[1][2][3] The term is derived from the field of community ecology, which is primarily concerned with patterns of species distribution, abundance and interactions.
There are four theoretical frameworks, or unifying themes, that each detail specific mechanistic processes useful for predicting empirical community patterns.
This model represents the classical theories of the niche-centric era of G. Evelyn Hutchinson and Robert MacArthur.
Source-sink models describe a framework in which dispersal and environmental heterogeneity interact to determine local and regional abundance and composition.
High levels of dispersal among habitat patches allow populations to be maintained in environments that are normally outside the species environmental range.