Climate change impacts on sagebrush-dominated landscapes: an ecohydrological perspective

Big sagebrush (Artemisia tridentata Nutall) dominates semi-arid landscapes across much of western North America. Sagebrush-dominated ecosystems provide important services such as wildlife habitat, nutrient and water cycling, and carbon storage. These ecosystems, however, have been reduced in distribution and quality due to economic and agricultural activity, infrastructure expansion, invasive species, and altered fire regimes.  In addition, the potential impact of changing climate and altered disturbance regimes on the distribution and abundance of sagebrush ecosystems remains unclear.  We characterized the ecohydrological conditions that support sagebrush ecosystems and applied the results to assess how climate change may shift the location areas capable of supporting sagebrush.  To further understand the potential impact of disturbances, we developed a model for sagebrush regeneration and quantified the probability of observing conditions that support regeneration under current and future climates.   Results suggest potential widespread contraction of sagebrush ecosystems in the southern and low elevation areas currently occupied by sagebrush, and possible expansion (albeit more limited) northward and upslope. The spatially explicit results illustrate the potential consequences of climate change and disturbances on sagebrush ecosystems across western United States.