River Conservation and Management E-Book

• Herausgeber: John Wiley & Sons
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 915

Veröffentlichungsjahr: 2012

Beschreibung

This book is intended for those with an academic, scientific and practical interest in river conservation and management. It provides an overview of how changes in legislation, policies, institutional responsibilities, science, technology, practical techniques and public perception have influenced how rivers have been managed over the past 20 years and the challenges that lie ahead during the next 20 years. The book is based on the international conference River Conservation and Management:20 Years On held at York. Thirty-one chapters, with contributions from North and South America, Europe, Asia and Australasia provide a wide-ranging perspective on this complex but profoundly important subject. Following an introduction that chronicles the most important contextual changes, the book is organized into four broad topics: * Catchment management, ecosystem integrity and the threats to river ecosystems - this covers progress on understanding and addressing the pressures affecting rivers, many of which will be amplified by climate change and increasing human demands for water; * Methods and approaches - illustrating some recent techniques that have been developed to assess condition and conservation status across different types of river; * Recovery and rehabilitation - providing an insight into the principles, practice, public involvement and institutional networks that support and make improvements to modified river reaches; * Integrating nature conservation into wider river management -demonstrating the importance of integrated planning, involvement of local communities and the use of adaptive management in achieving multiple environmental and economic benefits along rivers used for different purposes. The final chapter discusses the challenges faced in dealing with an uncertain future. More than 1200 different references and numerous web-site citations provide the reader with an invaluable source of knowledge on the subject area.

Leseprobe

Contents

Cover

Title Page

Copyright

List of Contributors

Preface

Catchment conservation, ecosystem integrity and threats to rivers systems

Methods and approaches

Recovery and rehabilitation

Integrating nature conservation within wider river management

Acknowledgements

Introduction

CHAPTER 1: Revisiting the Case for River Conservation

Introduction

The case for river conservation

Acknowledgements

Catchment Conservation, Ecosystem Integrity and Threats to River Systems

CHAPTER 2: From Channel to Catchment: A 20-Year Journey for River Management in England and Wales

Introduction

Beyond nature conservation: multi-functional catchment management

Twenty years of influencing policy and practice: improving the evidence base and knowledge needed for managing ‘natural’ rivers and catchment processes

Twenty years of inclusion: the role of stakeholders as agents of sustainable river basin management

The EC Water Framework Directive: triumph or tragedy?

Reflections on success and failure

Acknowledgements

CHAPTER 3: The Rivers and Streams of England and Wales: An Overview of their Physical Character in 2007–2008 and Changes Since 1995–1996

Introduction

Methods

Calculating the results

Results

Discussion

Acknowledgements

CHAPTER 4: Environmental Flow Allocation as a Practical Aspect of IWRM

Introduction

The development and application of IWRM

Environmental flows for rivers

Conclusions

Acknowledgements

CHAPTER 5: Assessing the Hydrological Effects of Forest Plantations in Brazil

Introduction

The development of plantation hydrology

Early plantation hydrology studies in Brazil

Experimental catchment studies in Brazil

Discussion

Conclusions

Acknowledgements

CHAPTER 6: In the Indus Delta it is No More the Mighty Indus

The mighty Indus River: at a glance

Significance of the Indus Delta

Building the world's largest irrigation infrastructure

Reduced flow of the River Indus: causes and consequences

Cost of environmental degradation in the Indus Delta

Pakistan flood 2010

Options for management

CHAPTER 7: A 20-Year View of Monitoring Ecological Quality in English and Welsh Rivers

Introduction

River monitoring in England and Wales

Taking stock – 20 years of river monitoring

Characterizing joint pressures in the River Wye catchment

Revealing relationships between biology, water quality and physical habitat

Conclusions – the prospects for using monitoring data

Acknowledgements

CHAPTER 8: Water Quality and Exurbanization in Southern Appalachian Streams

Introduction

Site description

Methods

Results

Discussion

Acknowledgements

CHAPTER 9: Understanding and Managing Climate Change Effects on River Ecosystems

Introduction

Empirical evidence of effects and trends

Climate change effects on river ecosystems: the bigger picture

Knowledge gaps and research priorities

Acknowledgements

CHAPTER 10: Scotland's Freshwater Pearl Mussels: The Challenge of Climate Change

Introduction

Ecology

Status

Direct climate change effects

Indirect climate change effects

Societal responses

Conclusions

Methods and Approaches

CHAPTER 11: Can Mediterranean River Plants Translate into Quality Assessment Systems? Venturing into Unexplored Territories

Introduction

Difficulties of developing indices for assessing Mediterranean Rivers

Previous macrophyte indices in Iberia

Possible solutions

A combined diatom– macrophyte index

The future of biological indices?

