Glacier National Park is rapidly losing its namesake as summer temperatures rise and its glaciers disappear (see figure on facing page). The park, which straddles both the Continental Divide and the U.S.-Canada border in Montana, has lost about two-thirds of its glaciers since 1850 (Hall and Fagre, 2003). Plant and animal species are struggling to keep pace as suitable habitats retreat uphill as the climate warms. For example, pine trees are invading open grassland as the tree line migrates to higher elevation, in turn reducing fodder available for grazing mountain goats, bighorn sheep, and other ungulates.

Glacier National Park exemplifies some of the key questions that land and natural resource managers face with climate change (Pederson et al., 2006):

• As glaciers recede, will loss of scenic value reduce the millions of dollars that tourists spend there each year?

• How will populations of the grizzly bear and other species fare under climate change?

• Will dwindling glacial melt reduce populations of trout, a staple of the grizzly’s diet and the fishing-tourism industry?

• Will droughts cause grizzlies and other large mammals to alter their seasonal movements in search of food, potentially exacerbating conflicts with human populations in and around the park?

• Will landslides increase, threatening animal and plant habitats and human-built infrastructure in the park?

• How will changes in water flowing out of the park into three major river systems—the Missouri/Mississippi, the Columbia, and the Saskatchewan/Nelson—alter availability downstream for irrigation and hydropower?

• Will fire become more frequent, and should more resources be allocated to fire-fighting or preemptive forest management?

All of these questions highlight the need for improved understanding of how plant and animal species will respond to climate change and other stresses. Projections of climate change on finer spatial scales would provide input for land managers to begin to assess the implications in their local context. Studies and models of the complex interactions among climate, biodiversity, ecosystem processes, and