduce pollution arising from intensive agriculture. To take another example, the pits created by opencast surface mining often are “reclaimed” by backfilling with overburden spoils or with tailings that were discarded during mining processes that isolate ores or other economic products from dross. The backfilled areas are commonly revegetated with native or exotic plants and used in a variety of ways. Indeed, in some countries, such as the United States, reclamation laws require that physically reclaimed land be stabilized and vegetated with grasses and legumes or another cover. Regard for public safety and health are also factors in reclamation designs, but without concern for a historical reference. To further add to the confusion, the term reclamation is also applied to the ecological engineering of urban or industrial aquatic systems (i.e., as the reconditioning of wastewater for productive use). Imprecise use of language of this sort, and that cited in the next section, is rampant not only in the field of ecological restoration but also in the emerging area of carbon credits and trading. Readers should be aware of the ambiguities and pitfalls in such technical shorthand and technocratic jargon and try to remain focused on the goals of environmental protection and ecological restoration. As does the SER Primer (2002), we recommend avoiding the ambiguous term reclamation in preference for simpler, clearer ones. For example, much intentional greening or regreening of physically modified reclaimed land qualifies simply as revegetation with a cover crop, afforestation or reforestation with one or a few tree species, and sometimes rehabilitation that involves a somewhat more sophisticated effort. For example, along public and private highways around the world, increasing attention is being given to revegetation and landscaping, specifically with native species in some places, so as to achieve aesthetically pleasing corridors for the motorists to enjoy and retention of topsoil along vast expanses of artificially sculpted roadside embankments. A few instances are known in which ecological restoration is announced to be the ultimate goal in mine site or roadway revegetation. The use of the term can be quite ambiguous in these settings. However, a physically reclaimed mine can indeed serve as a suitable site for holistic ecological restoration, as is evident in Virtual Field Trip 7.
Compensatory Mitigation Mitigation is the term used by public agencies in the United States and some other countries to describe an action of compensation for expected or incurred losses of environmental values resulting from activities undertaken for economic development or public works. The full term is compensatory mitigation, and it may be legally satisfied by revegetation, reclamation, rehabilitation, restoration, or other kinds of project work, as prescribed in permits that authorize the development or public works activities. It is common usage to say that a site has been mitigated. However, the term mitigation should not be used to refer to work that is
17_ch09:IP_Clewell
134
9/17/07
11:35 AM
Page 134
structure of an emerging profession
conducted at a project site because mitigation is only a tactic or strategy that literally aims to make milder or less severe the deleterious impacts of an intensive land use. It would be more accurate to say that mitigation requirements were satisfied by rehabilitation or other kinds of project work. In the manner that mitigation is currently used, the compensation does not mitigate or lessen the impact. Instead, it lessens the effects of environmental damage, commonly after the fact. Compensatory mitigation is sometimes used to refer to the long-term preservation of ecologically valuable lands that would otherwise be subject to development, which does not make milder or less severe the impacts that were allowed to happen. Again, this is a misleading use of technical jargon.
Creation Creation, or the intentional replacement of an ecosystem with another that is intended to be of greater value, has been a common strategy for satisfying compensatory mitigation requirements. Generally, uplands are scraped down with earthmoving equipment to intercept the water table so that a project site becomes a wetland. Then the site is revegetated with wetland species. Many attempts at wetland creation have failed, and creation is not prescribed nearly as often as in the past (National Research Council 1992). Some creation can qualify as ecological restoration on the assumption that earthmoving represents a contemporary condition that was legally mandated and that lay beyond the control of the practitioner. Even so, many created sites feature abrupt transitions from their surrounding landscapes, which deter normal flows and exchanges of organisms and materials. Many such sites may not qualify as holistic ecological restoration for that reason, and they would be more aptly designated by another term, such as rehabilitation. In the absence of a code of ecological nomenclature, comparable to those used in plant and animal taxonomy, we anticipate the mixed usage of terms to designate borderline restoration projects to continue in the future. We recommend that authors who designate projects as restoration should make some effort to equate and justify their work with the tenets of holistic ecological restoration, as summarized in the last chapter of this book. Expressed intent can overcome doubt.
Landscape Architecture and Design In Chapter 6 we discussed the term design vis à vis strategy and mentioned the increasingly intimate relationship between ecological restoration and landscape architecture. Indeed, when landscape or ecosystem design is done with nature and ecological design is the goal, there is much room for synergy and collaboration. However, we urge practitioners to avoid confusion in the terms used. The same problem occurs with regard to ecological engineering.
Ecological Engineering In the SER Primer (2002:12), we wrote that “ecological engineering involves manipulation of natural materials, living organisms and the physical–chemical environment to achieve specific human goals and solve technical problems. It thus differs from civil engineering, which
17_ch09:IP_Clewell
9/17/07
11:35 AM
Page 135
Relationship of Restoration to Related Fields
135
relies on human-made materials such as steel and concrete.” The evolving relationship between ecological restoration and ecological engineering remains somewhat murky in academia, where these sister disciplines sometimes appear as quarreling siblings. However, in realworld situations, practitioners are working in both fields simultaneously and making substantial contributions toward ecological improvement and human well-being. Ecological engineering was first proposed a generation ago by innovative and highly influential ecologist Howard T. Odum (1924–2002). He contended that many problems that are ordinarily resolved by civil engineering with the use of inert materials could be resolved effectively and much less expensively by use of biological materials—organisms—in a manner that relied on ecological principles and processes. Odum was personally engaged in developing ways to treat and recycle wastewater—mainly sewage effluent—in wetlands to remove suspended solids, excess nutrients, infectious organisms, and contaminants. This application of ecological engineering remains its crowning achievement and will only grow in importance as potable water supplies continue to decline globally. The field of ecological engineering developed in parallel and concurrently with the field of ecological restoration. Its principal membership association is the International Society of Ecological Engineering, which publishes the journal Ecological Engineering. Former students of H. T. Odum have been in the forefront of its development, notably eminent wetland ecologist William Mitsch of Ohio State University. The field has not been embraced unconditionally by traditional engineering fields and by civil engineers, whose mathematical precision and long history of preeminence cannot be matched by the “messy” introduction of living organisms by “upstart” ecologists. Recent acceptance by some ecological engineers of unpredictability, resulting from nonequilibrium dynamics, probably will perplex civil engineers even further. Ecological engineers have responded by going to great lengths to demonstrate that ecological science is as well founded and rigorous as that of traditional engineering. For example, Mitsch and Sven Jørgensen (2004), in their important book Ecological Engineering and Ecosystem Restoration, made the point repeatedly that ecological engineering is predicated on the principles of system ecology. This proposition may be true for wastewater treatment but not for most applications of ecological engineering that were enumerated by Patrick Kangas (2004) in his equally valuable book Ecological Engineering: Principles and Practice. Most of these were agronomic or silvicultural applications (soil bioengineering, bioremediation, phytoremediation, compost engineering), bioassay techniques (ecotoxicology), and advanced forms of food production (aquaculture, hydroponics). Kangas (2004) also listed wastewater treatment, wetland mitigation, and the reclamation of disturbed lands as applications of ecological engineering, and these are more readily identifiable with systems ecology but not necessarily with self-sustaining ecosystems. Some or perhaps many ecosystems designed or constructed under the aegis of ecological engineering are built to specifications that will facilitate or maximize ecological processes as the solution to a particular problem. Such ecosystems may include constructed civil engineering features (e.g., dikes, weirs, drainage tiles, culverts, pumps). They may need external subsidies of energy and materials, as would be typical of production systems. The installation of such ecosystems would rarely qualify as holistic ecological restoration. This in no way detracts from their usefulness and desirability, but they cannot be equated with holistic
17_ch09:IP_Clewell
136
9/17/07
11:35 AM
Page 136
structure of an emerging profession
ecological restoration. Nonetheless, we see many opportunities where engineered ecosystems can exist side by side with holistically restored ecosystems in well-functioning socioecological landscapes. For example, water discharged from land dedicated to agriculture could pass through a constructed wastewater treatment wetland for removal of contaminants and excess nutrients before entering a holistically restored ecosystem that provides many natural goods and services. When predictability is not at issue, the scope of many ecological engineering projects could be expanded until they qualify as restoration. Conversely, some authors argue that ecological restoration is really just a part of ecological engineering or that the two terms are synonymous or nearly so. Both Kangas (2004) and Mitsch and Jørgensen (2004) considered ecological restoration to be a subset of ecological engineering and not an independent discipline. We choose not to engage that contentious issue at this point. However, we strongly advocate that holistic ecological restoration be recognized by and evaluated according to the criteria stated in this book, including the use of a reference model based on a projection of the historic trajectory. In particular, we would not want ecological restoration to be identified with designer ecosystems that were constructed as expedients to fulfill narrowly conceived or short-term societal needs. Such projects address only selected elements of the objective quadrants in the four-quadrant model described in Figure 8.3 and therefore are flatland exercises deficient in intrinsic value. Happily, the field of ecological engineering is evolving just as rapidly as ecological restoration. Proponents of both fields are increasingly recognizing the realities of nonequilibrium and nonlinear dynamics in the ecosystems with which they are concerned. The notion of using nonhuman “ecological engineers” (Jones et al. 1994) as helpers and role models (Rosemund and Anderson 2003) in ecological design and restoration is encouraging. In closing this section, we note that the term ecological engineering is actually a metaphor. It is not really engineering. Instead, it is applied ecology of a sort that performs practical services for people in a manner that is superior to and less expensive than traditional engineering. Ecological engineers are simply offering a better service to the public than traditional engineers, and the latter should be seeking training in ecology if they are to remain competitive. Similarly, ecological restoration is really a metaphor that seems to capture the imagination of people of all cultures (and seems at times to be at risk of becoming a meaningless buzzword through misuse and overuse [Munro 2006]). Ecological restorationists do not restore; they restart, revitalize, reorient, or accelerate inherent ecological processes. Both fields have suffered from taking their metaphoric designations too seriously.
Restoration of Natural Capital Ecological economists combine biodiversity, ecosystems, natural landscapes, and the renewable and nonrenewable natural resources they contain under the rich and stimulating term natural capital. Jurdant et al. (1977) initially used that term in a report to the Quebec regional government, and Costanza and Daly (1992) introduced the concept to a large readership that embraced it. Natural capital is the fundamental assets on which all human societies and economies depend. The flows of natural goods and services that accrue from these stocks of natural capital are equivalent to the interest that accumulates from financial capital. For ease, economists commonly do not distinguish natural goods from natural services and desig-
17_ch09:IP_Clewell
9/17/07
11:35 AM
Page 137
Relationship of Restoration to Related Fields
137
nate all of them as natural services. Production systems and many abandoned lands represent natural capital; however, the array of natural goods and services in them generally is much smaller than those accruing from natural and cultural ecosystems. Stocks of natural capital, like those of financial capital, should be managed conservatively. Instead, most stocks are exploited for short-term gains that enrich the affluent at the expense of the needy. Stocks of natural capital already are too low to sustain the well-being of increasingly large numbers of people on Earth (Sanderson et al. 2002; Wackernagel et al. 2002). Some consequences of insufficient natural capital are hunger, deteriorating public health, political unrest, social chaos, warfare, genocide, and the embrace of fanaticism as the only available antidote. The restoration of ecosystems and other forms of natural capital becomes an obvious and essential remedy for this predicament (Clewell 2000; Clewell and Aronson 2006). Demographic increase and growing rates of per capita consumption promise to worsen the situation, which makes the need for restoration even more imperative. Comprehensive studies on the ecological footprint made by humans (Wackernagel and Rees 1996; MA 2005) compellingly show the increasingly essential need for both nature conservation (De Groot 1992; Balmford et al. 2002) and ecological restoration of degraded ecosystems for our well-being and perhaps our very survival. Only a few clear statements have been issued that address the urgent, pragmatic need to conduct ecological restoration (Cairns 1993; Clewell 2000). These calls have largely gone unheeded, despite their compelling importance for an international constituency. But the weight of the arguments and the attention paid to them are growing rapidly, as summarized in Aronson et al. (2007a) and described in articles intended for broad audiences by Paddy Woodworth (2006a, 2006b). Few restoration projects have been initiated ostensibly to recover losses of natural capital, such as those of Daniel Janzen in Costa Rica (see Janzen 2002 for an overview), Sue Milton (e.g., Milton et al. 2003), and David Tongway, John Ludwig, and co-workers (e.g., Ludwig et al. 1997; Tongway and Hindley 2004; see Virtual Field Trip 1). Ecological economists recognize the fundamental importance of ecosystems, from a single locale to the entire Earth, as the basis for all human economies. This understanding renews a tradition that was central to economic theory and application in the eighteenth and nineteenth centuries but was somehow lost in the twentieth century. Ecological economists have their own international society and journal, and they have developed a large and rapidly growing literature that we will not review here. Instead we concentrate on the necessary and urgent synergy of ecological economics, ecological restoration, and ecological engineering in the restoration of natural capital. RNC includes a range of core concepts, either directly or by inference, and activities, as follows: • Recognizing natural and seminatural systems as stocks of natural capital, including natural and cultural ecosystems and production systems devoted to agriculture, aquaculture, silviculture, and so on • Investing in stocks of natural capital that underwrite RNC ventures, including public, private (for-profit), and nongovernment organization (not-for-profit) investments • Augmenting stocks of natural capital through ecological restoration in a holistic sense; rehabilitating degraded production lands to improve their utility, such as preventing
17_ch09:IP_Clewell
138
9/17/07
11:35 AM
Page 138
structure of an emerging profession
soil erosion; eliminating soil compaction and increasing soil organic matter; establishing cover crops and nitrogen-fixing vegetation; eliminating the causes of desertification and salinization (Harris et al. 1996; Hobbs and Norton 1996; Whisenant 1999; Bainbridge 2007); and implementing all other appropriate technology offered by environmental engineering such as wastewater treatment, phytoremediation, and bioremediation (Kangas 2004) • Reintegrating fragmented landscapes in order to conserve biodiversity (e.g., corridors to connect existing conservation areas, setaside nature reserves) and to improve landscape resilience and sustainability (Hobbs and Saunders 1991, 1992) • Creating novel ecosystems that serve human needs in locations where ecosystems cannot be restored to a reference model for ecological or pragmatic reasons (Mitsch and Jørgensen 2004; Kangas 2004) • Planning for and encouraging the implementation of best management practices to protect and maintain natural capital stocks and to augment flows of natural goods and services • Restoring social capital with relevance to natural capital in order to increase public awareness of the flows of natural goods and services, to increase public respect for natural capital, to increase public appreciation for and participation in RNC activities, to distribute natural goods and services equitably, and to extract and use natural goods and services on a sustainable basis across generations We define RNC succinctly as the replenishment of natural capital stocks in the interests of long-term human well-being and ecosystem health. RNC is a broader concept than ecological restoration. Whereas the focus of ecological restoration is biological diversity and repairing self-organizing or “natural” systems with a specific reference model in mind, the emphasis of RNC incorporates all investments in natural capital stocks and their maintenance in ways that will improve the functions of both natural and human-managed ecosystems within landscapes while contributing to the socioeconomic well-being of people. Thus, RNC activities may include the holistic restoration of ecosystems and ecologically sound improvements to arable lands and other lands that are managed as production systems for useful purposes, improvements in the ecologically sustainable use of biological resources, and the establishment or enhancement of socioeconomic systems that facilitate the incorporation of knowledge and awareness of the value of natural capital into daily activities (Aronson et al. 2007b). Projects for RNC generally concentrate on improvements in socioecological landscapes, in contrast to ecological restoration, which is concerned primarily with natural and semicultural ecosystems. This difference in focus generally helps to distinguish ecological restoration from RNC, although exceptions exist. Some advocates of the restoration of ecosystems who are motivated by a biotic rationale, as explained by Clewell and Aronson (2006), and whose attention lies with the perpetuation of biodiversity may raise a concern here. They may argue that RNC’s human-centered focus obscures an essential tenet of the restoration and conservation movements: that ecosystems and all the processes and species they contain are worth restoring and preserving for their own sake, regardless of their economic (or other) value to people. Although we disagree with
17_ch09:IP_Clewell
9/17/07
11:35 AM
Page 139
Relationship of Restoration to Related Fields
139
their premises, as we explained in Chapter 3, we fully share their conclusions that ecosystems and species are worth restoring and preserving in accord with the principle that nature sustains us (Leopold 1949) and fulfills our values. However, our experience in less affluent parts of the world has shown that ecological restoration will not be appreciated or financed unless it benefits people directly. The intriguing and—for some—controversial term RNC was suggested by Cairns (1993) and further developed by Clewell (2000), Milton et al. (2003), Aronson et al. (2006a, 2006b, 2006c), and Aronson et al. (2007a). In this approach, restoration becomes a development strategy even more than a conservation tool. RNC has the advantage over ecological restoration per se of facilitating discourse and cooperation between ecologists and economists as they address the problems we face on this increasingly crowded planet. The importance of addressing pragmatic concerns in less affluent regions of the world requires restoration practitioners to approach their craft from the perspective of RNC. As indicated earlier, restoration and rehabilitation are not the only ways to develop these pathways. Conservation, the rational management of natural resources and anthropogenic systems, and reductions in rates of human reproduction and per capita consumer demand remain crucial. We advocate that restoration practitioners in less affluent regions also consider themselves RNC practitioners and that they be prepared to work simultaneously in both fields. Academic programs that train practitioners should include technical and conceptual instruction and hands-on training in RNC.
Sustainability Science Sustainability science is the study of the dynamic interactions between nature and society. The ultimate goal of sustainability science is to create and apply knowledge in support of decision making for sustainable development. The application of research in sustainability science is to resolve specific problems in an appropriate and effective manner (Clark and Dickson 2003; Kates et al. 2001). Like the terms mitigation, reclamation, and carbon trading, the word sustainability is subject to many interpretations, and a great deal has been written on the subject of its use and misuse. Yet it is a powerful word that is intimately connected with another word beginning with the same letter: survival. An enormous step forward toward human well-being and world peace would be for local and national economies everywhere to cease pursuing the kind of accelerated economic growth that seems to have become the goal nearly everywhere. Instead, some observers, including “hardnosed” economists (e.g., Daly and Cobb 1994), have recommended promptly changing course. Instead of promoting unsustainable growth, in today’s ever more crowded world we should manage economies to become stabilized and remain that way for subsequent generations (Costanza and Daly 1992; Daly and Farley 2004). This vision requires the conservation and wise use of natural resources (Young 2000) and an important admixture of RNC. As suggested in the previous section, the restoration of impaired ecosystems and production systems will increase the flows of goods and services for people and economies while creating jobs, livelihoods, and increased social capital. The obstacles to this radical change are gigantic. Ecological restoration and, more broadly, RNC should be recognized as central strategies of sustainability science. It is also important to
17_ch09:IP_Clewell
140
9/17/07
11:35 AM
Page 140
structure of an emerging profession
recognize and embrace the reality that the role of science is changing in the areas of human ecology and the environment in a way that compels natural and social scientists to work together and by doing so to narrow the academic and cultural distinction—or chasm— between them.
18_VFT7:IP_Clewell
9/17/07
11:36 AM
Page 141
VIRTUAL FIELD TRIP 7
Restoring Dogleg Branch in Florida, USA Andre F. Clewell
In Florida, a short headwater tributary to the Alafia River called Dogleg Branch and a 120meter-wide corridor of riverine mixed hardwood forest through which it flowed were removed in large part during opencast mining for phosphate ore. The State of Florida required reclamation to return the mined land to its approximate original elevation and contours and to replace the stream. Restoration of 8 hectares of forest was required as mitigation on the reclaimed land. This was the first forested wetland restoration in Florida to be required for satisfaction of a permit condition. Andre Clewell was the principal restoration practitioner. The reference model was a composite of data from ecological inventories of the forest along Dogleg Branch before mining and of similar forests along several other headwater tributaries nearby (Clewell et al. 1982). Opencast mining for phosphate in central Florida removes mostly sandy overburden to a depth of at least several meters above a matrix of phosphate-rich pebbles, sands, and clays that are extracted for processing (VFT Figure 7.1). The mined-out pit at Dogleg Branch was backfilled with overburden spoils and the surface covered by topsoil that had been removed from the original forest and stockpiled. Nursery-grown native trees about 0.5 meter tall were planted as soon as land reclamation was complete. In addition, mature cabbage palms (Sabal palmetto) from the original forest were transplanted. These are seen in VFT Figure 7.2 in the next year, which was designated as Year 1 of restoration. In addition, trees and undergrowth arose from the propagule bank in the salvaged topsoil. In Year 7, the planted trees had grown in height, as shown in VFT Figure 7.3, and were beginning to form a closed canopy. At this time, a few plants each of many species of native forest herbs and shrubs were transplanted among the young trees. Some transplants had been nursery grown, and most were directly transferred from unmined forest nearby. By Year 17, a maturing forest had developed (VFT Figure 7.4). The crown of one of the transplanted cabbage palms appears prominently in the center of the photo. The interior of the restored forest, shown in VFT Figure 7.5, lies close to the replacement stream. Saplings of Magnolia virginiana that appear prominently in the right foreground of VFT Figure 7.5 had grown from seeds produced by trees that were planted as nursery stock in Year 0. VFT Figure 7.6 shows the original forest along Dogleg Branch several days before it was cut down in preparation for mining and can be compared with the restored forest in VFT Figure 7.5. 141
18_VFT7:IP_Clewell
142
9/17/07
11:36 AM
Page 142
structure of an emerging profession
VFT Figure 7.1. Opencast mining for phosphate.
VFT Figure 7.2. Reclaimed land and initial tree plantings, Year 1.
The restoration project site was intentionally overplanted, relative to its reference model, with additional species of trees and undergrowth that occurred in the composite reference model. Overplanting ensured that the restored forest would have a full complement of plant species and functional groups of plants relative to the land area that was restored and its degree of heterogeneity. Empirical comparisons between the restored forest and its reference model were presented by Clewell et al. (2000).
18_VFT7:IP_Clewell
9/17/07
11:36 AM
Page 143
Restoring Dogleg Branch in Florida, USA
143
VFT Figure 7.3. Forest development, Year 7.
VFT Figure 7.4. Forest development, Year 17.
The restored mesic forest along the outer edges of the Dogleg Branch restoration project site grew in a landscape position that had supported frequently burned pine savanna before mining. Prescribed burning was not anticipated in the postmining landscape. Consequently, pine savanna was not included in restoration plans. Fire-suppressed pine savanna in the vicinity is colonized by several species of fire-intolerant oaks (Quercus spp.) and other native trees that prefer fire-free sites. This oak woodland represents a radical change in the historic ecosystem trajectory (see Figure 5.4). Regional variation in species composition among oak
18_VFT7:IP_Clewell
144
9/17/07
11:36 AM
Page 144
structure of an emerging profession
VFT Figure 7.5. Restored forest interior, Year 20.
VFT Figure 7.6. Original, premining forest.
woodlands allowed latitude to introduce uncommon native plant species such the pignut hickory tree (Carya glabra), which is held by Andre Clewell in VFT Figure 7.7. The Dogleg Branch restoration project site is a landscape mosaic that includes mesic forest (VFT Figure 7.7), hydric forest (VFT Figure 7.5), and the replacement stream (VFT Figure 7.8). Limnologists with the State of Florida inventoried the restored Dogleg Branch in Year 14 and reported that it was comparable in its biota (benthic macroinvertebrates), water quality, and physical habitat conditions with nearby streams on unmined land that occupied the same landscape position (FDEP 1999).
18_VFT7:IP_Clewell
9/17/07
11:36 AM
Page 145
Restoring Dogleg Branch in Florida, USA
VFT Figure 7.7. Restored mesic forest.
VFT Figure 7.8. Replacement stream for original Dogleg Branch.
145
18_VFT7:IP_Clewell
146
9/17/07
11:36 AM
Page 146
structure of an emerging profession
Dogleg Branch restoration was a pilot project in which restoration techniques were attempted in the spirit of intelligent tinkering. Some worked well and others poorly, if at all. For example, cabbage palm transplantation worked very well on mesic sites, and they produced copious seeds from which midstory trees have grown. However, cabbage palms planted in hydric sites soon died because of saturated soils. Other novel techniques were described and assessed by Clewell et al. (2000). Aftercare was needed to suppress the invasive nonnative grass Paspalum notatum, which was planted upslope as a pasture grass and whose seeds were repeatedly carried into the project site by surface runoff after rainfall.