Acknowledgements

CHAPTER 12: The Use of Bryophytes for Fluvial Assessment of Mountain Streams in Portugal

Introduction

Study area

Field sampling and data collection

Data analysis

Results

Discussion

Bryophyte communities

Conclusions

Acknowledgements

CHAPTER 13: Improvements in Understanding the Contribution of Hyporheic Zones to Biodiversity and Ecological Functioning of UK Rivers

Introduction

The state of knowledge in 1990

The UK science and policy context (1990–2010)

The current status of HZ research and its importance to understanding biodiversity and ecological functioning in rivers

Emerging issues and research gaps

Management and conservation

Conclusions

Acknowledgements

CHAPTER 14: Taxonomic Distinctness as a Measure of Diversity of Stream Insects Exposed to Varying Salinity Levels in South-Eastern Australia

Introduction

Methods

Results

Discussion

Acknowledgements

CHAPTER 15: Development of a Systematic, Information-Based Approach to the Identification of High Value Sites for River Conservation in New Zealand

Introduction

Methods

Results

Discussion

CHAPTER 16: Assessing the Conservation Status of Alder-Ash Alluvial Forest and Atlantic Salmon in the Natura 2000 River Network of Cantabria, Northern Spain

Introduction

Study area

Alder-ash alluvial forest

Fish communities

Methods

Results

Discussion

Conclusions

Acknowledgements

CHAPTER 17: The Use of Palaeoecological Techniques to Identify Reference Conditions for River Conservation Management

Introduction

Reference conditions

Palaeoecology and habitat restoration

Multi-proxy analysis

Case study – River Eye, Leicestershire, England

Contemporary conditions and archival data

Analysis of contemporary and palaeo communities

Future prospects

Acknowledgements

Recovery and Rehabilitation

CHAPTER 18: The Espace de Liberté and Restoration of Fluvial Process: When Can the River Restore Itself and When Must we Intervene?

Introduction

The Aire, Geneva: a peri-urban river

Deer Creek, California: restoring lateral and vertical connectivity in a rural stream

Conclusions

Acknowledgements

CHAPTER 19: Multi-Purpose, Interlinked and Without Barriers: The Emscher River Ecological Concept

Introduction

The Emscher River

The Emschergenossenschaft

Spatial and integrated river basin management

Creating space for a living river – Masterplan Emscher:future

Ecological concept

Creating an ecological hotspot – Emschermouth

Monitoring

Discussion

Conclusions

Acknowledgements

CHAPTER 20: Rehabilitation of the River Skerne and the River Cole, England: A Long-Term Public Perspective

Introduction

Case studies

River Skerne

River Cole

Methods

Results

Discussion

Conclusions

Acknowledgements

CHAPTER 21: The Unnatural History of the River Trent: 50 Years of Ecological Recovery

Introduction

Methods and data sources

Results

Discussion

Acknowledgements

CHAPTER 22: Key Factors in the Management and Conservation of Temporary Mediterranean Streams: A Case Study of the Pardiela River, Southern Portugal

Introduction

Study area

Methods

Results

Discussion

Conclusions

Acknowledgements

CHAPTER 23: The History, Development, Role and Future of River Restoration Centres

Introduction

Development of the River Restoration Centre in the UK

Development of the European Centre for River Restoration (ECRR)

National river restoration centres in Europe

River restoration centres worldwide

Prospects for the future

Conclusions

Integrating Nature Conservation Within Wider River Management

CHAPTER 24: From Stockholm to Rio II: The Natural and Institutional Landscapes Through Which Rivers Flow

Introduction

Institutional landscapes

Natural landscapes

Rivers as landscape integrators

Rivers and their biota as ecosystem engineers

Rivers as a key support for future life on earth

Ecological flows and ecosystem services: case studies

Discussion: river landscapes into the future

Future institutional landscapes

Acknowledgements

CHAPTER 25: What Have Rivers Ever Done For Us? Ecosystem Services and River Systems

Introduction

Methods: ecosystem services case studies

Results

Discussion

Acknowledgements

CHAPTER 26: The Glen Canyon Dam Adaptive Management Program: Progress and Immediate Challenges

Introduction

Adaptive management

Learning by doing

Fish removal and translocation experiments

The importance of monitoring

Current challenges and future opportunities

Conclusions

Acknowledgements

CHAPTER 27: An Individual-Based Model of Swan–Macrophyte Conflicts on a Chalk River

