The Transition from Mojave Desert to Great Basin Desert on the Nevada Test Site

Plant species and associations on the Nevada Test Site are located along elevation and precipitation gradients. Associa- tions in the Great Basin Desert had the highest species diversity. Rodent sign and productivity of annual plants are least in the lower and higher elevations and most abundant in the mid-elevations. Microbiotic crusts are most abundant in fine-textured soils and of low abundance in soils with active erosional processes. Texture of surface soils (0 to 5 centimeters (0 to 2 inches)) differs little among all associations except for a few that are correlated with playas and steep mountain slopes. However, differences among associations are observed for deeper substrates comprised of limestone, basalt, and tuff parent materials.