SMALL-SCALE AND LARGE-SCALE BIOGEOGRAPHY OF SUBTERRANEAN CRUSTACEAN FAUNAS OF THE VIRGINIAS

Data on number of subterranean crustaceans in river basins, in karst basins within a river basin, streams within a karst basin, riffles within a stream, and rocks within a riffle were analyzed with an emphasis on similarities at different geographic scales. Except at the smallest scale (individual rocks) the coefficient of variation of species number was roughly constant at 0.4, indicating some fractal properties of the variation. Using approximations for the log of the linear extent of each scale, species number increased linearly at a slope of 0.68 (P<0.005). This suggests an unsaturated regional fauna.