Introduction

Methods

Results

Discussion

Acknowledgements

CHAPTER 28: Integrating Habitat Conservation with Amenity and Recreational Uses Along an Urban Stretch of the Adige River, Northern Italy

Introduction

The Integrated Evaluation Model

Study areas

Harmonizing nature conservation and land use along the River Adige corridor in Verona

Ecological and hydrological assessment

Pressures and impacts

The Environmental Landscape Plan

Discussion

Conclusions

Acknowledgements

CHAPTER 29: A River in Crisis: The Lower River Murray, Australia

Introduction

The river–floodplain ecosystem

Governance

A developing crisis

Opportunities

Conclusions

Acknowledgements

CHAPTER 30: The Nevis River: An Example of River Conservation in the New Zealand Context

Introduction

Changes in river management since 1990

Nevis River

Trout fishery

Flora and fauna

Historic values

WCO hearing outcome

Conclusions

Dealing With an Uncertain Future

CHAPTER 31: Current and Future Challenges in Managing Natural System Variability for River Conservation in European River Basins

Introduction

Hydromorphology: a new terminology for river conservation

The need for predictive approaches

The role of fluvial geomorphology in river conservation

Geomorphology: a side-lined discipline?

Floods – living with uncertainty

A fluvial geomorphology approach to assessing flood risk

Challenges for the future

Acknowledgements

Plates

Index

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Library of Congress Cataloging-in-Publication Data

River conservation and management / edited by Philip J. Boon and Paul J. Raven.

Includes bibliographical references and index.

ISBN 978-0-470-68208-1 (cloth)

I. Boon, P. J. II. Raven, P. J.

QH75.A1R582 2012

333.95′16–dc23

2011029290

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

Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books.

List of Contributors

E. Ulrika Åberg

School of Geography, University of Leeds, UK

Francisca Aguiar

Forest Research Centre, Technical University of Lisbon, Portugal

Ghulam Akbar

Karakoram International University, Gilgit, Pakistan

César Álvarez

IH-Cantabria, Universidad de Cantabria, Santander, Spain

Mario Álvarez-Cabria

IH-Cantabria, Universidad de Cantabria, Santander, Spain

Lucy Baker

Environment Agency, Warrington, UK

José Barquín

IH-Cantabria, Universidad de Cantabria, Santander, Spain

Ernest F. Benfield

Department of Biological Sciences, Virginia Tech University, Blacksburg, USA

Philip J. Boon

Scottish Natural Heritage, Edinburgh, UK

Carolina Bozetti Rodrigues

Instituto de Pesquisas e Estudos Florestais (IPEF), Piracicaba, Brazil

Anna Braioni

Landscape architect, Verona, Italy

Maria Giovanna Braioni

Department of Biology, University of Padova, Italy

Peter Bridgewater

Joint Nature Conservation Committee, Peterborough, UK

David Brito

Instituto do Mar, Departamento de Zoologia, Coimbra, Portugal

Kristen K. Cecala

Warnell School of Forestry and Natural Resources, University of Georgia, Athens, USA

Lindsay Chadderton

The Nature Conservancy, Department of Biological Sciences, University of Notre Dame, USA

António Chambel

Centro de Geofísica, Universidade de Évora, Portugal

John F. Chamblee

Warnell School of Forestry and Natural Resources, University of Georgia, Athens, USA

Peter Cosgrove

Alba Ecology Ltd, Grantown on Spey, UK

Jeffrey A. Cymerman

Warnell School of Forestry and Natural Resources, University of Georgia, Athens, USA

Francis Daunt

Centre for Ecology and Hydrology, Edinburgh, UK

Silvio Frosini de Barros Ferraz

Depto de Ciências Florestais, ESALQ, Universidade de São Paulo, Brazil

Carolyn A. Dehring

Department of Insurance, Legal Studies and Real Estate, University of Georgia, Athens, USA

Walter de Paula Lima

Depto de Ciências Florestais, ESALQ, Universidade de São Paulo, Brazil

Ian Dodkins

Forest Research Centre, Technical University of Lisbon, Portugal

Isabelle Durance

Sustainable Places Institute, Cardiff University, UK

Mark Everard

Environment Agency, Bristol, UK

Alastair Ferguson

The Old Dairy, Saul, UK

Diego Fernández

IH-Cantabria, Universidad de Cantabria, Santander, Spain

Maria Teresa Ferreira

Forest Research Centre, Technical University of Lisbon, Portugal

Andrés García

IH-Cantabria, Universidad de Cantabria, Santander, Spain

David J. Gilvear

School of Biological and Environmental Sciences, University of Stirling, Scotland, UK

