Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/30/2015
Publication Date: 5/25/2016
Publication URL: http://handle.nal.usda.gov/10113/62574
Citation: Davies, K.W., Nafus, A.M., Boyd, C.S., Hulet, A., Bates, J.D. 2016. Effects of using winter grazing as a fuel treatment on Wyoming big sagebrush plant communities. Rangeland Ecology and Management. 69:179-184. doi: 10.1016/j.rama.2015.12.005. Interpretive Summary: Though winter grazing is a fuel treatment that can reduce wildfire severity and risk in dry sagebrush communities, its impact on plant community characteristics is largely unknown. We evaluated the effects of repeated winter grazing by cattle for five to six years at utilization levels of 40-60%. Winter grazed and ungrazed areas generally had similar vegetation characteristics. Consumption of prior years’ growth reduced herbaceous cover, which is an important habitat component for some wildlife species. The results of this study suggest that winter grazing can be applied without negatively impacting the native plant community. However, we suggest that winter grazing should be strategically applied to reduce the possibility of adversely impacting wildlife.
Technical Abstract: More frequent wildfires and incidences of mega-fires have increased the pressure for fuel treatments in sagebrush (Artemisia) communities. Winter grazing has been one of many fuel treatments proposed for Wyoming big sagebrush (A. tridentata Nutt. subsp. wyomingensis Beetle and A. Young) communities. Though fire risk and severity can be reduced with winter grazing, its impact on vegetation characteristics of Wyoming big sagebrush plant communities is largely unknown. We evaluate the effect of winter grazing at utilization levels between 40-60% at five sites in southeastern Oregon. Winter grazing was applied for five to six years prior to measurements. The winter grazed and ungrazed treatment generally had similar vegetation characteristics; however, a few characteristics differed. The consumption of prior years’ growth resulted in less large perennial bunchgrass, perennial forb, and total herbaceous cover and standing crop and litter biomass. Large perennial bunchgrass and perennial forb density and biomass and exotic annual grass and annual forb cover, density, and biomass did not differ between treatments suggesting that winter grazing is not negatively impacting resilience and resistance of these communities. Shrub cover was also similar between treatments. These results imply that winter grazing can be applied to reduce fine fuels in Wyoming big sagebrush communities without adversely affecting the native plant community. Winter grazing should, however, be strategically applied because the reduction in perennial grass and perennial forb cover with the consumption of prior years’ growth may negatively impact the habitat value for wildlife species that use herbaceous vegetation for concealment.