The Functional Consequences of Biodiversity (ebook)

Argumento de The Functional Consequences of Biodiversity (ebook)

Does biodiversity influence how ecosystems function? Might diversity loss affect the ability of ecosystems to deliver services of benefit to humankind? Ecosystems provide food, fuel, fiber, and drinkable water, regulate local and regional climate, and recycle needed nutrients, among other things. An ecosyste's ability to sustain functioning may depend on the number of species residing in the ecosystem--its biological diversity--but this has been a controversial hypothesis. There are many unanswered questions about how and why changes in biodiversity could alter ecosystem functioning. This volume, written by top researchers, synthesizes empirical studies on the relationship between biodiversity and ecosystem functioning and extends that knowledge using a novel and coordinated set of models and theoretical approaches.

These experimental and theoretical analyses demonstrate that functioning usually increases with biodiversity, but also reveals when and under what circumstances other relationships between biodiversity and ecosystem functioning might occur. It also accounts for apparent changes in diversity-functioning relationships that emerge over time in disturbed ecosystems, thereby addressing a major controversy in the field. The volume concludes with a blueprint for moving beyond small-scale studies to regional ones--a move of enormous significance for policy and conservation but one that will entail tackling some of the most fundamental challenges in ecology.

In addition to the editors, the contributors are Juan Armesto, Claudia Neuhauser, Andy Hector, Clarence Lehman, Peter Kareiva, Sharon Lawler, Peter Chesson, Teri Balser, Mary K. Firestone, Robert Holt, Michel Loreau, Johannes Knops, David Wedin, Peter Reich, Shahid Naeem, Bernhard Schmid, Jasmin Joshi, and Felix Schläpfer.0Preface xiii
List of Contributors xix
List of Figures xxi
List of Tables xxv
Chapter 1. Opening Remarks by Ann P. Kinxig
PART 1 Empirical Progress
Chapter 1. Biodiversity, Composition, and Ecosystem Processes: Theory and Concepts byDavid Tilman and Clarence Lehman 9
Introduction 9
Definitions of Diversity 11
Problems Related to Experiments and Observations 14
Diversity, Productivity, and Resource Dynamics 15
Sampling Effect Models 16
Niche Differentiation Models 23
Diversity and Stability 29
Measures of Stability 29
Components of Temporal Stability 30
Diversity and Temporal Stability in Multispecies Models 34
Summary 39
Acknowledgments 41
Chapter 2. Experimental and Observational Studies of Diversity, Productivity, and Stability by David Tilman, Johannes Kncps, David Wedin, and Peter Reich 42
Diversity and Stability 43
Diversity, Productivity, and Nutrient Dynamics 49
New Results from the Cedar Creek Biodiversity Experiment 53
Methods 53
Soil Nitrate 54
Community Cover and Biomass 54
Species Number and Composition 60
Weedy Invasion and Fungal Pathogens 63
Patterns in Native Grassland 65
Summary and Synthesis 67
Acknowledgments 70
Chapter 4. Biodiversity and the Functioning of Grassland Ecosystems: Multi-Site Comparisons by Andy Hector 71
Introduction 71
The BIODEPTH Project 72
Multiple Influences on Productivity 74
Differences between Locations 74
Species Richness versus Functional Groups 75
Richness versus Composition 79
Effects of Nitrogen Fixers 81
The Sampling Effect and Biodiversity Mechanisms 82
Testing the Sampling Effect 84
Summary of the BIODEPTH Results 89
Comparisons with Related Studies 89
Relationships within and between Sites 93
Summary 94
Acknowledgments 95
Chapter 5. Autotrophic-Heterotrophic Interactions and Their Impacts on Biodiversity and Ecosystem Functioning by Shahid Naeem 96
Introduction 96
Fundamentals 98
Classes of Trophically Defined Functional Groups 98
The Producer-Decomposer Codependency (PDC) 100
Fundamental Trophic Structure 101
Heterotrophic Diversity and Ecosystem Functioning 101
Decomposers and Producers Affect Each Other via Carbon Exchange 102
Consumers Affect the Biomass of Producers and Decomposers 103
Trophic Structure Influences Rates of Material Cycling 104
Heterotrophic Diversity Affects Levels and Stability of Ecosystem Processes 105
Heterotrophs Modulate Producer Diversity Effects 109