Terence Gledhill

Freshwater Biological Association, Ambleside, UK

Ted Gragson

Department of Anthropology, University of Georgia, Athens, USA

Malcolm T. Greenwood

Department of Geography, Loughborough University, UK

John F. Hamill

Grand Canyon Monitoring and Research Center, U.S. Geological Survey, Flagstaff, USA

Philip Harding

Environment Agency, West Bridgford, UK

Lee Hastie

Department of Zoology, University of Aberdeen, UK

Nigel T.H. Holmes

Alconbury Environmental Consultants, Warboys, UK

Lynda C. Howard

Department of Geography, Loughborough University, UK

Rudolf Hurck

Emschergenossenschaft, Essen, Germany

C. Rhett Jackson

Warnell School of Forestry and Natural Resources, University of Georgia, Athens, USA

Martin Janes

River Restoration Centre, Silsoe, UK

Anne E. Jensen

School of Earth and Environmental Sciences, The University of Adelaide, Australia

José A. Juanes

IH-Cantabria, Universidad de Cantabria, Santander, Spain

Ben Kefford

Department of Environmental Sciences, University of Technology, Sydney, Australia

Paul Kemp

Faculty of Engineering and the Environment, University of Southampton, UK

Jennifer D. Knoepp

U.S. Forest Service, Coweeta Hydrologic Laboratory, Otto, USA

G. Mathias Kondolf

Department of Landscape Architecture and Environmental Planning, University of California, Berkeley, USA

Terry Langford

Faculty of Engineering and the Environment, University of Southampton, UK

Andrew R.G. Large

School of Geography, Politics and Sociology, Newcastle University, UK

John Leathwick

Department of Conservation, Hamilton, New Zealand

Lei Guangchun

School of Nature Conservation, Beijing Forestry University, China

David S. Leigh

Department of Geography, University of Georgia, Athens, USA

Ana Lillebø

Centro de Estudos do Ambiente e do Mar, Universidade de Aveiro, Portugal

Lu Cai

School of Nature Conservation, Beijing Forestry University, China

John C. Maerz

Warnell School of Forestry and Natural Resources, University of Georgia, Athens, USA

Chris P. Mainstone

Natural England, Northminster House, Peterborough, UK

Richard Marchant

Department of Entomology, Museum of Victoria, Melbourne, Australia

Theodore S. Melis

Grand Canyon Monitoring and Research Center, U.S. Geological Survey, Flagstaff, USA

Atte Moilanen

Department of Biosciences, University of Helsinki, Finland

Manuela Morais

Centro de Geofísica, Universidade de Évora, Portugal

Ramiro Neves

Instituto do Mar, Departamento de Zoologia, Coimbra, Portugal

Malcolm D. Newson

Tyne Rivers Trust, Horsley, UK

Matthew T. O’Hare

Centre for Ecology and Hydrology, Edinburgh, UK

Jay O’Keeffe

UNESCO-IHE, Institute for Water Education, The Netherlands

Bárbara Ondiviela

IH-Cantabria, Universidad de Cantabria, Santander, Spain

Stephen J. Ormerod

Cardiff School of Biosciences, Cardiff University, UK

Laura Oti

IH-Cantabria, Universidad de Cantabria, Santander, Spain

David Ottewell

Environment Agency, Lichfield, UK

Helena Parsons

Environment Agency, Warrington, UK

Ana Pedro

Centro de Geofísica, Universidade de Évora, Portugal

Francisco J. Peñas

IH-Cantabria, Universidad de Cantabria, Santander, Spain

Paulo Pinto

Centro de Geofísica, Universidade de Évora, Portugal

Carlos Pinto Gomes

Instituto de Ciências Agrárias e Ambientais Mediterrânicas, Universidade de Évora, Portugal

Vanda Pires

Instituto de Meteorologia, I.P., Lisbon, Portugal

Miguel Potes

Centro de Geofísica, Universidade de Évora, Portugal

Catherine Pringle

Odum School of Ecology, University of Georgia, Athens, USA

Paul J. Raven

Environment Agency, Bristol, UK

Maria Recío

IH-Cantabria, Universidad de Cantabria, Santander, Spain

Anne L. Robertson

School of Human & Life Sciences, Roehampton University, UK

Joana Rosado

Centro de Geofísica, Universidade de Évora, Portugal

Rui Salgado

Centro de Geofísica, Universidade de Évora, Portugal

Gianpaolo Salmoiraghi

Department of Evolutionary Biology, Bologna University, Italy

Katharine Seager

Environment Agency, Warrington, UK

Emma L. Seddon

Department of Geography, Loughborough University, UK

Mechthild Semrau

Emschergenossenschaft, Essen, Germany

Ana Séneca

Centro de Investigação em Biodiversidade e Recursos Genéticos (CIBIO), Porto, Portugal