19_ch10:IP_Clewell
9/17/07
11:37 AM
Page 147
Chapter 10
Project Roles and Contexts
In this chapter we describe ecological restoration projects from the perspective of their organization and structure. We begin with the roles various personnel play in the development and execution of a project. Then we provide an outline of project contexts or circumstances in which projects are conducted. The various contexts have different strengths and weaknesses, which we identify. We note how projects tend to change over time from being exploratory and experimental at first to refined and standardized later. This information will let students and entry-level personnel know what they can expect and where they may want to concentrate their talents as their careers begin. As the chapter progresses, we will present material of broader interest.
Project Roles Who sponsors restoration projects? Who administers them? Who makes decisions, and who carries them out? Every ecological restoration project requires personnel to fulfill certain roles, beginning with the project sponsor and continuing with the restoration practitioner, project director, restoration planner, and project manager. In small or uncomplicated projects, the same person may assume two or more of these roles. Organization charts may identify project personnel with other titles; however, each of these roles is filled by someone, regardless of his or her title. Every project has at least one practitioner and sometimes many. Larger sponsoring organizations may add other levels to the organizational table for a project, such as an administrator to whom the project manager reports. Project organization becomes even more complex as contractors and subcontractors are included, with their own hierarchies of personnel and departments with project responsibility. We ignore these complexities and describe the basic project roles in this section.
Sponsor The organization or entity that undertakes an ecological restoration project and assumes the responsibility for its accomplishment is its sponsor. A sponsor may be a government agency or a transnational organization; a for-profit firm or corporation; a nongovernment organization (NGO); a philanthropic foundation; a school, university, or research institute; a public 147
19_ch10:IP_Clewell
148
9/17/07
11:37 AM
Page 148
structure of an emerging profession
museum, arboretum, or zoological park; a professional association; a branch of the military; a monastery or other religious order; a tribal council of elders; a women’s self-help group, which are becoming increasingly common in India and Latin America; another kind of community-based organization (CBO); or an individual landowner or manager. The sponsor approves the restoration project, provides or attracts funding, assembles personnel who will accomplish the project, provides an administrative structure, and provides oversight to ensure its satisfactory completion. The project may be accomplished in house using the sponsor’s own employees or members, or some or all of the work can be delegated to outside individuals, consulting firms, or other organizations under contract, purchase order, or some other agreement to provide services. Labor can be provided by paid personnel or by volunteers who work without monetary compensation. To a restoration practitioner who is contracted, the sponsor is usually known simply as the client.
Practitioner A restoration practitioner is someone who personally conducts or supervises ecological restoration in the field at project sites. Specifically, practitioners engage in project implementation and aftercare. In many projects, practitioners additionally inventory a project site before the initiation of restoration activities, select and inventory reference sites, prepare project plans, conduct or supervise site preparation activities, and monitor project sites that have undergone restoration. In other projects, sponsors delegate these responsibilities to others. A practitioner can be an employee of an organization that is conducting ecological restoration or a consultant, contractor, subcontractor, or volunteer who is engaged by that organization. A practitioner may also be the owner of the property that is undergoing restoration. A restoration project may be accomplished by a single practitioner, or two or more practitioners who work collectively on all aspects or separately on different aspects of a project. The chief practitioner, if one is appointed, supervises other practitioners and is responsible for the overall conduct of on-site restoration activities. A practitioner may assume broad responsibilities and authority for conducting restoration or may serve as a technician who performs specific tasks assigned by a supervisor.
Project Director The project director is the person who has a comprehensive vision for the project, including its technical, social, economic, strategic, political, historical, and other cultural aspects and implications. The project director is superior in rank to the project manager and is responsible for the overall technical direction and leadership of a project. The project director is critically involved with the conception of a project and the development of project plans. The project director formulates or approves project goals and objectives and selects or approves reference models and strategies for accomplishing restoration. The project director receives briefings from the project manager and evaluates project monitoring reports and other technical documents that may be produced. The project director ensures that executive officers, accountants, legal counsel, and other administrative officers of the sponsoring organization understand the project and carry out their respective responsibilities. The project director represents the project before boards of directors, philanthropic foundations, public officials, stakeholders, and the general public or delegates these duties to others.
19_ch10:IP_Clewell
9/17/07
11:37 AM
Page 149
Project Roles and Contexts
149
Restoration Planner The restoration planner (or a planning staff) prepares project plans, including maps, drawings, and written instructions as needed. Ideally, the practitioner contributes substantially to the planning process or even serves as the planner, as commonly happens on smaller projects that do not entail many government permits or outside contractors. The degree of detail in project plans may vary widely between projects, depending on project size and complexity and on the requirements of the sponsoring organization. Much detail may be required by government agencies whose approval is needed before project implementation. Project plans typically are appended to permits and are carried out as a permit condition. Detailed plans are also useful for preparing contract stipulations that are to be followed by the firm that provides practitioner services to the sponsoring organization. Penalties that affect monetary compensation are prescribed if contractors fail to comply with contract stipulations. In such instances, the planning function may include legal as well as technical capacity.
Project Manager In most projects, restoration practitioners are supervised and report to a superior who is either the project manager or someone who fulfills that role. The project manager is responsible for ensuring that a given restoration project is conducted satisfactorily on behalf of the sponsoring organization. The project manager administers day-to-day operations such as scheduling personnel, arranging for deliveries of planting stocks and equipment, ensuring adherence to contract stipulations, and approving expenditures. Sometimes the practitioner does most of this work, and the project manager ensures that it is accomplished. Another firm or organization that has been engaged to provide restoration services under contract sometimes appoints its own project manager. In such instances, the two project managers may communicate with each other, and practitioners receive directions primarily from the project manager in their own firm. Satisfactory restoration projects require that the practitioner and the project manager remain in close communication, more so than in construction projects, where tasks with more predictable outcomes are conducted. The success of many restoration projects depends on manipulating living organisms of different kinds, and the chances for surprise are much greater. The practitioner must react to unanticipated situations to ensure the success of the project. The project manager is obliged to ensure adherence to schedules, budgets, and contract stipulations, which may not allow for contingencies. In such instances, the practitioners should educate project managers and provide succinct information and persuasive logic that the managers can use effectively when interacting with people at higher administrative levels. We cannot overstate the importance of respectful and cordial relations between practitioner and project manager, particularly in ecological restoration projects of long duration.
Project Contexts The context of a restoration project consists of the circumstances under which it is conducted. The administrative structure of a project is the most important aspect of context. Other factors contributing to it are the availability of funding, labor, equipment, and materials such as planting stocks. Project site accessibility and seasonal constraints (e.g., inclement
19_ch10:IP_Clewell
150
9/17/07
11:37 AM
Page 150
structure of an emerging profession
weather) can also influence the context, as can regulatory and legal constraints. We emphasize administrative structure in the ensuing discussion. The ways in which different projects are administered vary widely. Project administration determines the degree of responsibility that the restoration practitioner is given, the amount of authority that the practitioner is allotted, and ultimately the flexibility that the restoration practitioner can apply to solve problems that arise. The North Branch Prairie project and the Dogleg Branch project illustrate two extremes in project administration and context. The North Branch Prairie project was described in Miracle Under the Oaks by William Stevens (1995) and critiqued by Peter Friederici (2006). The Dogleg Branch project is described in Virtual Field Trip 7. The North Branch Prairie project was initiated in 1977 by Steve Packard and a small group of environmental activists near Chicago, Illinois. Packard approached a public official in the Cook County Forest Preserve District and asked whether they could volunteer to clean up trash, cut some brush, scatter some seeds, and generally refurbish degraded prairies that the district owned. District personnel had wanted to begin such work themselves but were hampered by a lack of funds, and they accepted Packard’s offer. The work began and soon attracted other volunteers. The idea of restoring Chicago’s former ecosystems spread like a prairie wildfire. Soon, hundreds of citizens were spending their free time working along side Packard, essentially without plans or administrative structure. By 1993, more than 3,000 volunteers had restored more than 6,700 hectares of degraded prairie and associated oak savanna in an amazing display of civic altruism. Compare the North Branch Prairie story to that of the restoration of forested wetlands in the headwaters of Dogleg Branch on surface-mined and physically reclaimed land in Florida, described in Virtual Field Trip 7. That project required two years of work simply to obtain the required government permits. Permits were eventually issued after the mining company had conducted a four-year pilot project to demonstrate that native trees could be grown and a two-year ecological inventory of local forested wetlands that served as reference sites (Clewell et al. 1982). Professionals who were involved in the project included mining engineers, mine planners, environmental consultants, native nurseries, project managers, heavy equipment contractors, attorneys, top officials in state government, and large support staffs that produced many reams of paperwork. The project was a very costly and wellorchestrated production in which the actual restoration work at the project site seemed like an afterthought. The contrast between the North Branch Prairie and Dogleg Branch projects could scarcely have been greater. They demonstrate extreme examples of the contexts in which restoration practitioners find themselves working. There is no preferred way to organize, plan, and implement restoration projects. The particular circumstances for a project determine its context. The underlying difference between the North Prairie Branch and Dogleg Branch projects was that the former was an elective project, whereas the latter project required prior government approval. Let’s look at these two projects from the perspective of the restoration practitioner. At North Branch Prairie, almost everyone involved was a restoration practitioner. Steve Packard assumed the role of project director, and he and several others assumed the collective role of project manager as well. The Cook County Forest Preserve District was nominally the sponsor, and its personnel provided skeletal administration. Packard referred to existing ecological
19_ch10:IP_Clewell
9/17/07
11:37 AM
Page 151
Project Roles and Contexts
151
literature, a general knowledge of the few remnant patches of prairie and oak savanna, and the species list of an early naturalist as references and as an indication of historic trajectory. They essentially developed project plans as they worked on site. Their administrative mode was collegial. In other words, Packard and the other practitioners who worked most closely with him made project decisions by consensus. They assumed almost total responsibility for all restoration work. The Cook County Forest Preserve District retained basic authority for the project because the project took place on lands under their jurisdiction. District personnel established the bounds for project work to ensure that it was legal and complied with the district’s overall mission. Otherwise, Packard and his cadre assumed authority for project operations. In this context, the practitioners enjoyed broad flexibility to conduct the project as they saw fit (Packard 1988, 1993). The North Branch Prairie project was a grassroots, bottom-up endeavor that was not mandated by a public agency. Instead, the Cook County Forest Preserve District benefited from the broad public support of hundreds of citizens who volunteered their free time as restoration practitioners. This was a marvelous example of people taking collective responsibility for their own concerns in a manner that nicely reflects the four-quadrant model of ecological restoration (see Chapter 8). Ecological values were fulfilled directly by the restoration. The motivation for many volunteers was the fulfillment of individual values such as reconnecting with nature and responding to environmental crises, as described in Chapter 7. Public celebrations at the restored prairie were described by Holland (1994) and are among the evidence of the fulfillment of cultural values. The restored prairies and oak savannas represent natural capital and provide socioeconomic services. In great contrast, the Dogleg Branch project was conducted by only a few restoration practitioners, principally Andre Clewell and several colleagues. Because of safety and liability issues, no volunteers were invited or allowed on the property. The mining company was the sponsor, and its employees assumed the other roles of project administration, director, and project manager. Most were engineers. Detailed project plans were prepared by the company, which incorporated specific conditions that were required by permit from the State of Florida. These conditions, in turn, were based in part on a restoration plan written by Clewell that identified restoration goals, objectives, performance standards, and the reference model. The latter was embodied in the aforementioned document that described historic conditions and contemporary changes in the historic trajectory that were attributable to land use (mainly fire suppression that allowed broadleaved forest typical of river valleys to replace upland pine savannas). Much of the project work was conducted by earthmoving firms, tree planting crews, and other subcontractors hired by the mining company. The role of the restoration practitioner was largely to serve as a liaison with foremen of subcontracting companies, to test new restoration methods such as interplanting undergrowth species, to monitor forest development, and to suggest improvements to the restoration process for approval by mine managers. The Dogleg Branch project was required by the State of Florida (primarily; other government entities were also involved) and was administered from the top down by the mining company. Stakeholder involvement was limited to formal hearings that were required by law, in which citizens could express their interests. Comments were largely limited to local residents who were concerned about mining operations near their properties and environmental organizations that were generally opposed to surface mining. The intent of the project was to
19_ch10:IP_Clewell
152
9/17/07
11:37 AM
Page 152
structure of an emerging profession
repair environmental damage that was an unavoidable result of mining rather than to cause net ecological improvements. No fulfillment of the personal, cultural, and socioeconomic values described in Chapter 7 was intended. In other words, this was a compensatory mitigation project. After this and other restoration projects on mine lands were complete, the land was donated to the State of Florida and became the Alafia River State Park, which was a cultural improvement. However, negotiations for the donation of the land were initiated after Dogleg Branch was nearly restored, and the restoration site has not yet been opened for public access. Dogleg Branch restoration is narrowly focused as a flatland project in terms of the four-quadrant model in Chapter 8 in that it satisfies ecological and socioeconomic elements that are expressed in state policy that presumably represents the sentiment of the electorate. However, a number of restoration techniques were tested during the course of Dogleg Branch restoration, some for the first time. The results were made available for use by restoration practitioners who toured the site, attended conferences where the project was described, and read published descriptions (e.g., Clewell and Lea 1990; Clewell et al. 2000). Even more importantly, the Dogleg Branch Restoration project, and several others that were initiated at that time (Clewell 1999), demonstrated that complex forest and stream restoration could be conducted on land that had been literally turned upside down by mining. In this regard, the Dogleg Branch restoration project changed the perceptions of people who had not previously realized the potential of ecological restoration. This and similar restoration work has had the salubrious effect of hastening the era of ecological restoration and providing jobs for many practitioners in Florida and elsewhere. However, it has also given regulated interests a rationale for convincing government agencies to issue permits for development that will cause environmental damage with the promise that the damage will be compensated by ecological restoration as a form of mitigation. This strategy could be justified if regulated interests were required to successfully restore more than they damaged, but this eventuality awaits documentation as a normally occurring outcome. We hope that restoration practitioners will be more than battlefield physicians in the environmental wars.
Kinds of Contexts To our knowledge, no one has ever offered a systematic classification of contexts for ecological restoration projects. As a preliminary contribution, we will recognize four general contexts called the collegial, technocratic, bureaucratic, and autocratic contexts. We propose the term collegial context for projects such as the North Branch Prairie restoration, where project decisions are made in a collegial manner by consensus between practitioners (or some of them) and where practitioners assume much responsibility and at least some authority and have flexibility. We propose the term technocratic context for projects such as Dogleg Branch restoration, where the administration is top down and driven by legal mandates or contractual stipulations that must be fulfilled and where practitioners have almost no authority. Their responsibilities are rigidly prescribed, and they have little or no flexibility as they perform project tasks. Actually, practitioners did enjoy greater flexibility in the Dogleg Branch project than is ordinarily the case, because of the experimental nature of that project. We recently introduced the term technocratic as a motivation for conducting ecological restoration rather than as a context (Clewell and Aronson 2006). The autocratic context is easily described. It pertains to the few restoration projects that are conducted by one person—a restoration practitioner—who owns or controls the land,
19_ch10:IP_Clewell
9/17/07
11:37 AM
Page 153
Project Roles and Contexts
153
perhaps with the help of a few employees or some subcontractors who work at the discretion of the practitioner. In the United States, several owners of cattle ranches have converted rangeland back into native grassland, removed most domestic livestock, and dedicated the land to biodiversity conservation. They derive income from the land by leasing it for recreational hunting. These are examples of the autocratic context. Other autocratic restoration has occurred as people have transformed their backyards into native ecosystems. In the autocratic context, the practitioner serves as the project administrator, director, planner, and project manager and has complete authority for making all decisions and thus complete responsibility and flexibility. The bureaucratic context is by far the most common context for ecological restoration and also the most variable. The context derives its name from the fact that restoration practitioners are engaged by a hierarchical organization in which they occupy a particular position in the table of organization. The organization can be public or private, for profit or nonprofit. It can be a government agency that is charged with the management or protection of natural resources, such as a public park. It can be an NGO or CBO with interests in conservation. It can be a private company with land holdings, some of which could be made available to the public as a gesture of good will or as a profit-making venture. It can be a tribal village with common lands that are restored. Restoration practitioners who are engaged in the bureaucratic context may be employees, consultants who work under contract, members of NGOs and CBOs who volunteer their services, or members of a tribal village who participate in restoring common lands. Individual practitioners in the bureaucratic context do not have much authority in the administration of a project. The authority is vested in the leaders of the organization with which they are associated. In a national park, the authority would be held by the park manager or perhaps by administrators at a higher regional or national level. In a tribal village this authority may be held by the tribal elders. Practitioners have some degree of responsibility and, with it, at least some flexibility for resolving project problems on their own initiative. In this regard, they have more flexibility than they would in the technocratic context but less so than in the collegial and autocratic contexts. The distinction between contexts is not always clear. The collegial North Branch Prairie project had a touch of bureaucratic context in terms of the constraints imposed by the Cook County Forest Preserve District. Probably all projects with a collegial context have a modicum of bureaucratic control. Many projects that are sponsored by large organizations, such as those funded by the European Union, can be decidedly technocratic, even though they may be development projects or environmental improvement projects rather than compensatory mitigation. In these projects there can be little room for practitioner flexibility. Instead, the practitioner is relegated to ensuring that detailed plans are executed with precision, and the practitioner may have had no input into the planning process. The practitioner would be more aptly called a technician or technocrat rather than a practitioner.
Evolution of Contexts Ecological restoration has experienced a number of births as a discipline, each one representing a distinctive landscape, geographic location, organizational setting, or industry. It is not as if the entire field of ecological restoration were being reinvented. Instead, it is as if the idea of restoration were borrowed and refitted for use in a different situation. For example,
19_ch10:IP_Clewell
154
9/17/07
11:37 AM
Page 154
structure of an emerging profession
the phosphate mining industry in Florida and the peat mining industry in northern Europe adopted ecological restoration at about the same time and adapted it to their respective situations in a parallel manner on mined land. Ecological restoration in a holistic sense was first attempted in the Florida phosphate mining industry in 1978, when several restoration techniques for wetland ecosystems were fieldtested in small pilot plots. The work was encouraged by regulatory personnel who were searching for innovative ways to implement new state rules for mine reclamation by using native species. Initial results of the plot studies were encouraging (Swanson and Shuey 1980). Regulatory authorities began issuing mining permits that stipulated that wetland restoration be attempted. Several environmental consultants were hired by mining companies to test restoration methods at different project sites, among them the Dogleg Branch restoration site. Shortly thereafter, the Florida Institute of Phosphate Research (FIPR) was organized as a semiautonomous research and development agency for the phosphate mining industry and was funded from state severance taxes on phosphate ore. FIPR-sponsored conferences and research grants attracted academic personnel who provided scientific validation of these exploratory pilot projects. By about the year 2000, the strategies and techniques that worked well on former phosphate mines were developed and refined to the point that regulatory agencies could specify detailed prescriptions for restoration that led to reasonably predictable results. Before that time, much of the restoration work involved an experimental element similar to what Aldo Leopold (1949) called intelligent tinkering. In this manner, new restoration methods were attempted and older methods refined. Since that time, restoration has been reduced to applying well-tested methods in a uniform manner with a degree of certainty that approached that of construction projects. Project goals, reference models, and historic trajectories have been largely replaced by prescriptive permit criteria and performance standards. In short, the holistic ecological restoration of the past has been overtaken by a series of short-term ecological engineering solutions that use native species to recover aspects of ecosystem function (soil stability, water quantity and quality) and habitat for officially listed species of plants and animals. In northern Europe and parts of Canada, a comparable history evolved in the peat mining industry (J. Blankenburg, personal communication, 2006). Environmental concerns led to exploratory ecological restoration that was soon supplemented with ecological studies by university personnel. Strategies and techniques were refined until the process became a uniform ecological engineering exercise that is overseen by government authorities. Virtual Field Trip 6 describes university-sponsored research and development in peatland restoration. We see a trend in these examples from the phosphate mining and peat mining industries. This trend is driven in tandem by government regulators and regulated industries, both of which desire project brevity and uniformity and an empirical basis for determining project compliance with regulatory norms and eventual release from regulatory surveillance. Exploratory ecological restoration develops the basic strategies and techniques, ecological research and development refines them, and ecological engineers apply them thereafter. The process ensures a recovery of essential ecosystem services and some degree of recovery of biodiversity. The process is essentially a flatland exercise that addresses limited socioeconomic and ecological values and no personal and cultural values. The process also reflects current global attitudes in favor of rampant economic growth and development, as described by neo-
19_ch10:IP_Clewell
9/17/07
11:37 AM
Page 155
Project Roles and Contexts
155
classical economics, but tempered with mounting uneasiness about the consequences of resultant environmental degradation. Variations on this basic theme exist. For example, bauxite mining was causing much public concern in Western Australia because it was destroying jarrah (Eucalyptus marginata) forest. The mining industry recognized that the public outcry could force the closure of their operations, despite weaknesses in the regulatory process. In an outstanding display of corporate responsibility, the industry opted to regulate itself and develop a highly sophisticated restoration technology that emphasized biodiversity conservation and recognized some cultural values. Much attention has been paid to preserving biodiversity, to the point that a tissue culture laboratory was established to propagate rare plant species with low reproductive potentials. In this instance, industry efforts are identifiable with holistic ecological restoration.
Stewardship Models So far, we have emphasized what might be called industrial restoration, which is not typical of holistic ecological restoration but does provide the largest source of employment opportunities for restoration practitioners. From the standpoint of numbers of projects and the development of the field of holistic ecological restoration, environmental stewardship programs have been paramount. A steward is a caretaker. Environmental stewardship is the process of taking care of the environment. Many NGOs and some CBOs conduct long-term stewardship programs that consist of ecosystem management that sometimes includes ecological restoration. Volunteers commonly provide much of the labor, including practitioner tasks in restoration projects, as was described for the North Branch Prairie project. Sometimes restoration responsibilities are outsourced, at least in part, to firms that specialize in ecological restoration. Many stewardship projects are funded by contributions received from the members of NGOs and from philanthropic donations from foundations. Other funding is received in the form of grants from governments, transnational institutions, and larger NGOs. Other stewardship programs are conducted by public agencies whose mission is to protect and manage public lands, such as forest reserves, wildlife refuges, and parks. Financial support for these programs is provided as part of the appropriations of public funds to these agencies. Restoration projects may be conducted by employees of NGOs, CBOs, public natural resource agencies, or other organizations that sponsor stewardship programs. They may also be conducted by volunteers or more commonly by volunteers who work under the direction of employees. Other restoration projects may be outsourced to firms or private contractors who conduct most or all of the work, as happened in the project described in Virtual Field Trip 3. Common lands under the control of traditional cultures may undergo ecological restoration in the same manner. A tribal council of elders may be the administrative body, which consists of ordinary citizens who are respected for their age or sagacity. Restoration work may be performed by an entire community or tribe under the direction of the elders and as a form of community service. In the United States, such restoration sometimes is administered by federal land management agencies and contracted to Native American tribes that use public lands in a traditional manner (Anderson 2005). The context for most stewardship projects is bureaucratic, although a few are collegial or autocratic. The level of funding is quite variable between projects and commonly no more
19_ch10:IP_Clewell
156
9/17/07
11:37 AM
Page 156
structure of an emerging profession
than modest. Unlike the more technocratic projects that are driven by the expedients of regulatory agencies and regulated industries, there may be little concern for deadlines. Many projects are long term and ongoing. When ecological restoration is complete, ecosystem management begins seamlessly. Practitioners who work on such projects are inclined not to distinguish between restoration and management and to consider them inseparable. However, this leads to the conundrum mentioned earlier that an ecosystem remains in a state of permanent restoration and is never fully restored. One of the most high-profile stewardship projects took place at the 1,200-square-kilometer Guanacaste Conservation Area, in Costa Rica. This socioecological landscape is being restored largely to tropical dry forest in a manner that has benefited entire villages economically and culturally (Allen 2001; Janzen 2002). Stakeholders conducted the restoration under the direction of visionaries, including ecologist Daniel Janzen, who forged an unlikely yet effective coalition of Costa Rican agencies and politicians, local landowners, and international philanthropic organizations. The project combines all quadrants of the fourquadrant model (see Chapter 8) and features important elements of holistic ecological restoration.
