INTEGRATING SOIL MOISTURE ESTIMATES WITH MULTIPLE RANGE-WIDE DATASETS TO STUDY SAGEBRUSH RECOVERY AND RESPONSES TO RESTORATION ACROSS THE WESTERN UNITED STATES

Ecosystems dominated by sagebrush (Artemisia spp.) extend over much of the western United States and increasingly face threats from disturbances such as land-use, fire, and exotic annual grass invasion. Effective management includes restoration and habitat improvements, but costs and effectiveness vary. Understanding the conditions that determine timing and rate of sagebrush recovery is a pressing research need for managing this vast landscape. Soil conditions, such as moisture availability, have important effects on plant distributions, growth rates, and habitat conditions. Until now, soil moisture data have been inadequate to explain variability in vegetation patterns and habitat conditions for historic, contemporary, and projected scenarios. Because soil moisture is an important determinant of ecosystem resilience, we developed an integrated science framework for modeling and predicting sagebrush recovery across the sagebrush biome (1985–2020) using newly-developed monthly soil moisture products and environmental covariates. We integrated multiple datasets covering large extents, including vegetation estimates derived from remote sensing (Rangeland Condition, Monitoring, Assessment, and Projection), management practices (e.g., Land Treatment Digital Library, Conservation Efforts Database), and fire (Landsat Burned Area). When combined, these datasets yielded analysis-ready data at an unprecedented extent, including from >700 wildfires (nearly 2 million ha) and >270 other disturbances (nearly 80,000 ha). We assessed the influence of environmental factors (e.g., soil moisture), disturbance type (e.g., wildfire, brush removal), and restoration treatment (e.g., aerial seeding, herbicide application) on trends in sagebrush cover. Our results will facilitate stewardship of the sagebrush biome and hosted species by providing a variety of spatially explicit predictions and projections of sagebrush recovery, thereby informing regional planning and on-the-ground restoration efforts. These analyses also will support on-going efforts, including economic cost-effectiveness analyses, studies of sage-grouse (Centrocercus urophasianus) responses to post-fire restoration, and restoration prioritization tools.