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The Wetlands Handbook

EDITORS

Edward Maltby BSc PhDProfessor of Wetland and Water Science

Institute for Sustainable Water,Integrated Management and Ecosystem Research

University of LiverpoolLiverpool, L69 3GP, UK

Tom Barker BSc PhDResearch Ecologist



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Maltby-C000.indd iiMaltby-C000.indd ii 6/23/2009 10:12:16 AM6/23/2009 10:12:16 AM

THE WETLANDS HANDBOOK

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The Wetlands Handbook

EDITORS

Edward Maltby BSc PhDProfessor of Wetland and Water Science



Tom Barker BSc PhDResearch Ecologist



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This edition fi rst published 2009, © 2009 by Blackwell Publishing Ltd

Blackwell Publishing was acquired by John Wiley & Sons in February 2007. Blackwell’s publishing program has been merged with Wiley’s global Scientifi c, Technical and Medical business to form Wiley-Blackwell.

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Library of Congress Cataloguing-in-Publication Data

The wetlands handbook / edited by Edward Maltby, Tom Barker. p. cm. Includes bibliographical references. ISBN 978-0-632-05255-4 (hardback : alk. paper) 1. Wetlands. 2. Wetland management. I. Maltby, Edward. II. Barker, Tom. QH87.3.W479 2009 577.68–dc22 2008029043

A catalogue record for this book is available from the British Library.

Set in 9/11.5 pt Trump Mediaeval by Newgen Imaging Systems (P) Ltd, Chennai, IndiaPrinted and bound in Singapore

1 2009

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Contents

Preface, ix

Contributors, xi

SECTION I WETLANDS IN THE GLOBAL ENVIRONMENT, 1

The Changing Wetland Paradigm, 1 3

Edward Maltby

Global Distribution, Diversity and Human Alterations of Wetland Resources, 42 3

Dennis F. Whigham

Biodiversity in Wetlands, 63 5

Brij Gopal

Peat as an Archive of Atmospheric, Climatic and Environmental Conditions, 94 6

R. Kelman Wieder, Merritt R. Turetsky and Melanie A. Vile

SECTION II WETLANDS IN THE NATURAL ENVIRONMENT: HOW DO WETLANDS WORK?, 113

Introduction – The Dynamics of Wetlands, 115 5

Tom Barker and Edward Maltby

Hydrological Dynamics I: Surface Waters, Flood and Sediment Dynamics, 126 0

Chris Baker, Julian R. Thompson and Matthew Simpson

Hydrological Dynamics II: Groundwater and Hydrological Connectivity, 167 9

Dave J. Gilvear and Chris Bradley

Hydrological Dynamics III: Hydro-ecology, 198 4

Ab P. Grootjans and Rudy Van Diggelen

Biogeochemical Dynamics I: Nitrogen Cycling in Wetlands, 219 3

John R. White and K.R. Reddy

Biogeochemical Dynamics II: Cycling and Storage of Phosphorus in Wetlands, 2210 8

Curtis J. Richardson and Panchabi Vaithiyanathan

Biogeochemical Dynamics III: The Critical Role of Carbon in Wetlands, 2411 9

Nancy B. Dise

Wetland Biogeochemical Cycles and their Interactions, 2612 6

Jos T.A. Verhoeven

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vi Contents

Ecological Dynamics I: Vegetation as Bioindicator and Dynamic Community, 2813 2

Bernard Clément and Michael C.F. Proctor

Ecological Dynamics II: The Infl uences of Vertebrate Herbivory on Ecological Dynamics in 14 Wetland Ecosystems, 304

Isabel J.J. Van Den Wyngaert and Roland Bobbink

Ecological Dynamics III: Decomposition in Wetlands, 3215 6

Scott D. Bridgham and Gary A. Lamberti

SECTION III WETLANDS IN THE HUMAN ENVIRONMENT: HOW CAN WE UTILISE THE WORK OF WETLANDS?, 347

Introduction – Using Wetland Functioning, 3416 9

Tom Barker and Edward Maltby

Wetlands and Water Resources, 3517 7

Matthew P. McCartney and Michael C. Acreman

Wetland and Floodplain Soils: Their Characteristics, Management and Future, 3818 2

Hadrian F. Cook, Samuel A.F. Bonnett and Leendert J. Pons

The Role of Buffer Zones for Agricultural Runoff, 4119 7

Martin S.A. Blackwell, David V. Hogan, Gilles Pinay and Edward Maltby

Wetlands for Contaminant and Wastewater Treatment, 4420 0

Robert H. Kadlec

SECTION IV WETLAND ASSESSMENT: HOW CAN WE MEASURE THAT WETLANDS ARE WORKING?, 465

Introduction – Methodologies for Wetland Assessment, 4621 7

Joseph S. Larson

The United States HGM (Hydrogeomorphic) Approach, 4822 6

Mark M. Brinson

Development of a European Methodology for the Functional Assessment of Wetlands, 5123 3

Edward Maltby, Tom Barker and Conor Linstead

Wetlands Assessment in Practice: Development and Application in the 24 United States Regulatory Context, 545

R. Daniel Smith

Wetland Evaluation in Developing Countries, 5625 9

Henri Roggeri

Methodologies for Economic Evaluation of Wetlands and Wetland Functioning, 6026 1

R. Kerry Turner, Roy Brouwer and S. Georgiou

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Contents vii

SECTION V WETLAND DYSFUNCTIONING: WHAT HAPPENS WHEN WETLANDS DO NOT WORK?, 627

Introduction – How Do Wetlands Fail?, 6227 9

Katherine C. Ewel

Hydrological Impacts in and around Wetlands, 6428 3

Michael C. Acreman and Matthew P. McCartney

Biotic Pressures and Their Effects on Wetland Functioning, 6629 7

C. Max Finlayson

Human Impacts: Farming, Fire, Forestry and Fuel, 6830 9

Hans Joosten

SECTION VI WETLAND RESTORATION: MAKING WETLANDS WORK AGAIN, 719

Introduction – Re-establishment of Wetland Functioning, 7231 1

Edward Maltby

Restoration of Wetland Environments: Lessons and Successes, 7232 9

Arnold G. van der Valk

Replumbing Wetlands – Managing Water for the Restoration of 33 Bogs and Fens, 755

Russ P. Money, Bryan D. Wheeler, Andy J. Baird and A. Louise Heathwaite

Restoring Wetlands for Wildlife Habitat, 7834 0

Dieter Ramseier, Frank Klötzli, Ursula Bollens and Jörg Pfadenhauer

Wetland Conditions and Requirements for Maintaining Economically Valuable Species: 35 Waterfowl, Furbearers, Fish and Plants, 802

Lisette C.M. Ross and Henry R. Murkin

SECTION VII SUSTAINABLE UTILISATION OF WETLANDS: BALANCING ECOSYSTEM FUNCTIONING AND HUMAN NEEDS, 819

Introduction – Sustainable Wetlands in a Global Context, 8236 1

Tom Barker

Melaleuca37 Wetlands and Sustainable Development in the Mekong Delta, Vietnam, 829

