The role of heterogeneity on the spatiotemploral dynamics of host-parasite metapopulation

摘要

Subpopulations of organisms in different habitat patches may differ from each other in biotic (e.g., inherent growth rate and interaction strength) and abiotic (e.g., climatic and landscape pattern) components. Such heterogeneity can influence the mode and extent of dispersal of individuals among these subpopulations, which, in turn, may regulate their spatiotemporal dynamics. We have modelled a homogeneous metapopulation of the interacting host and parasite system; with closed boundary and dispersal limited to nearest neighbours, using the spatially explicit coupled map lattice approach. We have studied the role of heterogeneity in terms of landscape fragmentation and demographic heterogeneity on the spatiotemporal dynamics. The homogeneous metapopulation shows spatiotemporally synchronous dynamics in the long-term, which is independent of the exact forms of the dispersal function considered commonly. The primary role of both types of heterogeneity is to resist evolution of spatiotemporal synchrony in the lattice, and the dynamics in the metapopulation remains asynchronous for a very long time. Spatiotemporal synchrony in species population may be detrimental to persistence and is a potential problem for conservation biologists. Thus, evolution and maintenance of ecological and demographic diversity in nature seem to aid in species persistence at a metapopulation level. (C) 2004 Elsevier B.V. All rights reserved.