Variation-independent Mechanisms
Variation-independent mechanisms are
those that function independently of the presence of variation in space
in population
densities and environmental factors. They may be affected by the
presence of variation, but do not require them for their operation,
and in general still function in the presence of spatial variation. A
classic example is resource partitioning (Chesson 1991). Naturally,
variation-independent mechanisms are to be contrasted with variation-dependent
mechanisms. This distinction was first presented in Chesson
(2000). Note that
both varation-dependent and variation-independent mechanisms may
well operate together in a given ecological system (Chesson 2000).
The
related concepts to do with temporal variation are termed
fluctuation-dependent,
and fluctuation-independent
mechanisms.
References
Chesson, P.L.,
Case, T.J. 1986. Nonequilibrium community theories: chance,
variability, history, and coexistence. Pp 229-239 in J. Diamond and T.
Case, eds, "Community Ecology," Harper and Row
Chesson, P. 2000.
Mechanisms of maintenance of species diversity. Annual Review of
Ecology and Systematics 31, 343-66.