António Serafim

Centro de Geofísica, Universidade de Évora, Portugal

Cecília Sérgio

Centre for Environmental Biology (CBA), Lisbon University, Portugal

Peter Shaw

Faculty of Engineering and the Environment, University of Southampton, UK

Helena Silva

Centro de Geofísica, Universidade de Évora, Portugal

Iain Sime

Scottish Natural Heritage, Inverness, UK

Richard A. Stillman

School of Conservation Sciences, Bournemouth University, Poole, UK

Sue Tapsell

Flood Hazard Research Centre, Middlesex University, London, UK

H. Maurice Valett

Department of Biological Sciences, Virginia Tech University, Blacksburg, USA

Ian P. Vaughan

Cardiff School of Biosciences, Cardiff University, UK

Cristiana Vieira

Centro de Investigação em Biodiversidade e Recursos Genéticos (CIBIO), Porto, Portugal

Maria Cristina Villani

Department of Biology, University of Padova, Italy

Maureen Voigtlaender

Instituto de Pesquisas e Estudos Florestais (IPEF), Piracicaba, Brazil

Keith F. Walker

School of Earth and Environmental Sciences, The University of Adelaide, Australia

Niall Watson

Otago Fish and Game Council, Dunedin, New Zealand

Jon Watt

Waterside Ecology, Druimindarroch, UK

Jackson R. Webster

Department of Biological Sciences, Virginia Tech University, Blacksburg, USA

David West

Department of Conservation, Hamilton, New Zealand

Nigel Willby

School of Biological and Environmental Sciences, University of Stirling, UK

Kevin A. Wood

Centre for Ecology and Hydrology, Edinburgh, UK

Paul J. Wood

Department of Geography, Loughborough University, UK

Chris Woolgar

Faculty of Humanities, University of Southampton, UK

Tom Worthington

Faculty of Engineering and the Environment, University of Southampton, UK

Muhammad Zafar Khan

WWF Pakistan, Shahrah-e-Faisal Karachi, Pakistan

Preface

This book shares an ambitious aim with the international conference on which it is based – The Conservation and Management of Rivers: 20 Years On. The conference was held at the University of York (UK) from 6–9 September 2010. It was timed to fall exactly 20 years after an earlier conference on the same subject at the same venue, and coincided with the UN International Year of Biodiversity. Two questions formed the context for the event: what has been achieved in river conservation and management in the 20 years since the 1990 conference and what still needs to be done in the next 20 years? We did not ask the conference speakers to answer these questions formally, but aspects of both were addressed frequently during their presentations and occur throughout the chapters in this book. The world in 1990 was very different from the way it is today, and some of the changes – economic, geopolitical, social, cultural and technological – are summarized in Chapter 1 (Boon). These changes set the context for the book, as many of them have a profound influence on the way that river conservation and management activities are planned and undertaken.

To produce an edited volume that is a coherent treatment of the subject, and not merely the published conference proceedings, is a real challenge. It is not possible for a book containing 31 chapters to represent a comprehensive account of river conservation and management. Indeed, one of the main differences between the conference in 1990 and the one in 2010 is the huge expansion in the subject area that has taken place in many parts of the world over this 20-year period. While we are not claiming that the book is comprehensive, we have attempted to present a rounded picture of the subject area, both to give a flavour of current knowledge and to provide a source of published references (there are more than 1200) for further reading. We also wanted it to contain contributions from a wide geographical range. The previous book of the same name (Boon et al., 1992) contained 29 chapters led by authors from 14 countries, with about a third of the chapters from the UK. It is interesting that only five of those 14 countries are represented in the new volume: this book has 31 chapters from 11 countries, with half from the UK. The new book has no contributions from Scandinavia (compared with three in the first one); it has five chapters from southern Europe whereas none appeared in the 1990 book. The picture that emerges is of a subject area that is truly international, but with real variations in emphasis and approach in different parts of the world.

The programme from the 2010 York conference contained 62 papers divided among 10 topics. We have structured the layout of this book by grouping chapters into four broad themes that include some of the most important topics in river conservation and management today.

