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ARS Home » Pacific West Area » Dubois, Idaho » Range Sheep Production Efficiency Research » Research » Research Project #444848

Research Project: Plant Community Composition and Production of Intermountain West Grazing Lands

Location: Range Sheep Production Efficiency Research

Project Number: 2056-21500-001-006-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Sep 5, 2023
End Date: Sep 4, 2027

Objective:
1) Evaluate the effects of herded domestic sheep grazing on annual net primary productivity in long-term grazed areas compared to ungrazed areas (new exclosures) in montane meadows. 2) Evaluate the effects of herded domestic sheep grazing on plant community composition change in long-term grazed areas compared to ungrazed areas (new exclosures) in montane meadows.

Approach:
This study will take place in montane meadows used for summer range by domestic sheep. We will sample on an existing set of sites located across an elevation gradient in an active sheep grazing allotment. Each site includes one plot located within a sheep grazing exclosure, and a second plot located in an area with long term (70+ years) of sheep grazing history. We will quantitatively evaluate sheep grazing effects on annual net primary productivity using the movable cage method. At each site, will sample biomass inside and outside of exclosures and movable grazing cages repeatedly during the growing season. We will evaluate grazing effects on plant community composition by comparing plant cover and diversity inside and outside of selected areas where sheep grazing is experimentally removed after 2 years of experimental treatment. After processing the samples, we will statistically compare the outcomes in grazed and ungrazed plots, accounting for weather and site environmental attributes, using generalized linear mixed models. A graduate student from the University of Wyoming will be recruited to assist with and learn from accomplishing the objectives. Opportunities will be provided for the student to interact with stakeholders, present findings at scientist meetings, and collaborate in generating new projects enhancing the work accomplished under this agreement.