The effects of grazing and mowing on soil carbon and plant community composition within a drained lake bed. Donohoe, Gwen ^*,1, ¹ College of Agriculture, University of Saskatchewan, Saskatoon, Saskatchewan, Canada

ABSTRACT- In this study, three sites of native plant communities within the drained Paquia Lake were used to compare the differences in stored soil carbon and plant community composition under three different management practices. These practices included grazing cattle, mowing for hay production, and a natural/untouched control site. Pasquia Lake, located in West-Central Manitoba, Canada, was drained in the 1970s as part of government funded development project. Today the area is used for annual crops as well as rangeland for cattle production. The soils of the three sites were determined to be of the Gleysolic Order under the Canadian System of Soil Classification. Soil organic carbon and below ground biomass were measured. Both plant roots and organic matter were found to decrease in quantity under grazing and mowing pressures. Grazing and mowing were found to cause changes in plant community composition, which in turn affected the amount of carbon available in the s oil.

KEY WORDS: soil carbon, drained lake bed