Catchment conservation, ecosystem integrity and threats to rivers systems

The first section shows the progress (albeit painfully slow) since 1990 in making the aspirational goal of Integrated Catchment Management (ICM) a practical reality (Newson, Chapter 2). In Europe this has been greatly assisted by the passage of the EC Water Framework Directive, making ICM the basis for statutory 'river basin management plans' (Council of the European Communities, 2000). The threats to river systems that ICM attempts to address today differ little from those in 1990 (Boon, Chapter 1), although some, such as climate change (Ormerod and Durance, Chapter 9; Cosgrove et al., Chapter 10) were rarely discussed 20 years ago. Although significant progress has been made in tackling point-source pollution in many countries, diffuse water pollution remains a serious and widespread problem. For example, in Chapter 8 Webster et al. describe the effect of changing land-use and land-cover on the water chemistry of rivers in the Southern Appalachian mountains of the US, as people move out of the towns (described as 'exurbanization') to enjoy a new livelihood in forested and rural landscapes.

Water abstraction from rivers around the world has continued to grow over the last 20 years to serve an increasingly wide range of human uses. Two chapters provide evidence from contrasting regions of the profound effects of catchment land-use and water availability on river ecology. For example, in the tropical rivers of Brazil plantation forestry has a significant impact on stream flow (Lima et al., Chapter 5), while in the River Indus in Pakistan (Khan and Akbar, Chapter 6) one of the world's largest irrigation networks has had major impacts on river ecology and its delta as well as on human livelihoods. The need to put into practice Integrated Water Resource Management (IWRM), in particular to understand the importance of 'environmental flows' for supporting the needs of human society and river ecosystems, is further emphasized by case studies from East Africa (O'Keeffe, Chapter 4).

One of the main contrasts between 1990 and 2010 is the increased emphasis on 'hydromorphology' as a primary factor affecting river ecology and conservation. In 1990 the hydromorphological and ecological impacts of river engineering were known to some extent but not being researched systematically. Since then, several countries have devised methods for describing the condition of river habitats – notably in Europe, Australia and North America. For example, the development of River Habitat Survey in the UK (Raven et al., 1997) has provided a comprehensive inventory of the condition of river habitats and a measure of how much they have changed in England and Wales since the 1990s (Seager et al., Chapter 3). However, the ability to track changes in the physical, chemical, and biological quality of rivers requires well-planned, comprehensive, long-term monitoring data. Regrettably, such datasets are uncommon or incomplete, partly because of the costs of collecting the information. However, Vaughan and Ormerod (Chapter 7) argue strongly that it is essential to continue gathering extensive scientific data, and that their application for river conservation and management justifies the investment.

Methods and approaches

It is surely significant that the topic attracting the highest number of proposed presentations at the York conference in 2010 concerned 'Methods and Approaches', reflecting the many new developments that have taken place over the last 20 years. The six chapters selected for the second section of the book – from the UK, Spain, Portugal, Australia and New Zealand – illustrate that new methods and approaches are not limited geographically nor are they restricted to particular types of river habitats or species groups. In Chapter 13, Wood et al. describe the surge of interest in the UK over the past 20 years in the invertebrate fauna of hyporheic zones – a pattern repeated in many other countries. They suggest that this reflects an increasing awareness of the unique contribution that hyporheic zones make to biodiversity, their role in processing and storing nutrients, their potential significance for transporting pollutants within rivers, and increasing pressures on groundwater resources.

Over the past 20 years, approaches to river monitoring have broadened from a rather narrow focus on benthic macroinvertebrates, often in shallow riffles, to incorporate other organisms in a wider range of habitat types. For example, in Chapter 11, Dodkins et al. describe a new method for assessing the ecological status of intermittent Mediterranean rivers using diatoms and macrophytes, and in Chapter 12 Vieira et al. outline ways of classifying mountain streams in Portugal using bryophyte assemblages. Methods for analysing and interpreting biological data from rivers have also changed profoundly. For example, in Chapter 14 Marchant and Kefford describe a method used in Australian rivers in which the impacts of human disturbance on invertebrates can be assessed without the problems associated with sampling effort.

The way that new methods in river conservation and management are applied depends greatly on the legal and policy framework. For example, since 1990 the EC Habitats Directive has provided an incentive for devising new ways of assessing European rivers for conservation (Council of the European Communities, 1992). This is illustrated in Chapter 16 (Barquin et al.) which describes a decision-support tool, developed and tested on rivers in northern Spain, to assess the status of Atlantic salmon (Salmo salar) populations and alder-ash (Alnus glutinosa-Fraxinus excelsior) alluvial forest in Special Areas of Conservation. Outside Europe, other political imperatives have resulted in a more systematic approach for identifying representative sets of rivers with high nature conservation interest. This forms the subject of Chapter 15 (Leathwick et al.) which describes a way of selecting rivers important at national or regional levels in New Zealand, using high-resolution spatial data to define the distribution of river types and to estimate their present nature conservation value.