Advantages of Contexts The technocratic and collegial contexts each have great strengths that in large degree are mutually exclusive. The technocratic context features copious funding that supports a wide range of activities and labor costs throughout the life of a project. Another advantage is access to the expertise of specialists such as hydrologists, soil scientists, civil engineers, planners, and legal council. Yet another is access to support personnel and a wide range of equipment and technical capabilities, including geographic information system technology and accurate aerial photography and resource maps, mechanized equipment of all kinds that may be needed for site preparation, and sophisticated monitoring equipment such as automated weather stations and recorders for surface water and groundwater. The combination of these advantages allows projects to be planned thoroughly and performed rapidly by well-trained and experienced personnel. Project management capabilities generally are excellent in terms of scheduling tasks, ordering planting stocks, engaging outside expertise when needed, and conducting liaison with officials. Stakeholder input often is negligible, and volunteers are seldom used, both of which reduce the potential for delays. One of the great advantages of the collective context is that practitioners and any managers with whom they work agree by consensus on every aspect of project work from initial conceptualization until final evaluation. This process lends itself to incorporating stakeholders and interested citizens in all aspects of a project and giving them a sense of ownership. The restored ecosystem becomes valued by the community through their participation, and its advantages are understood and respected. Contingencies can be addressed fully as they appear, and practitioners have the distinct advantage of engaging in intelligent tinkering as a way of resolving unexpected issues. Practitioners derive great satisfaction from having the responsibility, authority, flexibility, and freedom to accomplish the entire project from start to finish. The collegial context has the greatest potential of the four contexts for satisfying the values and categorical aspects of all quadrants in the four-quadrant model described in Chapter 8.
19_ch10:IP_Clewell
9/17/07
11:37 AM
Page 157
Project Roles and Contexts
157
The autocratic context generally is less amenable than the collegial context to involving stakeholders and the public. The resources a landowner can devote to restoration are limited by fiscal and time constraints. However, the individual context can be a source of great personal satisfaction to the landowner or manager. The bureaucratic context shares some advantages of the technocratic context and the collective context, but it is necessarily an expedient that borrows an advantage from one at the cost of an advantage from the other.
20_VFT8:IP_Clewell
9/17/07
11:39 AM
Page 158
VIRTUAL FIELD TRIP 8
Setting Up a Long-Term Restoration Ecology Research Site in Southern France James Aronson and Edouard Le Floc’h
Over the past 5,000–10,000 years, the impact of human beings has been profound throughout the Mediterranean region, including southern France. However, in the last century the creative, sustaining bonds and synergy between people and their environments that had long existed in the past have been lost or cast aside. As a result of global changes and socioeconomic forces leading step by step to agricultural abandonment and related trends, cultural landscapes that were closely managed or “gardenified” in the past are changing into seminatural shrublands and woodlands of low biodiversity and little interest for people. Elsewhere, especially along the coast and around villages near big cities, cultural landscapes are being converted to periurban or extractive areas with short-term economic benefits for some and strongly negative environmental and economic impacts for society. Socioecological systems that functioned in the past are breaking down, perhaps irretrievably. Having coevolved with people over thousands of years, most Mediterranean landscapes and ecosystems need some intermediate level of disturbance by humans and livestock in order to maintain the moving mosaic character and ensure their multipurpose economic interest and cultural and biological heritage value. Given the decline of agricultural practices and the concurrent rural exodus throughout southern Europe, what can be done to direct ecosystem trajectories in the current socioeconomic context (Etienne et al. 1998; Aronson et al. 2002a)? Reference landscapes and landscape units still exist in abundance for this purpose. However, traditional knowledge and management systems are no longer relevant. Three management scenarios are possible for the region’s abandoned lands, of which the third is clearly the most attractive: • Let nature take its course, at the cost of reducing use options and biodiversity through secondary succession and shrub encroachment, even if it means increasing the frequency and severity of wildfires. • Let urbanization take its course, resulting in sprawl and overshoot in terms of groundwater and other basic resources. Cultural value losses will be great as well. • Develop new cultural landscape mosaics that retain something of the cultural heritage of the past, reduce the risk of wildfires, and accommodate a wide range of outdoor activities for a growing but carefully planned human community. Landscapes would incorporate areas of sustainable production of goods and areas for provision of leisure 158
20_VFT8:IP_Clewell
9/17/07
11:39 AM
Page 159
Setting Up a Long-Term Restoration Ecology Research Site in Southern France
159
VFT Figure 8.1. The projected regional expansion (more than 95%) and recession (less than 3%) of holm oak–dominated woodlands in southern France, on the basis of the current distribution and considering current rate of temperature increase caused by global warming. (Sources: Barbéro et al. 1992; Rambal and Ratte 2005)
and other ecosystem services and provide the greatest resilience in the face of climate change. It appears possible that the third scenario can be achieved under certain circumstances (see Marty et al. 2007). For example, agricultural and other production systems need to be adapted to local opportunities, including subsidies, and constraints. They should also be seen as rendering services to society by reducing the risk of wildfires and increasing the resilience of fire-prone landscapes in the face of land abandonment and global warming, predicted to lead to a massive increase in the potential zone where fire-prone holm oak woodlands will occupy in southern France over the next century (VFT Figure 8.1 ).
Cazarils: A Long-Term Ecological Restoration Research Site To test methods for facilitating and monitoring the cultural landscape mosaic scenario mentioned earlier, a long-term ecological restoration site was established in 1995 at the publicly owned Domaine de Cazarils, which covers 600 hectares, situated 30 kilometers north of Montpellier, France (VFT Figure 8.2). There is great landscape diversity as a result of the long agricultural and silvopastoral history (VFT Figure 8.3), and therefore the site represents a heritage landscape that could become a valuable experimental, demonstration, and training site. Before the twentieth century, farming, animal husbandry, and systematic cutting and clearing for firewood and charcoal production and other uses were constant here. Today, the site has been largely abandoned for the last 50–100 years. However, two full-time pastoralists
20_VFT8:IP_Clewell
160
9/17/07
11:39 AM
Page 160
structure of an emerging profession
VFT Figure 8.2. The Mas (farmhouse in Occitan) of Cazarils, surrounded by garrigue. The foundations and basic structure of the Mas are almost 1,000 years old.
VFT Figure 8.3. Natural landscape unit just downslope from the Mas (VFT Figure 8.2) transformed over centuries into a series of terraced fields. Large trees along field margins are carefully preserved downy oak (Quercus humilis), and surrounding hillsides are dominated by holm oak (Quercus ilex) and shrubs including boxwood (Buxus sempervirens) and cade (Juniperus oxycedrus), both of which are tolerant to browsing, cutting, and burning. Agriculture has ceased, but grazing by domestic ruminants helps keep the fields open, and the two shepherds regularly cut and burn woody biomass to favor herbaceous plant layers of more pastoral value for their goats and sheep.
20_VFT8:IP_Clewell
9/17/07
11:39 AM
Page 161
Setting Up a Long-Term Restoration Ecology Research Site in Southern France
VFT Figure 8.4. Aerial photograph of Cazarils in 1946. (Source: French National Geographic Institute)
161
VFT Figure 8.5. Aerial photograph of Cazarils in 1996. The thick white line indicates the limits of the Domaine of Cazarils. (Source: French National Geographic Institute)
are still present in the area at least 8 months of the year, both of whom benefit from regional subsidies. From a comparison of VFT Figures 8.4 and 8.5, it is apparent that abandonment of agriculture and woodcutting (mainly for charcoal production) in the last half century have led to a much denser and more homogenous vegetation cover. Consequently, the frequency of wildfires in the area is also increasing steadily, with large costs and risks for society. Our research program was intended to help clarify the management issues and options and help inform planning for holistic ecological conservation, restoration, and management of Mediterranean landscapes throughout southern Europe. Our primary concern was to develop methods for the evaluation of restoration projects rather than restoring the site per se. Accordingly, along the lines set out in the Guidelines for Developing and Managing Ecological Restoration Projects (see the Appendix), we undertook a detailed biological inventory of the site and established ten permanent topographic transects (Le Floc’h et al. 1998). Over a period of 6 years we conducted experiments and monitoring on plant and insect species diversity and turnover and the rate of leaf litter decomposition in various landscape units along the ten transects. In one of the abandoned fields, we also studied plant community and soil biota responses to various experimental manipulations of standing plant biomass and functional groups. We subjected grazed and ungrazed (fenced) blocks to several low-cost treatments aimed at manipulating plant community structure at the level of functional groups. Treatments included three types of elimination (manual removal of herbaceous or woody plants or chemical removal of all vegetation) and two enhancements (introduction of an annual nitrogen-fixing legume [Medicago polymorpha] and biodynamic fertilization with grape residue, a nitrogenrich organic matter available at low cost locally). These treatments were repeated annually for 3 years. The goal was to determine the feasibility of artificially maintaining open spaces or aiding and accelerating secondary succession of native vegetation according to the management decisions made by regional authorities or local stakeholders. Results for the first 5 years showed that it is possible to manipulate vegetation structure and soil fertility with significant results quickly (VFT Figure 8.6).
20_VFT8:IP_Clewell
162
9/17/07
11:39 AM
Page 162
structure of an emerging profession
VFT Figure 8.6. Vegetation plot monitoring procedure by the point quadrat method at Cazarils long-term research site.
However, it will be argued that the experimental methods we used would be difficult and prohibitively expensive to apply at large scales. Indeed, we considered them as proxies or substitutes for livestock grazing and selective elimination of unwanted woody plants by shepherds. This, we conclude, probably is the most cost-effective method to achieve appropriate vegetation management. Alternatively, if farming of new crops or of elite varieties of traditional crops is envisioned, the enhancement techniques we tested could indeed help significantly and inexpensively aid in restoring soil fertility. In both cases, skilled people would be needed to farm or to look after flocks or herds. Realistically speaking, economic subsidies probably would be needed for both groups, at least in initial phases. Yet there is ample precedent for this, and it seems highly likely that the cost would be far less in the long run than that of wildfire control. Financial data that would permit a cost–benefit analysis are lacking at present, but new evaluation tools must also be developed to permit a holistic eco-economic evaluation. For example, the range of users of the public lands would be much greater than if nothing is done to maintain open areas and corridors. Biodiversity at the landscape scale would be higher, and ecosystem resilience would also be higher. The emerging question here, and in several of the other Virtual Field Trips we have taken is, How can the ecological and economic evaluation of the restoration and reintegration effort be merged into one? An additional question of importance is what local people prefer for these landscapes. There are no immediate answers to these two questions.
21_ch11:IP_Clewell
9/17/07
11:40 AM
Page 163
Chapter 11
Recognizing the Profession and the Professional
In the title of this book we identified ecological restoration as an emerging profession. It may be premature to identify ecological restoration as a profession just yet, but a trend in that direction is pronounced. A profession commonly meets several criteria: • A profession provides a particular service. • Those who practice the profession have undergone training or apprenticeship that qualifies them for their professional work. • These professionals accumulate experience in their professional practice, which increases their expertise and thus their qualification as practitioners. • Professionals form associations to establish thresholds and standards of training, demonstrated ability, and experience for entry and promotion within the profession and to set the standards of quality for professional practice. Associations set other norms for their professions, such as the boundaries that define the limits of that profession. Associations give formal recognition to their members in accordance with their professional credentials. • Members of the profession conduct their practice according to a code of ethics that they develop through their professional association. This code requires professionals to meet or exceed the standards and norms set by the professional association in their practice, to keep current with advances in the knowledge and techniques of their profession, to respect one another and their professional association in matters relating to their profession, and to interact honestly and forthrightly with clients and others with whom they engage professionally. Professionals can be identified as such because they are certified by their professional association or licensed by a government licensing board. Certification is a declaration by a professional association (or another, generally nongovernment body) that a person has attained a particular level of competence, as evidenced by completion of training, passage of an examination, or some other measure. People obtain certification by presenting their credentials for evaluation by an independent professional certification board established by a professional association and authorized to confer certification. The board consists of the candidate’s peers, usually senior members of the profession. Criteria for certification reflect the norms and standards adopted by the professional association. Periodic recertification may be required to 163
21_ch11:IP_Clewell
164
9/17/07
11:40 AM
Page 164
structure of an emerging profession
ensure that certified people keep current in their field and to allow them the opportunity to be upgraded in their level of certification as their professional capabilities grow. Licensing is a government function that gives a person permission to do something that is otherwise forbidden. The award of a license is a government privilege, not an individual right. In many well-established professions, certification is replaced by licensing, whereby a government board issues a license that allows the professional to practice within its jurisdiction. Government licensing boards generally are staffed by or work closely with senior practitioners in the profession. The criteria for issuing licenses may be developed or sanctioned by a professional association, commonly in concert with academic leaders in that field. Currently, ecological restoration is not a formally recognized profession and has no professional certification process. Certification and licensing are available in some related fields, for which restoration practitioners can apply if they meet the qualifications. For example, in Australia there exists an Australian Association of Bush Regenerators that admits members with experience who are nominated and accepted by a panel (B. Debincat, personal communication, 2006). The Society of Wetland Scientists, the Ecological Society of America, and the Wildlife Society are three professional associations that offer certification, which some restoration practitioners hold. The American Society of Landscape Architects participates with state governments in the United States to license practitioners of that profession, and many restoration practitioners are also licensed landscape architects. Public agencies commonly prefer that certain kinds of work be performed or overseen by certified or licensed professionals. Many private firms engage certified or licensed professionals as employees and contractors. Sometimes these firms must engage these professionals to satisfy conditions stipulated by contracts and government permits. Government bureaus may insist on engaging certified or licensed professionals. By doing so, these public agencies ensure that they cannot be faulted for sanctioning what could be perceived as substandard work. All these reasons provide distinct incentives to become a certified or licensed professional and to join, support, and participate in the activities of professional associations. Many public works projects, compensatory mitigation projects, and mine reclamation projects are required by law to be overseen by licensed civil engineers or sometimes by landscape architects or people licensed in other professions. Such projects may consist in large part of ecological restoration work. However, engineers must take ultimate responsibility for preparing project plans and their implementation. Licensed civil engineers who work for public agencies ensure that other licensed engineers have sealed restoration project plans (i.e., have impressed pages of the plans with their license number) and supervise project site work. Restoration practitioners have the disadvantage of having to comply with the norms and standards imposed by other professions whose missions are not primarily, if at all, concerned with ecological restoration. Restoration practitioners may make recommendations with regard to project planning and implementation, but ultimately they must comply with the decisions of other professionals. The certification of professional restoration practitioners would help them attract project work and give them more responsibility for planning and executing projects. More importantly for the field of ecological restoration, the very existence of a certification program is a strong statement that ecological restoration is no longer a diffuse movement or a curious sideline. Instead, it is a mainstream activity that demands serious consideration. For that reason,
21_ch11:IP_Clewell
9/17/07
11:40 AM
Page 165
Recognizing the Profession and the Professional
165
a much broader array of professionals in related fields, and government officials, will want to become more knowledgeable about the field. There are drawbacks to certification and particularly to licensure. One is that a certification program can be manipulated by unscrupulous people who could find ways to discourage application or increase requirements so that only a few elitists are certified. In turn, these people could monopolize opportunities to secure project work. Certification must be inclusive, not exclusive. Another drawback is that standardization could be encouraged and innovation discouraged, which would be damaging to a profession such as ecological restoration that is interdisciplinary and thrives on originality. If a certification program becomes available in ecological restoration, we encourage application as long as the program creates a community of certified professionals who intend to improve themselves and the restoration profession throughout their careers. Certified professionals should be active participants in and advocates of their professions and should guard closely against intentional or inadvertent actions that would weaken the profession. In other words, certification should not be considered just a credential that a restorationist adds to his or her résumé. Instead, it should intensify one’s dedication to the restoration profession and motivate participation in professional activities. In a field as interdisciplinary and innovative as ecological restoration, the principal basis for awarding certification should be one’s documented project experience, rather than academic credentials or the completion of a specified curriculum. The program should be administered by seasoned practitioners, not by outside authorities in a top-down manner. Those who evaluate applications should serve on a rotating basis to stimulate the active participation of certified practitioners everywhere in the growth and development of a vibrant profession. Rotation would also prevent the entrenchment of a clique that could assume tight control of the certification process. The alternative to certification would be for everyone interested in natural resource conservation and management to become restorationists at heart and knowledgeable about restoration practice. Everyone would then become a practitioner, or at least a restorationist, including civil and ecological engineers, environmental stewards, and public land managers. This may happen and would obviate certification. Alternatively, a professional certification program could accelerate the process by which everyone became seriously interested in restoration and eventually became restorationists at heart.
21_ch11:IP_Clewell
9/17/07
11:40 AM
Page 166
22_ch12 (pt5):IP_Clewell
9/17/07
11:44 AM
Page 167
pa r t v
Holistic Ecological Restoration
In this short section we offer a synthesis of holistic ecological restoration, the direction we see restoration taking in the future. The synthesis amplifies and refines much of the content in Chapter 1 with principles developed in subsequent chapters.
167
22_ch12 (pt5):IP_Clewell
9/17/07
11:44 AM
Page 168
22_ch12 (pt5):IP_Clewell
9/17/07
11:44 AM
Page 169
Chapter 12
The Concept of Holistic Ecological Restoration: A Synthesis
In this book we have consistently used ecological restoration in a holistic sense and in a manner that complements the way Pandey (2002) used it when he introduced that term. Pandey (2002) specified that holistic restoration included both ecological and social components. He called for self-sustaining, functional ecosystems and viewed holistic ecological restoration as a way to protect biodiversity. He said that these ecosystems should provide services to society in support of sustainability science and mentioned the sequestration of carbon dioxide to reduce global climate change as an example of a restored ecosystem service. In this book, we define the ecological component of holistic ecological restoration along the lines that were presented in The SER Primer on Ecological Restoration (SER 2002). We specified that partial measures that could only contribute to holistic ecological restoration did not qualify by themselves as holistic. We incorporated Pandey’s social component of holistic ecological restoration in terms of the values in the socioeconomic quadrant of the four-quadrant model for ecological restoration (Chapter 8). We added values in the personal and cultural quadrants, which Pandey (2002) intimated but did not specify. Values from the ecological quadrant of the four-quadrant model were suggested in his ecological component. In this chapter, we present a synthesis of holistic ecological restoration. We prepared this synthesis from relevant material in the overview (Chapter 1) and added ideas that were developed in subsequent chapters in a manner that summarizes our understanding of the field. Ecological restoration in a holistic sense is the process of assisting the recovery of an impaired ecosystem to a condition of wholeness. Impairment usually is caused or intensified by human activity, whether intentional or inadvertent. Ecosystem impairment may occur in response to the incremental degradation of an ecosystem over time, to acute damage that occurs at a single time, and to the destruction of an ecosystem by the removal of its biota and inert organic matter. Some common effects of ecosystem impairment are as follows: • Losses of specialized species and relative or actual gains of generalist species • Colonization by invasive species • Simplification of community structure • Reduction in microclimate control • Changes in the frequency distribution of plant life forms 169
22_ch12 (pt5):IP_Clewell
170
9/17/07
11:44 AM
Page 170
holistic ecological restoration
• Losses in beneficial soil properties • Reduction in capacity for mineral nutrient retention • Reduction in capacity to regulate the moisture regime Restoration practitioners manipulate the biota or the physical environment to recover— or accelerate the recovery of—an impaired ecosystem to a desired condition. This condition is expressed in terms of species composition and community structure (or ecosystem integrity), ecological functioning (or ecosystem health), self-organization, and the capacity for self-sustainability. Although ecological restoration is overtly directed at ecosystem improvement, it is ultimately conducted to fulfill people’s values. These include ecological values, socioeconomic values, cultural values, and personal values. The particular values that are relevant to a given restoration project should be identified in advance by the stakeholders, or at least endorsed by them. Restoration projects that are sanctioned and—to the extent possible—planned and implemented by stakeholders and the broader community in accord with these values will be appreciated, respected, protected, managed, and used in manner that benefits people and the ecosystem. As a model for planning, a reference is selected that the restored ecosystem is eventually intended to emulate. The reference can be a document that describes the desired, long-term outcome or target for restoration. Alternatively, the reference can be one or more actual intact ecosystems that represent the desired outcome. The content and the quality of the reference may vary widely between projects, depending on the availability of information and sites on which it can be developed. The reference represents a projection of the historic trajectory of the ecosystem before its impairment. The historic trajectory is the sequential development of an ecosystem in the past in response to environmental conditions, random localized flux in environmental conditions, and random states caused by dynamic processes of the ecosystems themselves. Under stable environmental conditions, the historic trajectory oscillates within a narrow variance that may approach apparent stasis. Under less stable conditions, the variance and thus the trajectory fluctuate, sometimes substantially. The reference should make allowances for the kinds of fluctuations that are likely to occur in response to contemporary and anticipated future environmental conditions that may not have occurred in the past and may intensify in the future from such causes as global warming, rising sea level, land usage, and encroachment by urbanization. In summary, restoration necessarily restores to the future because ecosystems and their environments are dynamic. Restoration to a prior state, as if time reversed itself, is not an option. Nonetheless, restoration to an apparent prior state can, and often does, occur. It is more likely to be achieved under one or more of the following conditions: • Environmental conditions remain stable • Impairment was modest and can be corrected rapidly, especially if the physical environment needs no intervention • The number of characteristic species is low because of extreme environments or some other exceptional conditions • Few pathways for ecosystem recovery exist because of multiple stresses in the environment or extreme homogeneity in the environment • Human interference with otherwise natural processes is either low or constant
22_ch12 (pt5):IP_Clewell
9/17/07
11:44 AM
Page 171
The Concept of Holistic Ecological Restoration: A Synthesis
171
If other conditions prevail, the restored ecosystem may deviate from its target in some ways upon reaching the same stage of ecological development. Regardless of whether a restored ecosystem closely emulates its intended target, it should demonstrate ecological attributes that would be expected in any intact ecosystem. They are as follows: • An appropriate species composition that is sufficient to allow development of appropriate community structure • An absence of invasive, nonnative species • The presence of all functional species groups as designated in the reference model or their likely spontaneous appearance later • Suitability of the physical environment to support the biota • Normal ecosystem function or at least the absence of signs of dysfunction • Integration with the surrounding landscape in terms of normal flows and exchanges of organisms, materials, and sources of energy • An absence of external threats from the immediate landscape to the integrity and health of the restored ecosystem to the greatest practicable extent In addition, the restored ecosystem should be resistant or resilient to anticipated stresses and disturbances. A restoration project reaches completion as soon as an impaired ecosystem exhibits evidence of self-organization and self-sustainability and lacks any indication of arrested development. At that point, the ecosystem can continue its own development toward a target state or reference condition. Thereafter, any manipulations that are made to the restored ecosystem are recognized as ecosystem management (as applied externally by technical personnel) or as traditional or local cultural practices (as applied by people who live intimately and harmoniously with the land). In other words, ecological restoration “repairs” an ecosystem, and management or cultural practices keep it in working order. If an ecosystem has coevolved with cultural practice, whereby the nonhuman components and culture have simultaneously molded each other, it is known as a cultural ecosystem. Two or more alternative ecosystem states of cultural ecosystems may occur at a given site as a result of differences in sustainable cultural practices. Cultural ecosystems are ecologically equivalent to other “noncultural” ecosystems, and they demonstrate the same seven ecological attributes that were previously listed. Any alternative state can be selected as the model of ecological restoration as long as that state can be maintained after restoration by a continuation of cultural practices or equivalent management. Practices that were responsible for the transformation of an ecosystem to a cultural state, and for maintaining that state, are considered natural and normal. However, practices that lead to degradation or conversion to intensively managed production systems are excluded. This, then, is our synthesis of holistic ecological restoration. Take a moment and imagine that you are traveling; it does not matter where. Near every village along your route you see one or more signs that point toward local ecological restoration projects. Sometimes you can see practitioners—many of them ordinary citizens and youths from schools—busy at work as you pass by. Some of these practitioners hold certificates in restoration that they earned in continuing education programs at local colleges. Imagine that government agencies and nongovernment organizations are encouraging and supporting these local initiatives with
22_ch12 (pt5):IP_Clewell
172
9/17/07
11:44 AM
Page 172
holistic ecological restoration
equipment, personnel, and funds that may not otherwise be available. Imagine that the news media actually carry stories about how these projects are progressing and what they will mean to people and the environment upon their completion. Turn back to Figure 8.6 and imagine that the four axes of the four-quadrant model are beginning to curve upward toward a common point of unity in response to this activity. Imagine what it could be like and help make it happen!
