Location: Forage and Range Research
Project Number: 2080-21000-018-057-R
Project Type: Reimbursable Cooperative Agreement
Start Date: Oct 1, 2022
End Date: Aug 30, 2025
The first objective is to develop an herd management area (HMA)-specific habitat index by identifying and mapping usable space within HMAs. The second objective is to use three common rangeland health indicators to evaluate the relationship between Appropriate Management Level and habitat condition through time. The third objective is to produce an HMA resilience index based on region-specific climate change projections.
USDA Agricultural Research Service (ARS) will: * Utilize several nationwide geospatial layers to identify a wild horse and burros (WHB) habitat index or usable space within each herd management area (HMA) that the Bureau of Land Management (BLM) currently administers. The usable space can be defined as the spatial domain that the WHB actually use within each HMA and thus is the critical area that is being impacted by WHB populations that exceed the appropriate management levels (AML) for each HMA. Post assessments of WHB on the landscape can be done more transparently in this identified usable space. This identification of habitat index will be done across all 177 HMA that are distributed in the US Western States. * Within each usable space the relationships between AML and habitat conditions will be assessed through time. Time series of AML will be associated with landscape metrics such as % bare ground, % annual invasive grasses and soil moisture that have been derived using satellite platforms. High resolution imagery from unmanned aerial vehicles (UAV) aka drones will be used to validate the satellite products. This imagery will be collected at selected ecoregions that provide a narrative about ecosystem variability for all HMA. * Once the relative magnitude of the effects of WHB over the rangeland indicators have been evaluated for current / historic conditions then this relative effects will be used with climate change projections of forage availability and soil moisture conditions for the future. This assessment will provide a transparent idea of the level of resilience that each HMA can have under increasing WHB populations and harsher climatic conditions.