R.J. Safford, Edward Maltby, Duong Van Ni and Nick P. Branch

Multiple Use of Wetlands in Eastern Africa, 8538 0

Reint Jacob Bakema, Geoffrey W. Howard and Adrian P. Wood

Deterioration and Rehabilitation of the Lower Danube Wetlands System, 8739 6

Angheluta Vadineanu

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viii Contents

The Pantanal of Mato Grosso: Linking Ecological Research, Actual Use and Management for 40 Sustainable Development, 908

Wolfgang J. Junk, Carolina J. Da Silva, Karl Matthias Wantzen, Catia Nunes da Cunha and Flavia Nogueira

Wetlands for conservation and recreation use in the Norfolk and Suffolk Broads, 9441 4

Tom Barker, Steve Crooks and Johan Schutten

Everglades and Agriculture in South Florida, 9642 1

Robert H. Kadlec

Conclusions: Wetlands for the Future, 9843 3

Edward Maltby and Tom Barker

Glossary, 1003

Index, 1007

Colour plates appear in between pages 530–531

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Preface

Wetlands are diverse ecosystems that link people, wildlife and environment in special and often interdependent ways through the essential life-support functions of water. Yet, once armed with the technology, human endeavour has focussed primarily on the large-scale dehydra-tion of these landscapes, apart from exceptional and localised circumstances such as the creation of mediaeval fi sh ponds, more recent aquacul-ture developments, decoy habitats for hunting or aquatic gardens. Although considerably depleted in area compared with their historical extent, a new perspective of wetlands is now emerging and it is this change in attitude that underpins the philosophy, rationale and motivation behind the present text.

The term, ‘wet land’ has been long used pejo-ratively, inferring land conditions that are less than ideal for the majority of practical purposes. ‘Wetland’ is a relatively new entry in dictionaries, even in the United States, where its more techni-cal usage originated, probably in the 1950s in such publications as an inventory of wetland wildlife habitats by Shaw and Fredine in 1956. The term generally has been applied with an ecological, rather than any wider functional, connotation. Webster’s interpretation, for example, setting aside the plethora of recent technical defi nitions, states, ‘swamps and marshes, especially as an area preserved for wildlife’ (Merriam-Webster 2006). This restricted but common view of wetlands has supported a dichotomy between those areas that may, or even should, be altered for more directly ‘productive’ uses, and those that should or could reasonably become part of a network of protected sites. The basis of the latter designation is embed-ded in the more traditional thinking of nature conservation, emphasising species and communi-ties (especially those that are rare, threatened or endangered) or exceptional examples of a particu-lar ecosystem type. This rationale has supported

some cutting edge scientifi c research on the fun-damental ecology of individual species, commu-nities and wetland types, together with improved understanding of the management requirements for maintenance of particular ecological charac-teristics, such as application of burning, grazing, water management, and the harvesting or control of wildlife populations.

Conservation viewpoints, however, can over-look the much wider role of wetlands as parts of complex human and socio-economic landscapes, in which it is essential to consider ecology and economics together in a more coherent approach to decision-making, rather than as separate and in confl ict. A generally held conservation-ecological perspective may view wetlands primarily as natu-ral communities, with the management objective of maintaining the species, patterns and processes within individual wetlands. A more recent per-spective is functional, viewing wetlands as ‘living machines that provide services to humans’ (Keddy 2000). This case has been argued for some time by Maltby (Maltby 1986, 1988; Maltby et al. 1994) because it puts wetland protection and manage-ment into the context of societal values such as water quality, fl ood risk reduction and fi sheries support. Politicians as well as the general public can more easily evaluate these benefi ts against competing economic returns compared to the traditional nature conservation criteria. A strict interpretation of this view may infer that as long as particular functions are performed, the precise character of the ecosystem is of little signifi cance compared with its utilitarian values. The two views, however, are not contradictory. Particular species and communities may have specifi c and even unique functional roles. They are, never-theless, examples of different perspectives of wetlands. Such apparently divergent scientifi c positions on the signifi cance of these ecosystems to society and our environment can contribute to

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x Preface

confusion and misunderstanding, especially in the implementation of appropriate policies. The paradigm presented in The Wetlands Handbook attempts to break down the artifi cial divisions between the natural science of wetlands and the societal criteria for their management. Such greater coherence is essential in deciding on their future; a future capable of harnessing their full, but often hidden and ignored, values.

The editors thank Rosemary Maltby for tire-less editorial assistance in the early stages of the project in managing contributors and reviewers. Vicky Cook manipulated manuscripts across dif-ferent computer networks.

Jos Verhoeven, Dennis Whigham and Mark Brinson, together with many unnamed reviewers gave their time freely to scrutinise manuscripts and provide advice.

Delia Sandford’s patience and encouragement made it possible to complete the task of mobilis-ing so many experts.

Leendert Pons passed away before being able to see the fi nal outcome of his labours. His enthu-siasm for, and knowledge of, soils will be sadly missed.

REFERENCES

Keddy P.A. 2000. Wetland Ecology. Principles and Conservation. Cambridge University Press, Cambridge, UK.

Maltby E. 1986. Waterlogged Wealth. Earthscan, London.

Maltby E. 1988. Wetland resources and future pros-pects – an international perspective. In: Zelazny J. and Feierabend J.S. (editors), Increasing Our Wetland Resources. National Wildlife Federation, Washington, DC, pp. 3–14.

Maltby E., Hogan D.V., Immirzi C.P., Tellam J.H. and van der Peijl M.J. 1994. Building a new approach to the investigation and assessment of wetland eco-system functioning. In: Mitsch W.J. (editor), Global Wetlands: Old World and New. Elsevier, Amsterdam, pp. 637–658.

Merriam-Webster 2006. Merriam Webster’s Dictionary and Thesaurus. Merriam Webster Inc., Springfi eld MA. ISBN: 0877798516.

Shaw S.P. and Fredine C.G. 1956. Wetlands of the United States. Their Extent and Their Value to Waterfowl and Other Wildlife. US Fish and Wildlife Service, Circular 39, 67 pp.