23_Appendix:IP_Clewell
9/17/07
11:45 AM
Page 173
Appendix
Guidelines for Developing and Managing Ecological Restoration Projects, 2nd Edition Andre Clewell, John Rieger, and John Munro
Contents Preface to the Second Edition Introduction Conceptual Planning Preliminary Tasks Implementation Planning Implementation Tasks Post-Implementation Tasks Evaluation and Publicity
Preface to the Second Edition The first edition of these Guidelines for Developing and Managing Restoration Projects was published on the website of the Society for Ecological Restoration International (SER) on June 24, 2000. This new edition brings the guidelines into conformity with The SER Primer on Ecological Restoration (SER 2002) and expands the text for clarity and insight. Substitutions have been made for some terms, e.g., “implementation” for “installation.” The numbering of the guidelines was retained, although some titles were modified. Peer review for the second edition was provided by the membership of SER’s Science and Policy Working Group and of the SER Board of Directors. This edition was approved as an official SER document by the Board of Directors on December 15, 2005.
Introduction This document describes the procedures for conducting ecological restoration in accord with the norms of the discipline that were established in The SER Primer on Ecological Restoration (SER 2002, http://www.ser.org/). Each procedure is stated in terms of a guideline that leads restoration practitioners and project managers stepwise through the process of ecological restoration. Adherence to these 51 guidelines will reduce errors of omission and commission that compromise project quality and effectiveness. The guidelines are applicable to the 173
23_Appendix:IP_Clewell
174
9/17/07
11:45 AM
Page 174
Appendix
restoration* of any ecosystem—terrestrial or aquatic—that is attempted anywhere in the world and under any auspices, including public works projects, environmental stewardship programs, mitigation projects, private land initiatives, etc. Users of the SER Guidelines are advised to become familiar with The SER Primer in advance and refer to it for definitions of terms and discussions of concepts. Design issues and the details for planning and implementing restoration projects lie beyond the scope of these guidelines. We leave such complexities to the authors of manuals and the presenters of workshops who address these topics. Ecological restoration is the process of assisting the recovery of an ecosystem that has been degraded, damaged, or destroyed. It is an intentional activity that initiates or accelerates ecosystem recovery with respect to its health (functional processes), integrity (species composition and community structure), and sustainability (resistance and resilience to disturbance). Restoration ensures abiotic support from the physical environment, suitable flows and exchanges of organisms and materials with the surrounding landscape, and the reestablishment of cultural interactions upon which the integrity of some ecosystems depends. Restoration attempts to return an ecosystem to its historic trajectory, i.e., to a state that resembles a known prior state or to another state that could be expected to develop naturally within the bounds of the historic trajectory. The restored ecosystem may not necessarily recover its former state, since contemporary constraints and conditions can cause it to develop along an altered trajectory. In accord with the SER Primer, these SER Guidelines assume that ecological restoration is accomplished once the assistance of a restoration practitioner is no longer needed to ensure long-term ecosystem sustainability. However, ecosystem management may be required to prevent recurrent degradation of restored ecosystems on account of alterations in the environment or anthropogenic changes. Such activities are considered management rather than restoration. In other words, ecological restoration makes ecosystems whole again, and ecological management keeps them whole. Correspondingly, some restored ecosystems will require management in the form of traditional cultural practices. This distinction between restoration and management (including cultural practices) facilitates resource planning and budgeting, and it protects ecological restoration efforts from being held liable for subsequent inconsistencies or misjudgment in ecosystem management. The project guidelines are numbered for convenience. They do not necessarily have to be initiated in numerical order, and some may be accomplished concurrently. The guidelines are grouped into six phases of project work: conceptual planning (including feasibility assessments), preliminary tasks (upon which subsequent planning relies), implementation planning, project implementation, post-implementation tasks (monitoring and aftercare), and evaluation and publicity. We recommend that a diary be kept for each guideline to document project activities as they happen and to record all relevant information for each guideline as it is generated. Tabular data, graphics, and ancillary documents can be appended. Narratives in the form of written responses to Guidelines #1 through #36 collectively comprise a comprehensive ecological restoration plan that can be filed with public agencies, funding institutions, permitting authorities, corporate offices, and other interested parties. The narratives serve as the basis for preparing progress reports and applications for continuing financial support. They become *“Restoration” when used alone in this document connotes “ecological restoration.”
23_Appendix:IP_Clewell
9/17/07
11:45 AM
Page 175
Appendix
175
invaluable to new practitioners and management personnel who are assigned in mid-project. When the project has been completed, the narratives comprise a thorough and well organized case history which only needs editing to generate a final report and to prepare articles for publication.
Conceptual Planning Conceptual planning identifies the restoration project site, specifies restoration goals, and provides relevant background information. Conceptual planning is conducted when restoration appears to be a feasible option but before a decision has been made to exercise that option. Conceptual planning provides preliminary information such as observations from site reconnaissance and perhaps a few representative measurements. Detailed, systematic inventories of ecosystem properties and the biota are not included in this phase of activity. Written responses to Guidelines #1 through #16 collectively comprise the conceptual plan and broadly characterize the proposed restoration project.
1. Identify the Project Site Location and Its Boundaries Delineate project boundaries and portray them as maps, preferably generated on a smallscale aerial photograph and also on soil and topographic maps that show the watershed and other aspects of the surrounding landscape. Use of GPS, land survey, or other measurement devices as appropriate is encouraged.
2. Identify Ownership Give the name and address of the landowner(s). If an organization or institution owns or manages all or part of the site, give the names and titles of key personnel. Note the auspices under which the project will be conducted—public works, environmental stewardship, mitigation, etc. If there is more than one owner, make sure that all are in agreement with the goals and methods proposed for the restoration program.
3. Identify the Need for Ecological Restoration Tell what happened at the site that precipitated the need for restoration. Describe the improvements that are anticipated following restoration. Benefits may be ecological, economic, cultural, aesthetic, educational, and scientific. Ecological benefits may amplify biodiversity, improve food chain support, etc. Economic benefits are natural services (also called social services) and products that ecosystems contribute towards human wellbeing and economic sustainability. Ecosystems in this regard are recognized and valued as natural capital. Cultural improvements may include social performance and rituals, passive recreation, and spiritual renewal. Aesthetic benefits pertain to the intrinsic natural beauty of native ecosystems. Educational benefits accrue from advances in environmental literacy that students gain from participating in, or learning about, ecological restoration. Scientific benefits accrue when a restoration project site is used for demonstration of ecological principles and concepts or as an experimental area.
23_Appendix:IP_Clewell
176
9/17/07
11:45 AM
Page 176
Appendix
4. Identify the Kind of Ecosystem to Be Restored Name and briefly describe the kind of ecosystem that was degraded, damaged, or destroyed, for example, tropical dry forest, vernal pool, semiarid steppe, shola (India), chalk meadow (Europe), cypress swamp (USA), etc. Other descriptors should be added to facilitate communication with those who may not be familiar with the natural landscapes in the bioregion. These descriptors should include the names of a few characteristic or conspicuous species and should indicate community structure (desert, grassland, savanna, woodland, forest, etc.), life form (herbaceous perennial, succulent, shrub, evergreen tree, etc.), predominant taxonomic categories (coniferous, graminaceous, etc.), moisture conditions (hydric, xeric, etc.), salinity conditions (freshwater, brackish, saline, etc.), and geomorphological context (montane, alluvial, estuarine, etc.). Reference to readily accessible published descriptions can augment or replace some of these descriptors.
5. Identify Restoration Goals Goals are the ideal states and conditions that an ecological restoration effort attempts to achieve. Written expressions of goals provide the basis for all restoration activities, and later they become the basis for project evaluation. We cannot overemphasize the importance of expressing each and every project goal with a succinct and carefully crafted statement. All ecological restoration projects share a common suite of ecological goals that consist of recovering ecosystem integrity, health, and the potential for long-term sustainability. They are listed as the attributes of restored ecosystems in Section 3 of the SER Primer and have been formalized as restoration standards in the SER Standards for Ecological Restoration (in preparation, to be posted at http://www.ser.org/). They deserve to be restated, at least by reference to the SER Standards, for each restoration project. Otherwise, they can be underappreciated or overlooked by authorities and other interested parties who are not well versed in ecological restoration. A project may have additional ecological goals, such as to provide habitat for particular species or to reassemble particular biotic communities. Statements of ecological goals should candidly express the degree to which recovery can be anticipated to a former state or trajectory. Some ecosystems can be faithfully restored to a known or probable historic condition, particularly when degradation or damage is not severe and where human demographic pressures are light, plant species richness is low on account of rigorous environmental conditions, and where the ecologically young vegetation in a newly restored ecosystem tends to resemble the mature vegetation of the pre-disturbance state. Even so, the restored ecosystem will undoubtedly differ in some respects from its model, owing to the complex and seemingly random (stochastic) aspects of ecosystem dynamics. Other restorations may not even approximate a historical model or reference, because contemporary constraints or conditions prevent restoration to a former, historic condition. Restoration can be conducted in any of five contexts. The appropriate context should be identified in the project goals in order to underscore the intent of restoration and to avoid or minimize subsequent misunderstandings, conflict and criticisms. They are: • Recovery of a degraded or damaged ecosystem to its former state. • Replacement of an ecosystem that was entirely destroyed with one of the same kind. The new ecosystem must be entirely reconstructed on a site that was denuded of its vegeta-
23_Appendix:IP_Clewell
9/17/07
11:45 AM
Page 177
Appendix
177
tion (terrestrial systems) or its benthos (aquatic systems). Replacements are common on surface-mined lands and brownfields (severely damaged urban and industrial lands). • Substitution of another kind of ecosystem from the bioregion to replace one which was removed from a landscape that became irreversibly altered. This option is important for restoring natural areas in an urban context where, for example, original hydrologic conditions cannot be restored. • Substitution of a replacement ecosystem where an altered environment can no longer support any naturally occurring type of ecosystem in the bioregion. The replacement ecosystem may consist of novel combinations of indigenous species that are assembled to suit new site conditions as, for example, at a retired solid waste disposal site. • Substitution of a potential replacement ecosystem, because no reference system exists to serve as a model for restoration. This option is relevant in densely populated regions of Eurasia, where many centuries of land use have obliterated all remnants of original ecosystems. All ecological restoration projects have cultural goals (viz. Guideline #3), even though such goals may be implied in the enabling legislation that authorizes public agencies to conduct or permit project work. All cultural goals should be stated clearly, because they provide the basis for public understanding of the benefits of a project. Public appreciation is conducive to garnering fiscal support, to accommodation of project activities by public agencies, to attracting stakeholder participation in project planning and implementation, and to commanding respect for the restored ecosystem by local residents.
6. Identify Physical Site Conditions in Need of Repair Many ecosystems in need of restoration are dysfunctional on account of damage to the physical environment, such as soil compaction, soil erosion, surface water diversion, and impediments to tidal inundation. The physical environment must be capable of sustaining viable, reproductive species populations that comprise the biota of the restored ecosystem.
7. Identify Stressors in Need of Regulation or Re-initiation Stressors are recurring factors in the environment that maintain the integrity of an ecosystem by discouraging the establishment of what would otherwise be competitive species. Examples are fires, anoxia caused by flooding or prolonged hydroperiod, periodic drought, salinity shocks associated with tides and coastal aerosols, freezing temperatures, and unstable substrates caused by water, wind, or gravity as on beaches, dunes, and flood plains. In some ecosystems, stressors may include sustainable cultural activities, such as the periodic harvest of biotic resources and the ignition of fires. These should be identified as stressors of cultural origin.
8. Identify and List the Kinds of Biotic Interventions That Are Needed Many restoration projects require manipulation of the biota, particularly vegetation, to reduce or eradicate unwanted species and to introduce or augment populations of desirable
23_Appendix:IP_Clewell
178
9/17/07
11:45 AM
Page 178
Appendix
species. Invasive non-native species generally require extirpation. Other species, native or non-native, may be removed if they retard or arrest biotic succession. Species that may need introduction include mycorrhizal fungi, N-fixing bacteria, other soil microbiota and, in aquatic environments, benthic infauna (animals that live in sediments). Mobile animals generally colonize restored habitats spontaneously; however, animal introductions are sometimes needed. Animals can be enticed to colonize project sites by providing perches for birds, distributing coarse detritus for small animal cover, preparing a variety of different substrates in streams as habitat for macroinvertebrates, etc.
9. Identify Landscape Restrictions Population demographics of many species at a project site may be adversely affected by external conditions and activities offsite in the surrounding landscape. Land and water usage are commonly at fault. Restoration should not be attempted if the landscape is likely to be heavily compromised. Restoration of some aquatic ecosystems depends entirely on making ecological improvements elsewhere in the catchment, and all restoration work is accomplished offsite. An example of an impact from offsite would be discharge of turbid or polluted water such as agricultural runoff that reaches a proposed project site. Another example would be recurrent flooding and consequent sedimentation in a lowland site that was caused by unrestrained runoff following harvest of montane forest. In this instance, restoration efforts might be better directed at afforestation (forest recovery) in highlands. The hydrologic regime in any project site can be altered offsite by dams, drainage projects, diversions of runoff caused by highways and other public works, and by impervious surfaces on developed land. Water tables can be depressed gradually by transpiration following reforestation and can be raised acutely after timber harvest or after ditches are filled. Fire frequency is reduced by intentional suppression and by landscape fragmentation that interrupts the cover of flammable vegetation. Fire hazards develop in the form of dense brush in response to fire suppression. Exotic species colonization onsite is commonly traced to infestations offsite. The presence or abundance of birds and other mobile animals in the restored ecosystem depends on the health of other ecosystems in the landscape that comprise parts of their territories. Hazards elsewhere in the landscape such as these should be identified and evaluated in terms of their potential to compromise restoration efforts, and the possibility that they can be ameliorated should be assessed realistically.
10. Identify Project Funding Sources Potential external funding sources should be listed if internal funding is inadequate.
11. Identify Labor Sources and Equipment Needs Personnel may have to be hired, volunteers invited, and other labor contracted. Determine the need and availability of special equipment.
23_Appendix:IP_Clewell
9/17/07
11:45 AM
Page 179
Appendix
179
12. Identify Biotic Resource Needs and Sources Biotic resources may include seeds, other plant propagules, nursery-grown planting stocks, and animals for establishment at the project site. Some stocks are commercially available. Others, such as seeds of native plants, may have to be collected from other natural areas.
13. Identify the Need for Securing Permits Required by Government Agencies Permits may be required for tasks such as the excavation or filling of streams and wetlands, other earthwork activities, herbicide use, and prescribed burning. Other permits may be applicable for the protection of endangered species, historic sites, etc.
14. Identify Permit Specifications, Deed Restrictions, and Other Legal Constraints Zoning regulations and restrictive covenants may preclude certain restoration activities. Legal restrictions on ingress and egress could prevent the implementation of some restoration tasks. If the restoration is to be placed under conservation easement, the timing of the easement must be satisfied and manipulations to the environment may have to be completed prior to the effective date of the easement. If restoration is to be conducted under contract or as mitigation or mitigation banking, contract conditions and permit specifications must be compatible with the restoration plan and incorporated into it. If they are not, negotiations may have to be conducted with the agency in charge.
15. Identify Project Duration Project duration can greatly affect project costs. Short-term restoration projects can be more costly than longer-term projects. The longer the project, the more the practitioner can rely on natural recovery and volunteer labor to accomplish specific restoration objectives that are identified below in Guideline #27. In accelerated restoration programs such as mitigation projects, costly interventions must substitute for these natural processes.
16. Identify Strategies for Long-Term Protection and Management Ecological restoration is meaningless without reasonable assurance that the project site will be protected and properly managed into the indefinite future. To the extent possible, threats to the integrity of a restored ecosystem on privately owned land should be minimized by mechanisms such as conservation easements or other kinds of zoning. External threats can be reduced by buffers and binding commitments from neighboring landowners. Alternatively, the restored ecosystem could be legally transferred to a public resource agency or nongovernmental organization. However, the protection and management of restored ecosystems on public lands are not guaranteed, and a formal commitment for that purpose by the responsible agency is desirable.
23_Appendix:IP_Clewell
180
9/17/07
11:45 AM
Page 180
Appendix
Preliminary Tasks Preliminary tasks are those upon which project planning depends. These tasks form the foundation for well-conceived restoration designs. Preliminary tasks are fulfilled after the completion of conceptual planning and the decision to proceed with the restoration project.
17. Appoint a Restoration Practitioner Who Is in Charge of All Technical Aspects of Restoration Restoration projects are complex, require the coordination of diverse activities, and demand numerous decisions owing in part to the complex nature of ecosystem development. For these reasons, leadership should be vested in a restoration practitioner who maintains overview of the entire project and who has the authority to act quickly and decisively to obviate threats to project integrity. Many smaller projects can be accomplished by a single practitioner who functions in various roles—from project director and manager to field technician and laborer. Larger projects may require the appointment of a chief restoration practitioner who oversees a restoration team that includes other restoration practitioners. The chief practitioner may delegate specific tasks but retains the ultimate responsibility for the attainment of objectives. Ideally, the expertise of the chief practitioner should be solicited by project planners. If restoration is a subcontractual component of a larger project, the chief practitioner should enjoy equal status with other subcontractors to prevent actions that could complicate scheduling, compromise restoration quality, and inflate costs. In any event, the chief practitioner and the project manager should maintain open lines of communication. Practitioner responsibilities are sometimes divided according to the organizational charts of larger corporations and government bureaus. Pluralistic leadership augments the potential for errors in project design and implementation. In mitigation projects, agency personnel become silent co-partners with the chief practitioner when they mandate particular restoration activities as permit specifications. This practice reduces the chief practitioner’s capacity for flexibility and innovation, including the prompt implementation of mid-course corrections. The preparation of a written guidance document, based upon responses to these guidelines, will help promote the judicious execution of the restoration project in cases of pluralistic leadership.
18. Appoint the Restoration Team For larger projects, the chief practitioner may need the collaboration of other practitioners to supervise labor crews and subcontractors and also of technical personnel with critical skills and expertise. Collectively, they comprise the restoration team. It is essential that the responsibilities of each individual are clearly assigned and that each person be given concomitant authority.
19. Prepare a Budget to Accommodate the Completion of Preliminary Tasks The budget addresses labor and materials and includes funds needed for reporting. It recommends or specifies a schedule of events.
23_Appendix:IP_Clewell
9/17/07
11:45 AM
Page 181
Appendix
181
20. Document Existing Project Site Conditions and Describe the Biota This guideline builds on preliminary information in the responses to Guidelines #3 and #4 and is significantly more comprehensive and detailed. Documentation for this guideline should include a systematic inventory that quantifies the degree of degradation or damage. Species composition should be determined and species abundance estimated. The structure of all component communities should be described in sufficient detail to allow a realistic prediction of the effectiveness of subsequent restoration efforts. Soils, hydrology, and other aspects of the physical environment should be described. Such information is critical later in project evaluation, which depends in part upon being able to contrast the project site before and after restoration. Properly labeled and archived photographs are essential for documenting any restoration project. Numerous photos should be taken with care during good photographic conditions prior to conducting any restoration work. Photographic locations and compass directions should be recorded, so that before and after photos can be compared. Close-up and wide angle photos should be included, with some taken from an elevated position as from the cargo bed of a truck. Videotapes, aerial photographs, and oblique aerial photos from a low-flying aircraft are helpful.
21. Document the Project Site History That Led to the Need for Restoration Site history that was identified for Guideline #3 is expanded, if necessary, to provide a comprehensive overview. The years during which impacts occurred should be recorded. Historical aerial photos that show the pre-disturbance state and that show disturbance events are helpful.
22. Conduct Pre-Project Monitoring as Needed Often it is useful or requisite to obtain baseline measurements on such parameters as water quality, groundwater elevation, and gross metabolism of soil organisms for a year or more prior to initial project installation. If so, these measurements will continue throughout the life of the project as part of the monitoring program. Unanticipated extremes in data can indicate problems that might require mid-course correction to prevent the collapse of the project. Upon project completion, the data are assessed to help evaluate the effectiveness of restoration.
23. Establish the Reference Ecosystem or “Reference” The reference model represents the future condition or target on which the restoration is designed and which will serve later as a basis for project evaluation. The reference can consist of the pre-disturbance condition if it is known, one or more undisturbed sites with the same type of ecosystem, descriptions of such sites, or another document, as described in Section 5 of the SER Primer. The reference must be sufficiently broad to accommodate the amplitude of potential endpoints that could reasonably be expected from restoration. The selection of the reference increases in difficulty in instances where contemporary constraints and conditions alter the historic trajectory or in other instances where the
23_Appendix:IP_Clewell
182
9/17/07
11:45 AM
Page 182
Appendix
bioregion lacks comparative ecosystems of the kind being restored. In extreme cases, the only concrete reference data may consist of a list of native species that could potentially contribute to the assembly of an ecosystem with the intended community structure. The degree to which the reference can serve as a model for a restoration project and for its evaluation depends on its specificity and its appropriateness, and both can vary widely among projects. In some projects, the reference can serve almost as a template. In others, it can only hint at the direction of development.
24. Gather Pertinent Autecological Information for Key Species The chief practitioner should access whatever knowledge is available regarding the recruitment, maintenance, and reproduction of key species. If necessary, trials and tests of species establishment and growth can be conducted by the restoration team prior to project implementation.
25. Conduct Investigations as Needed to Assess the Effectiveness of Restoration Methods and Strategies Innovative restoration methods may require testing prior to their implementation at the project site. Experimental plots or small-scale “pilot projects” may demonstrate feasibility or reveal weaknesses in restoration design and execution prior to attempting larger-scale restoration. Pilot projects are particularly useful in attempting the restoration of a particular kind of ecosystem for the first time in a bioregion.
26. Decide Whether Ecosystem Goals Are Realistic or Whether They Need Modification The selection of realistic goals is crucial. The potential for the achievement of some goals that were identified during conceptual planning (Guideline #5) may now appear unrealistic in light of more thorough information generated subsequently. Other goals could be added. At this time, the project team should reassess the selection of goals in Guideline #5 and make modifications if warranted.
27. Prepare a List of Objectives Designed to Achieve Restoration Goals In order to achieve restoration goals, explicit actions are undertaken to attain specific end results. Each end result is called an objective. For example, if the goal is to recover the former forest ecosystem on land that was converted for the production of row-crops, one objective might be to establish tree cover with a designated species composition and species abundance at a finite location in that field. In restoration projects that are conducted under contract, objectives are ordinarily “time certain,” meaning that they are to be done within a specified length of time in order to accommodate project planning, budgeting, and regulatory concern. Objectives are subject to precise empirical determination, as will be described in Guideline #36. Objectives are selected with the anticipation that their completion will allow the fulfillment of project goals. Goals are less amenable to precise empirical determination, because they require measurements of innumerable parameters that are constantly subject to
23_Appendix:IP_Clewell
9/17/07
11:45 AM
Page 183
Appendix
183
change on account of ecosystem dynamics. For that reason, objectives are used as indicators of the achievement of goals. Ecological objectives are realized by manipulating the biota and/or the physical environment. Some are executed at the beginning of restoration, such as removing a road, filling a previously excavated canal, or adding organic matter or lime to the soil. Other objectives require repetitious actions, such as the periodic ignition of prescribed fires or the removal of recurring invasive species that threaten the establishment of desirable vegetation. Some objectives may require actions that take place offsite to improve conditions onsite. The number of ecological objectives for an ecological restoration project may vary from one to many, depending upon project goals and the degree to which the ecosystem was degraded or damaged. Cultural objectives pertain to the realization of cultural project goals. These objectives may involve publicity campaigns, public celebrations of restoration in progress, participation of stakeholders and school children in restoration implementation and monitoring, and other actions that ensure cultural intimacy with ecosystem recovery.
28. Secure Permits Required by Regulatory and Zoning Authorities These permits were identified in Guidelines #13 and #14.
29. Establish Liaison with Interested Public Agencies Ecological restoration is necessarily an endeavor of public concern, even if it is conducted on privately owned land without public expenditure. A restored ecosystem provides beneficial natural services well beyond property boundaries. Since restoration generally contributes to public wellbeing, public agencies that are responsible for natural resource protection and management should be aware of any restoration projects within their jurisdictions, regardless of ownership and funding. Upon their recognition, restoration projects can be afforded protection, favorable publicity, attentive management, or other favorable accommodation by public agencies. Site tours, websites, newsletters, and press releases are ways of establishing liaison with public agencies. Interagency memoranda can inform other agencies of restoration projects initiated by a sponsoring agency on public land.
30. Establish Liaison with the Public and Publicize the Project Local residents automatically become stakeholders in the restoration. They need to know how the restored ecosystem can benefit them personally. For example, the restoration may attract ecotourism that will benefit local businesses, or it may serve as an environmental education venue for local schools. If residents favor the restoration, they will protect it and vest it with their political support. If they are unaware of the restoration and its public benefits, they may vandalize or otherwise disrespect it.
