2004 Annual Report for GNC03-021
Effects of Prairie Dogs on Sustainability of Cattle Grazing in Mixed-Grass Prairie
Summary
This study determined the difference in disappearance of vegetation between cattle and prairie dogs on pastures with prairie dog towns. During the summers of 2002 and 2003, data were collected on pastures in south-central South Dakota. Forage removed by prairie dogs on the on-town sites was three times as great as forage removed by cattle on the on-town sites for the June and July sampling periods. Cattle removed two times more forage on off-town sites than on on-town sites. Stocking rates on pastures with prairie dog towns should be adjusted to account for forage disappearance due to prairie dogs.
Objectives/Performance Targets
The objective of this study was to determine the difference in disappearance of vegetation between cattle and prairie dogs on pastures with prairie dog towns.
Accomplishments/Milestones
Our study clearly indicates that prairie dog towns reduce forage available to cattle. In the case of this study, prairie dog town acres provided only half the forage to livestock as did the same sites without prairie dogs. This reduction likely involves both a shift in composition toward less desirable plant species and a reduction in accessibility due to clipping.
Traditional carrying capacity calculations are based on vegetation seral stage, which is primarily influenced by species composition. While such calculations would indicate a reduction in carrying capacity for acres of prairie dog town, the result would be an overestimate. Further adjustments must be made to account for the forage being removed by prairie dogs. Prairie dogs on cattle pastures should be treated in a similar fashion to other herbivores such as elk or insects that compete with cattle for forage. Without this adjustment, the risk of abusing the pasture, both on- and off-town, by overgrazing exists.
Impacts and Contributions/Outcomes
The results of this project have not been adopted yet.
Outputs resulted in several publications:
Stoltenberg, M.B. 2004. Effects of Prairie Dogs on Plant Community Composition and Vegetation Disappearance in Mixed-Grass Prairie. Thesis. South Dakota State University, Brookings, SD.
Stoltenberg, M.B, P.S. Johnson, A.J. Smart, and L. Xu. 2004. Effects of prairie dogs and cattle on vegetation disappearance on prairie dog towns in mixed-grass prairie. p. 94-98 In: Beef Cattle Research Report, South Dakota State University, Brookings, SD.
Stoltenberg, M.B, P.S. Johnson, L. Xu., and A. Smart. 2004. Effects of prairie dogs and cattle on vegetation disappearance on prairie dog towns in mixed-grass prairie. p. 193. In Abstracts: Rangelands in transition. Society for Range Management 57th Annual Meeting. Jan 24-30, Salt Lake City, UT.
Stoltenberg, M., P.S. Johnson, A.J. Smart, and Lan Xu. 2004. Contributions of prairie dogs and cattle to vegetation disappearance on prairie dog town in mixed-grass prairie. The South Dakota Center for Biocomplexity Studies Rushmore Regional Conference on Biocomplexity, August 11-12, 2004, at the Holiday Inn City Centre in Sioux Falls, South Dakota. Available Online at http://www.sdepscor.org/cbs/Abstracts.htm.