Data are presented from the results of a 14-year study of changes in composition of a desert rodent community following habitat perturbation. We studied rodent populations in an area where herbicide treatment reduced shrub cover from 19.7 percent to less than one percent and increased grass cover from 1.3 percent to 22.3 percent. In the first two years following the perturbation, Dipodomys ordii was the most abundant species in the shrub habitats. From 1976 through 1984, the rodent community in both areas was dominated by D. merriami and D. ordii was absent or occurred at low densities in both habitats. Species richness was highest in 1976 and 1985 following successive "wet" seasons. In 1985, following three above average wet seasons, D. ordii once again became the most abundant rodent in the grass habitat. Neotoma micropus increased in abundance with increased grass cover. These results suggest interspecific competition between D. ordii and D. merriami during average to dry periods of limited resources. Successive wet seasons allow D. ordii, which has higher fecundity, to increase because resources are not limiting during such periods. Successive wet seasons result in increased species richness due to immigration of opportunistic species like Sigmodon hispidus and Reithrodontomys megalotis.