Riparia (eBook)

Foreword 11
Preface 13
1 Introduction 16
Overview 16
Purpose 17
Hydrological Context 19
Ecological Context 22
Landscape Context 24
Cultural Setting 26
Rationale for Riparian Ecology 27
Setting the Stage 33
2 Catchments and the Physical Template 34
Overview 34
Purpose 35
Catchments and Hierarchical Patterns of Geomorphic Features 37
Catchment Form and Channel Networks 38
Catchment History 40
Hierarchical Patterns of Geomorphic Features in Catchments 43
Geomorphic Processes and Process Domains 47
Headwater Erosion 48
Channel Processes 49
Floodplain and Channel Interactions 53
Hydrologic Connectivity and Surface Water–Groundwater Exchange 54
Surface Connectivity and Flooding 55
The Dynamics of the Linked Surface–Subsurface Hydrologic System 60
Conclusions 62
3 Riparian Typology 64
Overview 64
Purpose 64
The Historical Context 66
Theoretical Basis for Classification 68
Application of Ecological Information 70
Inventory 70
Classification 71
Emerging Classification Concepts 72
Geomorphic Classification 73
Hierarchical Classification 74
Rosgen’s Classification 80
Geomorphic Characterization (Aspect I) 82
Morphologic Description (Aspect II) 84
The Process Domain Concept 85
The Hydrogeomorphic Approach 87
Biotic Classification 88
Soils 88
Plants 89
Wildlife 90
Treating Complexity and Heterogeneity in Classification Systems 91
Attributes of an Enduring Classification System 92
Conclusions 93
4 Structural Patterns 94
Overview 94
Purpose 95
Life History Strategies 96
Morphological and Physiological Adaptations of Riparian Plants 97
Reproductive Strategies 102
Distribution, Structure, and Abundance 106
Identification of Riparian Zones Based on Soils and Vegetation Type 106
Biophysical Characteristics of Riparian Soils 107
Organic Matter 108
Moisture 109
Fauna 111
General Distributions of Aboveground and Belowground Communities 112
Lateral Zonation 112
Longitudinal Zonation 115
Successional and Seasonal Community Patterns 119
Vegetative Succession 119
Faunal Succession 127
Density, Basal Area, and Biomass 127
Biological Diversity 129
Diversity Theory and Measurement 130
Vegetative Diversity 133
Site and Catchment Patterns 133
Refuges 134
Factors Controlling Species Richness 135
Faunal Diversity 136
Diversity of Soil Organisms 136
Aboveground Fauna Diversity 137
5 Biotic Functions of Riparia 140
Overview 140
Purpose 141
Water Use and Flux 142
Nutrient Fluxes 146
Overview of Cycles and Processes 147
Production Ecology 150
Growth and Metabolism of Riparian Trees 150
Timing of Growth and Rates of Net Primary Production 152
Litterfall 158
Mortality Rates 160
Root Production 162
Decomposition Dynamics 164
Principles of Decomposition Dynamics 164
Litter Quality 164
Exogenous Nutrient Supply 165
Temperature 165
Oxygen Tension 165
Nutrient Dynamics During Decay 166
Factors Controlling Immobilization of Nitrogen 166
Initial Litter Quality 166
Exogenous Nutrient Supply 166
Anaerobic Decay 167
Temperature 167
Mechanisms of Nitrogen Immobilization 167
Nitrogen Accumulation in Microbial Biomass 168
Nitrogen Accumulation in By-Products of Microbial Activity 168
Decomposition of Riparian Litter 169
Information Fluxes 170
Microclimate 171
Conclusions 173
6 Biophysical Connectivity and Riparian Functions 174
Overview 174
Purpose 175
Patch Dynamics and a Landscape Perspective of Catchments 176
Nutrient Flows 178
Riparian Zones as Buffers Against Nutrient Pollution from Upland Runoff 179
Riparian Zones as Buffers Against High In-Stream Nutrient Levels 183
Particle-Nutrient Considerations 187
Energy Flows and Food Webs 188
Energy Flows Between Riparia and Adjoining Aquatic Systems 189
Large Animal Connections 194
The Functional Grouping of Large Animal Interactions 195
