A general model of populations in patchy habitats

摘要

A general model is proposed for study of the effects of the spatial arrangement of habitat patches on population dynamics of resident populations. Previously proposed models are shown to be inadequate or undesirable for the detection of such effects. The proposed model is a stochastic discrete-time simulation model, in which within-patch processes are modeled using a discrete approximation to the logistic equation. The explicit spatial arrangement of patches is included, and the exchange of organisms via interpatch dispersal depends on three sets of parameters: (i) the fraction of organisms which disperse from each patch, (ii) the distance which organisms disperse, and (iii) the distance from which dispersers can detect new patches. A set of simulation experiments was performed, to study the effects of the detection distance [parameter (iii) above] on the effect of the spatial arrangement of habitat patches on population dynamics. It was found that for low and high detection distances patch spatial arrangement is relatively unimportant. However, for intermediate detection distances the spatial arrangement has an important impact on population dynamics.