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Contributors

Michael C. Acreman Hydro-ecology and Wetlands, Centre for Ecology and Hydrology, Wallingford, Oxfordshire, UK

Andy J. Baird Room 3.68, School of Geography, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, UK

Reint Jacob Bakema Freelance Rural Devel-opment Consultant, PO Box 5767, Kampala, Uganda

Chris Baker Wetlands and Water Resources Management, Wetlands International Headquar-ters, Horapark 9, 6717 LZ Ede, The Netherlands

Tom Barker Institute for Sustainable Water, Integrated Management and Ecosystem Research, Nicholson Building, University of Liverpool, Liverpool L69 3GP, UK

Martin S.A. Blackwell Biogeochemistry of Soils and Water Group, North Wyke Research, Oke-hampton, Devon, EX20 2SB, UK

Roland Bobbink B-Ware Research Centre, Radboud University, PO Box 9010, 6500 GL, Nijmegen, The Netherlands

Ursula Bollens Landschaftsarchitekturbüro, aspLandschaftsarchitekten AG, Tobeleggweg 19, 8049 Zürich, Switzerland

Samuel A.F. Bonnett Institute for Sustainable Water, Integrated Management and Ecosystem Research, Nicholson Building, University of Liverpool, Liverpool L69 3GP, UK

Chris Bradley School of Geography, Earth and Environmental Sciences, University of Birming-ham, Birmingham, UK

Nick P. Branch School of Human and Environmental Sciences, University of Reading, Whiteknights, PO Box 227, Reading, RG6 6AB, UK

Scott D. Bridgham Center for Ecology andEvolutionary Biology and Environmental Stud-ies Program, 5289 University of Oregon, Eugene 97403, OR, USA

Mark M. Brinson Biology Department, East Carolina University, Greenville, NC 27858, USA

Roy Brouwer Department of Environmental Economics, Institute for Environmental Studies, VU University Amsterdam, The Netherlands

Bernard Clément Unité Mixte de Recherches ‘Ecobio’ 6553, Centre National de la Recherche Scientifi que, Université de Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex, France

Hadrian F. Cook School of Geography, Geol-ogy and the Environment, Kingston University, River House, 53-57 High Street, Kingston upon Thames, Surrey KT1 1LQ, UK

Steve Crooks Phil Williams and Associates Ltd, 550 Kearny Street, 9th Floor, San Francisco, CA 94108-2404, USA

Carolina J. Da Silva Mato Grosso State Univer-sity, Cáceres Brazil

Nancy B. Dise Department of Environmental & Geographical Sciences, Manchester Metropolitan University, John Dalton Building, Chester Street, Manchester M1 5GD, UK

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xii Contributors

Katherine C. Ewel USDA Forest Service, 60 Nowelo St., Hilo, H1 96720 USA;Present address: School of Forest Resources and Conservation, PO Box 110410, University of Florida, Gainesville, FL 32611 USA

C. Max Finlayson Institute for Land, Water and Society, Charles Sturt University, PO Box 789, Albury, NSW 2640, Australia

S. Georgiou Centre for Social and Economic Research on the Global Environment, University of East Anglia, Norwich, and University College London, London, UK

Dave J. Gilvear School of Biological & Environ-mental Sciences, University of Stirling, Stirling FK9 4LA, UK

Brij Gopal School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India

Ab P. Grootjans IVEM, Center for Energy and Environmental Studies, University of Gronin-gen, Nijenborgh 4, 9747 AG Groningen, The Netherlands

Louise Heathwaite Centre for Sustainable Water Management, Lancaster Environment Centre, University of Lancaster, Lancaster LA1 4YQ, UK

David V. Hogan Environmental Consultant, 291 Pinhoe Road, Exeter, Devon, EX4 8AD, UK

Geoffrey W. Howard IUCN East Africa Regional Offi ce, PO Box 68200, Nairobi, Kenya

Hans Joosten Institute of Botany and Landscape Ecology, University of Greifswald, GrimmerStrasse 88, D 17487 Greifswald, Germany

Wolfgang J. Junk Working Group Tropical Ecology, Max-Planck-Institute for Limnology, 24306 Plön, p.b. 165, Germany

Robert H. Kadlec University of Michigan, and Wetland Management Services, Chelsea, MI, USA

Frank Klötzli ETH, Institute of Integrative Biology, Universitätstrasse 16, 8092 Zürich, Switzerland

Gary A. Lamberti Department of Biological Sci-ences, University of Notre Dame, Notre Dame 46556, IN, USA

Joseph S. Larson Environmental Institute, Uni-versity of Massachusetts, Amherst, MA, USA

Conor Linstead Institute for Sustainable Water, Integrated Management and Ecosystem Research, Nicholson Building, University of Liverpool, Liverpool L69 3GP, UK

Edward Maltby Institute for Sustainable Water, Integrated Management and Ecosystem Research, Nicholson Building, University of Liverpool, Liverpool L69 3GP, UK

Matthew P. McCartney International Water Management Institute, Addis Ababa, Ethiopia

Russ P. Money South East Region Water Resources Specialist, Natural England, Government Buildings, Coley Park, Reading RG1 6DT, UK

Henry R. Murkin Institute for Wetland and Waterfowl Research, Ducks Unlimited Canada, PO Box 1160, Stonewall, Manitoba R0C 2Z0, Canada

Flavia Nogueira Federal University of Mato Grosso, 78070-030 Cuiabá, Av. Fernando Correa s/n, Brazil

Catia Nunes da Cunha Federal University of Mato Grosso, 78070-030 Cuiabá, Av. Fernando Correa s/n, Brazil

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Contributors xiii

Jörg Pfadenhauer Vegetation Ecology, Technis-che Universitaet Muenchen, Am Hochanger 6,Building 219, 85350 Freising-Weihenstephan, Germany

Gilles Pinay School of Geography, Earth and Environmental Sciences, University of Birming-ham, Edgbaston, Birmingham B15 2TT, UK.

Leendert J. Pons (deceased) Agricultural University, Wageningen, The Netherlands

Michael C.F. Proctor School of Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, UK

Dieter Ramseier ETH, Institute of Integrative Biology, Universitätstrasse 16, 8092 Zürich, Switzerland

K.R. Reddy Wetland Biogeochemistry Laboratory, Soil and Water Science Depart-ment, University of Florida, Gainesville, FL 32611, USA

Curtis J. Richardson Duke University Wetland Center, Nicholas School of the Environment, Levine Science Center, Durham, NC 27708, USA

Henri Roggeri IUCN National Committee of The Netherlands, Plantage Middenlaan 2-K, 1018 DD Amsterdam, The Netherlands

Lisette C.M. Ross Institute for Wetland and Waterfowl Research, Ducks Unlimited Canada, PO Box 1160, Stonewall, Manitoba R0C 2Z0, Canada

R.J. Safford BirdLife International, Wellbrook Court, Girton Road, Cambridge CB3 0NA, UK

Johan Schutten Ecology, Environmental Sci-ence Directorate, Scottish Environment Protec-tion Agency, Carseview, Castle Business Park, Stirling FK9 4SW, UK

Matthew Simpson WWT Consulting, Wildfowl & Wetlands Trust, Slimbridge, Gloucestershire GL2 7BT, UK

R. Daniel Smith Research Ecologist, Engineer-ing Research and Development Center, Wet-lands and Coastal Ecology Branch, 3909 Halls Ferry Road, Vicksburg, MS 39180, USA

Julian R. Thompson Wetland Research Unit, Department of Geography, UCL, Pearson Build-ing, Gower Street, London WC1E 6BT, UK

