Sagebrush (Artemisia spp.)-dominated shrublands are one of the most widespread ecosystems in western North America but also among the most imperiled due to interactions among land use, fire, and exotic plants. Global climate change models predict an accelerated loss of sagebrush due to synergistic feedbacks among disturbance patterns and vegetation response; only 20% would remain under the most extreme scenario of >6 C increase by the end of this century (Fig. 1). Much of the current sagebrush distribution within the Great Northern Landscape Conservation Cooperative (GNLCC) would be lost. The conservation status of Greater sage-grouse (Centrocercus urophasianus), the most visible of >350 plant and wildlife species that depend on sagebrush, recently was determined to be warranted for listing but precluded by higher priorities. Because listing decisions are based partially on a long-term (>100 yr) probability of persistence, predicted habitat changes due to climate change may be sufficiently large to overwhelm current trajectories of landcover change.
The GNLCC includes a large number of fringe populations of greater sage-grouse in central Oregon, Idaho, and Montana (Fig. 2). In addition, the Columbia Basin populations of sage-grouse in Washington are spatially and genetically isolated from core regions of the range-wide distribution. Dispersal among these populations may be limited because of environmental or geographical barriers. In the absence of dispersal for recolonization, stochastic events within the population, such as outbreak of West Nile virus, or long-term shifts in sagebrush distribution likely will result in local population extinctions.
Our proposed study is designed to identify sage-grouse populations at risk of extinction within the GNLCC based on (1) their relative isolation from neighboring populations and core regions of the sage-grouse distribution and (2) landcover changes predicted under global climate change models.
FYOur proposed study is based on 2 primary objectives: (1) identify the ecological minimums of environmental variables required by sage-grouse, and (2) use global climate change models to project future locations and long-term viability of sage-grouse populations. Our study area includes the sage-grouse range within the GNLCC, which spans the states of Washington, Idaho, Montana, Wyoming, and Colorado
FY2010Objectives:
Develop models of environmental variables that represent an ecological minimum required by sage-grouse Model changes in sage-grouse distribution or population vulnerability relative to changes in these environmental variables predicted under climate change scenarios Conduct preliminary analyses of genetic variation within and among sage-grouse populations to determine dispersal probabilities.
