| The aboveground responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of consumer groups to these disturbances are less well known. Invertebrates are an important component of soil ecosystems in tallgrass prairie, making up a diverse assemblage of organisms that perform a diverse set of functions. However, factors influencing their distribution and abundance are not well known.; We conducted studies examining the influence of different land management practices on the distribution of soil invertebrates at the Konza Prairie Biological Station (KPBS). We sampled the Belowground Plot Experiment at KPBS, a long-term experimental manipulation which addresses the influence of fire, mowing, and nutrient additions on belowground processes and organisms. Results indicated that native North American earthworms (Diplocardia spp.) were favored by the occurrence of fire and/or mowing, whereas an exotic European earthworm (Aporrectodea trapezoides) was more abundant in unburned, unmowed plots which had received fertilizer amendments. We suggest that changes in microclimate and/or belowground resource quality associated with absence of fire and mowing may be responsible for differences in native and exotic earthworm distributions. In another field study, we examined the differences between native and exotic earthworms with respect to their activity in the soil and their influence on plant nutrition. Native earthworms were more active during the growing season, but appeared to decrease availability of N to plants during the experiment.; We examined another group of soil invertebrates, the cicadas, at the landscape level and in the plot level study. We examined emergence densities of four annual cicada species in upland grassland, lowland grassland, and lowland forest locations. Two species (Tibicen aurifera and Cicadetta calliope) were more abundant in upland landscape positions, and one species (Tibicen pruinosa) emerged only from forested areas. At all landscape positions, cicada emergence resulted in significant fluxes of N from belowground to aboveground (∼4 kg ha−1). In the Belowground Plot Experiment, cicadas showed dramatic, species specific, responses to fire, mowing and fertilization treatments. T. aurifera emerged exclusively from unburned plots, whereas C. calliope was more abundant in burned plots which were not mowed, suggesting resource partitioning between species. |