Merritt R. Turetsky Department of Integrative Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada

R. Kerry Turner Centre for Social and Economic Research on the Global Environment, University of East Anglia, Norwich, UK

Angheluta Vadineanu Department of Sys-tems Ecology and Sustainability, University of Bucharest, Splaiul Independentei 91-95, 050095, Bucharest, Romania

Panchabi Vaithiyanathan Divers Alert Net-work, 6, West Colony Place, Durhan, NC 27705, USA

Isabel J.J. van den Wyngaert Alterra, PO Box 47, 6700 AA Wageningen, The Netherlands

Arnold G. van der Valk Department of Ecology, Evolution, and Organismal Biology, Iowa State University of Science and Technology, Ames, IA 50011-1020, USA

Rudy Van Diggelen Ecosystem Management Research Group, Department of Biology, Uni-versity of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium

Duong Van Ni Hoa An Research Station, Can Tho University, Can Tho, Vietnam

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xiv Contributors

Jos T.A. Verhoeven Landscape Ecology, Institute of Environmental Biology, Utrecht University, PO Box 80084, 3508 TB Utrecht, The Netherlands

Melanie A. Vile College of Liberal Arts and Sciences, Department of Biology, Villanova University, 800 Lancaster Avenue, Villanova, PA 19085, USA

Karl Matthias Wantzen Aquatic-Terrestrial Interaction Group, Institute of Limnology, University of Konstanz, Postfach M659, 78457 Konstanz, Germany

Bryan D. Wheeler Department of Animal and Plant Sciences, University of Sheffi eld, Sheffi eld, UK

Dennis F. Whigham Smithsonian Environmen-tal Research Center, Box 28, Edgewater, MD 21037, USA

John R. White Department of Oceanography and Coastal Sciences, Wetland and Aquatic Biogeochemistry Laboratory, Energy Coast & Env Building #3239, Louisiana State University, Baton Rouge, LA 70803, USA

R. Kelman Wieder Department of Biology, 105 St. Augustine Center, Villanova University, 800 Lancaster Avenue, Villanova, PA 19085, USA

Adrian P. Wood Wetland Action, 1070NB Amsterdam, The Netherlands

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Section I

Wetlands in the Global Environment

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1 The Changing Wetland Paradigm

EDWARD MALTBY

Institute for Sustainable Water, Integrated Management and Ecosystem Research, University of Liverpool, Liverpool, UK

The Wetlands Handbook, 1st edition. Edited by E. Maltby and T. Barker. © 2009 Blackwell Publishing, ISBN 978-0-632-05255-4

INTRODUCTION

Never has there been such strong political or institutional rhetoric, more effective governmen-tal and non-governmental organisations, or the present level of scientifi c information to promote more sound environmental management of the world’s natural resources. Yet loss and degrada-tion of wetlands continues without well-informed public or political support and often in the face of signifi cant opposition from one or other sector of civil society. This introductory chapter examines some of the fundamental historical, but changing, relationships between humans and wetlands. It is intended to serve as a context within which sci-ence can establish a more compelling case and evi-dence base for appropriate stewardship of wetland ecosystems, and as a clearer recognition emerges of the factors that impede progress towards a more rational use of their natural capital (Costanza et al. 1997; Balmford et al. 2002). Further, it pres-ents the specifi cations for the scope of wetland science in a rapidly changing social, economic and natural world.

Human perception of, and relationships with, wetlands have evolved alongside the transforma-tions that have taken place in the organisation of society, technological developments and sci-entifi c knowledge. Additionally, wetlands have distinctive relationships with particular interest groups and with human communities in different parts of the world. Most notable are the contrasts

in perspective between developed and developing countries, particularly in identifying the point of balance between conservation and use of wet-lands. For some parts of society, wetlands have particular iconic status associated with history, literature, myth, religious or cultural signifi cance. For others it is an ethical or moral commitment to their biodiversity that underpins the case for their conservation. Yet others view wetlands as just another natural resource, to be used sustain-ably or unsustainably, or simply drained for non-wetland use if this can achieve greater fi nancial or economic returns (see Chapter 2). The range of consideration, then, is from the philosophical and ethical to the utilitarian viewpoint. It is only by awareness of the intimate, intricate and varied links among wetlands, human culture, biological diversity and wider environmental characteristics, that it is possible to appreciate fully the complex-ity of possible future as well as current manage-ment objectives. Our ability to attain specifi c wetland management goals, however, is depen-dent not only on the adequacy and coordination of the relevant experience, scientifi c and technical knowledge but on the availability of institutional and other enabling mechanisms to maintain and manage these ecosystems in the face of sometimes fi ercely competing resource demands.

WETLANDS IN PERSPECTIVE

An intimate part of the evolutionary driving force

Landscapes and ecosystems that we now label wetlands have played seminal parts in Earth


4 EDWARD MALTBY

and human history. Life itself could only have originated in the presence of free water, but whether it was fresh or salt, shallow or deep, is not possible to answer. The origin of the earliest microfossils, thought to have been between 3.46 and 3.85 billion years ago, is in dispute (Schopf 1993; Sankaran 2002), but liquid water was nec-essary to prevent desiccation and death. Beyond such possible beginnings, wetlands were the site of evolution of many highly specialised spe-cies (Chapter 3), and it is likely that key steps in human evolution took place among hominins in the wetland margins of rivers, lakes and the sea. The so-called ‘aquatic ape’ theory suggests that the fatty acids in fi sh caught by these early com-munities were important in enabling the brain capacity to develop, culminating in the evolution of modern humans (Morgan 1982).

Many species of plant and animal have survived within wetland boundaries where counterparts outside have perished. The reasons for survival of specialised species and communi-ties are varied but include: the plentiful, though frequently periodic, supply of water; specifi c and varied adaptations to waterlogged condi-tions; the moderating microclimate in extreme environments (especially signifi cant in desert regions); the large extent of many wetland areas; environmental conditions hostile to poten-tially competing predatory or invasive species; and often, diffi culty of access for humans. The role of wetland boundaries as an evolutionary driving force has yet to be fully explored, but certainly deserves greater attention (Naiman et al. 1988).

Four characteristics of wetlands contribute especially to the biodiversity associated with these ecosystems:

change over time through ecological succes-• sion (Figures 1.1 and 1.3);

zonation both within and at the boundary of • the ecosystem (Figure 1.2);

change over time through seasonal or more • frequent hydrological or ‘pulsing’ cycles or indi-vidual events;

adjacent ecosystems with generally contrasting • features.

Wetlands often are transient features in land-scape development, and can be regarded in many cases as the authors of their own destruction. The inherent processes of natural change, such as sedimentation, peat growth and soil develop-ment lead to hydrologic changes that may be less favourable for existing plants and animals than for competitors. So too, a plant assemblage may alter conditions in ways that make the habitat less favourable for survival of its own component spe-cies, and more favourable for the development of a different community. Wetland ecosystems can pass through many such ‘seral’ stages, emphasis-ing their dynamic yet temporary character.