31. Arrange for Public Participation in Project Planning and Implementation to Fulfill Cultural Goals Many ecological restoration projects are conducted in technocratic manner, particularly those that are intended to satisfy contract conditions and permit stipulations required by
23_Appendix:IP_Clewell
184
9/17/07
11:45 AM
Page 184
Appendix
public agencies. The public is commonly excluded except at legally required and sometimes perfunctory public hearings. Restoration is planned, implemented, and monitored by trained professionals without the assistance of volunteers from the public who may be perceived as liability risks for insurance purposes and who could complicate scheduling and supervision. Public participation could increase project costs and threaten timely project completion. However, the exclusion of the public can cause other problems such as those mentioned in Guideline #30. Public agencies should consider incentives for the restoration team to incorporate local residents and other stakeholders in all phases of project work. By doing so, the public will develop a feeling of ownership, and participants may assume a stewardship role for the completed project.
32. Install Roads and Other Infrastructure Needed to Facilitate Project Implementation Ordinarily, restoration projects remove roads and other infrastructure. However, improvements or new construction may be necessary to provide access to project sites or otherwise facilitate project implementation and maintenance. For instance, infrastructure improvement could reduce down time, improve safety, create opportunities for public relations tours, reduce trafficking through sensitive habitats, and discourage erosion from surface runoff on exposed land. Haul roads, staging areas, and fire lanes should be constructed as needed. To the extent possible, infrastructure should be removed in a subsequent task during project implementation.
33. Engage and Train Personnel Who Will Supervise and Conduct Project Implementation Tasks Project personnel who lack restoration experience or knowledge of particular methods will benefit from attending workshops and conferences that provide background information. Otherwise, the chief practitioner should provide or arrange for training. Ideally, everyone who engages in the restoration, including laborers, should be briefed on project goals and objectives.
Implementation Planning Implementation plans describe the tasks that will be performed to realize project objectives. These tasks collectively comprise the project design. The care and thoroughness with which implementation planning is conducted will be reflected by how aptly implementation tasks are executed.
34. Describe the Interventions That Will Be Implemented to Attain Each Objective The chief practitioner designates and describes all actions, treatments, and manipulations needed to accomplish each objective listed in Guideline #27. For example, if the objective is to establish tree cover with a designated species composition and species abundance on for-
23_Appendix:IP_Clewell
9/17/07
11:45 AM
Page 185
Appendix
185
mer cropland, one intervention could be to plant sapling trees of the designated species at specified densities. Restoration projects should be designed to reduce the need for mid-course corrections that inflate costs and cause delays. In that regard, special care should be given to the design of site preparation activities that precede the introduction of biotic resources. Once biotic resources are introduced, it may become exceedingly difficult and expensive to repair dysfunctional aspects of the physical environment on account of inadequate site preparation. Some restoration interventions require aftercare or continuing periodic maintenance after initial implementation. These tasks are predictable and can be written into the implementation plans under their respective objectives. Examples of maintenance tasks include the repair of erosion on freshly graded land and the removal of competitive weeds and vines from around young plantings.
35. Acknowledge the Role of Passive Restoration Commonly, some but not all aspects of an ecosystem require intentional intervention to accomplish restoration. For example, if a correction to the physical environment is all that would be needed to initiate the recovery of the biota, then the practitioner would limit restoration activities to making that correction. To ensure that all aspects of ecosystem recovery have been considered, the restoration plan should acknowledge those attributes that are expected to develop passively without intervention. In the example, the practitioner would state that no manipulations were needed for the recovery of the biota. Realize that ecological restoration is an intentional process that involves at least modest intervention on the part of a practitioner. If recovery occurs without any intervention, it should be called natural reestablishment or designated by another term besides “ecological restoration.”
36. Prepare Performance Standards and Monitoring Protocols to Measure the Attainment of Each Objective A performance standard (also called a design criterion or success criterion) is a specific state of ecosystem recovery that indicates or demonstrates that an objective has been attained. For example, if the objective is to reestablish tree cover with a particular species composition and abundance on former cropland (as stated in the example for Guideline #27) and an intervention to realize that objective is to plant tree saplings of particular species at specified densities (as stated in the example for Guideline #34), then a plausible performance standard would be the establishment of a young forest that contained certain species of trees with minimal thresholds for tree species density, tree height, and collective canopy closure within a specified timeframe. Another potential example of performance standards would be the attainment of a threshold percentage of herbaceous vegetative cover in a seeded area within a given timeframe. Satisfaction of some performance standards can be attained by a single observation—for example, to determine whether a canal has been filled. Other performance standards require a series of monitoring events to document trends towards the attainment of a specified numeric threshold for a physical parameter or for a particular level of plant abundance or growth.
23_Appendix:IP_Clewell
186
9/17/07
11:45 AM
Page 186
Appendix
Performance standards require careful selection so as to engender confidence in their power to measure the attainment of an objective. Otherwise, the objectivity of the performance standard may be biased by the initial results of implementation. Monitoring protocols should be geared specifically to performance standards. Other monitoring generates extraneous information and inflates project costs. Monitoring protocols should be selected that allow data to be gathered with relative ease, thereby reducing monitoring costs. When a monitoring protocol is selected, a procedure for the analysis of monitoring data should be specified. For example, a statistical procedure could be designated—and a confidence interval stipulated—for determining significant differences. Performance standards are of particular utility in restoration projects that are conducted by contractors or that are required to satisfy permit conditions. The attainment of performance standards represents hard evidence that objectives have been met, that contractors can be paid, and that permit holders can be released from regulatory liability. Conversely, nonattainment demonstrates non-compliance that can lead to enforcement actions and legal sanctions. In a less technocratic context, the need for inclusion of performance standards in a restoration project diminishes. In smaller, less complex projects, or in projects where time of completion is not an issue, performance standards need not be specified. Instead, an ecological evaluation can be substituted in accord with Guideline #49.
37. Schedule the Tasks Needed to Fulfill Each Objective Scheduling can be complex. Some interventions can be accomplished concurrently and others must be done sequentially. Planted nursery stock may have to be contract-grown for months or longer in advance of planting and must be delivered in prime condition. If planting is delayed, planting stocks may become root-bound and worthless. If direct seeding is prescribed, seed collecting sites will have to be identified. The seed must be collected when ripe and possibly stored and pre-treated. Site preparation for terrestrial systems should not be scheduled when conditions are unsuitable. For example, soil manipulations cannot be accomplished if flooding is likely, and prescribed burning must be planned and conducted in accordance with applicable fire codes. The temporary unavailability of labor and equipment can further complicate scheduling. Workdays may have to be shortened for safety during especially hot weather and in lightning storms. Wet weather may cause equipment to become mired. Schedules should reflect these eventualities. Tasks for most objectives are implemented within a year or two. Some tasks may have to be delayed. For example, the re-introduction of plants and animals that require specialized habitat requirements may have to be postponed several years until habitat conditions become suitable.
38. Obtain Equipment, Supplies, and Biotic Resources Only appropriate items should be procured. For example, machinery should be selected that does not compact the soil inordinately or damage it when making turns. Degradable materials such as organic mulch are generally preferable to persistent ones such as plastic ground covers. Nursery-grown plants should be accepted only in peak condition, and their potting
23_Appendix:IP_Clewell
9/17/07
11:45 AM
Page 187
Appendix
187
soil should consist of all natural materials. Care should be taken to ensure that regional ecotypes of biotic resources are obtained to increase the chances for genetic fitness and to prevent introduction of poorly adapted ecotypes. However, a wider selection of ecotypes and species may be advantageous in order to pre-adapt the biota at project sites undergoing environmental change. Nurseries sometimes supply superior trees that have been selected for timber quality. These may have to be interplanted with “inferior” stock to facilitate ecosystem processes other than fiber production. For instance, deformed trees may be valuable for their wildlife cavities. Named cultivars and hybrids are unacceptable other than as temporary cover or nurse crops, because they do not represent natural species or taxa.
39. Prepare a Budget for Implementation Tasks, Maintenance Events, and Contingencies Budgeting for planned implementation tasks is obvious. However, budgeting for unknown contingencies is equally important. No restoration project has ever been accomplished exactly as it was planned. Restoration is a multivariate undertaking, and it is impossible to account for all eventualities. Examples of contingencies are severe weather events, depredations of deer and other herbivores on a freshly planted site, colonization by invasive species, vandalism, and unanticipated land use activities elsewhere in the landscape that impact the project site. The need to make at least some repairs is a near certainty. Generally, the cost of repair increases in relation to the time it takes to respond after its need is discovered. For these reasons, contingency funds should be budgeted for availability on short notice.
Implementation Tasks Project implementation fulfills implementation plans. If planning was thorough and supervision is adequate, implementation can proceed smoothly and within budget.
40. Mark Boundaries and Work Areas The project site should be staked or marked conspicuously in the field, so that labor crews know exactly where to work.
41. Install Permanent Monitoring Fixtures The ends of transect lines, photographic stations, bench marks, and other locations that will be used periodically for monitoring are staked or otherwise marked on-site and, if possible, identified with GPS coordinates. Staff gauges, piezometer wells, or other specified monitoring equipment is installed, marked, and their locations identified with GPS coordinates.
42. Implement Restoration Tasks Restoration tasks were identified in Guideline #34, and these are now implemented to fulfill the ecological restoration objectives. The chief practitioner supervises project implementation or delegates supervision to project team members. Responsibility for proper
23_Appendix:IP_Clewell
188
9/17/07
11:45 AM
Page 188
Appendix
implementation generally should not be entrusted to subcontractors, volunteers, and labor crews who are doing the work. The cost of retrofitting exceeds the cost of appropriate supervision.
Post-Implementation Tasks The attainment of objectives may depend as much on aftercare as it does on the care given to the execution of implementation tasks. The importance of post-implementation work cannot be overemphasized.
43. Protect the Project Site Against Vandals and Herbivory Security of the project site should be reviewed following project implementation. Vandalism may include youths who use project sites for recreational activities (e.g., camp fires, dirt bike riding). Grazing animals include domestic livestock, feral swine, deer, elephants, geese, nutria and many others. Beaver can destroy a newly planted site by plugging streams and culverts. Nuisance animals may require trapping and relocation or the construction of fenced exclosures.
44. Perform Post-Implementation Maintenance Conduct any maintenance activities that were described in Guideline #34.
45. Reconnoiter the Project Site Regularly to Identify Needs for Mid-Course Corrections The chief practitioner needs to inspect the project site frequently, particularly during the first year or two following an intervention, to schedule maintenance and to react promptly to contingencies.
46. Perform Monitoring as Required to Document the Attainment of Performance Standards Monitoring and the reporting of monitoring data are expensive. For that reason, monitoring should not be required until the data will be meaningful for decision-making. Regular reconnaissance (Guideline #45) may negate the need for frequent monitoring. Not all monitoring can be postponed. Some factors, such as water elevations and water quality parameters, are usually measured on a regular schedule to provide interpretable data. Sometimes monitoring is required to document survival of planting stock. A more effective substitute would be to require the replacement of stock that did not survive in lieu of monitoring.
47. Implement Adaptive Management Procedures as Needed Adaptive management as a restoration strategy is highly recommended, if not essential, because what happens in one phase of project work can alter what was planned for the next
23_Appendix:IP_Clewell
9/17/07
11:45 AM
Page 189
Appendix
189
phase. A restoration plan must contain built-in flexibility to facilitate alternative actions for addressing underperformance relative to objectives. The rationale for initiating adaptive management should be well documented by monitoring data or other observations. The project manager should realize that restoration objectives may never be realized for reasons that lie beyond the control of the chief practitioner. If so, then new goals (Guideline #5) and objectives (Guideline #27) may have to be substituted to ensure the recovery of a functional, intact, and otherwise whole ecosystem.
Evaluation and Publicity Assessments are conducted to ensure the satisfaction of project objectives and goals. The project is publicized for public and technical consumption.
48. Assess Monitoring Data to Determine Whether Performance Standards Are Met and Project Objectives Are Attained The results of data analysis should be documented in writing. If performance standards are not met within a reasonable period of time, refer to Guideline #47. Guideline #48 is ignored for smaller projects for which no performance standards were specified in Guideline #36.
49. Conduct an Ecological Evaluation of the Newly Completed Project This guideline requires satisfaction for those projects for which no performance standards were specified in Guideline #36. The evaluation should compare the restored ecosystem to its condition prior to the initiation of restoration activities (Guideline #20). The evaluation should determine whether or not the ecological goals from Guideline #5 were met, including the ecological attributes of restored ecosystems, as specified in the SER Standards. Technical publication is normally the way that an evaluation is presented. To satisfy the requirements of scientific rigor that some journals expect, this evaluation may require more documentation of site conditions than those that are available from monitoring data. For that reason, an ecological investigation is apropos for all completed restoration projects. Some restoration projects are conducted by enduring institutions that have the capacity for followup investigations to provide a conservation perspective on the valued ecosystems after they have undergone restoration. To facilitate this possibility, care should be given to use inventory protocols that can be readily repeated for comparative purposes.
50. Determine Whether Cultural Project Goals Were Met These goals were specified in Guideline #5.
51. Publicize and Prepare Written Accounts of the Completed Restoration Project All too often, project personnel walk away from a completed project to begin another without stopping to consider the magnitude of their work and its benefits to the public and the environment. Sometimes a final report is required by contract or as a permit condition. Even if it
23_Appendix:IP_Clewell
190
9/17/07
11:45 AM
Page 190
Appendix
is not, preparation of a final report is warranted to serve as an archival record of the project. The public deserves to be informed of a completed project and the benefits that accrue from it. News releases, media events, and public celebrations are all in order. Popular articles for public consumption can be prepared in non-technical language. Such publicity keeps ecological restoration in the public eye. If policy makers and politicians are aware of successfully completed projects, they will be more inclined to promote and fund new projects. Technical accounts of the project are equally important. Case histories become a treasure trove of information for all restoration practitioners who want to improve their professional proficiency. Case histories can be published in technical journals, trade journals, and posted on Internet sites. Papers and posters can be presented at conferences.
24_Glossary:IP_Clewell
9/17/07
11:46 AM
Page 191
glossary
The following definitions pertain to the usage of terms in this book. Some terms may have broader or additional meanings that are not listed. abiotic. Pertaining to the nonliving or physical aspects of an ecosystem such as soil, moisture, nutrients, and climatic factors. afforestation. The planting of open land with trees. agroforest. Forest or woodland that was intentionally planted with species that provide food or other economic products to people. alluvial. Pertaining to sediments and any other materials that are carried by streams onto floodplains, where they are deposited. alternative state. A cultural ecosystem that differs from the natural (nonanthropogenic) ecosystem that previously occupied a given site. anoxia. Lacking oxygen, as in a saturated soil. Related to hyponoxia. anthropogenic. Having an origin that was influenced or shaped by people. biodiversity. The diversity of life at all levels of organization, including the genetic level, all taxonomic levels (species, genus, family, etc.), and all ecological levels (species populations, communities, ecosystems, etc.), and roles performed. biota. All species (or all taxa recognized at some other level of classification), both plant and animal, that occur at a given location. cambium. Layer of cells beneath bark that divide to produce new vascular tissue. If cambium is killed, vascular tissue (called phloem) that transfers carbohydrates from leaves to roots is not renewed, starving the roots and killing the plant. cation exchange capacity. The capacity of positively charged ions to go in and out of solution in soil water and thereby become available to plants as nutrients. certification. Formal recognition by one’s peers of a person’s professional experience and capabilities. climax. A mature community or ecosystem that is apparently stable and persistent in its present state under existing environmental conditions. Sometimes called old growth by foresters to avoid identification with largely discredited ecological theory based on the climax concept. 191
24_Glossary:IP_Clewell
192
9/17/07
11:46 AM
Page 192
Glossary
community. The assemblage of organisms that occurs at a specified location or a particular portion of it, such as the plant community, insect community, or epiphytic community. community structure (or simply structure). The physical appearance of a community as determined by the sizes, life forms, abundance, and distribution of the predominant plant species. competition. The tendency of neighboring organisms to use the same volume of space and the same resources (water, nutrients, solar radiation). creation. The intentional replacement of an ecosystem with another kind of ecosystem of greater value, as is often required for compensatory mitigation. cultural ecosystems. Ecosystems that have developed under the joint influence of natural processes and human-imposed organization. degradation. The incremental and progressive impairment of an ecosystem caused by stress events or disturbances that occur with such frequency that recovery does not occur. desertification. Degradation that causes a site to become progressively drier, although true desert conditions are not necessarily attained. disturbance. A natural or anthropogenic event that changes the structure, content, or function of an ecosystem, usually in a substantial manner (also called perturbation). Alternatively, one incremental event in a sequence that causes ecosystem degradation. ecocline. Gradual change in community composition along an environmental gradient. ecological economics. The union of economics and ecology, with the economy conceived as a subsystem of the biosphere that is sustained by flows or throughput from the biosphere. ecological engineering. The manipulation and use of living organisms or other materials of biological origin to solve problems that affect people. ecological footprint. Any measure of human demand on the biosphere to provide resources and absorb wastes. ecological restoration. The process of assisting the recovery of an impaired ecosystem. ecology. The study of interactions between living organisms and between organisms and their environment. ecosystem. The complex of living organisms and the abiotic environment with which they interact at a specified location. ecosystem management. The manipulation of natural areas by technical managers to maintain ecosystem integrity and health. ecotone. A transition zone between distinct ecosystems. ecotype. Populations within a species that are genetically adapted to a particular set of environmental conditions and that commonly express only subtle if any distinguishing morphological features that reveal their genetic composition. flatlander. Said of a person with a nonholistic approach to ecological restoration, specifically with interests in only one quadrant in the four-quadrant model or in selected elements within its objective quadrants. forb. Herb that is not a grass or grasslike. four-quadrant model. Model that proposes that ecological restoration satisfies values concurrently of an ecological, socioeconomic, personal, and cultural nature. fragmentation. The division of a formerly continuous natural landscape into smaller natural units that are isolated from each other by lands that were converted for economic production or development.
24_Glossary:IP_Clewell
9/17/07
11:46 AM
Page 193
Glossary
193
fuel load. The potentially combustible materials, both living and nonliving, in an ecosystem. fuelwood. Wood gathered for domestic heating and cooking. function. Said of the dynamic aspects of ecosystems, such as photosynthesis, primary production, sequestering and recycling of mineral nutrients, and maintenance of food webs. Sometime restricted in meaning to these metabolic activities and sometimes expanded to include all ecosystem processes. functional group. Two or more species in the same ecosystem that carry out the same function or process. fynbos. Naturally occurring, species-rich, nutrient-poor, and pyrogenic shrublands with a Mediterranean climate in the Cape region, South Africa. Gaia. Concept that considers planet Earth and all its living beings to be interconnected as a single, self-regulating organism or as a single, self-organizing whole. The concept can be considered as real, allegorical, or metaphysical, depending on context. gardenified. Said of a landscape that has been modified, domesticated, or made less dangerous or threatening to people yet maintains a somewhat natural or rural appearance. garrigue. Species-rich, pyrogenic, and anthropogenic shrublands of Mediterranean climates that occupy a variety of soils around the Mediterranean Basin of Europe, northern Africa, and Asia Minor. geomorphology. The description and interpretation of land forms. goal. A desirable and ideal condition. grazier. In Australia, one who raises domestic livestock, comparable to a rancher or ranchero in the Western Hemisphere. habitat. The place where the individuals of a species live and where living conditions are suitable for that species. health. State or condition of an ecosystem in which its dynamic attributes are expressed within normal ranges of activity, relative to its ecological stage of development. herbivore. An animal that feeds on plants. Herbivory is the state or condition of feeding on plants. historic fidelity. Similarity to an ecosystem or community that previously occurred. Similar to historic authenticity, which connotes exact replication. holistic ecological restoration. Ecological restoration that attempts to recover an impaired ecosystem to a condition of wholeness (intactness) rather than simply to make a partial improvement. human well-being. The state whereby a person experiences contentment with living conditions and is able to pursue reasonable goals with some likelihood of success. Wealth is not necessarily a precondition of well-being. hydrology. The study of hydrodynamics, including the input, retention, output, and recycling of water. hydroperiod. The duration that a soil or substrate is inundated or saturated over the course of a year. hyponoxia. Soil condition in which oxygen levels are low. Related to anoxia. impact. A disturbance or other harmful occurrence to an ecosystem or landscape, caused by intentional or inadvertent human activity. impairment. The state or condition of an ecosystem or landscape that has been degraded, damaged, or destroyed by impact or disturbance.
24_Glossary:IP_Clewell
194
9/17/07
11:46 AM
Page 194
Glossary
indigenous. Native to a given location. intact. Said of an ecosystem that is functioning normally and expresses characteristic species composition and community structure for its developmental stage. integrity. State or condition of an ecosystem that expresses attributes of biodiversity (e.g., composition and structure) within normal ranges for its ecological stage of development. interspecific. Between species. intervention. A specific action of a restoration practitioner, such as site preparation activities, invasive species removal, or desirable species introduction. invasive species. A nonnative species (usually) whose populations proliferate at the expense of native species and co-opt space and habitat that would otherwise be occupied or recaptured by native species. keystone species. A species that has a substantially greater positive influence on other species than would be predicted by its abundance or size. K-strategist. Persistent, generally long-lived plant that is either competition tolerant or, in a high-stress environment, stress tolerant and that dedicates its energy reserves to the formation of vegetative rather than reproductive structures. Contrast r-strategist. landscape. An assemblage of ecosystems that are arranged in recognizable patterns and that exchange organisms and materials such as water. life form. The distinguishing features of a plant, such as woody or herbaceous, evergreen or deciduous, spiny or spineless. local ecological knowledge (LEK). Current and ever-expanding, useful knowledge about species and ecosystems, as gathered by people who live in rural landscapes in a sustainable manner. See also traditional ecological knowledge. manipulation. See intervention. mesic. Said of a terrestrial ecosystem with soils that are generally moist, rather than dry (xeric) or wet (hydric), or of a species that occurs in a mesic habitat. microclimate. Abnormal atmospheric conditions, relative to those of the more widespread macroclimate in the immediate area, caused by community structure (e.g., shade, windbreaks) and processes (e.g., transpiration) in an ecosystem. mitigation. An approach or strategy used by government agencies to require that unavoidable environmental damage be compensated by ecological restoration or another activity (e.g., rehabilitation, reclamation, enhancement). monitor. Systematically gather information on an ecosystem, sometimes repetitiously using a standard protocol. mycorrhiza. A mutual association between a plant root and a fungus in the soil whose hyphae (strands) penetrate the root and extract carbohydrate while providing the root with phosphorus and other mineral nutrients. natural capital. Stocks of natural resources as they occur in natural and managed landscapes and from which flow natural goods and services. These resources can be renewable (e.g., ecosystems, organisms), nonrenewable (e.g., fossil fuels, minerals), replenishable (e.g., the atmosphere, potable water, arable soils), and cultivated (e.g., crops, forest plantations). natural goods and services. Foods, fibers, fuels, or other materials and products of economic or cultural value that are supplied by ecosystems and various economically valuable ser-
24_Glossary:IP_Clewell
9/17/07
11:46 AM
Page 195
Glossary
195
vices that ecosystems provide to people, such as floodwater retention and erosion control— all without direct costs of production and maintenance. nongovernment organization (NGO). A private, nonprofit organization that usually receives funding from individual donations or philanthropic sources and provides services that are otherwise generally unavailable. nutrients. Mineral elements needed for plant metabolism and growth, such as phosphorus, calcium, magnesium, and iron. objective. A specific, short-term, and direct result that is desired from project work and will contribute eventually to the achievement of project goals. palynology. The study of pollen that is preserved or fossilized in sedimentary deposits and whose abundance and age—or relative age—can be determined. performance standard. A value or threshold condition that is determined by monitoring and that, when attained, verifies that a particular objective has been achieved. plankton. Plant or animal, commonly microscopic, that lives suspended in water. practitioner. Someone who applies practical skills and knowledge. prairie. In North America, grassland. pristine. Untouched or entirely uninfluenced by people. process. Dynamic aspect of an ecosystem or landscape, sometimes considered synonymous with function, including interactions such as transpiration, competition, parasitism, animal-mediated pollination and seed dispersal, mycorrhizal relationships, and other symbiotic relationships. production system. Land or landscape unit allocated to the production of food, fiber, pasturage, aquaculture, or other marketable commodities that could also be consumed for subsistence, and is usually maintained with external inputs of energy (e.g., fossil fuels) and materials (e.g., lime, agrochemicals). propagule. Any plant reproductive structure, sexual or vegetative, such as a seed, spore, or rootstock that proliferates. provenance. The geographic place of origin or source of seeds, nursery stock, and other propagules and organisms that arrive at or are intentionally introduced at a project site. pyrogenic. Said of an ecosystem that is maintained by the periodic incidence of fire. reallocation. The rededication of ecosystems for new uses of an economic type, other than the transformation of an ecosystem to an alternative state. reclamation. Conversion of land perceived as being useless to a productive condition, commonly for agriculture and silviculture. Recovery of productivity is the main goal. reference model (also called the reference). One or more actual ecosystems (called reference sites) or written ecosystem descriptions on which restoration planning is based and that can serve as a basis for evaluating a completed restoration project. rehabilitation. The recovery of ecosystem processes to regain normal function and ecosystem services without necessarily restoring the biodiversity of the reference or its projected trajectory. reintegration. The process of reversing landscape fragmentation. resilience. The capacity of an ecosystem to persist on a given trajectory and with a given set of dynamics in the face of disturbances. resistance. The capacity of an ecosystem to avoid disturbance.
