Despite often violent fluctuations in nature, species extinction is rare. California red scale, a potentially devastating pest of citrus, has been suppressed for fifty years in California to extremely low yet stable densities by its controlling parasitoid. Some larch budmoth populations undergo extreme cycles; others never cycle. In Consumer-Resource Dynamics, William Murdoch, Cherie Briggs, and Roger Nisbet use these and numerous other biological examples to lay the groundwork for a unifying theory applicable to predator-prey, parasitoid-host, and other consumer-resource interactions. Throughout, the focus is on how the properties of real organisms affect population dynamics. The core of the book synthesizes and extends the authors' own models involving insect parasitoids and their hosts, and explores in depth how consumer species compete for a dynamic resource. The emerging general consumer-resource theory accounts for how consumers respond to differences among individuals in the resource population. From here the authors move to other models of consumer-resource dynamics and population dynamics in general. Consideration of empirical examples, key concepts, and a necessary review of simple models is followed by examination of spatial processes affecting dynamics, and of implications for biological control of pest organisms. The book establishes the coherence and broad applicability of consumer-resource theory and connects it to single-species dynamics. It closes by stressing the theory's value as a hierarchy of models that allows both generality and testability in the field.

Table of Contents:
Preface xi 1. Introduction 1 Why Consumer-Resource Interactions? 1 On Theory and Models 2 Themes 4 2. Population Dynamics: Observations and Basic Concepts 6 Types of Population Dynamics: Phenomena to Be Explained 6 Some Essential Concepts 15 Appendix 26 3. Simple Models in Continuous Time 30 The Lotka-Volterra Model 31 Local Stability Analysis 36 Effects of Stabilizing and Destabilizing Processes: A Survey 42 Combining Stabilizing and Destabilizing Processes: From Neutral Stability to Limit Cycles 53 Simple Models of Stage and Spatial Structure: The Creation of Indirect Density Dependence 60 Basic and Potential General Properties of Predator-Prey Systems 69 Appendix 72 4. Simple Models in Discrete Time 83 Single-Species Models in Discrete Time 84 Discrete-Generation Parasitoid-Host Models 93 Hybrid Discrete-Time/Continuous-Time Models 106 Appendix 111 5. An Introduction to Models with Stage Structure 119 Preamble: Single-Species Populations with Stage Structure 121 The Basic Stage-Structured Host-Parasitoid Model 134 Ecological Processes Inducing Instability 147 Ecological Processes Inducing Stability 149 Single-Generation Cycles in Parasitoid-Host Models 160 Appendix 170 6. Dynamical Effects of Parasitoid Lifestyles 179 Parasitoid Lifestyles 180 Four Mechanisms Inducing Greater Gain from Older Hosts 186 A Unifying Framework and Extensions 199 A More General Model: The Generic Gain Model 205 The Nature and Origins of Delayed-Feedback Cycles and Single-Generation Cycles: Insights from a Simplified Model 207 Concluding Remarks 216 7. State-Dependent Decisions 219 Effects of Egg Load on Parasitoid Decisions 220 Effects of Limits to Egg Production 236 A General Dynamical Theory of Parasitoid Behavior 242 8. Competition between Consumer Species 245 Lotka-Volterra Competition Model: Competition for an Implicit Resource 247 Exploitative Competition for an Explicit Resource 255 Competition in Discrete Time 274 Effects of Age Structure on Competition 281 Non-Equilibrial Mechanisms of Coexistence 301 Effects of Spatial Structure on Competition 310 Concluding Remarks 317 9. Implications for Biological Control 318 A Comparative Approach to Evaluating Natural Enemies 321 Spatial Processes and Control 336 Need for Experimental Tests 340 10. Dynamical Effects of Spatial Processes 341 Spatial Processes among Subpopulations 341 Spatial Processes within Populations: Aggregated Attacks and Other Sources of Variation in Risk among Individuals 366 Connection between Processes within Populations and among Subpopulations 392 11. Synthesis and Integration across Systems 394 Shared Theory for Different Kinds of Consumer-Resource Interactions 394 Connection between Consumer-Resource Dynamics and Single-Species Dynamics in Theory and Nature 399 Cycles in Real Systems: Single-Species Models for Many-Species Systems 410 General Conclusions/Considerations 414 12. Concluding Remarks 416 Literature Cited 425 Index 451