Organization of North American desert rodent associations: insights from geographic comparisons and perturbation experiments.

Abstract

In this essay I use my own research on North American desert rodents to illustrate how comparative geographic studies and experimental perturbations at local sites give different, sometimes seemingly conflicting insights into the patterns and processes that characterize assemblages of species. In general, results of the two approaches can be reconciled, and they support the hypotheses that community organization is by no means entirely random, but determined in part by deterministic effects of limited food availability, interspecific competition, and other interactions. On the other hand , either approach by itself is inadequate and sometimes misleading, because ecological processes operate in different ways and have different effects on different spatial and temporal scales.