Community Patterns in Source‐Sink Metacommunities

We present a model of a source-sink competitive metacommunity, defined as a regional set of communities in which local diversity is maintained by dispersal. Although the conditions of local and regional coexistence have been well defined in such systems, no study has attempted to provide clear predictions of classical community-wide patterns. Here we provide predictions for species richness, species relative abundances, and community-level functional properties (productivity and space occupation) at the local and regional scales as functions of the proportion of dispersal between communities. Local (alpha) diversity is maximal at an intermediate level of dispersal, whereas between-community (beta) and regional…