24_Glossary:IP_Clewell
196
9/17/07
11:46 AM
Page 196
Glossary
restoration ecology. The science on which the practice of ecological restoration is based and that provides the concepts and models on which practitioners depend. Alternatively, the science that advances the frontiers of theoretical ecology through studies of restored ecosystems and those that are undergoing restoration. restoring natural capital (RNC). Replenishment of natural capital stocks in the interests of long-term human well-being and ecosystem health. Natural capital is restored through ecological restoration and other ecologically sound improvements in natural landscapes and those managed for production. RNC efforts are reinforced by the elevation of people’s awareness of and respect for the importance of natural capital in their daily lives. revegetation. Establishment of plant cover on open land, usually with one or few species, irrespective of their provenance. riparian. Pertaining to rivers, such as a forest that occupies a river floodplain. r-strategist. Plant that is short-lived, weedy, and opportunistic that colonizes open and disturbed environments, is intolerant of competition, and expends its energy reserves on reproduction rather than vegetative development. Contrast K-strategist. ruderal. Weedy. runoff. Rainfall or other water that moves to lower elevations by spreading across the land surface rather than flowing through a defined channel. salinization. Process by which soil in the root zone becomes increasing more saline (salty) through the evaporation of irrigation water or another cause generally related to land use. savanna. Vegetation consisting of dense grasses or sedges, commonly with forbs intermixed, that is interrupted at wide intervals by shrubs and trees that grow individually or as conspicuous clumps or patches. sedge. Grasslike plants that belong to the family Cyperaceae and that commonly replace grasses in wet sites. seed bank (or propagule bank). Seeds (and other propagules) in the soil that can replenish the vegetation after disturbance. self-organizing. Said of an ecosystem that develops and functions in response to its internal processes. Synonym: autogenic. self-sustainable. Said of a self-organizing ecosystem that persists indefinitely, although not without transformations in response to its own internal dynamics, environmental flux, and longer-term changes in environmental conditions. sere. All developmental stages collectively of an ecosystem as a new ecosystem matures or a disturbed ecosystem recovers. Each stage can be called a seral stage or seral community. silviculture. The establishment and maintenance of trees or a forest, generally for the production of wood or another marketable commodity. socioecological landscape. A landscape that consists of a mixture of natural or gardenified ecosystems, production systems, and sometimes developed land such as residences, farm buildings, and even light industry, all units of which are functionally interrelated. spatial. Pertaining to size, dimensions, or location. species composition. All the different kinds of species that occur at a site. stakeholder. Any person who is affected in any way—positively or negatively and directly or indirectly—by an activity, including an ecological restoration project.
24_Glossary:IP_Clewell
9/17/07
11:46 AM
Page 197
Glossary
197
state. The appearance, expression, or manifestation of an ecosystem or landscape as determined by species composition, the life forms and sizes of individuals, and community structure. stress. A normally occurring condition or recurring event that is more detrimental to some species than to others and that largely determines species composition and abundance in an ecosystem. Examples of stress include freezing temperatures, drought, salinity, and unavailability of nutrients. subsistence. The provision of food, fuel, and other essentials for use by an individual, family, or tribal village, as opposed to marketable commodities that can be sold or traded. succession. The sequence of stages that occur in species composition (particularly) and in species abundance, community structure, and the complexity of interspecific interactions as an ecosystem develops or recovers from disturbance. Contrast sere. sustainability science. The study of dynamic interactions between nature and society, so as to apply knowledge in support of decision making for sustainable economic development. target. The intended long-term outcome (endpoint or goal) of a restoration project, which sometimes is not fully achieved until long after restoration project work has ceased. temporal. Pertaining to time and duration. threshold of irreversibility. A degree of impairment to an ecosystem that, when it is surpassed, is too severe to allow recovery of that ecosystem to its former, intact state by unassisted succession. Ecological restoration is needed. traditional cultural practices. The application of traditional ecological knowledge that leads to the development and maintenance of cultural ecosystems. traditional ecological knowledge (TEK). Ecological knowledge derived through societal experiences and perceptions that are accumulated in a traditional society through interaction with nature and natural resources. TEK commonly originates through trial and error and often is passed down to subsequent generations by oral tradition. See also LEK. trajectory. The sequence of biotic expressions of an individual ecosystem in the past, from which future expressions may be predicted. vascular plants. Plants containing vascular tissue (xylem, phloem), including all trees, flowering plants, and ferns and excluding algae, fungi, and mosses. zooplankton. Plankton consisting of animal species.
24_Glossary:IP_Clewell
9/17/07
11:46 AM
Page 198
25_Refs:IP_Clewell
9/17/07
11:47 AM
Page 199
references
Akerman, J. A. Jr. 1976. Florida Cowman: A History of Florida Cattle Raising. Florida Cattlemen’s Association, Kissimmee. Allen, W. 2001. Green Phoenix, Restoring the Tropical Forests of Guanacaste, Costa Rica. Oxford University Press, Oxford. Altieri, M. A., and W. H. Whitcomb. 1980. Weed manipulation for insect pest management in corn. Environmental Management 4:483–489. Anderson, M. K. 2005. Tending the Wild: Native American Knowledge and the Management of California’s Natural Resources. University of California Press, Berkeley. Apostol, D., and M. Sinclair (eds.). 2006. Restoring the Pacific Northwest. The Art and Science of Ecological Restoration in Cascadia. Island Press, Washington, DC. Arno, S. F., and C. E. Fiedler. 2006. Ponderosa pine and interior forests. Pp. 194–215 in D. Apostol and M. Sinclair, eds. Restoring the Pacific Northwest. The Art and Science of Ecological Restoration in Cascadia. Island Press, Washington, DC. Aronson, J., J. N. Blignaut, S. J. Milton, and A. F. Clewell. 2006a. Natural capital: The limiting factor. Ecological Engineering 28:1–5. ———, A. F. Clewell, J. N. Blignaut, and S. J. Milton. 2006b. Ecological restoration: A new frontier for conservation and economics. Journal for Nature Conservation 14:135–139. ———, S. Dhillion, and E. Le Floc’h. 1995. On the need to select an ecosystem of reference, however imperfect: A reply to Pickett & Parker. Restoration Ecology 3:1–3. ———, C. Floret, E. Le Floc’h, C. Ovalle, and R. Pontanier. 1993a. Restoration and rehabilitation of degraded ecosystems in arid land semi-arid lands. I. A view from the South. Restoration Ecology 1:8–17. ———, C. Floret, E. Le Floc’h, C. Ovalle, and R. Pontanier. 1993b. Restoration and rehabilitation of degraded ecosystems. II. Case studies in Chile, Tunisia and Cameroon. Restoration Ecology 1:168–187. ———, E. Le Floc’h, and C. Ovalle. 2002a. Semi-arid woodlands and desert fringes. Pp. 466–485 in M. Perrow and A. Davy, eds. Handbook of Ecological Restoration. Vol. 2. Restoration in Practice. Cambridge University Press, Cambridge. ———, S. J. Milton, and J. N. Blignaut. 2006c. Conceiving the science, business and practice of restoring natural capital. Ecological Restoration 22:22–24. ———, S. J. Milton, and J. N. Blignaut (eds.). 2007a. Restoring Natural Capital: Science, Business and Practice. Island Press, Washington, DC. ———, S. J. Milton, and J. N. Blignaut. 2007b. Restoring natural capital: Definitions and rationale. Pp. 3–8 in J. Aronson, S. J. Milton, and J. N. Blignaut, eds. Restoring Natural Capital: Science, Business and Practice. Island Press, Washington, DC. ———, C. Ovalle, J. Avendaño, L. Longeri, and A. Del Pozo. 2002b. Agroforestry tree selection in central Chile: Biological nitrogen fixation and plant growth in six dryland species. Agroforestry Systems 56:155–166. Bainbridge, D. A. 2007. A Guide for Desert and Dryland Restoration: New Hope for Arid Lands, Island Press, Washington, DC. 199
25_Refs:IP_Clewell
200
9/17/07
11:47 AM
Page 200
References
Baird, K., and J. P. Rieger. 1989. A restoration design for least Bell’s vireo habitat in San Diego County. Pp. 462–467 in D. L. Abel, ed. Proceedings of the California Riparian Systems Conference: Protection, Management and Restoration for the 1990s. Gen. Tech. Rep. PSW-110, California Pacific Southwest Forest and Range Experiment Station, Forest Service, U.S. Department of Agriculture, Berkeley. Baker, W. L. 2002. Indians and fire in the Rocky Mountains: The wilderness hypothesis renewed. Pp. 41–76 in T. R. Vale, ed. Fire, Native Peoples, and the Natural Landscape. Island Press, Washington, DC. Bakker, J. P., and T. Piersma. 2006. Restoration of intertidal flats and tidal salt marshes. Pp. 174–192 in J. van Andel and J. Aronson, eds. Restoration Ecology: The New Frontier. Blackwell Science, Oxford. Balée, W. 2000. Elevating the Amazonian landscape. Forum for Applied Research and Public Policy 15:28–33. Balmford, A., A. Bruner, P. Cooper, R. Costanza, S. Farber, R. E. Green, M. Jenkins, P. Jefferiss, V. Jessamy, J. Madden, K. Munro, N. Myers, S. Naeem, J. Paavola, M. Rayment, S. Rosendo, J. Roughgarden, K. Trumper, and R. K. Turner. 2002. Economic reasons for conserving wild nature. Science 297:950– 953. Barbéro, M., R. Loisel, and P. Quézel. 1992. Biogeography, ecology and history of Mediterranean Quercus ilex ecosystems. Vegetatio 99/100:19–34. Bernhardt, E. S., M. A. Palmer, J. D. Allan, G. Alexander, K. Barnas, S. Brooks, J. Carr, S. Clayton, C. Dahm, J. Follstad-Shah, D. Galat, S. Gloss, P. Goodwin, D. Hart, B. Hassett, J. Jenkinson, S. Katz, G. M. Kondolf, P. S. Lake, R. Lave, J. L. Meyer, T. K. O’Donnell, L. Pagano, B. Powell, and E. Sudduth. 2005. Synthesizing U.S. river restoration efforts. Science 308:636–637. Blignaut, J. N., J. Aronson, P. Woodworth, S. Archer, N. Desai, and A. F. Clewell. 2007. Restoring natural capital: An ethical reflection. Pp. 9–16 in J. Aronson, S. J. Milton and J. N. Blignaut, eds. Restoring Natural Capital: Science, Business and Practice. Island Press, Washington, DC. Blondel, J., and J. Aronson. 1999. Biology and Wildlife of the Mediterranean Region. Oxford University Press, Oxford. Bond, W. J., and J. E. Keeley. 2005. Fire as global “herbivore”: The ecology and evolution of flammable ecosystems. Trends in Ecology and Evolution 20:387–394. ———, G. F. Midgley, and F. I. Woodward. 2003. The importance of low atmospheric CO2 and fire in promoting the spread of grasslands and savannas. Global Change Biology 9:973–982. ———, and B. W. van Wilgen. 1996. Fire and Plants. Chapman & Hall, New York. Bonnicksen, T. M. 1988. Restoration ecology: Philosophy, goals, and ethics. The Environmental Professional 10:25–35. Bowman, D. M. J. S. 1998. The impact of aboriginal landscape burning on the Australian biota. New Phytologist 140:385–410. Boyer, K. E., and J. B. Zedler. 1999. Nitrogen addition could shift plant community composition in a restored California salt marsh. Restoration Ecology 7:74–85. Bradshaw, A. D. 1987. Reclamation of land and ecology of ecosystems. Pp. 53–74 in W. R. Jordan III, M. E. Gilpin, and J. D. Aber, eds. Restoration Ecology: A Synthetic Approach to Ecological Research. Cambridge University Press, Cambridge. ———, and M. J. Chadwick. 1980. The Restoration of Land, the Ecology and Reclamation of Derelict and Degraded Land. University of California Press, Berkeley. Bradstock, R. A., J. E. Williams, and A. M. Gill (eds.). 2002. Flammable Australia: The Fire Regimes and Biodiversity of a Continent. Cambridge University Press, Cambridge. Cairns, J. Jr. 1988. Restoration ecology: The new frontier. Pp. 1–11 in J. Cairns Jr., ed. Rehabilitating Damaged Ecosystems. CRC Press, Boca Raton, FL. ———. 1993. Ecological restoration: Replenishing our national and global ecological capital. Pp. 193–208 in D. Saunders, R. Hobbs, and P. Ehrlich, eds. Nature Conservation 3: Reconstruction of Fragmented Ecosystems. Surrey Beatty & Sons, Chipping Norton, NSW, Australia. ———. 1995. Restoration ecology: Protecting our national and global life support systems. Pp. 1–12 in J. Cairns Jr., ed. Rehabilitating Damaged Ecosystems, 2nd edition. Lewis, Boca Raton, FL. Callenbach, E. 1975. Ecotopia. Banyan Tree Books, Berkeley. Carpenter, S., B. Walker, J. M. Anderies, and N. Abel. 2001. From metaphor to measurement: Resilience of what to what? Ecosystems 4:765–781. Chepstow-Lusty, A., M. R. Frogley, M. B. Bush, and J. Aronson. 2005. 80,000 yr of vegetation and climate change on the Bolivian Altiplano prior to the Last Glacial Maximum. Quaternary Research 63:90–98.
25_Refs:IP_Clewell
9/17/07
11:47 AM
Page 201
References
201
———, and M. Winfield. 2000. Inca agroforestry: Lessons from the past. Ambio 29:322–328. Clark, W. C., and N. M. Dickson. 2003. Science and technology for sustainable development special feature: Sustainability. Proceedings of the National Academy of Sciences (USA) 100:8059–8061. Clement, C. R. 1999. 1492 and the loss of Amazonian crop genetic resources. I. The relation between domestication and human population decline. Economic Botany 53:188–202. ———. 2006. Demand for two classes of traditional agroecological knowledge in modern Amazonia. Pp. 33–50 in D. A. Posey and M. J. Balick, eds. Human Impacts on Amazonia: The Role of Traditional Ecological Knowledge in Conservation and Development. Columbia University Press, New York. Clewell, A. F. 1989. Natural history of wiregrass (Aristida stricta Michx., Gramineae). Natural Areas Journal 9:223–233. ———. 1995. Downshifting. Restoration and Management Notes 13:171–175. ———. 1999. Restoration of riverine forest at Hall Branch on phosphate-mined land, Florida. Restoration Ecology 7:1–14. ———. 2000. Editorial: Restoration of natural capital. Restoration Ecology 8:1. ———. 2001. Resistance to restoration. Ecological Restoration 19:3–4. ———, and J. Aronson. 2006. Motivations for the restoration of ecosystems. Conservation Biology 20:420– 428. ———, R. S. Beaman, and M. E. Lasley. 1998. Long-Term Vegetational Monitoring at the Mississippi Sandhill Crane National Wildlife Refuge, 1997. Mississippi Sandhill Crane National Wildlife Refuge, Gautier. ———, J. A. Goolsby, and A. G. Shuey. 1982. Riverine forests of the South Prong Alafia River system, Florida. Wetlands 2:21–72. ———, J. P. Kelly, and C. L. Coultas. 2000. Forest restoration at Dogleg Branch on phosphate-mined and reclaimed land, Florida. Pp. 197–204 in W. L. Daniels and S. G. Richardson, eds. Proceedings, 2000 Annual Meeting of the American Society for Surface Mining and Reclamation, Tampa, Florida, June 11–15, 2000. American Society of Surface Mining, Lexington, KY. ———, and R. Lea. 1990. Creation and restoration of forested wetland vegetation in the Southeastern United States. Pp. 195–231 in J. A. Kusler and M. E. Kentula, eds. Wetland Creation and Restoration: The Status of the Science. Island Press, Washington, DC. ———, J. Rieger, and J. Munro. 2005. Guidelines for Developing and Managing Ecological Restoration Projects, 2nd edition. Society for Ecological Restoration International (www.ser.org/) and Society for Ecological Restoration International, Tucson, AZ. Costanza, R., and H. E. Daly. 1992. Natural capital and sustainable development. Conservation Biology 6:37–46. ———, W. J. Mitsch, and J. W. Day Jr. 2006. Creating a sustainable and desirable New Orleans. Ecological Engineering 26:317–320. Craft, C. B., S. W. Broome, and C. L. Campbell. 2002. Fifteen years of vegetation and soil development following brackish-water marsh creation. Restoration Ecology 10:248–258. Daily, G. (ed.). 1997. Nature’s Services. Island Press, Washington, DC. Daly, H. E., and J. B. Cobb Jr. 1994. For the Common Good: Redirecting the Economy Toward Community, the Environment, and a Sustainable Future, 2nd edition. Beacon, Boston. ———, and J. Farley. 2004. Ecological Economics: Principles and Applications. Island Press, Washington, DC. D’Antonio, C. M., and J. C. Chambers. 2006. Using ecological theory to manage or restore ecosystems affected by invasive plant species. Pp. 260–279 in D. A. Falk, M. A. Palmer, and J. B. Zedler, eds. Foundations of Restoration Ecology. Island Press, Washington, DC. ———, and L. Meyerson. 2002. Exotic species and restoration: Synthesis and research needs. Restoration Ecology 10:703–713. Davis, M. A., and L. B. Slobodkin. 2004a. Letter. Frontiers in Ecology and the Environment 2:44–45. ———, and L. B. Slobodkin. 2004b. The science and values of restoration ecology. Restoration Ecology 12:1–3. Day, G. M. 1953. The Indian as an ecological factor in the northeastern forest. Ecology 34:329–346. Day, J. W., J. Barras, E. Clairain, J. Johnston, D. Justic, G. P. Kemp, J.-Y. Ko, R. Lane, W. J. Mitsch, G. Steyer, P. Templet, and A. Yañez-Arancibia. 2005. Implications of global climatic change and energy cost and availability for the restoration of the Mississippi delta. Ecological Engineering 24:253–265.
25_Refs:IP_Clewell
202
9/17/07
11:47 AM
Page 202
References
De Groot, R. S. 1992. Functions of Nature. Wolters-Noordhoff, Groningen, The Netherlands. Denevan, W. M. 1992. The pristine myth: The landscape of the Americas in 1492. Annals of the Association of American Geographers 82:369–385. Desai, N. 2003. Sacred Grove: Potential Reference Site for Restoration Project. Restoration Ecology Promotion Booklet 2003. SER-India Publication Series No. 4. SER India, Pune. Descheemaeker, K., J. Nyssen, J. Poesen, D. Raes, M. Haile, B. Muys, and S. Deckers. 2006. Runoff on slopes with restoring vegetation: A case study from the Tigray highlands, Ethiopia. Journal of Hydrology 331:219–241. Diamond, J. 1992. The Third Chimpanzee. The Evolution and Future of the Human Animal. HarperCollins, New York. ———. 2005. Collapse. How Societies Choose to Fail or Succeed. Penguin, New York. Dodson, S. I., T. F. H. Allen, S. R. Carpenter, A. R. Ives, R. L. Jeanne, J. F. Kitchell, N. E. Langston, and M. G. Turner. 1998. Ecology. Oxford University Press, New York. Drury, W. H., and I. C. T. Nisbet. 1973. Succession. Journal of the Arnold Arboretum 54:331–368. Egan, D., and E. A. Howell. 2001. The Historical Ecology Handbook: A Restorationist’s Guide to Reference Ecosystems. Island Press, Washington, DC. Egler, E. E. 1954. Vegetation science concepts 1. Initial floristic composition, a factor in old-field vegetation development. Vegetatio Acta Geobotanica 4:412–417. Etienne, M., J. Aronson, and E. Le Floc’h. 1998. Abandoned lands and land use conflicts in southern France. Piloting ecosystem trajectories and redesigning outmoded landscapes in the 21st century. Pp. 127–140 in P. W. Rundel, G. Montenegro, and F. Jaksic, eds. Landscape Degradation and Biodiversity in Mediterranean-Type Ecosystems. Ecological Studies Series No. 136. Springer, Berlin. Ewel, J. J., and F. E. Putz. 2004. A place of alien species in ecosystem restoration. Frontiers in Ecology and the Environment 2:354–360. Falk, D. A. 2006. Process-centered restoration in a fire-adapted ponderosa pine forest. Journal for Nature Conservation 14:140–151. ———, M. A. Palmer, and J. B. Zedler (eds.). 2006a. Foundations of Restoration Ecology. Island Press, Washington, DC. ———, M. A. Palmer, and J. B. Zedler. 2006b. Integrating restoration ecology and ecological theory: A synthesis. Pp. 341–346 in D. A. Falk, M. A. Palmer, and J. B. Zedler, eds. Foundations of Restoration Ecology. Island Press, Washington, DC. Farina, A. 2000. The cultural landscape as a model for the integration of ecology and economics. BioScience 50:313–320. FDEP (Florida Department of Environmental Protection). 1999. Ecological Assessment of Reclaimed Streams, Hillsborough, Hardee and Polk Counties, Sampled October 1998. Bureau of Laboratories, Division of Administration and Technical Support, Florida Department of Environmental Protection, Tallahassee. Feiertag, J. A., D. J. Robertson, and T. King. 1989. Slash and turn. Restoration and Management Notes 7:13–17. Forman, R. T. T. 1995. Land Mosaics: The Ecology of Landscapes and Regions. Cambridge University Press, Cambridge. ———, and M. Gordon. 1986. Landscape Ecology. Wiley, New York. Friederici, P. 2006. Nature’s Restoration: People and Places on the Front Lines of Conservation. Island Press/Shearwater Books, Washington, DC. Gondard, H., S. Jauffret, J. Aronson, and S. Lavorel. 2003. Plant functional types: A promising tool for management and restoration of degraded lands. Applied Vegetation Science 6:223–234. Grant, C. D. 2006. State-and-transition successional model for bauxite mining rehabilitation in the jarrah forest of Western Australia. Restoration Ecology 14:28–37. Grime, J. P. 1974. Vegetation classification by reference to strategies. Nature 250:26–31. ———. 1977. Evidence for the existence of three primary strategies in plants and its relevance to ecological and evolutionary theory. American Naturalist 111:1169–1194. ———. 1979. Plant Strategies and Vegetation Processes. Wiley, Chichester, UK. Grumbine, R. E. 1994. What is ecosystem management? Conservation Biology 8:27–38. Gunderson, L. H. 2000. Ecological resilience—in theory and application. Annual Review of Ecology and Systematics 31:425–439.
