Topic
Density dependence
About: Density dependence is a research topic. Over the lifetime, 874 publications have been published within this topic receiving 44157 citations.
Papers published on a yearly basis
Papers
TL;DR: It is shown that density dependence is a pervasive feature of population dynamics, and that this holds across widely different taxa, and the value of using multiple modes of analysis to quantify the relative empirical support for a set of working hypotheses that encompass a range of realistic population dynamical behaviors is underscore.
Abstract: Population limitation is a fundamental tenet of ecology, but the relative roles of exogenous and endogenous mechanisms remain unquantified for most species. Here we used multi-model inference (MMI), a form of model averaging, based on information theory (Akaike's Information Criterion) to evaluate the relative strength of evidence for density-dependent and density-independent population dynamical models in long-term abundance time series of 1198 species. We also compared the MMI results to more classic methods for detecting density dependence: Neyman-Pearson hypothesis-testing and best-model selection using the Bayesian Information Criterion or cross-validation. Using MMI on our large database, we show that density dependence is a pervasive feature of population dynamics (median MMI support for density dependence = 74.7–92.2%), and that this holds across widely different taxa. The weight of evidence for density dependence varied among species but increased consistently with the number of generations monitored. Best-model selection methods yielded similar results to MMI (a density-dependent model was favored in 66.2–93.9% of species time series), while the hypothesis-testing methods detected density dependence less frequently (32.6–49.8%). There were no obvious differences in the prevalence of density dependence across major taxonomic groups under any of the statistical methods used. These results underscore the value of using multiple modes of analysis to quantify the relative empirical support for a set of working hypotheses that encompass a range of realistic population dynamical behaviors.
1,958 citations
TL;DR: The Allee effect describes a scenario in which populations at low numbers are affected by a positive relationship between population growth rate and density, which increases their likelihood of extinction.
Abstract: The Allee effect describes a scenario in which populations at low numbers are affected by a positive relationship between population growth rate and density, which increases their likelihood of extinction The importance of this dynamic process in ecology has been under-appreciated and recent evidence now suggests that it might have an impact on the population dynamics of many plant and animal species Studies of the causal mechanisms generating Allee effects in small populations could provide a key to understanding their dynamics
1,889 citations
TL;DR: In large-herbivore populations, environmental variation and density dependence co-occur and have similar effects on various fitness components and how that variability affects changes in population growth rates is examined.
Abstract: ▪ Abstract In large-herbivore populations, environmental variation and density dependence co-occur and have similar effects on various fitness components. Our review aims to quantify the temporal variability of fitness components and examine how that variability affects changes in population growth rates. Regardless of the source of variation, adult female survival shows little year-to-year variation [coefficient of variation (CV 30%). Old females show senescence in both survival and reproduction. These patterns of variation are independent of differences in body mass, taxonomic group, and ecological conditions. Differences in levels of maternal care may fine-tune the temporal variation of early survival. The immature stage, despite a low relative impact on population growth rate compared with the adult stage, ma...
1,718 citations
742 citations
Book•
1 Jan 2006
TL;DR: This chapter discusses Density Dependence in Populations with Discrete Generations, the theory of r- and K-selection, and the results of early tests of the Lotka-Volterra Models.
