EFFECTS OF SUCCESSIONAL DYNAMICS ON METAPOPULATION PERSISTENCE

Abstract

The classical (Levins) metapopulation scenario envisions a species persisting in a network of habitat patches through a balance between frequent local (within-patch) extinctions and recolonizations. Although this is the dominant paradigm for species in fragmented habitats, empirical support is limited, and it has been argued that very restrictive conditions on migration rates are required: high enough for recolonization to balance extinctions, but low enough that local populations do not fluctuate in synchrony. Through simulation and analysis of a stochastic spatial model, we argue that the likelihood of persistence via the classical scenario is strongly affected by some basic properties of within-patch successional dynamics whose importance has not been emphasized in metapopulation theory: the distribution of successional stage durations, and whether patches are “refractory” vs. immediately available for recolonization after an extinction has occurred. These properties are tied to the biological causes o...