25_Refs:IP_Clewell
9/17/07
11:47 AM
Page 203
References
203
———, and C. S. Holling (eds.). 2002. Panarchy: Understanding Transformations in Human and Natural Ecosystems. Island Press, Washington, DC. Hall, M. 2005. Earth Repair: A Transatlantic History of Environmental Restoration. University of Virginia Press, Charlottesville. Harper, J. L. 1987. The heuristic value of ecological restoration. Pp. 35–45 in W. R. Jordan III, M. E. Gilpin, and J. D. Aber, eds. Restoration Ecology: A Synthetic Approach to Ecological Research. Cambridge University Press, Cambridge. Harris, J. A., P. Birch, and J. Palmer. 1996. Land Restoration and Reclamation Principles and Practice. Addison Wesley Longman, Essex, UK. ———, R. J. Hobbs, E. Higgs, and J. Aronson 2006. Ecological restoration and global climate change. Restoration Ecology 14:170–176. ———, and R. van Diggelen. 2006. Ecological restoration as a project for global society. Pp. 3–15 in J. van Andel and J. Aronson, eds. Restoration Ecology: The New Frontier. Blackwell Science, Oxford. Hebb, E. A., and A. F. Clewell. 1976. A remnant stand of old-growth slash pine in the Florida panhandle. Bulletin of the Torrey Botanical Club 103:1–9. Hey, D. L., and N. S. Philippi. 1995. Flood reduction through wetland restoration: The upper Mississippi River basin as a case history. Restoration Ecology 3:4–17. ———, and N. S. Philippi. 1999. A Case for Wetland Restoration. Wiley, New York. Higgs, E. S. 1997. What is good ecological restoration? Conservation Biology 11:338–348. Hilderbrand, R. H., A. C. Watts, and A. M. Randle. 2005. The myths of restoration ecology. Ecology and Society 10:19. www.ecologyandsociety/vol10/iss1/art19/. Hiremath, A. J., and B. Sundaram. 2005. The fire–lantana cycle hypothesis in Indian forests. Conservation and Society 3:26–42. Hobbs, R. J. 2002. The ecological context: A landscape perspective. Pp. 22–45 in M. Perrow and A. J. Davy, eds. Handbook of Ecological Restoration. Cambridge University Press, Cambridge. ———, and D. A. Norton. 1996. Towards a conceptual framework for restoration ecology. Restoration Ecology 4:93–110. ———, and D. A. Saunders. 1991. Reintegration of fragmented landscapes: A preliminary framework for the Western Australian wheatbelt. Journal of Environmental Management 33:161–167. ———, and D. A. Saunders. 1992. Reintegration of Fragmented Landscapes: Towards Sustainable Production and Nature Conservation. Springer, New York. ———, and K. N. Suding. 2007. New Models for Ecosystem Dynamics and Restoration. Island Press, Washington, DC. ———, and L. R. Walker. In press. Old field succession: Development of concepts. In V. A. Cramer and R. J. Hobbs, eds. Old Fields Dynamics and Restoration of Abandoned Farmland. Island Press, Washington, DC. Holland, K. M. 1994. Restoration rituals. Restoration and Management Notes 12:121–125. Holling, C. S. 1973. Resilience and stability of ecological systems. Annual Review of Ecology and Systematics 4:1–24. ———, and L. H. Gunderson. 2002. Resilience and adaptive cycles. Pp. 25–62 in L. H. Gunderson and C. S. Holling, eds. Panarchy, Understanding Transformations in Human and Natural Systems. Island Press, Washington, DC. House, F. 1996. Restoring relations: The vernacular approach to ecological restoration. Restoration and Management Notes 14:57–61. Janzen, D. H. 1988. Tropical ecological and biocultural restoration. Science 239:243–244. ———. 1992. The Neotropics. Restoration and Management Notes 10:8–13. ———. 1998. Gardenification of wildland nature and the human footprint. Science 279:1312–1313. ———. 2002. Tropical dry forest restoration: Area de Conservación Guanacaste, northwestern Costa Rica. Pp. 559–584 in M. R. Perrow and A. J. Davy, eds. Handbook of ecological restoration. Vol. 2. Restoration in practice. Cambridge University Press, Cambridge. Jones, C. G., J. H. Lawton, and M. Shachak. 1994. Organisms as ecosystem engineers. Oikos 69:373–386. Jordan, W. R. III. 1986. Restoration and the reentry of nature. Restoration and Management Notes 4:2. ———. 1994. “Sunflower forest”: Ecological restoration as the basis for a new environmental paradigm. Pp. 17–34 in D. A. Baldwin Jr., J. DeLuce, and C. Pletsch, eds. Beyond Preservation, Restoring and Inventing Landscapes. University of Minnesota Press, Minneapolis.
25_Refs:IP_Clewell
204
9/17/07
11:47 AM
Page 204
References
———. 2003. The Sunflower Forest: Ecological Restoration and the New Communion with Nature. University of California Press, Berkeley. Jurdant, M., J. L. Bélair, V. Gerardin, and J. P. Ducroc. 1977. L’inventaire du Capital-Nature. Méthode de Classification et de Cartographie Écologique du Territoire. Service des Etudes Ecologiques Régionales, Direction Régionale des Terres, Pêches et Environnement, Quebec. Kangas, P. C. 2004. Ecological Engineering: Principles and Practice. Lewis Publishers, CRC Press, Boca Raton, FL. Kates, R. W., W. C. Clark, R. Corell, J. M. Hall, C. C. Jaeger, I. Lowe, J. J. McCarthy, H. J. Schellnhuber, B. Bolin, N. M. Dickson, S. Faucheux, G. C. Gallopin, A. Grübler, B. Huntley, J. Jäger, N. S. Jodha, R. E. Kasperson, A. Mabogunje, P. Matson, H. Mooney, B. Moore III, T. O’Riordan, and U. Svedin. 2001. Sustainability science. Science 292:641–642. Krauss, S., and T. Hua He. 2006. Rapid genetic identification of local provenance seed collection zones for ecological restoration and biological conservation. Journal for Nature Conservation 14:190–199. Kuhn, T. S. 1996. The Structure of Scientific Revolutions, 3rd edition. University of Chicago Press, Chicago. Kurz, H., and D. Wagner. 1957. Tidal marshes of the Gulf and Atlantic coasts of north Florida and Charleston, South Carolina. Florida State University Studies 24:1–168. Lackey, R. T. 2004. Societal values and the proper role of restoration ecologists. Frontiers in Ecology and the Environment 2:45–46. Lamb, D., and D. Gilmour. 2003. Rehabilitation and Restoration of Degraded Forests. IUCN (The World Conservation Union) and WWF (World Wide Fund for Nature), Gland, Switzerland. Lavorel, S., S. McIntyre, J. Landsberg, and T. D. A. Forbes. 1997. Plant functional classification: From general groups to specific groups based on response to disturbance. Trends in Ecology and Evolution 12:474– 478. Le Floc’h, E., J. Aronson, S. S. Dhillion, J. L. Guillerm, A. Grossmann, and E. Cunge. 1998. Biodiversity and ecosystem trajectories: First results from a new LTER in southern France. Acta Oecologica 19:283–293. Leopold, A. 1949. A Sand County Almanac. Oxford University Press, Oxford, reprinted in 1970 by Ballantine, New York. ———. 1953. The Round River. Oxford University Press, New York. Leopold, L. B. (ed.). 1993. Round River. From the Journals of Aldo Leopold. Oxford University Press, Oxford. Lovelock, J. E. 1991. Gaia, a planetary emergent phenomenon. Pp. 30–42 in W. I. Thompson, ed. Gaia 2: Emergence the New Science of Becoming. Lindisfarne, Hudson, NY. Ludwig, J. A., and D. J. Tongway. 1996. Rehabilitation of semiarid landscapes in Australia: II. Restoring vegetation patches. Restoration Ecology 4:398–406. ———, D. Tongway, D. Freudenberger, J. Nobel, and K. Hodgkinson (eds.). 1997. Landscape Ecology: Function and Management: Principles from Australia’s Rangelands. CSIRO. Canberra. Lugo, A. E. 1978. Stress and ecosystems. Pp. 62–101 in J. H. Thorp and J. W. Gibbons, eds. Energy and Environmental Stress in Aquatic Ecosystems. DOE Symposium Series (CONF-771114). National Technical Information Service, Springfield, VA. Luken, J. O. 1990. Directing Ecological Succession. Chapman & Hall, New York. MA (Millennium Ecosystem Assessment). 2005. Ecosystems and Human Well-Being: Synthesis. Island Press, Washington, DC. MacArthur, R. H., and E. O. Wilson. 1967. The Theory of Island Biogeography. Princeton University Press, Princeton, NJ. Mann, C. C. 2005. 1491, New Revelations of the Americas before Columbus. Vintage, New York. Manning, A. D., D. B. Lindenmayer, and J. Fischer. 2006. Stretch goals and backcasting: Approaches for overcoming barriers to large-scale ecological restoration. Restoration Ecology 14:487–492. Martin, R. E., and C. T. Cushwa. 1966. Effects of heat and moisture on leguminous seed. Pp. 159–175 in Proceedings of the Fifth Annual Tall Timbers Fire Ecology Conference. Tall Timbers Research Station, Tallahassee, FL. Marty, P., J. Aronson, and J. Lepart. In press. Dynamics and restoration of abandoned farmland and other old fields in southern France. In V. A. Cramer and R. J. Hobbs, eds. Old Fields: Dynamics and Restoration of Abandoned Farmland. Island Press, Washington, DC. Maschinski, J., and S. J. Wright. 2006. Using ecological theory to plan restorations of the endangered beach jacquemontia (Convolvulaceae) in fragmented habitats. Journal for Nature Conservation 14:180–189.
25_Refs:IP_Clewell
9/17/07
11:47 AM
Page 205
References
205
McCarthy, H. 1993. Managing oaks and the acorn crop. Pp. 213–228 in T. C. Blackburn and K. Anderson, eds. Before the Wilderness: Environmental Management by Native Californians. Anthropological Papers, No. 40. Ballena, Banning, CA. McCarty, K. 1998. Landscape-scale restoration in Missouri savannas and woodlands. Restoration and Management Notes 16:22–32. McDonald, T. 2005. Grassland restoration: Strengthening our underpinning. Ecological Management and Restoration 6:2. McHarg, I. L. 1967. Design with Nature. Wiley, New York. Milton, S. J., W. R. J. Dean, and D. M. Richardson. 2003. Economic incentives for restoring natural capital in southern African rangelands. Frontiers in Ecology and the Environment 1:247–254. Mitsch, W. J., and S. E. Jørgensen. 2004. Ecological Engineering and Ecosystem Restoration. Wiley, Hoboken, NJ. Moreira, F., A. I. Queiroz, and J. Aronson. 2006. Restoration principles applied to cultural landscapes. Journal for Nature Conservation 14:207–216. Munro, J. W. 2006. Ecological restoration and other conservation practices: The difference. Ecological Restoration 24:182–189. Naeem, S. 1998. Species redundancy and ecosystem reliability. Conservation Biology 12:39–45. ———. 2006. Biodiversity and ecosystem functioning in restored ecosystems: Extracting principles for a synthetic perspective. Pp. 210–237 in D. A. Falk, M. A. Palmer, and J. B. Zedler, eds. Foundations of Restoration Ecology. Island Press, Washington, DC. ———, and S. Li. 1997. Biodiversity enhances ecosystem reliability. Nature 390:507–509. National Research Council. 1992. Restoration of Aquatic Ecosystems, Science, Technology, and Public Policy. National Academy Press, Washington, DC. Naveh, Z. 2000. The total human ecosystem: Integrating ecology and economics. BioScience 50:357– 361. Noble, J., N. MacLeod, and G. Griffin. 1997. The rehabilitation of landscape function in rangelands. Pp. 107–120 in J. Ludwig, D. Tongway, D. Freudenberger, J. Noble, and K. Hodgkinson, eds. Landscape Ecology, Function and Management: Principles from Australia’s Rangelands. CSIRO Publishing, Collingwood, Australia. Norgaard, R. B. 1987. Economics as mechanics and the demise of biological diversity. Ecological Modelling 38:107–112. Orr, D. W. 1994. Earth in Mind. Island Press, Washington, DC. ———. 2002. The Nature of Design. Ecology, Culture, and Human Intervention. Oxford University Press, New York. Osenberg, C. W., B. M. Bolker, J.-S. S. White, C. M. St. Mary, and J. S. Shima. 2006. Statistical issues and study design in ecological restorations: Lessons learned from marine reserves. Pp. 280–302 in D. A. Falk, M. A. Palmer, and J. B. Zedler, eds. Foundations of Restoration Ecology. Island Press, Washington, DC. Ovalle, C., J. Aronson, A. Del Pozo, and J. Avendaño. 1990. The espinal: Agroforestry systems in the Mediterranean-type climate region of Chile. Agroforestry Systems 10:213–239. ———, J. Aronson, A. Del Pozo, and J. Avendaño. 1999. Restoration and rehabilitation of mixed espinales in central Chile: 10-year report and appraisal. Arid Land Research and Management 13:369–381. ———, L. Longeri, J. Aronson, A. Herrera, and J. Avendaño. 1996. N2-fixation, nodule efficiency and biomass accumulation after two years in three Chilean legume trees and Tagasaste (Chamaecytisus proliferus subsp. palmensis). Plant and Soil 179:131–140. Packard, S. 1988. Just a few oddball species: Restoration and the rediscovery of the tallgrass savanna. Restoration and Management Notes 6:13–20. ———. 1993. Restoring oak ecosystems. Restoration and Management Notes 11:5–16. Pahl-Wostl, C. 1995. The Dynamic Nature of Ecosystems: Chaos and Order Entwined. Wiley, Chichester, UK. Pandey, D. N. 2002. Sustainability science for mine-spoil restoration. Current Science 83:593–602. Pausas, J. G. 1997. Resprouting of Quercus suber in NE Spain after fire. Journal of Vegetation Science 8:703–706. ———, R. A. Bradstock, D. A. Keith, J. E. Keeley, and the GCTE (Global Change in Terrestrial Ecosystems) Fire Network. 2004. Plant functional traits in relation to fire in crown-fire ecosystems. Ecology 85:1085–1100.
25_Refs:IP_Clewell
206
9/17/07
11:47 AM
Page 206
References
Perry, D. A. 1995. Self-organizing systems across scales. Trends in Evolution and Ecology 10:241–244. Pickett, S. T. A., and P. S. White. 1985. The Ecology of Natural Disturbance and Patch Dynamics. Academic Press, San Diego, CA. Ponting, C. 1991. A Green History of the World. London: Sinclair-Stevenson. Prober, S. M., and K. R. Thiele. 2005. Restoring Australia’s temperate grasslands and grassy woodlands: Integrating function and diversity. Ecological Management and Restoration 6:16–27. Pyne, S. J. 1995. World Fire: The Culture of Fire on Earth. University of Washington Press, Seattle. Ramakrishnan, P. S. 1994. Rehabilitation of degraded lands in India: Ecological and social dimensions. Journal of Tropical Forest Science 7:39–63. Rambal, S., and J.-P. Ratte. 2005. Forêts méditerranéennes, sécheresse et changements climatiques. Site d’information sur les écosystèmes forestiers. GIP Ecofor, Paris. www.sief.ifn.fr/articles/resultat/article2 .htm. Raunkaier, C. 1934. The Life Forms of Plants and Statistical Plant Geography. Clarendon, Oxford. Rogers-Martinez, D. 1992. The Sinkyone intertribal park project. Restoration and Management Notes 10:64–69. Rokich, D. P., K. W. Dixon, K Sivasithamparam, and K. A. Meney. 2002. Smoke, mulch, and seed broadcasting effects on a woodland restoration in Western Australia. Restoration Ecology 10:185–194. Rosemund, A. D., and C. B. Anderson. 2003. Engineering role models: Do non-human species have the answers? Ecological Engineering 20:379–387. Rosenfeld, J. S. 2002. Functional redundancy in ecology and conservation. Oikos 98:156–162. Sanderson, E. W., M. Jaiteh, M. A. Levy, K. H. Redfrod, A. V. Wannebo, and G. Woolmer. 2002. The human footprint and the last of the wild. BioScience 52:891–904. Sauer, L. J. 1998. The Once and Future Forest. Island Press, Washington, DC. SER (Society for Ecological Restoration, Science & Policy Working Group). 2002. The SER Primer on Ecological Restoration. SER, Tucson, AZ. www.ser.org/. Sikka, A. K., J. S. Samra, V. N. Sharda, P. Samraj, and V. Lakshmanan. 2003. Low flow and high flow responses to converting natural grassland into bluegum (Eucalyptus globulosus) in Nilgiris watersheds, South India. Journal of Hydrology 270:12–26. Simberloff, D., I. M. Parker, and P. N. Windle. 2005. Introduced species policy, management, and future research needs. Frontiers in Ecology 3:12–20. Smith, K. D. 1994. Ethical and ecological standards for restoring upland oak forests (Ohio). Restoration and Management Notes 12:192–193. Smith, T. M., H. H. Shugart, and F. I. Woodward (eds.). 1997. Plant Functional Types. Cambridge University Press, Cambridge. Stevens, W. K. 1995. Miracle under the Oaks. Pocket Books, New York. Stevenson, H. M. 1976. Vertebrates of Florida. University Press of Florida, Gainesville. Stritch, L. 1990. Landscape-scale restoration of barrens-woodland within the oak–hickory mosaic. Restoration and Management Notes 8:73–77. Suding, K. N., and K. L. Gross. 2006. The dynamic nature of ecological systems: Multiple states and restoration trajectories. Pp. 190–209 in D. A. Falk, M. A. Palmer, and J. B. Zedler, eds. Foundations of Restoration Ecology. Island Press, Washington, DC. ———, K. L. Gross, and G. Houseman. 2004. Alternative states and positive feedbacks in restoration ecology. Trends in Ecology and Evolution 19:46–53. Swanson, L. J., and A. G. Shuey. 1980. Freshwater marsh reclamation in west central Florida. Pp. 51–61 in D. P. Cole, ed. Proceedings of the Seventh Annual Conference on the Restoration and Creation of Wetlands. Hillsborough Community College, Tampa, FL. Swetnam, T. W., C. D. Allen, and J. L. Betancourt. 1999. Applied historical ecology: Using the past to manage for the future. Ecological Applications 9:1189–1206. Tansley, A. G. 1935. The use and abuse of vegetational concepts and terms. Ecology 16:284–307. Temperton, V. M., R. J. Hobbs, T. Nuttle, and S. Halle (eds.). 2004. Assembly Rules and Restoration Ecology. Island Press, Washington, DC. Todd, N. J. 2005. A Safe and Sustainable World: The Promise of Ecological Design. Island Press, Washington, DC. Tongway, D. J., and N. L. Hindley. 2004. Landscape Function Analysis: Procedures for Monitoring and As-
25_Refs:IP_Clewell
9/17/07
11:47 AM
Page 207
References
207
sessing Landscapes with Special Reference to Minesites and Rangelands, Version 3.1. CD. CSIRO Sustainable Ecosystems, Canberra. ———, and J. A. Ludwig. 1996. Rehabilitation of semiarid landscapes in Australia. I. Restoring productive soil patches. Restoration Ecology 4:388–397. ———, C. Valentin, and J. Seghieri. 2001. Banded Vegetation Patterning in Arid and Semi-Arid Environments: Ecological Processes and Consequences for Management. Ecological Studies No. 149. Springer Verlag, New York. Trousdell, K. B., and M. D. Hoover. 1955. A change in ground-water level after clearcutting of loblolly pine in the coastal plain. Journal of Forestry 53:493–498. Vale, T. R. 2002. Fire, Native Peoples, and the Natural Landscape. Island Press, Washington, DC. Vallauri, D., J. Aronson, and M. Barbéro. 2002. An analysis of forest restoration 120 years after reforestation on badlands in the southwestern Alps. Restoration Ecology 10:16–26. Vallejo, R., J. Aronson, J. G. Pausas, and J. Cortina. 2006. Restoration of Mediterranean woodlands. Pp. 193–209, in J. van Andel and J. Aronson, eds. Restoration Ecology: The New Frontier. Blackwell Science, Oxford. Wackernagel, M., and W. E. Rees. 1996. Our Ecological Footprint: Reducing Human Impact on the Earth. New Society Publishers, Gabriola Island, BC, Canada. ———, N. B. Schulz, and D. Deumling. 2002. Tracking the ecological overshoot of the human economy. Proceedings of the National Academy of Science, USA 99:9266–9271. Walker, B. H. 1992. Biological diversity and ecological redundancy. Conservation Biology 6:18–23. Waltner-Toews, D., J. J. Kay, C. Neudoerffer, and T. Gitau. 2003. Perspective changes everything: Managing ecosystems from the inside out. Frontiers in Ecology and the Environment 1:23–30. Wellnitz, T., and N. L. Poff. 2001. Functional redundancy in heterogeneous environments: Implications for conservation. Ecology Letters 4:177–179. Westman, W. E. 1977. How much are nature’s services worth? Science 197:960–964. ———. 1978. Measuring the inertia and resilience of ecosystems. BioScience 28:705–710. Wharton, C. H. 1966. Man, fire and wild cattle in North Cambodia. Annual Proceedings of the Tall Timbers Fire Ecology Conference 5:23–65. ———. 1969. Man, fire and wild cattle in Southeast Asia. Annual Proceedings of the Tall Timbers Fire Ecology Conference 8:107–167. Whisenant, S. G. 1999. Repairing Damaged Wildlands: A Process-Orientated, Landscape-Scale Approach. Cambridge University Press, Cambridge. White, P. S., and J. L. Walker. 1997. Approximating nature’s variation: Selecting and using reference information in restoration ecology. Restoration Ecology 5:338–349. Wilber, K. 2001. A Theory of Everything, an Integral Vision for Business, Politics, Science and Spirituality. Shambhala, Boston. Woodworth, P. 2006a. What price ecological restoration? The Scientist April:39–45. ———. 2006b. Working for water. The World Policy Journal Summer:31–43. Wunderlin, R. P., and B. F. Hansen. 2003. Guide to the Vascular Plants of Florida, 2nd edition. University Press of Florida, Gainesville. Wyant, J. G., R. A. Meganck, and S. H. Ham. 1995. A planning and decision-making framework for ecological restoration. Environmental Management 6:789–796. Yates, C. J., and R. J. Hobbs. 1997. Woodland restoration in the Western Australian wheatbelt: A conceptual framework using a state and transition model. Restoration Ecology 5:28–35. Young, T. 2000. Restoration ecology and conservation biology. Biological Conservation 92:73–83. Zedler, J. 1999. The continuing challenge of restoration. Pp. 116–126 in C. Meine and R. L. Knight, eds. The Essential Aldo Leopold, Quotations and Commentaries. University of Wisconsin Press, Madison. ———, and R. Langis. 1991. Comparisons of constructed and natural salt marshes of San Diego Bay. Restoration and Management Notes 9:21–25.
25_Refs:IP_Clewell
9/17/07
11:47 AM
Page 208
26_Authors:IP_Clewell
9/17/07
11:48 AM
Page 209
about the authors and collaborators
Authors Andre F. Clewell taught botany at Florida State University in Tallahassee for 16 years before entering private practice as a restoration practitioner and plant ecologist. He owned a consulting firm for 22 years. He served as president of the Society for Ecological Restoration and is co-coordinator of the RNC Alliance. His research interests include ecosystem inventory and characterization, restoration ecology, and plant systematics. James Aronson is head of the restoration ecology group at the Center of Functional and Evolutionary Ecology (Centre National de la Recherche Scientifique, CNRS) in Montpellier, France and curator of restoration ecology at the Missouri Botanical Garden, USA. He has worked in projects and programs related to the restoration and rehabilitation of degraded ecosystems for more than 20 years, in many parts of the world. He is co-coordinator of the RNC Alliance.
