Disturbances, such as fire and grazing, play important roles in determining grassland plant community composition and soil microbial dynamics, as well as regulating the flows of carbon (C) and nitrogen (N) between the two groups of organisms. In a mixed grassland of the southern Great Plains, we tested the hypotheses that spring-season fire would increase the absolute biomass and relative proportion of C4 grasses in the plant community, and decrease soil microbial biomass N, thereby increasing microbial C:N ratios. We also tested the hypothesis that clipping (to simulate grazing) would reduce effects of fire, with a greater reduction of fire effect corresponding to an increased frequency of clipping. Contrary to our hypothesis, C4 grasses showed no significant treatment responses. Treatment effects were limited to C3 grasses, and clipping was more important than fire in terms of effects on plant community composition. However, because of its greater capacity to reduce aboveground litter, fire had the greater impact on soil microbial C. Contrary to the hypothesized outcome, no significant effects of disturbance on soil microbial N were observed. This suggests that control of N cycling in this ecosystem is primarily microbial in nature, though dependent on inputs of plant C via litter. Interactions between fire and clipping were observed in litter mass, highlighting the importance of litter inputs for plant-soil nutrient feedbacks. The Rangeland Ecology & Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact lbry-journals@email.arizona.edu for further information. Migrated from OJS platform August 2020
Scholarly peer-reviewed articles published by the Society for Range Management. Access articles on a rolling-window basis from vol. 1, 1948 up to 5 years from the current year. Formerly Journal of Range Management (JRM). More recent content is available by subscription from SRM.