Structure of Desert Rodent Communities: A Critical Review of Questions and Approaches

Three attributes of communities—the number, relative abundances, and phenotypic attributes of coexisting species—together define their “structure,” as the term has been used in the literature. Most ecologists have tried to uncover determinants of community structure by analyzing patterns of morphology or resource use, or by experimentally manipulating the species composition or environmental context of communities. Less often used is a mechanistic analysis of processes operating at the level of individuals or populations. I discuss the logical basis for each of these approaches and illustrate their virtues and limitations with examples drawn from work on heteromyid rodents. While pattern analytic and experimental approaches have provided an efficient means of identifying proximate determinants of species number and relative abundance, a mechanistic approach holds more promise for answering questions about the ultimate determinants of phenotypic patterns within communities