Vulnerability Assessment and Strategies for the Sheldon National Wildlife Refuge and Hart Mountain National Antelope Refuge Complex.

摘要

This report provides the results of the Refuge Vulnerability Assessment (RVA) for the Sheldon National Wildlife Refuge and Hart Mountain National Antelope Refuge Complex (Refuge Complex). The purpose of the RVA is to assess the cumulative impacts of stressors on refuge resources over multiple timeframes and develop mitigation and adaptation strategies to address those impacts. The Refuges are located in northwest Nevada and southeast Oregon in an arid landscape characterized by expanses of sagebrush punctuated by isolated mountain ranges. Both Refuges were established primarily for the conservation of pronghorn, though many sensitive species and habitats are present on the Refuges and surrounding lands. Both spatial and non-spatial models were used to assess resource response to land use and environmental stressors. Spatial models looked specifically at snapshots in time at 2010 and 2025, while non-spatial assessments produced continuous results from 2000 to 2100. The spatial assessments focused on the subset of stressors that are readily characterized in a spatially explicit manner at the scale of the project area, using one modeling tool. All priority resources were addressed in the spatially explicit assessments. The second set of assessments focused solely on vegetation resources, and on the subset of stressors that are not readily modeled in a spatially explicit manner at the scale of the project area, using other modeling tools. These tools permit an in-depth assessment of how vegetation resources may change in response to biotic and abiotic processes, including grazing and climate change.