| Darcy C. Henderson, Ben H. Ellert, and M. Anne Naeth |
| Authors are Graduate Student, Department of Renewable Resources, University of Alberta, 751 General Services Building, Edmonton, Alberta, Canada, T6G 2H1, Research Scientist, Land Resource Sciences, Agriculture and Agri-Food Canada, P.O.B. 3000, Lethbridge, Alberta, Canada, T1J 4B1, and Professor, Department of Renewable Resources, University of Alberta, 751 General Services Building, Edmonton, Alberta, Canada, T6G 2H1. |
Abstract |
| The regional scale response of soil carbon mass to long-term grazing exclusion was investigated in the Canadian Great Plains. Vegetation, litter, macro-organic matter and soil were sampled in paired grazed and ungrazed treatments from 9 independent locations along an environmental gradient in southern Alberta. Vegetation and litter carbon mass were greater on ungrazed treatments, but no consistent grazing effect was observed for macro-organic matter (roots, subsurface litter) or soil (fine particles > 2mm) carbon mass per equivalent soil mass. Soil carbon in mixed grass prairie was positively correlated with clay content, but no grazing effect could be detected when this subset (n = 7) was analyzed by ANCOVA. Comparison of multiple sites with a consistent sampling and reporting method revealed no general trend in the response of soil carbon to grazing. Current range management practices to maintain range types in good to poor condition appear to be consistent with maintaining the soil organic matter pool in the northern Great Plains. |
| Key Words: mixed grass prairie, equivalent soil mass, bulk density, clay, carbon sequestration |