Many shallow lakes and ponds in the post-glacial landscapes of the northern hemisphere quickly fi lled in, to become marshes where inor-ganic sediment dominated, or fens where the detritus was peaty. In some places, such as the Somerset levels or Malham Tarn (Figure 1.3) in

Birch

Hazel

Pine Eim Grass

Planta

in

0

5000

10 000

Fig. 1.1 Enumeration of pollen grains in sediments can assist reconstructions of past vegetation types, human interventions and climates. Here, for example, hazel replaced birch some 9000 years BP but was itself replaced briefl y by pine at 7000 BP. Populations of elm made an abrupt decline some 5000 years BP, to be replaced in part by grasses and plantain. (Source: O’Connell 1987.)


The Changing Wetland Paradigm 5

Greenfrog

Minkfrog

Uplandgrasses Lowland

grasses SedgeCattail

Hardstem

Ambystomasalamanders

American toad

Newts

Wood frogSpring peeperGray tree frog

Plethodonsalamanders

Bull frog

Leopard frog– - -

Fig. 1.2 Zonation of amphibian species according to degree of waterlogging, standing water depth, and consequent plant zonation. (From Keddy 2000.)

Topographicdepression

Humified Sphagnum peat

Eriophorum peat

Glacial drift

Marl

Fen peatwith wood

150 m

12

9

6

3

m

0

Sand

Silt and clay

Sphagnum peat

This part of the original lake has infilled with sediment and has further developed initially as a fen wetland with some woodland cover

and subsequently as a bog

Fig. 1.3 Profi le reconstruction from peat borings of Tarn Moss, which occupies part of the basin of Malham Tarn, a small lake in Yorkshire, England. (Taken from Moss 1998 and based on Pigott and Pigott 1959,1963.)


6 EDWARD MALTBY

the UK, fens were transformed into bogs as the peat surface layer grew, becoming increasingly separated from the infl uence of nutrient-rich groundwater. As a result, the upper peat became acidifi ed and increasingly reliant on precipita-tion alone for nutrients. Eventually, such bogs may outgrow their ability to maintain a perma-nently high water table, and trees can become established, the roots of which can accelerate the rate of desiccation. The formerly aquatic ecosys-tem may thus become transformed into dense woodland.

Often, through the process of succession, a pattern of zonation occurs in the boundary zone of a wetland. This is particularly the case around lake margins, fl oodplain depressions and rivers. This zonation tends to indicate in space what is likely to happen over time in the wetland itself. Thus, the sequence: open water–fl oating swamp–marsh with emergent vegetation–wet grassland–shrub–woodland, may be discovered by taking a vertical core through the marginal

woodland surface (Figure 1.3). A wetland may vary in structure and composition depending on its stage of development. This is the result of natural change in which a lake, marsh, bog and woodland may occupy the same space over just a few centuries or, at most, millennia.

Typically, wetlands also have considerable internal diversity. Mire ecosystems demonstrate this well, for example the hummock-hollow com-plexes of blanket bogs and the varied microrelief features of other mires. This produces distinc-tive microhydrological gradients and associated zonation of plant species which, in turn, provide separate niches for different invertebrates and birds that feed on them (Figure 1.4). Extensive wetland areas are usually made up of complex arrays of different ecosystems, refl ecting varia-tions in hydroperiod, substrate, water quality and human intervention. For example, the Florida Everglades (‘river of grass’) actually comprise open water meandering channels (‘sloughs’), various marsh communities, fl oating or anchored

Round-leaved sundewDrosera rotundifolia

Hummock

High ridge

Low ridge

1

2

3

45

6 Pool

T3

T2

T1

50 cm

A1

A2

A3

A4

A R

othw

ell/S

A W

alla

ce

Hollow

Great sundewDrosera anglica

Oblong-leaved sundewDrosera intermedia Intermediate bladderwort

Utricularia intermedia

1 Sphagnum imbricatum2 Sphagnum rubellum3 Sphagnum magellanicum4 Sphagnum papillosum5 Sphagnum pulchrum6 Sphagnum cuspidatum

Fig. 1.4 Niche zonation of wetland species in an oligotrophic hummocky wetland. (From Ratcliffe and Oswald 1988.)



tree islands and permanent tree-dominated hummocks where the bedrock is more elevated. The inherent variations in depth, distribution and duration of surface fl ooding add to this diversity of habitat and enhances species diversity (e.g. Ogden 2005).

Human cultural signifi cance

Wetlands throughout the world have undergone different patterns of change over time. While the nature and timing of successional change can be interpreted by the analysis of environmentalindicators such as pollen, macrofossils, diatomfrustules, chemical, physical and magnetic prop-erties of the sediment and organic matter at different levels in the subsurface stratigraphy(Figures 1.1 and 1.3), there is often a close rela-tionship with contemporary environmental features, which are preserved within the timeline of the stratigraphic sequence. These data, obtained by sediment cores and excavations, can illustrate events in society and periods of human develop-ment, manipulation of the cultural landscape and environmental change (see Chapter 4). The famous prehistoric trackway across the Somerset levels, known as the ‘Sweet Track’ (Coles and Coles 1989), is preserved in a peat deposit that is subject to successional development, dominated now by birch woodland.

There are also well documented cases in Scandinavia of deliberate burials in bogs, for example Tollund Man and Elling Woman, both found in a bog near Silkeborg, Denmark, and Grauballe Man, also found in Denmark. The burials, all discovered in the 1950s, are thought to have had some ritual or ceremonial sacrifi cial signifi cance (Glob 1965). Perhaps the best-known example in the UK is that of Lindow Man, found in Lindow Moss, Cheshire in 1984. This was the body of a man in his thirties, who had been the victim of a ritual killing before being buried in the peat in about 550 BC (Turner and Scaife 1995).

Wetlands can tell us as much about ambient environmental change as they can about changes in the wetland ecosystem itself (Figure 1.3). An interpretation of the history of an area of extensive

fl oodplain rivers, associated peat deposits, and contemporary human communities in what is now the Norfolk Broads, UK, from 7000 years ago to present, can be found in Moss (2001).

Seasonal hydrological patterns, such as fl ooding from snowmelt or seasonal rains alternating with drawdown or drought, means that some of the world’s largest wetlands may alternate between aquatic-dominated and terrestrial-dominated ecosystems over the same space. This is true for many of the large wetlands of Africa, such as the Okovango Delta, and extensive fl oodplains such as those of the Kafue Flats, Inner Niger Delta, the Hadejia-Nguru and the Tana (Chapter 38). It is also the case in the Pantanal (Chapter 40) where evolutionary adaptation among species is linked clearly to the fl ood cycle or ‘pulse’.

