Modeling density dependence in heterogeneous landscapes: Dispersal as a case study

JOURNAL OF THEORETICAL BIOLOGY

卷:265

Article

Lloyd-Smith, James O.

关键词: Population dynamics;    Spatial heterogeneity;    Movement ecology;    Resource competition;    Metapopulation;   

DOI  :  10.1016/j.jtbi.2010.03.032

来源: Elsevier

【 摘 要 】

Population models often pose density-dependent rates as relations between current population size on a habitat patch, n, and some threshold size defined by limiting resources, r. In fourteen recent modeling studies incorporating density-dependent dispersal, formulations of the density-dependent rate (or probability) fall into two distinct groups, expressing the rate as a function of n-r or n/r. These two depictions of the same process differ fundamentally: they can cause strikingly different dynamics in otherwise identical systems and they have different scaling properties in heterogeneous landscapes. Here I consider the implications of the two formulations under two broad ecological scenarios: scramble competition for an equally divided resource (e.g. food) and contest competition for an unequally divided resource (e.g. nest sites). In both cases, simple arguments show that the nit form is preferable when density dependence is driven by individual access to resources. Other circumstances may require different formulations, but modelers must ensure that these have appropriate scaling and non-equilibrium behavior. (c) 2010 Elsevier Ltd. All rights reserved.

【 授权许可】

Free