Soil Arthropod Response to Prairie Burning

Soil arthropod response to altered litter production in a Wisconsin prairie was examined after a long established biennial spring burning program was modified by substituting raking for burning in some experimental blocks, and substituting no disturbance for burning in others. Very few species were favored by increased surface litter in undisturbed blocks. After two biennial burnings or rakings, a drop in species numbers, density of individuals, and diversity of herbivore—decomposers occurred in undisturbed, and to a lesser extent, in raked blocks. Predatory soil arthropod species showed no response. These results suggest that soil detritus levels dropped slowly in response to decreased plant productivity in undisturbed blocks. The drop in soil arthropod community diversity which occurred in undisturbed blocks indicates a direct productivity—diversity relationship. Other field experiments show the same direct productivity—diversity relationship among consumers or terrestrial producers, but an inverse relationship among aquatic producers.