Patch dynamics and metapopulation theory: the case of successional species

We present a mathematical framework that combines extinction-colonization d ynamics with the dynamics of patch succession. We draw an analogy between t he epidemiological categorization of individuals (infected, susceptible, la tent and resistant) and the patch structure of a spatially heterogeneous la ndscape (occupied-suitable, empty-suitable, occupied-unsuitable and empty-u nsuitable). This approach allows one to consider life-history attributes th at influence persistence in patchy environments (e.g., longevity, colonizat ion ability) in concert with extrinsic processes (e.g., disturbances, succe ssion) that lead to spatial heterogeneity in patch suitability. It also all ows the incorporation of seed banks and other dormant life forms, thus broa dening patch occupancy dynamics to include sink habitats. We use the model to investigate how equilibrium patch occupancy is influenced by four critic al parameters: colonization rate? extinction rate, disturbance frequency an d the rate of habitat succession. This analysis leads to general prediction s about how the temporal scaling of patch succession and extinction-coloniz ation dynamics influences long-term persistence. We apply the model to herb aceous, early-successional species that inhabit open patches created by per iodic disturbances. We predict the minimum disturbance frequency required f ar viable management of such species in the Florida scrub ecosystem. (C) 20 01 Academic Press.