A STOCHASTIC METAPOPULATION MODEL WITH VARIABILITY IN PATCH SIZE AND POSITION

Analytically tractable metapopulation models usually assume that every patch is identical, which limits their application to real metapopula tions. We describe a new single species model of metapopulation dynami cs that allows variation in patch size and position. The state of the metapopulation is defined by the presence or absence of the species in each patch. For a system of n patches, this gives 2(n) possible state s. We show how to construct and analyse a matrix describing transition s between all possible states by first constructing separate extinctio n and colonisation matrices. We illustrate the model's application to metapopulations by considering an example of malleefowl, Leipoa ocella ta, in southern Australia, and calculate extinction probabilities and quasi-stationary distributions. We investigate the relative importance of modelling the particular arrangement of patches and the variation in patch sizes for this metapopulation and we use the model to examine the effects of further habitat loss on extinction probabilities. (C) 1995 Academic Press, Inc.