Guides to Virtual Field Trips James Blignaut is a professor of ecological economics at the University of Pretoria, South Africa, and director of two companies that facilitate economic development and the restoration of natural capital. He is editor of the South African Journal of Economic and Management Sciences. His professional interests are environmental fiscal reform, natural resource accounting, payments for ecosystem goods and services, combating invasive alien plant species, restoring natural capital, and local economic development. He is director of Africa’s Search for Sound Economic Trajectories (ASSET) and co-coordinator of the RNC Alliance. Narayanan Krishnakumar has been conservator of forests (planning and development) in Tamil Nadu Forest Department, southern India, since 2004. A keen naturalist, he previously served as director of the Arignar Anna Zoological Park and as wildlife warden in the Indira Gandhi National Park & Wildlife Sanctuary in Pollachi. His interests include conservation biology, restoration ecology, wildlife and forest management, and zoo management. Edouard Le Floc’h was for 42 years a researcher at the Centre d’Ecologie Fonctionnelle et Evolutive (Centre National de la Recherche Scientifique, CNRS), Montpellier, France, until his retirement in 2006. A plant ecologist by training, he worked for 34 years in the arid zones of 209
26_Authors:IP_Clewell
210
9/17/07
11:48 AM
Page 210
About the Authors and Collaborators
North Africa, especially Tunisia, the Sahel, and the Middle East. His research and consulting activities covered primary and secondary productivity, ecosystem vulnerability to degradation and desertification, and ecological restoration of arid and semiarid land ecosystems. John Ludwig is a landscape ecologist with a special interest in the restoration of rangelands and mine sites. He is a researcher with the Tropical Savannas Cooperative Research Centre and is based at Australia’s Commonwealth Scientific and Industrial Research Organisation laboratory in Atherton, Queensland. T. S. Srinivasa Murthy, a member of the Indian Forest Service, has been executive director of the Society for Social Forestry Research and Development, Tamil Nadu, India since 2004. He previously served in the social forestry wing of the Tamil Nadu Forest Department for 4 years, and 6 years in the nongovernment Foundation for Revitalisation of Local Health Traditions under the Danish International Development Agency–aided Medicinal Plants Conservation project of South India. Carlos Ovalle has served as a senior researcher at the Instituto de Investigaciones Agropecuarias in Chile for more than 25 years. His research focus is the development of new agroforestry systems for use on degraded soils, and strategies to unite economic development and nature conservation in central Chile. George Ramseur Jr. is a restoration specialist with the Mississippi Department of Marine Resources, charged with planning and implementing projects from estuarine marsh creation to maritime forest and prairie restoration. A geologist and anthropologist, he has worked as a petroleum and environmental geologist, land manager, and consultant for 20 years. His particular interests include the use of prescribed fire, invasive plant eradication, and environmental challenges in the aftermath of hurricane Katrina. Achim Schäfer is a landscape economist at the Institute for Sustainable Development of Landscapes of the Earth at the University of Greifswald, Germany, where has served since 1966. His projects concern the sustainable economic use of restored peatlands and forests. David Tongway is a visiting fellow at the Australian National University, Canberra, Australia after a career that spanned 38 years with the Commonwealth Scientific and Industrial Research Organisation. He devised a method for rapid assessment of soil productive potential that incorporates micromorphology, chemistry, physics, pedology, land system mapping, and biology that is applicable over a range of climates and land forms in Australia and elsewhere. Rudi van Aarde is professor of zoology and director of the Conservation Ecology Research Unit at the University of Pretoria, South Africa. His research focuses on the ecological restoration of animal communities, especially those of elephants, in coordination with conservation efforts taking place throughout southern Africa. Wendelin Wichtmann is an agricultural engineer in the Institute for Sustainable Development of Landscapes of the Earth at the University of Greifswald, Germany, where he has served since 1994. He is involved with wetland restoration and nature protection projects, and he develops site-specific management plans for arable lands and peatlands.
27_index:IP_Clewell
9/17/07
11:49 AM
Page 211
index
Aesthetics, 7, 109, 120, 121 Africa, 14, 26, 41, 59, 99–103, 100–103 Africa’s Rural Initiatives for Sustainable Environments (ARISE), 99, 100, 103 Agriculture agroforests, 41, 49 Central Chile, 33, 35 creation of farmland, 40, 125 irrigation, 27, 112, 113, 115 by native peoples, 40–41, 45, 48 as a production system, 11, 49 Southern India, 112, 113, 115 use of controlled fire, 8, 39–40 Alaska, 78 Amazon Basin, 41 Aquatic ecosystems, 22, 27, 56, 57, 64, 65 ARISE. See Africa’s Rural Initiatives for Sustainable Environments Asia, 41 Australia, 14–18, 15–18, 40–41, 59, 132, 155 Bacteria, 19, 57, 63, 66 Biodiversity, 47, 110, 111, 138 California, 39–40 Canada, 21, 154 Canals and channelization, 11, 21, 49, 66 Carbon sequestration, 10, 63, 95, 99, 129 Case history, 91, 95, 190. See also Virtual Field Trips CBO. See Community-based organizations Certification and licensing, 163–165 Chile, 33–37, 34–37 Climate. See Global climate change; Microclimate Climax community, 28, 29, 30, 47–48 Colonization and introduced species, 57, 92–93 by invasive species, 22, 169 of restoration site, 78, 86, 178 and species composition, 22, 29, 77
Communication with the local community, 50, 90, 94, 183 with the media, 91, 94 with peers, 95 with property owners, 66, 90, 175 with public agencies, 183 publicity, 91, 94, 183, 189–190 with stakeholders, 90, 94 Community, local celebrations, 91, 110, 151 communication with, 50, 90, 94, 183 community-based interventions: Illinois, 151; South Africa, 99–103, 100–102; Southern India, 112–115, 113–114 local and traditional knowledge, 50, 171 public participation, 183–184 restoration goals for, 89, 183–184 sense of place, 7, 110, 119 Community-based organizations (CBO), 148, 153, 155 Community structure biodiversity, 47, 110, 111, 138 species abundance, 78, 181 species composition: impacts of impairment, 22–24, 169; redundancy, 58; regulated by stressors, 21, 29, 31; site description, 181; and the target condition, 7, 47–48, 55–62 and succession (see Climax community; Seral community) Competition, 22, 29 Connectivity, 7, 10–13, 36 Contracts, 57, 89, 90, 148, 149, 179 Costa Rica, 156 Criteria, design or success. See Performance standards Cultural considerations, 8, 33–37, 34–37, 89, 171, 177, 183. See also Ecosystems, cultural; Landscapes, cultural; Values, cultural Desertification, 14–15, 15, 16, 26–27, 26 Developing nations, 19, 20. See also Poverty
211
27_index:IP_Clewell
212
9/17/07
11:49 AM
Page 212
Index
Director, project, 148 Disease, 21, 40, 81 Disturbance, natural, 20–21, 22, 29, 77 Drought, 31, 33, 67 Ecoclines, 10–11 Ecoliteracy, 110, 118–119, 118, 120 Ecological considerations, 5, 63–64, 110–111, 117, 121, 130, 183. See also Values, ecological Ecological enhancement, 12 Ecological restoration. See Restoration Economic considerations budget and accountability, 94, 180, 187 funding and sponsors, 147–148, 152–153, 178 mitigation banks and credits, 74 monetary value of an ecosystem, 25 natural resource goods, 107, 110 restoration of natural capital, 99, 136–139 wages, 102 Ecosystems assembly rules, 95, 111 creation, 134 cultural: alternative states in landscapes, 45–48, 46; evidence for, 39–41; fire and restoration, 41–45; overview, 171; use of term, 38–39, 48–49 dynamic nature, 7, 9–10 (See also Rehabilitation; Resilience; Resistance) effects of impairment, 21–25, 169–170 gardenified, 49–50, 51, 158 key qualities, 11, 171 overview and use of term, 10–11, 176 patch dynamics, 12, 29–30, 31 production, 11, 49 reallocation and impairment, 20–21 reference (see Models, reference) self-sustaining and self-organizing nature, 8, 50, 67–68, 86–87, 171 socioecological, 50 states and processes, 9–10 succession (see Models, for ecological succession; Succession, ecological) types of complexities, 31–32 values (see Values, ecological) Ecotones, 10–11 Ecotopia, 119, 119, 121 Ecotypes, 93, 128, 187 Education, public about restoration site, 89, 94, 95, 118–119, 118 ecoliteracy, 89, 110, 118–119, 118, 120, 138 restoration training, 101, 112–113, 184 small business, 113–114, 114 through public participation, 183–184 Engineering, 11, 134–136, 164–165 Environmental crisis response, 106, 119, 120 Equipment, 24, 64, 89, 90, 178 Espinales (pseudo-savanna), 33, 34, 35, 36
Ethics, 19, 25, 97, 104, 120, 163. See also Values, personal Europe, 45–46, 46, 49, 132, 158. See also France; Germany Exotic species. See Invasive species Extinction, 77, 125 Farmland. See Agriculture Fencing, 16–17, 90, 102, 120, 187, 188 Finance. See Economic considerations Fire controlled, 8, 39–40, 41, 66, 71–72, 72 ecological impacts, 21, 22 ecological resistance to, 67, 171 effects on seed germination, 43–45 natural causes, 21, 29, 30, 44 and restoration, 41–45, 66, 71–72, 72, 178 Fishing, 107, 108 Floods, 64, 178 Florida Dogleg Branch restoration project, 77, 133, 141–146, 142–145, 150, 151–152 Everglades, 29 Hall Branch restoration project, 67 invasive species, 60, 67 mining restoration projects, 67, 79–80, 154 Flux, 30, 31 Food web, 10, 30, 63 Forestry clear-cutting and salinization, 27 coppiced or pollarded trees, 46 fuelwood harvest, 99, 102, 107, 112 prescribed burning, 42–45 as a production system, 11, 49 row-planted plantations, 21, 51, 70, 71, 125–128, 126, 127 silvopastoral landscape, 50, 160 use of draft horses, 71, 72 Forests, 20, 23, 43–44, 112–115, 113–114 France, 158–162, 159–162 Frontier zone, 12, 77 Functional groups, 63–64 Fungi, 10, 19, 24, 56, 57 Gaia, 105, 119, 119, 121 Generalists. See r-strategists Genetics, 57, 92–93, 108, 187 Germany, 125–129, 126–129, 154 Global climate change, 8, 31, 45, 78–79, 78, 169 Global positioning system (GPS), 175, 187 Grasslands Australia, 132 Europe, 46, 46, 125 North America, 21, 39–40, 45, 70–74, 71–74, 150 Grazing, 62, 63, 188. See also Livestock, grazing Groundwater. See Water table
27_index:IP_Clewell
9/17/07
11:49 AM
Page 213
Index Guidelines or Developing and Managing Ecological Restoration Projects, 88, 173–190 Habitat considerations, 10, 14, 17, 19, 24, 108–109 Herbicides, 44, 50, 51, 62 Himalayas, 23–24 Hunting, 107, 109, 153 Hurricane Katrina, 23, 25 Hydrology, 21, 49, 64, 66, 90, 132–133, 178 Illinois, 150–151 Impairment, ecological, 20–25, 169–170 India Deepor Beel fisheries, 108 forest restoration in Pune, 120 forest restoration in Tamil Nadu, 112–115, 113–114 invasive species, 59 spirituality, 109, 109, 111, 120 Insects, 17, 21, 24, 57, 58, 108 Invasive species colonization by, 22, 169 overview and use of term, 59–61 and restoration, 12, 66, 74, 178 Inventory, ecological, 86, 89, 148, 150, 181 Irrigation, 27, 90–91, 112, 113, 115 Keystone species, 41, 44, 182 K-strategists, 22, 24, 28, 29, 47, 57, 59 Labor. See Personnel Land issues, 24, 66, 90, 132–133, 153, 175 Landscapes architecture and design, 134 banded patterns, 14–15, 15, 16 connectivity, 7, 36 context, 65–66, 178 cultural: alternative ecosystem states, 45–48, 46; evidence for, 39–41; range of types, 48–51, 49; use of term, 38–39 external threats, 66 fragmentation, 8, 12, 138 gardenified, 49–50, 51, 158 restoration to increase heterogeneity, 36 site restrictions, 66, 178 socioecological, 50 spatial scale and mosaic pattern, 12 Legal considerations, 44, 66, 149, 150, 151, 179, 186 LEK. See Local ecological knowledge Levees or dikes, 11, 21, 49, 66 Life history, 29. See also K-strategists; r-strategists Litter, 17, 23–24. See also Fire, and restoration Livestock compaction of soil, 14, 17, 24 fuel from manure, 102 grazing: Alps, 49; Australia, 17; Chile, 35; ecological effects, 14; Germany, 125, 126; protection of restoration site (see Fencing)
213
as a production system, 11 sustainable management practices, 36 Local ecological knowledge (LEK), 50 Management best management practice, 125 ecosystem, 131, 171 resource, 11, 47, 50–51, 99 top-down, 50–51 water, 35, 36, 99, 112, 113, 115, 128 Management of restoration projects accountability and cost control, 94, 180, 187 adaptive, 91, 188–189 administrative roles, 147–149 communication with property owners, 66, 90, 175 contingencies, 72, 88, 149, 156, 187 data management, 73–74, 76, 78, 88, 181, 182 decision making, 63, 152, 156 diary with narratives, 174–175 long-term protection, 179 organization chart, 147, 180 permits and contracts, 57, 89, 90, 148, 149, 179 personnel (see Personnel) scheduling, 88, 90, 186 security issues, 90, 188 site inspections, 188 by stakeholders, 63, 156 Manager, project, 149 Media, 91, 94, 110 Mediterranean region, 45–46, 46, 158 Microclimate, 23, 67 Microsites, 77 Mining bauxite, 155 introduced or colonizing species after, 59, 63 peat, 154 reclamation, 56, 133, 141 restoration project in Australia, 80 restoration projects in Florida, 67, 79–80, 154 (See also Virtual Field Trips, mining restoration in Florida) temple in India, 109 Mississippi, 23, 70–74, 71–74, 118 Mitigation, 74, 133–134 Models for ecological succession: “degradation in reverse,” 27–28, 29, 30–31; disequilibrium theory, 86; equilibrium theory, 27–29, 30–31; multiequilibrium theory, 30, 45; nonequilibrium theory, 30, 135 four-quadrant representation of values, 97, 116–122, 117–122, 151, 172 initial floristic composition, 29, 31 reference: data interpretation, 78; developmental trajectories, 9, 80–87, 81, 82, 83, 85, 170; overview, 57, 75, 89, 170; selection, 78–79,
27_index:IP_Clewell
214
9/17/07
11:49 AM
Page 214
Index
Models (continued) 181–182; temporal considerations, 79–80, 81, 96; types, 75–76 stewardship, 155–156 Monitoring ecological function, 65, 80 ecological resilience, 67 fixtures on site, 187 performance evaluation, 86, 89, 91, 93–96, 189 See also Performance standards Native peoples, 8, 40–41, 45, 48, 50, 111, 155 Natural disasters, 23, 25, 25, 64, 178 Nature balance of, 28 design with, 92 disturbances, 20–21, 22, 29 as pristine, 40, 48 reconnection with, 105–106, 119, 120 role of humans in, 5, 41, 61 The Nature Conservancy (TNC), 70, 74 Nature reserves, 70, 71, 138 NGO. See Nongovernment organizations Nitrogen, 8, 24 Nitrogen fixation, 35, 36, 37, 63, 115, 161 Nongovernment organizations (NGO), 110, 137, 147, 153, 155 Nonnative species, 58–59, 60–62. See also Invasive species North America, 40, 45, 47–48, 60–61, 79 Nutrients eutrophication, 27, 64 fertilizers, 50, 64, 161 mycorrhizae and uptake, 24 recycling, 10 released by fire, 44 in the soil, 17, 21, 24, 26 Oxygen, 21, 65 Peatlands, 125–129, 126–129, 154 Performance standards, 68, 90, 91, 185–186, 188, 189 Permits, 57, 89, 90, 148, 149, 179 Personnel selection, 89, 101, 148, 178, 180 training, 88, 90, 101–102, 101, 112–113, 184 volunteer hours, 94 wages, 102 Perturbation, 20–21 Photography, 73–74, 76, 89, 94, 175, 181 Planner, restoration, 149 Plants. See Pollen records; Vegetation Pollen records, 29, 40, 76 Pollution, 8, 21, 24, 44, 49, 108 Population dynamics, 10, 19, 22, 23 Poverty, 19, 99, 100, 112 Practitioner, restoration, 8, 12, 148, 149, 152–153, 163–165, 180
Precipitation, 14, 24, 27 Production system, 11, 12–13, 47, 50–51, 137, 151–152. See also Agriculture; Forestry Property owners, 66, 90, 153, 175 Provenance, genetic, 92–93 Public. See Community, local Publicity, 91, 94, 183, 189–190 Reclamation, 132–133 Recovery, ecological, 27–30 Recreational land use, 24, 49, 110 Redundant species, 58 Rehabilitation, 132, 134 Religion. See Spirituality Remediation, 135, 138 Research, 57, 95–96, 110, 182 Reserves, 70, 71, 138 Resilience, 11, 58, 67, 80, 171 Resilience Alliance, 50 Resistance, 11, 67, 171 Resource management, 11, 47, 50–51, 99 Restoration dynamic nature, 7–8, 80–87 ecological attributes of restored ecosystems, 55–69 emerging profession: recognition, 163–165; relationship to related fields, 130–140; scientific and social context, 5–6, 123 holistic, 1, 12, 117, 154, 169–172 motivations for, 97, 104 overview, 7–13, 35, 174 partial, 12 passive, 185 projects (see Restoration projects) species, 12 techniques and guidelines (see Restoration process) use of term, 3, 5, 8, 9, 12, 13, 105 Restoration of natural capital (RNC), 99, 136–139 Restoration process endpoint (see Models, reference; Restoration projects, evaluation; Target condition) guidelines: conceptual planning, 89, 175–179; evaluation, 91, 189; implementation planning, 90, 184–187; implementation tasks, 90, 187–188; overview, 88, 173–175; post-implementation tasks, 90–91, 131, 188–189; preliminary tasks, 89–90, 180–184; publicity, 91, 94, 183, 189–190 introduced soil, 57, 80, 92 introduced species, 12, 56–62, 92–93 (See also Revegetation) precautionary approach, 58 site description, 95, 175, 176, 177, 181 site preparation, 187 and succession theories, 30–32 temporal considerations, 79–80, 81, 96, 179 use of fire, 41–45 Restoration projects case history, 91, 95, 190 (See also Virtual Field Trips)
27_index:IP_Clewell
9/17/07
11:49 AM
Page 215
Index context, 149–157, 176–177 design, 91–92 evaluation, 86, 91, 93–96, 189 goal setting, 89–90, 96, 176–177, 182 (See also Target condition, nine ecological attributes) management (see Management of restoration projects) objectives, 182–183, 184–185 performance standards, 68, 90, 91, 185–186, 188, 189 planning: conceptual, 65–66, 68, 84, 89, 175–179; implementation, 90, 149, 184–187 publicity, 91, 94, 183, 189–190 report, 91, 190 roles, 147–149 scope, 11, 12, 89 spatial scale, 12–13 stewardship models, 155–156 Revegetation contract stipulations, 57 definition, 133 equipment and supplies, 179, 186–187 espinale of Chile, 35 forest species of India, 114–115 genetic provenance, 92–93 irrigation, 90–91 mining restoration site in Florida, 141 performance standards, 90, 185 with reeds, 128, 128, 129 roadway, 133 species composition, 56–58 strategy selection, 92, 178 tree planting techniques, 36, 126–128, 126, 127, 142 Riparian areas degradation in South Africa, 99, 100 first-order and second-order streams, 77 floodplains, 66 mining area in Florida, 144, 145 r-strategists, 48 water characteristics, 27, 64, 65 water discharge, 26, 64, 65 RNC. See Restoration of natural capital Roads, 49, 90, 133, 184 r-strategists, 22, 24, 48, 59, 62 Runoff agricultural, 11, 24, 64 onto project site, 25, 66, 89 rainfall, 14, 24, 25, 26, 27, 35–36, 64 urban, 24 Salinity, 21, 27, 64 Sea level change, 31, 79 Seasonal considerations, 20, 43, 149–150 Seeds collection, 72, 90 commercially-produced, 50–51, 93 dispersal, 10, 56, 60, 66, 77
215
germination, 43–45 sources, 76, 179, 187 SER. See Society of Ecological Restoration International Seral community, 28, 29, 30, 31, 47–48, 78, 94–95 The SER Primer on Ecological Restoration, 2–3, 11, 48, 130, 132, 134, 173 Societal considerations, 5–6, 19, 50, 139. See also Values, socioeconomic Society of Ecological Restoration International (SER), 2–3, 5, 88, 173, 176 Soil chemistry, 21, 26, 109 compaction, 14, 24, 64 deposition, 66 ecology, 57, 65, 178 erosion, 14, 18, 27, 66, 100 improvement, 17 moisture, 17, 24, 25, 64, 170 nutrients in, 17, 21, 24, 26 stabilization, 128 topsoil salvage, 57, 80, 92 Spain, colonization by, 33, 41 Spatial scale, 12–13, 30, 77 Specialists. See K-strategists Species composition. See Community structure, species composition Spirituality, 106, 109, 109, 111, 120 Sponsors, 147–148, 152–153 Stakeholders, 7, 66, 90, 94 Stewardship, 41, 51, 120, 155–156, 158 Stochastic events, 9, 10, 77, 176 Stressors, 20–21, 22, 29, 65, 67, 177 Succession, ecological, 22, 27–31, 45, 86, 135 Sustainability science, 139–140 Sustainable practices, 50, 119, 128, 128, 129, 171 Target condition community structure, 7, 47–48, 55–62, 170 ecological function, 7–8, 63–64, 80, 170 ecological resilience, 67, 80 ecological self-sustainability, 67–68, 86–87, 170, 171 estimated from reference ecosystem, 57, 73–74 landscape context, 7, 65–66 modeled with developmental trajectory, 9, 80–87, 81, 82, 83, 85, 143 nine ecological attributes, 55–69, 89 physical environment, 7, 64–65 relationship with project design, 91–92 selection, 28, 31, 46 species composition, 7, 47–48, 55–58, 170 TEK. See Traditional ecological knowledge TNC. See The Nature Conservancy Topsoiling, 57, 80, 92 Tourism, 99, 109 Traditional ecological knowledge (TEK), 50, 171
27_index:IP_Clewell
216
9/17/07
11:49 AM
Page 216
Index
Trajectory, ecological, 9, 80–87, 81, 82, 83, 85, 143, 170 Values cultural: in four-quadrant model, 116, 118–119, 119, 120, 121, 122; overview, 109–111, 109, 116; prairie restoration, 151 ecological: economic, 24; in four-quadrant model, 116, 117, 119, 119, 121, 122; overview, 96, 104–105, 107–109; part of the cultural landscape, 48; prairie restoration, 151 four categories, 16 personal: in four-quadrant model, 116, 118, 119, 120, 121, 122; fulfillment, 7, 106, 118; overview, 105–106; prairie restoration, 151 socioeconomic: in four-quadrant model, 116, 117–118, 119–120, 119, 121, 122; overview, 106–109, 108, 116–117; prairie restoration, 151; in restoration of natural capital, 137, 138 Vandalism, 90, 188 Vegetation bands, 14–15, 15, 16 ecological value, 14, 16–17, 24, 107–109, 159, 169 effects of fire on, 42, 43–45 function groups, 63–64 indigenous species, 58–62 introduction at restoration site (see Revegetation) nurse, 58 of restored ecosystem, 56 stress indicators, 65 vertical stratification, 22–23, 30, 77 Virtual Field Trips communal savanna in South Africa, 99–103, 100–103, 107
cultural landscapes in Central Chile, 33–37, 34–37 desertified vegetation in Australia, 14–18, 15–18 drained peatlands in Germany, 125–129, 126–129, 154 forest restoration in Southern India, 112–115, 113–114 mining restoration in Florida, 77, 133, 141–146, 142–145, 150, 151–152 overview, 2 restoration research site in France, 158–162, 159–162 wet prairie in Mississippi, 70–74, 71–74, 76, 82 Water management, 35, 36, 99, 112, 113, 115, 128 Water rights, 99 Water table, 25, 27, 64, 65, 79, 125 Web sites, 88, 94, 95 Wetlands ecological value, 108 intertidal, 21, 25, 79 reclamation, 125, 132–133 restoration, 31, 57, 95–96 wastewater treatment in, 135, 136 Wildlife corridors, 19, 66, 138 hunting, 107, 109, 153 indigenous species, 56, 58–62 management, 51, 63, 188 nonnative, 60, 61 on restored peatlands, 128 Wind, 23
28_bd of dir:IP_Clewell
9/17/07
11:49 AM
Page 217
Island Press Board of Directors Victor M. Sher, Esq. (Chair) Sher & Leff San Francisco, CA Dane A. Nichols (Vice-Chair) Washington, DC Carolyn Peachey (Secretary) Campbell, Peachey & Associates Washington, DC Drummond Pike (Treasurer) President The Tides Foundation San Francisco, CA Robert Baensch Director, Center for Publishing New York University New York, NY
Charles C. Savitt President Island Press Washington, DC
Merloyd Ludington Lawrence Merloyd Lawrence Inc. Boston, MA
Susan E. Sechler Senior Advisor The German Marshall Fund Washington, DC
William H. Meadows President The Wilderness Society Washington, DC Henry Reath Princeton, NJ Will Rogers President The Trust for Public Land San Francisco, CA Alexis G. Sant Trustee and Treasurer Summit Foundation Washington, DC
Nancy Sidamon-Eristoff Washington, DC Peter R. Stein General Partner LTC Conservation Advisory Services The Lyme Timber Company Hanover, NH Diana Wall, Ph.D. Director and Professor Natural Resource Ecology Laboratory Colorado State University Fort Collins, CO Wren Wirth Washington, DC
