Interior Columbia Basin Forests and Rangelands, 1930s to Present *

Forest and rangeland ecosystems of the interior Northwest U.S. are remarkably diverse and productive, owing to great variety in climate, geology, landforms, floral and faunal species, and ecosystem processes (Bailey, 1995; Franklin and Dyrness, 1988). Recurring disturbances, such as those caused by fires, insects, pathogens, and weather are essential to maintaining this diversity (Agee, 1993, 1994; Arno, 1976, 1980; Hall, 1976; Hessburg et al., 1994; Turner, 1987, 1989). Terrestrial plant communities include dry, short-grass prairies and sagebrush hills; dry ponderosa pine and Douglas fir forests; cool and moist midmontane western hemlock and western red cedar forests; high-elevation whitebark pine and subalpine larch forests, krummholz, and heath. Alpine tundra, rock barrens, and glaciers occupy many of the highest elevations.