Variation-dependent mechanisms are
those that require variation in space in either population
densities or environmental factors for their operation. In the
study of species coexistence, the storage
effect and nonlinear
competitive variance , in their spatial manifestations, are
variation-dependent mechanisms of
species coexistence. Fitness-density
covariance is also a variation-dependent mechanism. Naturally,
variation-dependent mechanisms are to be contrasted with variation-independent
mechanisms. This distinction was first presented in Chesson
related concepts to do with temporal variation are termed fluctuation-dependent,
mechanisms, as discussed in Chesson (2000b).
Chesson, P. 2000a.
General theory of competitive coexistence in
spatially varying environments. Theoretical Population Biology 58,
Chesson, P. 2000b.
Mechanisms of maintenance of species diversity. Annual Review of
Ecology and Systematics 31, 343-66.