Pacific Salmon Influences on Riparian Ecosystems 198
Conclusions 201
7 Disturbance and Agents of Change 204
Overview 204
Purpose 205
Major Categories of Change 207
Human Demography 207
Resource Use 207
Technology Development 212
Social Organization 212
Riparian Disturbances 212
Defining Anthropogenic Disturbance 213
Understanding History: Basic Concepts and Approaches 213
Legacies and Lag-Times 215
Cumulative Effects 215
Historical Examples of Riparian Alterations 216
Pervasive Human-Mediated Changes 219
Disturbance Ecology: Responses to Stress 220
Ecological Consequences of Flow Regulation 222
Theory 223
Extent of Flow Regulation 225
Effects on Native Species and Processes 227
Alterations to Energy and Nutrient Budgets 230
Basic Ecological Principles 232
Consequences of Global Climate and Land Use Changes 233
Climate Change 233
Changes in Temperature Regimes 237
Changes in Precipitation and Runoff Regimes 237
Early Snowmelt Runoff 238
Increased Precipitation Variability 238
Reduced Discharge 239
Can Riparia Adapt to Climate Change? 239
Land Use Change 240
Temperature Regimes 240
Nutrient Enrichment 243
Invasive Species 245
Conclusions 247
8 Management 248
Overview 248
Purpose 249
Riparian Management: A Recent and Evolving Concern 250
Economic Valuation of Riparia 252
Social and Cultural Perspective 253
Suitable Management Institutions 256
Information Collection and Dissemination 258
Riparian Management: A Process Linked to Catchment and to River Management 261
Riparian Benefits from Catchment Management 261
Riparian Benefits from River Management 263
Catchments and Rivers Benefit from Riparian Management 266
Riparian Management: A Highly Specific Process 268
Adaptiveness 269
Sustainability 270
Appropriateness 272
Timber Harvest Practices 272
Revegetation of Riverbanks 272
Human Dimension of Riparian Management 274
Shared Socioenvironmental Visions 275
Social-Ecological Systems 276
Communication Needs 281
Conclusions 283
Riparian Management as an Emerging Issue 283
9 Conservation 284
Overview 284
Purpose 285
Conserving Riparia for Biodiversity 286
Conserving Riparia for Ecosystem Services 289
Conserving Riparia for their Hydrologic Effects 291
Riparian Conservation in a Management Context 292
Human Benefits from Riparian Conservation 297
Emergence of New Conservation Legislation 299
Riparian Conservation for the Long Term 302
Approaching Scientific Uncertainty in Ecological Problem Solving 302
Integrating Ecological Knowledge with the Social and Ethical Aspects 303
Conclusions 303
10 Restoration 306
Overview 306
Purpose 307
General Principles and Definitions 309
Returning to More Natural Hydrologic Regimes 310
Developing a Restoration Plan 316
Getting Organized 317
Identifying Problems and Opportunities 317
Defining Goals and Objectives 318
Implementing, Monitoring, and Evaluating 319
Financial Incentives 320
Setting Priorities 321
Assessing the Ecological Integrity of Riparia 323
Specific Enhancements 329
Implementing Riparian Silvicultural Practices 329
Reintroducing Large Woody Debris 329
Designing Riparian Buffer Zones 332
Prescribed Grazing 334
Optimizing Riparia for Biodiversity 337
Conclusions 337
11 Synthesis 342
Overview 342
Purpose 343
Riparia as Keystone Units of Catchment Ecosystems 344
Riparia as Nodes of Ecological Organization 346
A Unified Perspective of Riparian Ecology 347
Developing a Future Vision 348
Scenario Development 349
Forecasting, Prediction, and Projection 350
Emerging Perspectives, Tools, and Approaches 352
Emerging Perspectives 353
Emerging Tools and Approaches 356
Aboveground 356
Belowground 361
General Techniques 363
Principles for the Ecological Management of Riparia 365
Global Environmental Change 367
Conclusions 370
Bibliography 372
Index 430