In community or ecosystem ecology, the term metapopulation is used for the idea of a population structured as several smaller, geographically isolated subpopulations (the degree of isolation may vary, but that's getting ahead of myself).

The population dynamics of a species or population subdivided into patches of habitat are governed by colonization and extinction on a local, patch-by-patch basis. Other factors that may affect overall population persistence include size and number of patches, migration rates between patches (which depends on the species' dispersal ability and the distance or other barriers between patches), and of course local population dynamics.

Historically, the idea of metapopulations came out of the study of island biogeography, which was extended for application to other naturally-occurring island-like settings, such as mountaintops and small, isolated habitats (such as some national parks and nature reserves). So situations other than islands can sometimes be described with some of the most accurate mathematical models in biology.