Response of Big Sagebrush Plant Communities

Response of Big Sagebrush Plant Communities to Climate Change, Grazing, and Cheatgrass Throughout the 21st Century

The big sagebrush region in the Western U.S. is variable in elevation, topography, and climate, and plant communities there are likely to respond to climatic change in a variety of ways. This presentation will describe research that uses a simulation model to evaluate the availability of water for plants under future climate scenarios to evaluate how climate change will affect 200 widespread big sagebrush sites and identify which locations will be especially impacted. Additional pressures from grazing and cheatgrass-wildfire interactions under future climate will also be discussed. The simulations indicate that changes in big sagebrush biomass will be variable across sites, with both increases and decreases projected. Sites with increases in biomass were primarily in the eastern half of the region or at high elevation. Moderate and heavy livestock grazing modified these outcomes and resulted in larger perennial grass and herbaceous grass declines. Under future climate, several previously uninvaded sites in the northeast region became suitable for cheatgrass, promoting increases in wildfire and plant community change. The rangewide approach used by the presenters identifies areas that will change under future climate to help inform the prioritization of limited conservation resources.