Chapter 17 (Seddon et al.) provides a different perspective by looking back in time to determine how river invertebrate assemblages have been affected by past hydromorphological alterations to river channels and river beds. These techniques include analysis of historical archives (such as maps and photographs), and detailed palaeoecological investigations of sedimentary records and the sub-fossil insect remains that they contain. The reconstruction of past conditions can then be used to guide future efforts in river rehabilitation.

Recovery and rehabilitation

'Recovery and rehabilitation' is the subject for the third section of the book. One of the most significant outcomes from the 1990 rivers conference was the creation in the UK of the River Restoration Project, later to become the River Restoration Centre. This development, and the subsequent formation of river restoration bodies in other parts of Europe, the US, Asia and Australia is discussed in Chapter 23 (Holmes and Janes). The other chapters in this section provide a series of case studies from different countries to illustrate the way that the philosophy and practice of river restoration has evolved over the last 20 years. Many of the principles and practices of river restoration at the time of the 1990 York conference (Gore, 1985; Petersen et al., 1992) are just as relevant today. However, there is now a greater emphasis on working at the catchment scale rather than restoration of short stretches of river, primarily for demonstration purposes (Newson, Chapter 2). The importance of allowing rivers space in which natural fluvial processes can bring about recovery is a particularly strong theme. The espace de liberté approach, in which an area of the river corridor is set aside for river migration and flooding, forms the theme of Chapter 18 (Kondolf). Two case studies, one urban and one rural, show that where stream power and sediment load are sufficient, rivers can 'restore themselves' while minimizing conflicts with human uses. The importance of catchment-scale restoration is demonstrated further in Chapter 19 (Semrau and Hurck) showing how improvements to physical habitats and water quality in an industrialized catchment in Germany are helping to bring about economic and ecological regeneration. Since York 1990, the importance of local community support for river restoration has become widely recognized. The results of a study of two river restoration schemes in England (Åberg and Tapsell, Chapter 20) demonstrate that active participation influences the perception, satisfaction and appreciation of river rehabilitation by local residents and will help in future planning of new schemes.

As problems associated with point-source river pollution in the UK and many other countries have abated, more emphasis has been placed on restoring physical habitat. Nevertheless, this book would be incomplete without a reminder of the profound importance of water quality in river ecology and conservation. In Chapter 21, Langford et al. describe 50 years of ecological recovery in the River Trent, once one of the most polluted rivers in England. They suggest how the technological, legal and economic measures that helped the recovery could be applied to polluted rivers in other parts of the world.

The difficulties of river management and rehabilitation are compounded when water flows for only part of the year. Most Mediterranean streams such as the Pardiela River in Portugal (Rosado et al., Chapter 22) are temporary, characterized by seasonal events of flood and drought. Although aquatic communities are adapted to this pattern and uncertainty, a combination of climate change and increasing demand for water is adding to their vulnerability. The chapter demonstrates the importance of designing conservation and rehabilitation strategies to suit local circumstances, especially in those parts of the river where the pressures are most intense.

Integrating nature conservation within wider river management

The inclusion of the fourth and final section in the book, and the absence of a similar section from the 1992 volume, serves to illustrate a significant shift in emphasis between 1990 and 2010. In the UK at least, the government bodies responsible for river management and those responsible for nature conservation now work much more closely together than they did 20 years ago. This is well illustrated by the 2010 York conference which was organized and funded by the respective bodies in the four countries of the UK. The final section of the book begins with the concept of 'ecosystem goods and services', a subject that did not feature at all in the 1990 conference or in the subsequent book. However, since the Millennium Ecosystem Assessment was published (2005) it has become increasingly commonplace to view nature conservation principally as a way of safeguarding ecosystem services (Boon, Chapter 1). In Chapter 24, Bridgewater et al. summarize some of the principal international events, such as the World Conference on Environment and Development in 1992, that have shaped global environmental policy, and which show a transition from a 'traditional' approach to nature conservation to one based more on the value of nature to human society. Two case studies from China, the Yangtze and Yellow rivers, illustrate the link between ecological flows and the provision of ecosystem services and lead into a more detailed consideration of the topic in Chapter 25 (Everard). This explores the differences in the environmental and economic outcomes of management intervention (e.g. fishery improvement, 'hard engineering' on river banks) using an ecosystems approach compared with more traditional narrowly-focused evaluation methods.