The multifunctional benefi ts that arise from the often rapid and dramatic alternation of wet and dry conditions are signifi cant for wildlife, but also provide the basis for the sustainable econo-mies of many human populations; however, with increasing frequency the ‘natural’ hydrology is threatened by dams and irrigation projects. In an analysis of seven case studies covering more than a third of all fl oodplains in Africa, Drijver and Marchand (1985) concluded that, ‘notwith-standing the possible impact of water management projects, the negligence of ecological side-effects generally means a deterioration of environmental quality at the expense of the existing economic situation for the local people and of the natural conservation values. This often decreases the intended advantages of a project, and can even outweigh them’. More recent economic analyses have demonstrated the gross economic failures of many irrigation schemes (e.g. Barbier et al. 1993, 1997).

Wetlands can experience acute impacts from individual extreme events such as storms, fl oods and droughts because of their marginal loca-tions and particular vulnerability to hydrological change, but where these impacts are part of the natural hydrological dynamic, recovery is rapid. The benefi ts to adjacent ecological or human sys-tems of protection from damage can be dramatic. The particular role of mangroves and fl oodplain


8 EDWARD MALTBY

forests in reducing storm surges and fl ood hazardbecame only too evident in the case of the Boxing Day 2004 tsunami in the Indian Ocean. The pro-tection conferred by mangroves was generally greatest at some distance from the area of maxi-mum impact. A study by Danielsen et al. (2005) found that a 100 m-wide stand of mangrove trees at a density of 30 trees per 100 m2 had the capac-ity to reduce fl ow pressure by >90%. The dam-age infl icted on the coastal zone was exacerbated by previous human activities. In Tamil Nadu, India, for example, villages situated behind man-grove stands suffered no damage in the midst of destruction in adjacent areas, and on the coast where mangroves had been cleared, villages were completely destroyed (Danielsen et al. 2005). Dahdouh-Guebas et al. (2005) reported that 50% of the world’s mangrove forests were destroyed during the second half of the twentieth century. The main reasons given were complete clear-ance of mangroves, insuffi cient regrowth follow-ing a prior clearing, and excess growth of ‘weed’ species, which partly or fully replaced the adult mangroves (Dahdouh-Guebas et al. 2005).

A CULTURAL DRIVING FORCE

Some key stages in Earth history and turning points in human culture

Wetlands have featured prominently in Earth history and human development. Just two exam-ples serve to illustrate. The fi rst is represented by the tropical peat-swamps of 250 million years ago that were responsible for formation of the exten-sive coal deposits of the Carboniferous period. Sieffermann (1988) has described the modern day analogues of their formation from Central Kalimantan. Movement of continents over geo-logical time, and associated climatic change, shifted the highly compressed and transformed geological product of the ancient tropical peat-lands into the higher latitudes of Europe and North America, where they would power the Industrial Revolution of the early nineteenth cen-tury. These fossil fuels, together with the patterns

of world trade, have had immense impacts on economic and cultural development. They are also the major agents of human-induced climate change.

There is considerable debate over the possible roles of both intact and drained contemporary wetlands in contributing to climatic change by the emissions of radiatively-active gases such as methane, nitrous oxide and carbon dioxide or by moderating it through sequestration and storage of new carbon in organic matter and peat. It is perhaps ironic that it should be the reconversion to CO2 of carbon previously captured by ancient wetlands that has contributed to accelerated atmospheric warming.

Such a relationship is a strong reminder of the importance of biogeochemical coupling between wetlands and the larger global system, and the importance of time, and rate of change, as consid-erations in environmental management. Whereas carbon and other elements may be sequestered from the atmosphere in the course of natural wet-land development and geological transformation over many thousands and, in some cases, millions of years, human exploitation may cause this store to be depleted at a rate several orders of magni-tude faster. Arguably, the fundamental challenge to achieving optimum patterns of wetland use is to avoid unbalancing natural process rates, and this is illustrated dramatically whenever peat-lands are subjected to drainage, that is when the rate of oxidation of accumulated organic matter greatly exceeds the rate of addition of new mate-rial to the peat mass (Immirzi and Maltby 1992).

The second example is the role of wetlands as a force that has encouraged collective natural resource management and societal development (Bayliss-Smith and Golson 1992). For millennia, prehistoric communities thrived and benefi ted from the natural goods and services of wetlands –including food, water, materials for building, shelter and clothing – which cost nothing more than human energy to utilise. Wetlands, rivers and lakes played extremely important roles in the evolution of prehistoric communities, and were the sites of the earliest stages in the development of tool-producing hominins. The socio-economic



development of prehistoric communities in north-eastern Europe has been interpreted by Dolukhanov (1992) in terms of increasingly suc-cessful adaptation to the riverine–lacustrine environment by means of intensifi ed foraging strategies. Excavations of the many post-glacial lake margin and riverine settlements in northern Europe and Russia provide excellent examples of the intimate and highly dependent relation-ships that existed between humans and wetlands in Mesolithic and Neolithic Europe (Coles and Coles 1989).

Even while this prehistoric dependency per-petuated in Europe, the development of simple water control structures and associated irriga-tion techniques, made possible by topography and the predictable annual fl ood cycle, was transforming the economy of the fl oodplain peoples of the Middle East. Many consider that in the great alluvial valleys and associated del-taic systems of the Nile, Tigris and Euphrates, the regularly inundated fertile fl oodplain was an essential element in the development of early

The lower Mesopotamia Plain was home to some of the earliest known civilisations. They were founded on the sustainable use of the region’s water resources, which enabled the establishment of sophisticated and highly organised irrigation systems. It is thought that land occupation occurred from between 9000–8000 BC, with the southern region, including the wetlands, colonised at around 5000–4500 BC

by Ubaidians. These people were the fi rst to practice irrigated agriculture on a large scale, to occupy suitable parts of the marshes and to introduce trade for support of early industry. The Ubaidians dominated the marsh people, and mixed with the original hunters and fi sher-men in a pre-Sumerian culture. The subsequent kingdom of Sumer was concentrated in the wet-lands, which were much more extensive than in the modern era. The relative security affordedby the marshes enabled a prosperous civilisation

to develop in the midst of a hostile desert envi-ronment. Cities with suburbs, temples, defen-sive walls and dykes, gardens and orchards were supported by the agricultural production of irrigated farmlands, the rich produce of the marshes, and an advanced system of commerce. Evidence from cities such as Ur confi rms that the basic units of life in the present day marshes, for example the reed-house: mudhif (Figure 1.5),or the long canoe: mashuf (Figure 1.6), can be traced back to the Sumerians. This dem-onstrates continuity in the mode of land use, and a cultural connection for more than 5000 years. Some of the earliest examples of writ-ten language come from Sumer; the origins of the biblical account of the Creation, and the fl ood of Noah may be from Sumerian literature (such as the epic of Gilgamesh), thus bequesting an immense culture and philosophy to future generations.

civilisations. Whilst these may not have been the only ‘cradles’ where early human communities moved from prehistoric, more or less nomadic, lifestyles to new forms of cultural organisation, they provide an excellent illustration of how people could adapt to, harness, and modify the natural functioning of fl oodplain wetlands to create agricultural wealth and relative security of food supplies.

