Adaptive responses to spatial aggregation and habitat destruction in heterogeneous landscapes

Question: How does the spatial aggregation of landscape structure affect the ecological and evolutionary dynamics of metapopulations? Mathematical methods: Analytical and numerical analysis of a generalized Levins type metapopulation model using procedures developed in adaptive dynamics theory. Key assumptions: Landscapes are composed of patches of two types that are spatially aggregated with constant autocorrelation. Patch type determines population extinction rates but not the ability to establish new populations. Local populations are genetically identical. Predictions: Niche switching following habitat disturbance is critically dependent upon landscape composition as well as phenotypic plasticity. Landscape configurations can result in evolutionary trapping. Increasing the degree of spatial aggregation can lead to a decline in evolutionary attractors, corresponding to a potential reduction in biodiversity. Conclusions: The results are at odds with the commonly held opinion that aggregating spatial heterogeneity is a mechanism for promoting and sustaining biodiversity. Metapopulation models developed to investigate adaptive responses to landscape degradation would benefit if spatial variation in habitat structure, and not just population structure, is incorporated.