Distribution patterns of Ohio soil dictyostelids in relation to physiography

Eighty-five sites in eight physiographically defined environments were sampled for dictyostelid slime molds. Sixteen species were isolated. Four are rare and were found at only one site. Nine of the remaining 12 coexist in all eight environments. The distribution pattern of each species, however, based on importance values as well as statistical analysis, is distinctive. We feel we have defined the optimum environment for seven species in Ohio: Dictyostelium minutum, D. discoideum, D. purpureum, D. polycephalum, Polysphondylium violaceum, P. pallidum, and Acytostelium leptosomum. These data may help characterize the niches dictyostelid species occupy at the much smaller scale of the soil/leaf mold interface.