Targeted grazing by sheep to control invasive species and reduce wildfire risk
The project
Cheatgrass (Bromus tectorum) invasion increases wildfire risk and negatively impacts sagebrush ecosystems and rangeland-based agricultural production in the western United States. In sagebrush ecosystems, diverse native plant communities tend to be more resistant to invasion and resilient to disturbances, like wildfire. Grazing has been suggested as a tool to combat cheatgrass and thus promote more resilient vegetation communities. However, most research on targeted grazing of cheatgrass has been done with cattle. Studies on targeted grazing of sheep on cheatgrass remain sparse, despite interest from stakeholders. This project is answering the question of whether sheep can be used to reduce cheatgrass and wildfire risk, while also examining the economic costs and benefits of this practice.
In 2022, our transdisciplinary team established a sheep targeted grazing experiment at a management-relevant scale on the Sawtooth National Forest in Idaho to examine vegetation responses and belowground processes affected by grazing. Grazing treatments are comparing dormant-season grazing in spring and fall, when cheatgrass is growing but most perennial species are not, to “traditional” summer grazing. In addition to assessing treatment effects on the composition of aboveground vegetation and fuel loads, we are examining impacts on soil processes to enhance understanding of the ecological mechanisms underpinning our results. Fire behavior models and economic models will estimate the financial and societal costs and benefits of adopting sheep targeted grazing practices.
If you have any questions about the study, please contact Dr. Kelly Hopping at kellyhopping@boisestate.edu.
Team
Dr. Kelly Hopping, Boise State University
Renee Kehler, U.S. Forest Service
Dr. Marie-Anne de Graaff, Boise State University
Dr. April Hulet, Brigham Young University
Dr. Sergio Arispe, Oregon State University
Dr. Laura Villegas Ortiz
Madelyn Sorrentino, Boise State University
Kowitz Sheep Company
Plateau Farms
Flat Top Sheep Company
Press
Funding
This project is supported by the Western Sustainable Agriculture Research and Education program under award number SW22-938.