Abstract: Preface. Mathematical Symbols Used. Part I: Single Species Populations. 1. Density Independent Growth. Introduction. Fundamentals of Population Growth. Types of Models. Density Independent vs. Density Dependent Growth. Discrete or "Geometric" Growth in Populations with Non-overlapping Generations. Exponential Growth in Populations with Overlapping Generations. Exponential Growth in an Invasive Species. Applications to Human Populations. The Finite Rate of Increase and the Intrinsic Rate of Increase. Stochastic Models of Population Growth and Population Viability Analysis. Summary. 2. Density Dependent Growth and Intraspecific Competition. Introduction. Density Dependence in Populations with Discrete Generations. Density Dependence in Populations with Overlapping Generations. Nonlinear Density Dependence of Birth and Death Rates and the Allee Effect. Time Lags and Limit Cycles. Chaos and Behavior of the Discrete Logistic Model. Adding Stochasticity to Density Dependent Models. Laboratory and Field Data. Behavioral Aspects of Intraspecific Competition. Summary. 3. Population Regulation. Introduction. What is Population Regulation?. Combining Density Dependent and Density Independent Factors. Tests of Density Dependence. Summary. 4. Populations with Age Structures. Introduction. Survivorship. Fertility. Mortality Curves. Expectation of Life. Net Reproductive Rate, Generation Time and the Intrinsic Rate of Increase. Age Structure and the Stable Age Distribution. Projecting Population Growth in Age Structured Populations. The Leslie or Population Projection Matrix. A Second Version of the Leslie Matrix. The Lefkovitch Modification of the Leslie Matrix. Dominant Latent Roots and the Characteristic Equation. Reproductive Value. Summary. 5. Metapopulation Ecology. Introduction. Metapopulations and Spatial Ecology. MacArthur and Wilson and the Equilibrium Theory. The Levins or Classical Metapopulation. Extinction in Metapopulations. Metapopulation Dynamics of Two Local Populations. Source-Sink Metapopulations and the Rescue Effect. Non-equilibrium and Patchy Metapopulations. Spatially Realistic Models. Minimum Viable Metapopulation Size. Assumptions and Evidence for the Existence of Metapopulations in Nature. Summary. 6. Life History Strategies. Introduction. Power Laws. The Metabolic Theory of Ecology. Cole and Lewontin. The theory of r- and K-selection. Cost of Reproduction and Allocation of Energy. Clutch Size. Latitudinal gradients in Clutch Size. Predation and its Effects on Life History Characteristics. Bet Hedging. The Grime General Model for Three Evolutionary Strategies in Plants. Summary. Part II: Interspecific Interactions. 7. Interspecific Competition. Introduction. Interspecific Competition: Early Experiments and the Competitive Exclusion Principle. The Lotka-Volterra Competition Equations. Laboratory Experiments and Competition. Resource Based Competition Theory. Spatial Competition and the Competition-Colonization Trade-off. Evidence for Competition From Nature. Indirect Evidence for Competition and "Natural Experiments". Summary. 8. Mutualism. Introduction. Modeling Mutualism. Summary. 9. Host-Parasite Interactions. Introduction. Factors Affecting Microparasite Population Biology. Modeling Host-Microparasite Interactions. Dynamics of the Disease. Immunization. Endangered Metapopulations and Disease. Social Parasites. Summary. 10. Predator/Prey Interactions. Introduction. The Lotka Volterra Equations. Early Tests of the Lotka-Volterra Models. Functional Responses. Adding Prey Density Dependence and the Type II and III Functional. Responses to the Lotka Volterra Equations. The Graphical Analyses of Rosenzweig and MacArthur. Use of a Half Saturation Constant in Predator/Prey Interactions. Parasitoid/Host Interactions and the Nicholson-Bailey Models. Section Summary. Field Studies. Trophic Cascades. The Dangers of a Predatory Lifestyle. Escape from Predation. Summary. 11. Plant-Herbivore Interactions. Introduction. Classes of Chemical Defenses. Constitutive vs. Induced Defense. Plant Communication. Plant-Parasitoid Communication. A Classic Set of Data Reconsidered. Novel Defenses/Herbivore Responses. Detoxification of Plant Compounds by Herbivores. Plant Apparency and Chemical Defense. Soil Fertility and Chemical Defense. The Optimal Defense Theory. Modeling Plant-Herbivore Population Dynamics. Summary. References. Appendix 1: Exercises. Appendix 2: Matrix Algebra: the Basics. Index
566 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 12 |
| 2024 | 38 |
| 2023 | 49 |
| 2022 | 84 |
| 2021 | 20 |
| 2020 | 28 |