Short-Term Effects of Chemical and Mechanical Cover Management on Decomposition Processes in a Grassland Soil

Abstract

Knowledge of the ecological consequences of vegetation management is increasingly important because of the extent to which plant communities are subjected to mechanical and chemical manipulations. Many land areas may be intensively managed for short time periods and then abandoned to natural succession or restored to their original condition. The ecological fate of these areas, or the success in their restoration, largely depends upon alterations in habitat quality-including changes in organic decomposition processes and soil biota. Research on the ecological effects of vegetation cover management has most frequently concerned changes in species composition, primary production, and microclimate as a function of grazing and mowing intensity or herbicide applications (e.g. Hopkins 1954; Fox 1964; Penfound 1964; Schuster 1964; Rauzi & Hanson 1966; Kincaid Williams 1966; Bernardon, Huss & McMully 1967; and Tabler 1968). Consequently, little attention has been given to the influence of cover manipulation on decomposition of organic matter, nutrient cycling and the biotic components of ecosystems which influence these processes. The present study was undertaken to provide insight into the short-term effects of cover management on several aspects of decomposition processes in grassland soil. Criteria for evaluating biotic effects were net changes in soil organic matter content and root biomass, decomposition rates of cellulose, and density of soil microflora and microarthropods. Insight into the responses of the physical environment to alterations of cover was gained by periodic measurements of soil temperature and moisture.