Causes, Mechanisms and Consequences of Dispersal

Publisher Summary The movement (or dispersal) of propagules among suitable patches of habitats is an essential ingredient of metapopulation dynamics. At the birth of the metapopulation concept, only colonization was considered (i.e., movement to empty patches). However, all patches within a metapopulation are, to some extent, exchanging individuals due to dispersal, even those that are already occupied. This phenomenon leads to a re-enforcement of the extant local populations (the rescue effect). This chapter focuses on condition-dependent dispersal because it is important to take condition dependence into account to make realistic predictions about the dispersal evolution and its consequences. In more recent developments of metapopulation theory, dispersal has been considered to be a function of the density in the patch of departure and other features such as the patch size and the distance between patches. In addition to these attempts, dispersal was largely considered to be unconditional of the status of the individual, the potential donor, and recipient patches, as well as the matrix between patches.