EFFECTS OF SUBTERRANEAN MAMMALIAN HERBIVORES ON VEGETATION

Fossorial herbivores are common in Eurasia, North and South America, a nd Africa, particularly in arid and semiarid regions. There is ample e vidence, although often indirect and semiquantitative, that they have local and broad-scale effects on vegetation. These effects arise from feeding, harvesting, and caching, local soil disturbances, and longer- term changes in soil structure and topography, many aspects of which a re similar among the diversity of fossorial herbivores. Often, the net effect of these animals' activities is alteration of composition of p lant species and increased plant diversity. Standing crop of plants of ten is reduced, and long- and short-term changes in productivity can o ccur. Better understanding of the rules that govern diet selection and burrow size, dynamics, and geometry are needed to predict effects of these animals under specific environmental conditions.