Deterministic communities are persistent and resilient. Populations will remain about the same from year to year unless some outside force depresses one or more of them. A deterministic community would be characterized by species showing little overlap in the use of resources and a high degree of morphological divergence from one another. Competing species coexist because the conditions favoring one do not persist long enough for others to be excluded. There is no particular coherence to a community.
Environments typically consist of a mosaic of habitats with various histories of disturbance.
In stochastic communities, there is consistent low recruitment so that adult populations rarely, if ever, reach densities where interspecific competition is likely to be important. Presence of a dominant predator may serve to keep populations reduced to a level where competitive exclusion is unimportant. This might be considered a special case of stochastic community. Formative communities contain exotic species which evolved independently of other species in the community and have been recently introduced by human activities. In some communities the majority of the species are recently introduced to the area from various parts of the world, and thus adapted neither to the local environment nor to each other.