Cooperative Fish and Wildlife Research Units Program: Idaho
Education, Research and Technical Assistance for Managing Our Natural Resources

Monitoring of forage availability, utilization, and residual biomass is the primary basis for making livestock management decisions in grazingland systems. Knowing the distribution of grazing across landscapes helps assess the impacts of livestock on wildlife populations. However, field measures of livestock impacts are often unreliable at the ranch scale due to heterogeneous patterns of vegetation and grazing. New technologies can improve field measures and provide new perspectives on grazing impacts at landscape scales. We are assessing grazing impacts at ranch scales that integrates plot-based field utilization measurements with livestock GPS collar data and remotely-sensed measures of grazing intensity. We are also evaluating and improving existing field methods for estimating utilization and residual biomass, and pairing field observations with livestock GPS-collar data to validate maps of biomass change based on remote sensing as an index of grazing intensity. The project is a collaboration between USGS Idaho Cooperative Fish & Wildlife Research Unit, University of Idaho, NRCS, The Nature Conservancy, and ranchers. The resulting estimates of grazing intensity across pastures will improve our understanding of livestock impacts on Greater Sage-grouse populations. The results of this project will be built into the RangeSat online tool (https://rangesat.nkn.uidaho.edu/) to analyze and visualize forage availability and grazing intensity.