This text adequately applies the research undertaken during the last 15 years on the topic. Desertification has become increasingly politicized and there is a need to present and explain the facts from a global perspective. This book tackles the issues surrounding desertification in a number of ways from differing scales (local to global), processes (physical to human), the relationship of desertification to current global development and management responses at different scales. Desertification has been mainstreamed and integrated into other areas of concern and has consequently been ignored as a cross cutting issue. The book redresses this balance.

Making use of much original data and information that has been undertaken by many scientists andpractitioners during the last decade in different parts of the world,Desertification, Land Degradation and Sustainability is organised according to the principles of adaptive management and hierarchy theory and clearly explains desertification within a framework of evolving and interacting physical and socio-economic systems. In addition to research data the book also draws from the National Action Plans of different countries, the IPCC Fourth Assessment on Climate Change and the Millennium assessments.

Clearly structured throughout, the content of the book is organised at different scales; local, regional and global. It also specifically explains processes linking top-down and bottom- up interactions and has a strong human component. The historical, cultural and physical context is also stressed.

Clearly organised into the following distinct sections:

a) Concepts and processes

b) Data

c) Impacts

d) Responses

e) Case studies.

This text is essential for anyone studying desertification as part of an earth and environmental science degree.

Anton Imeson has spent the last 15 years as a Professor responsible for research and teaching in desertification at the Physical Geography and Soil science Laboratory of the University of Amsterdam, as a participant and co-ordinator of many research projects funded by the mainly by the EU (EG Medalus Scape Efeda, Desertlinks, Desire and Ermes as COST acgtions); as a participant and consultant for UN organisations (UNDP, UNDP). He has contributed to the EU Soil Strategy on Desertification and is a member of the organising committee of many Scientific and Policy conferences on desertification.Editor ofLand Degradation and Development, Earth Surface Processes and Landforms andEarth Science Reviews.

Acknowledgement xv

Introduction: Scope and approach 1

Part I The Nature of Desertification 3

1 Desertification, its causes and why it matters 5

1.1 The nature of desertification 7

1.2 The links between global and local desertification 27

1.3 Discussion: desertification as a world-wide and historical phenomenon 27

1.4 Discussion: life and its feedback with the environment 31

1.5 Discussion: the adaptation of people and cultures to desertification 32

1.6 Discussion: Data and evidence for land degradation 34

1.7 Conclusion: why land degradation and desertification occur 35

References and further reading 36

2 Responses to desertification 41

2.1 Finding answers 41

2.2 Conclusion: The causes of land degradation today 51

2.3 Conclusion: strategies to mitigate desertification 52

References and further reading 53

3 Desertification indicators: from concept to practice 57

3.1 Introduction 57

3.2 Approaches to desertification indicators 62

3.3 Global and regional indicators of land degradation and desertification 65

3.4 Applying selected concepts in practice 68

3.5 Desertification, resilience and stability 75

3.6 The soil and water conservation and protection functions 84

3.7 Spatial variability and discontinuity 95

3.8 Hydrological indicators of desertification 100

3.9 Water in the soil and landscape 105

References and further reading 109

Part II Local Desertification Impact and Response 115

4 Key processes regulating soil and landscape functions 117

4.1 Introduction 117

4.2 Fine scale processes 123

4.3 The provision of the hydrological function, runoff and sediment transport 130

4.4 The protection function of the land and erosion 132

4.5 The long-term impact: the vigil network sites in the USA 134

4.6 Hydrological response: what happens to the land when it rains 135

4.7 Water 136

4.8 Nature, natural capital and land degradation 142

4.9 Soil stability 144

4.10 Soil response and soil behaviour 145

4.11 Catchment response, hydrology and the soil 146

4.12 Discussion: vegetation patterns as responses to land degradation processes 148

4.13 Controlled desertification experiments 149

References and further reading 149

5 Human impact on degradation processes 155

5.1 Introduction 155

5.2 Soil erosion processes 156

5.3 Response of soil structure to cultivation and farming 158

5.4 Gully erosion 162

5.5 Grazing and erosion 165

5.6 The impact of fire on land degradation processes 167

5.7 Case 1: Blue Ridge Foothills 168

5.8 Case 2: Human impact in the Atlantic States 169

5.9 Case 3: Impact of forest logging in California Casper Creek 169

5.10 Case 4: Karuah Forest, New South Wales, Australia 170

5.11 Case 5: Afforestation in Spain 171

5.12 Case 6: Soil erosion impacts in Europe 171

5.13 Case 7: Human impact in the Central Cordillera of Columbia 174

5.14 Case 8: Bolivia Tarije 175

5.15 The sediment load and soil erosion 176

5.16 Monitoring methods to verify impact and management on erosion 177

5.17 Water resource development irrigation as responses 179

5.18 Soil conservation principles and erosion 180

5.19 Conceptual approaches to soil conservation 182

References and further reading 185

6 Responses to land degradation from perception to action 191

6.1 Introduction 191

6.2 Environmentally sensitive areas 199

6.3 The European policy, response, and governance 200

6.4 Applying the adaptive systems approach explicitly 207

6.5 Responding with laws to protect the land and soil 213

6.6 European law and the requirements of the convention 217

6.7 The European soil strategy 219

6.8 Romania: A model national action plan 220

6.9 Italy and the convention 225

References and further reading 230

Part III Global Desertification Impact and Response 237

7 Global desertification today 239

7.1 Desertification today 239

7.2 Global balances and fluxes 247

7.3 Case study: desertification and the crash in property prices 254

7.4 Brazil 257

7.5 Namibia 259

7.6 Dust and sandstorms in China 262

References and further reading 263

8 Desertification, ecosystem services and capital 267

8.1 Introduction 267

8.2 Interactions between desertification and ecosystem services 281

8.3 The impact of desertification on ecosystem services 284

References and further reading 290

9 The way forward: global soil conservation and protection 293

9.1 Introduction 293

9.2 Iceland 294

9.3 The call for action 296

9.4 Europe 299

9.5 Support to the UNCCD 301

9.6 The importance of international co-operation 302

References and further reading 303

Appendix A: Soil basics 305

References and further reading 309

Index 311