The terms ‘hydraulic civilisation’ and ‘hydrau-lic society’ have been used to describe the distinctive systems that emerged as human com-munities met the wetland challenge through the organised use of the broad fl oodplain environ-ment and the regular fl ood cycle (Steward 1949; Wittlfogel 1957; Mitchell 1973).

The successful maintenance of modifi ed hydro-logical regimes required considerable cooperation and organisation, especially as populations grew and became increasingly concentrated. Rules and laws became necessary to ensure effi cient management of the agricultural systems (see Box 1.1). Food surpluses and demand stimulated

Box 1.1 The legacy of the Mesopotamian wetlands – cultural and technological


10 EDWARD MALTBY

soils. Additionally, they mark the establishment of pathways for contamination of natural waters by the runoff from increasingly modifi ed agri-cultural ecosystems, and with waste from new synthetic surfaces and urban concentrations. Thus, the drainage waters from irrigated lands in historic Mesopotamia were enriched in salts and, in modern Iraq, with pesticide residues and nutrients. The dramatic consequences were recognised early. Around 4400 BC, clay tablet archives in the temple of Lagash, which managed a large agricultural area, recorded an increase in salinity of one particular fi eld from 1.1% to

The Sumerian dynasties were eventually overtaken by other peoples and nations whose great agricultural wealth, based largely on irriga-tion, supported successive empires. Documents of the Babylonian King Hammurabi (who ruled from c. 1792–1750 BC) refer to maintenance and construction of canals and to the establishment of a ‘whole network of irrigation, navigation and defence waterways …’ (Metz 2004).

Maximum development of the canal sys-tem was achieved under the Abbasid Caliphs(c. 750–1258 AD) but came to an abrupt end with

the Mongol invasions. Siltation and salinisation led to the abandonment of agricultural land and a dramatic reduction in agricultural production. Restoration commenced at the beginning of the twentieth century when Sir William Willcocks surveyed possible development options.

Throughout all of this period, there was no attempt to alter the essential character of the broader wetland complex until the dramatic scale of intervention by the Saddam regime (see e.g. Maltby 1994; Partow 2001; Metz 2004; and below).

Fig. 1.5 A traditional reed mudhif on a small island in the recently refl ooded marshes at Suq Al-Shuyukh. (Photo by E. Maltby.)

Fig. 1.6 A modern, smaller version of the original long canoe, or mashuf currently being used in the Iraqi marshlands. (Photo by E. Maltby.)

trade, supporting further population growth and the increased differentiation of individual roles within society that are familiar today. Urban and civic development were made possible by harvesting the ‘green revolution’ in which the alluvial wetland landscape was both resource base and enabling mechanism. The small-scale water diversions and supply pathways that enabled more concentrated agriculture and increased productivity were, however, the prototypes of progressively larger dam and levee structures, which later came to sever the natural linkages between rejuvenating fl oodwaters and fl oodplain



35% just 1 year later (Woolley 1965). The diffuse pollution from agriculture, and the need to deal with highly concentrated wastes from towns and cities, are today among the greatest sources of impact on freshwater ecosystems.

Traditionally, wetland management, whether it be hydraulic structures for fl oodplain protec-tion or water diversion, water control techniques for growing taro in New Guinea or rice in the Philippines, or grazing and drainage control in the English fens, has demanded communal effort. Bayliss-Smith and Golson (1992) cite the fenland village of Cottenham, in the UK, as an example of the strength and range of the community’s organ-isation since medieval times. Access to various resources was controlled by detailed regulation, often leading to disputes arising from ‘the army of complicated rights and interlocking interests’ (Darby 1983). Such ‘peasant power’ over the wetland was considered by entrepreneurs to be ‘a conservative force that obstructed improve-ment’. Bayliss-Smith and Golson (1992) cite this as evidence of a paradox of wetland management: ‘Successful drainage by cooperative management, if sustained, can also provide an opportunity for the expropriation of wealth and the emergence of inequality, and this tendency may be resisted’.

Historic attitudes

Since prehistoric times, the utilisation of wetlands throughout the developed world can be likened to the ‘passing frontier of nature replaced by a per-manently and suffi ciently expanding frontier of technology’ (Sauer 1938). Generations of school-children have learned, unqualifi ed until recently, about the laudable achievements of the drainage of the English Fens to create rich farmland (Darby 1983), and of the remarkable engineering to establish agricultural polders in the Netherlands where once there had been sea (Idema et al. 1998). The parallel perceptions of wetlands such as bogs and swamps as disease-ridden, dangerous to life, inhospitable, and of little value unless altered, has been promoted extensively in the literature (historic, factual and fi ctional) and more recently through the twentieth century cinematic media

(see Mitsch and Gosselink 2000). A questionnaire in primary schools showed that antipathy to wetlands is learned between the ages of 6 and 10(Anderson and Moss 1993). For centuries ‘the drainage of wetlands has been seen as a progres-sive, public-spirited endeavour, the very antith-esis of vandalism’ (Baldock 1984). Such attitudes echo Carl Sauer’s 1938 analysis, ‘the recklessness of an optimism that has become habitual, but which is residual from the brave days when north European free-booters overran the world and put it under tribute. We have not yet learned the dif-ference between yield and loot. We do not like to be economic realists’.

Throughout history, the benefi ts that we pre-sume were appreciated by early human cultures and traditional users of wetlands were either ignored or dismissed as less signifi cant by more powerful sectoral interest groups. Technology enabled the rapid and progressive alteration of wetlands, for example about two thirds of the Netherlands, once part of the complex delta of the Rhine, Meuse, Ems and Scheldt rivers, would be regularly inundated were it not for dams, dykes and engineering works built since the eighth century. Opening new land for agriculture has been the most common argument, at least in the developed world, for reclamation of waterlogged places, although for some areas, such as the Hula Valley in Israel, the eradication of malaria was also a compelling part of the rationale (Maltby 1986).

Despite the increasingly wide recognition of their importance, the degradation and loss of wetlands continues worldwide, and includes well publicised examples such as the shrinkage of Lake Chad (Figure 1.7) in Africa (Coe and Foley 2001) and Central Asia’s Aral Sea (see Chapter 25), the desertifi cation of the marshlands of southern Iraq (Maltby 1994; Partow 2001), the drainage of the tropical peatlands of central Kalimantan for for-estry (Figures 1.8 and 1.9) and for a failed ‘Mega-rice’ project (Morrogh-Bernard et al. 2002), and the progressive desiccation and eutrophication of the Florida Everglades (see Chapter 42). Such major losses foreclose options and considerably reduce the resource base for sustainable development.


12 EDWARD MALTBY

Fig. 1.7 The progressive contraction over time of Lake Chad owing to diversion of river water for irrigation and other uses (UNEP 2002). (Reproduced with permission from UNEP.) See Plate 1.7 for colour version of this image.