Unfortunately, the uncertainties surrounding the ecological impact of human activities in and around rivers sometimes hinder good decision-making by those responsible for regulation and management. This is where an 'adaptive management' approach can be extremely valuable, using the results of environmental monitoring to help modify management actions. Since the 1990 conference this subject has grown in importance. An example of applying adaptive management to rivers in the US is the subject of Chapter 26, in which Hamill and Melis describe how fish populations in the Colorado River have benefited from adapting the patterns of water release from Glen Canyon dam.

Integrating nature conservation within the broader needs of river management often means balancing conflicting interests. For example, Chapter 27 (Wood et al.) shows how mathematical modelling techniques can be used to test the outcomes of different management options in chalk rivers in southern England. In these rivers aquatic vegetation is important for nature conservation and provides habitat for salmon and trout which support economically valuable fisheries, but in some locations it is intensively grazed by mute swans (Cygnus olor). A more intricate example of balancing competing uses is provided by Braioni et al. (Chapter 28) citing an urban reach of the River Adige in northern Italy. This river represents a complex ecological, environmental, historical and socio-economic network in which history, landscape and nature are inextricably linked; an 'environmental landscape plan' has been developed as a way of safeguarding and managing the river corridor in a sustainable way.

Unfortunately, there are many rivers throughout the world where human exploitation is unrestrained and where a lack of integrated management results in damage to habitats and species. The River Murray in South Australia, where river flows have been depleted by severe drought and exacerbated by over-allocation of water resources, provides a salutary lesson (Jensen and Walker, Chapter 29). Voluntary agreements are often not sufficient to protect important natural values of rivers; legal instruments may also be needed as an environmental safety-net. An example is the use of Water Conservation Orders (Watson, Chapter 30) which have been applied to 13 rivers in New Zealand. The benefit of this approach is illustrated by the Nevis, a river flowing through a largely unmodified mountain landscape, where nature conservation and recreation (fishing and kayaking) are both important.

The final chapter in the book (Large, Chapter 31) returns to one of the recurring themes – the need to bring together the disciplines of hydrology, geomorphology and ecology in river basin planning and management. The chapter emphasizes the huge challenges ahead, not only in this area but in finding ways to put monetary values on a range of river ecosystem components, functions and processes. This will require much better coordination of research and a more effective use of the results it generates. To what extent these aspirations are met over the next 20 years remains to be seen.

References

Boon PJ, Calow P, Petts GE (eds) (1992) River Conservation and Management. John Wiley & Sons Ltd: Chichester.

Council of the European Communities (1992) Council Directive 92/43/EEC of 21 May 1992 on the conservation of natural habitats and of wild fauna and flora. Official Journal of the European Communities L206: 7–50.

Council of the European Communities (2000) Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 establishing a framework for Community action in the field of water policy. Official Journal of the European Communities L327: 1–73.

Gore JA (1985) The Restoration of Rivers and Streams. Butterworth: Boston.

Millennium Ecosystem Assessment (MA) (2005) Ecosystems and Human Well-being. Synthesis Report. Island Press: Washington DC.

Petersen RC, Petersen LB-M, Lacoursière J (1992) A building-block model for stream restoration. In River Conservation and Management, Boon PJ, Calow P, Petts GE (eds). John Wiley & Sons Ltd: Chichester; 293–309.

Raven PJ, Fox P, Everard M, Holmes NTH, Dawson FH (1997) River Habitat Survey: a new system for classifying rivers according to their habitat quality. In Freshwater Quality: Defining the Indefinable? Boon PJ, Howell DL (eds). The Stationery Office: Edinburgh; 215–34.

Acknowledgements

We would like to thank the Organizing Group for their contributions in planning the conference programme at York upon which this book is based. The Group comprised Nigel Holmes, Chris Mainstone, Peter Maitland, Vicky Morgan, Malcolm Newson, Roger Owen, Chris Spray and Howard Platt. We also wish to acknowledge the financial support for the conference from the following organizations: Environment Agency, Scottish Environment Protection Agency, Northern Ireland Environment Agency, Scottish Natural Heritage, Natural England, Countryside Council for Wales, Joint Nature Conservation Committee, Yorkshire Water and John Wiley and Sons Ltd. We are grateful to all the referees who reviewed the manuscripts contained in this book and, by doing so, improved the quality of the final product.

Philip J. BoonPaul J. Raven

Introduction