Introduction: An Ecoregional Assessment of the Wyoming Basins

The Wyoming Basins Ecoregional Assessment (WBEA) area in the western United States contains a number of important land cover types, including nearly one-fourth of the sagebrush (Artemisia spp.) in North America. Although relatively unap-preciated until recent decades, the broad open landscapes dominated by sagebrush communities have received increasing attention for their ecological value and the resources that they contain (Knick and Con-nelly 2011). As many as 350 wildlife species depend on sagebrush ecosystems for all or part of their life requirements (Wisdom et al. 2005a). Within the WBEA, intact sagebrush landscapes provide an important stronghold for populations of greater sage-grouse (Centrocercus urophasianus), recently listed as a candidate species under the Endangered Species Act (U.S. Department of the Interior 2010). Numerous other plant and vertebrate species of state or national concern also occur within the WBEA study area (Ch. 2). Conserving sagebrush ecosystems is a major conservation challenge that will require an understanding not only of current trajectories and scales of habitat change due to natural and an-thropogenic disturbances (Leu and Hanser 2011), but also the potential exacerbation of these trends from climate change (Wiens and Bachelet 2010, Miller et al. 2011). The WBEA area contains significant amounts of resources important to sustain human populations. Oil, gas, and wind energy development as well as the necessary infrastructure for energy transmission are dominant land uses that can fragment landscapes and influence resource availability (Doherty et al. 2011, Naugle et al. 2011). Livestock grazing also occurs throughout the WBEA area, potentially altering vegetation structure and quality as well as other ecosystem processes (Freilich et al. 2003). Recreation and wilderness amenities on these lands impose additional physical and legal demands to more traditional commodity uses (Knick et al. 2011). Over half of the sagebrush within the WBEA area is public land; the largest land areas are managed by the U.S. Bureau of Land Management (BLM) and the U.S. Forest Service (FS) for multiple uses. Less than two percent of the sagebrush in the WBEA area receives legal protection from conversion of land cover in which only natural processes are allowed to influence the system (Ch. 1). Because most sagebrush habitats are managed by public agencies, federal land use actions can impact a large proportion of sagebrush habitats and their dependent wildlife. The ecological importance of the WBEA area coupled with its abundant natural resources create a complex challenge for balancing land and resource use …