Food Webs

Kevin S. McCann is associate professor of integrative biology at the University of Guelph.

"This is a must-read for ecologists interested in ecosystem dynamics."--Choice "This is potentially an indispensable book for ecologists and paleoecologists alike, synthesizing food-web theory and outcomes from population-level up to whole-ecosystem-level approaches. McCann offers clear explanations of the dynamics of food webs using a mathematical approach, and while the book will be of particular use to graduate students, it may also be of substantial use to undergraduate students as an advanced but very thorough introduction to the subject."--Jo Hellawell, Priscum "Food Webs is an imaginative but very concise book in terms of methodology and selection of concepts. It is extremely coherent, though some may think extremely selective in the models and concepts used. But to build a food web theory across different scales of organization, from single populations to real multispecies interaction networks, this selectivity is needed, and the unifying concept of stability makes it fascinating."--Jose M. Montoya, Ecology "[T]his is a very exciting book that communicates theoretical concepts to a broad ecological audience. In addition, the overview over the countless seminal studies by McCann and co-workers make this book unique and a highly recommended read for all ecologists."--Ulrich Brose, Basic & Applied Ecology

• Preface xi Part 1: THE PROBLEM AND THE APPROACH Chapter 1. The Balance of Nature: What Is It and Why Care? 3 1.1 Balancing a Noisy System 3 1.2 Ecosystem Stability and Sustainability 6 1.3 Of Food Webs, Stability, and Function 9 1.4 Ecological Instability and Collapse 10 1.5 A Theory for Food Webs 17 Chapter 2. A Primer for Dynamical Systems 20 2.1 Qualitative Approaches to Complex Problems 20 2.2 Dynamical Systems 22 2.3 Case Study: Hopf Bifurcation in an Aquatic Microcosm 42 2.4 Summary of Key Points 45 Chapter 3. Of Modules, Motifs, and Whole Webs 47 Part 2: FOOD WEB MODULES: FROM POPULATIONS TO SMALL FOOD WEBS Chapter 4. Excitable and Nonexcitable Population Dynamics 53 4.1 Continuous Resource Dynamics 53 4.2 From Nonexcitable to Excitable Population Dynamics 56 4.3 Stage-Structured Resource Dynamics 61 4.4 Empirical Evidence for Excitable Dynamics 63 4.5 Summary: The Dual Nature of Population Growth Rates 65 Chapter 5. Consumer-Resource Dynamics: Building Consumptive Food Webs 67 5.1 Interaction Strength 67 5.2 Consumer-Resource Interactions: Two Qualitative Responses to Changes in a Parameter 71 5.3 Summary 79 5.4 Further Assumptions about the C-R Model 80 5.5 Some Nonequilibrium Thoughts 83 5.6 C-R Dynamics in Nature 84 5.7 Summary 88 Chapter 6. Lagged Consumer-Resource Dynamics 89 6.1 Discrete Consumer-Resource Interactions 90 6.2 Stage-Structured Consumer-Resource Dynamics 94 6.3 Stage-Structured Interactions and Alternative States 97 6.4 Empirical Results 100 6.5 Summary 101 Chapter 7. Food Chains and Omnivory 103 7.1 A Familiar Modular Example: Food Chains 105 7.2 Omnivory 110 7.3 Stage Structure and Food Chain Stability 116 7.4 Empirical Results 118 7.5 Summary 121 Chapter 8. More Modules 123 8.1 Generalists and Food Web Dynamics 123 8.2 The Diamond and the Intraguild Predator 132 8.3 Empirical Results 137 8.4 Summary 140 Part 3: TOWARD WHOLE SYSTEMS Chapter 9. Coupling Modules in Space: A Landscape Theory 145 9.1 Variability, Space, and Food Webs 145 9.2 Individual Traits and a Landscape-Scale Module 147 9.3 Mobile Adaptive Consumers 151 9.4 Food Webs in Space 155 9.5 Asymmetric Flux Rates through Food Webs 160 9.6 Dynamical Implications on the Landscape 162 9.7 Empirical Evidence 164 9.8 Summary 169 Chapter 10. Classic Food Web Theory 170 10.1 The Classic Approach 170 10.2 Matrices and Local Stability 172 10.3 Gershgorin Discs for Community Matrices: An Intuitive Approach to Eigenvalues 172 10.4 A Controlled Approach to Food Web Matrices 175 10.5 Some Classic Whole-Matrix Results 178 10.6 Recent Whole Community Approaches 184 10.7 Summary 188 Chapter 11. Adding the Ecosystem 189 11.1 Grazing Food Webs and Whole Ecosystems 189 11.2 The N-R-D Module 192 11.3 Detritus and C-R Interactions 194 11.4 Nonequilibrium Dynamics and Detritus as a Distributor 197 11.5 Discussion 199 11.6 Summary 199 Chapter 12. Food Webs as Complex Adaptive Systems 201 12.1 Searching for Empirical Signatures 201 12.2 Adaptive Behavior, Changing Food Web Topology, and Ecosystem Size 202 12.3 Empirical Results for Canadian Shield Lake Ecosystems 206 12.4 Subsidies, Opportunists, and Homogenization 213 12.5 Humans in the Food Web 215 Bibliography 219 Index 235