Summary of Empirical Findings 111
Implications for Autotroph-Only Models 112
Decomposers 113
Trophic Levels 113
Material Pools 113
Discussion 114
Chapter 6. Empirical Evidence for Biodiversity-Ecosystem Functioning Relationships by Bernhard Schmid, Jasmin joshi, and Felix Schldpfer 120
Introduction 120
Plant Diversity Effects on Ecosystem Functioning 123
General Patterns under Uniform Conditions 124
General Patterns under Variable Conditions 136
Biodiversity Effects among Trophic Levels 140
Review of Empirical Studies 140
Importance of Biological Interactions 140
Designing Empirical Studies to Measure Biodiversity-Ecosystem Functioning Relationships 141
Relevance of Existing Studies 141
Suggestions for Future Studies 148
Acknowledgments 150
Chapter 7. The Transition from Sampling to Complementarity by Stephen Pacala and David Tilman 151
Conclusions 165
PART 2 Theoretical Extensions
Chapter 8. Introduction to Theory and the Common Ecosystem Model by Stephen Pacala and Ann P. Kinzig 169
The Common Ecosystem Model 171
Summary of the Basic Model 174
Chapter 9. Successional Biodiversity and Ecosystem Functioning by Ann P. Kinzig and Stephen Pacala 175
Introduction 175
The Successional Niche in a Simple Mechanistic Ecosystem Model 179
Case Studies 183
Results 185 Competition-Colonization in a Simple Mechanistic Ecosystem Model 193
Local versus Global Performance 195
Cases Considered 197
Results 202
Conclusions 212
Chapter 10. Environmental Niches and Ecosystem Functioning by Peter Chesson, Stephen Pacala, and Claudia Neuhauser 213
Introduction 213
Environmental Niches 215
Temporal Niches 216
Spatial and Spatio-Temporal Niches 222
Ecosystem Functioning 223
Ecosystem Functioning with Spatial Niches 224
Ecosystem Functioning with Temporal Niches: Lottery Models 226
Ecosystem Functioning with Temporal Niches: a Mediterranean Ecosystem 228
Discussion 237
Acknowledgments 244
Appendix 245
Cahpter 11. Biodiversity and Ecosystem Functioning: The Role of Trophic Interactions and the Importance of System Openness by Robert D. Holt and Michel Loreau 246
Introduction 246
The Sampling Effect Model and Community Assembly 247
Importance of Trophic Complexity and System Openness 248
Toward an Ecosystem Model with Trophic Interactions 250
Case I: Ecosystem Closed at Top, Open at Bottom 252
Case II: Ecosystem Closed at Bottom, Open at Top 256
Discussion 256
Conclusions 259
Acknowledgments 262
PART 3 Applications and Future Directions 12. Linking Soil Microbial Communities and Ecosystem Functioning by Teri C. Baker, Ann P. Kinzig, and Mary K. Firestone 265
Introduction 265
Challenges in Linking Microbial Communities and Ecosystem Functioning 266
Application of Macroscale Diversity Theory to Microorganisms 267 Microbial Ecology Contribution to the Study of Ecosystem Functioning 268
Ecosystem Science and Microbial Ecology 269
Linking Microbial Community Composition and Ecosystem Functioning: A Review of Concepts and Models 271
Broad versus Narrow Processes 271
Application of Physiological Ecology 272
Microbial Strategies: Physiological Constraints and Trade-Offs 276
Timeline of Microbial Response: Conceptual Model of Microbial Role in Ecosystem Functioning 278
Microbial Response: Four Phases 278
Microbial Community Response to Modulator versus Resource Change 282
Relevance to the Timescale of Global Changes 284
Conclusions and Future Research Needs 285
Acknowledgments 287
Appendix
Linking Microbial Community Composition and Ecosystem Functioning. Incorporating Microbial Dynamics in the Common Ecosystem Model 287
Chapter 13. How Relevant to Conservation Are Studies Linking Biodiversity and Ecosystem Functioning? by Sharon P. Lawler, Juan J. Armesto, and Peter Kareiva 294
Introduction 294
Conservation Philosophies and Ecological Science 295
Studies of Biodiversity-Ecosystem Functioning Relationships: Origins and Recent Critiques 298
Four Unresolved Issues 301
Relating Biodiversity Theory and Experiments to Losses in Biodiversity Caused by Humans 308
Where Should Biodiversity Research Move in the Future If It Is to Best Address Conservation Problems? 310
Do Conservationists Need the Results of Biodiversity Experiments to Justify Their Work? 312
Acknowledgments 313
Chapter 14. Looking Back and Peering Forward by Ann P. Kinzig, Stephen Pacala, and David Tilman 314
References 331
Index 359