Fig. 1.8 Aerial view of pristine peat-swamp forest in the upper catchment of Sungai (River) Sabangau in Central Kalimantan, Indonesia. (Photo by J. Rieley & S. Page.)

Fig. 1.9 View along primary channel excavated in Block C of the Mega Rice Project in Central Kalimantan, Indonesia, one year after construction and immediately following the disastrous fi res of 1997. (Photo by J. Rieley & S. Page.)



NEW TRENDS AND PERSPECTIVES

The last 30 years or so has witnessed some remarkable changes in attitudes to wetlands that have placed them increasingly on the scientifi c as well as political agenda. The main features of these are associated with the following:

an increasing scientifi c focus on wetlands • within the environment and conservation movement;

raised awareness of the socio-economic signifi -• cance of wetland functioning and the delivery of ecosystem services;

wider recognition of the far-reaching conse-• quences of wetland degradation and loss, espe-cially in relation to climate change;

opportunities for wetlands, particularly in • the developing world, to deliver improvements in the welfare and livelihoods of local people through integrated development and poverty alleviation initiatives;

progressive recognition of the potential or • actual role of wetlands within various policy frameworks, including specifi c legislative instru-ments to deliver the wider objectives of sustain-able development (e.g. Clean Water Acts of the United States (Chapter 24), and the new European Water Framework Directive).

It should be remembered also that wetlands may have potential and actual disadvantages such as providing habitat for disease vectors e.g. malaria, schistosomiasis, onchocerciasis and liver fl uke (Carpenter and LaCasse 1955; Githeko et al. 2000; Gallup and Sachs 2001), and as sources of radiatively-active gases such as nitrous oxide and methane. There are some concerns that climate change and wetland res-toration may increase such disadvantages. Generally, however, it is the modifi cation of natural wetlands, especially through the expan-sion of irrigation channels and reservoirs, that increases the abundance of disease vectors (Maltby 1986), whilst the drainage of organic wetland soils is likely to generate a greater load of greenhouse gases (and certainly more quickly) than maintenance of wetlands as intact hydrological systems.

The Ramsar Convention as standard-bearer: an evolving instrument

The importance of wetland conservation in order to safeguard the essential habitat require-ments of migratory birds was the primary driv-ing force leading to the establishment of the Ramsar Convention on Wetlands of International Importance Especially as Waterfowl Habitat (Ramsar 1971; Table 1.1), the only international agreement to cover a specifi c single group of eco-system types. Established in 1971, it recognised the vital importance of protecting not just single wetlands but networks of wetlands, linked chain-like over long distances, to safeguard breeding, over-wintering, resting and feeding sites for migratory birds. However, such a cause celebre was also perceived by many as an indulgence on the part of richer nations that poorer countries could ill-afford in the face of the more pressing problems of poverty, food shortages, lack of eco-nomic development and burdens of foreign debt. Initially, therefore, many developing countries were reluctant to sign up to the Convention.

This position changed dramatically after the Conference of Parties in 1987 at Regina, Canada (Ramsar 1987), owing in large measure to two developments (Table 1.2). These were:

progressive modifi cations to the criteria for • designation of wetlands of international impor-tance, which recognised much more their wider functional signifi cance; and

elaboration of the ‘wise use’ concept to empha-• sise the benefi ts of wetlands in contributing to sustainable development (Box 1.2).

Table 1.1 The Ramsar Convention in 2007.

Established 1971, Ramsar, IranPresent No. of Contracting Parties (2007) 157No. of wetland sites listed (by 2007) 1708Total wetland area (ha) listed (2007) 153 000 000

Mission Statement: ‘The Convention’s mission is the conservation and wise use of all wetlands through local, regional and national actions and international cooperation, as a contribution towards achieving sustainable development throughout the world’ (Ramsar COP8, 2002).


14 EDWARD MALTBY

The modifi cations to the Ramsar criteria were infl uenced by a growing scientifi c literature, which has revealed the functional importance of wetlands, for example in fl ood control, main-tenance of water quality and fi sheries support.

It was held that most people can relate more readily to the functions that support human val-ues rather than those characteristics associated with traditional nature conservation, especially the maintenance of populations of migratory

Table 1.2 Summary of wetland criteria in Conference of Parties (COP) 1 and 4, pre and post the Regina conference in 1987.

CoP 1 Cagliari, 1980 CoP 4, Montreux, 1989

1. Quantitative criteria for identifying wetlands of importance to waterfowl. A wetland should be considered internationally important:• if it regularly supports either 10 000 ducks, geese, swans

or coots; or 20 000 waders;• if it regularly supports 1% of the individuals in a

population of one species or subspecies of waterfowl;• if it regularly supports 1% of the breeding pairs in a

population of one species or subspecies of waterfowl.

1. Specifi c criteria based on waterfowl. A wetland should be considered internationally important:• if it regularly supports 20 000 waterfowl; or• if it regularly supports substantial numbers of individuals

from particular groups of waterfowl, indicative of wetland values, productivity or diversity; or

• where data on populations are available, it regularly supports 1% of the individuals in a population of one species or subspecies of waterfowl.

2. General criteria for identifying wetlands of importance to plants or animals. A wetland should be considered internationally important:• if it supports an appreciable number of a rare, vulnerable,

or endangered species or subspecies of plant or animal;• if it is of special value for maintaining the genetic and

ecological diversity of a region because of the quality and peculiarities of its fl ora and fauna;

• if it is of special value as the habitat of plants or animals at a critical stage of their biological cycles;

• if it is of special value for its endemic plant or animal species or communities.

2. General criteria based on plants or animals. A wetland should be considered internationally important:• if it supports an appreciable assemblage of rare, vulnerable,

or endangered species or subspecies of plant or animal, or an appreciable number of individuals of any one or more of these species; or

• if it is of special value for maintaining the genetic and ecological diversity of a region because of the quality and peculiarities of its fl ora and fauna; or

• if it is of special value as the habitat of plants or animals at a critical stage of their biological cycle; or

• if it is of special value for one or more endemic plant or animal species or communities.

3. Criteria for assessing the value of representative or unique wetlands. A wetland should be considered internationally important if it is a particularly good example of a specifi c type of wetland characteristic of its region.

3. Criteria for representative or unique wetlands. A wetland should be considered internationally important:• if it is a particularly good representative example of a

natural or near-natural wetland, characteristic of the appropriate biogeographical region; or

• if it is a particularly good representative example of a natural or near-natural wetland, common to more than one biogeographical region; or

• if it is a particularly good representative example of a wetland, which plays a substantial hydrological, biological or ecological role in the natural functioning of a major river basin or coastal system, especially when it is located in a transborder position; or

• if it is an example of a specifi c type of wetland, rare or unusual in the appropriate biogeographical region.

This is a synopsis of a more comprehensive review by Stroud (in preparation).
