The Functional Consequences of Biodiversity

Preface 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