A version of this paper was presented at the Third International Partners in Flight Conference, March 20-24, 2002, Asilomar Conference Grounds, California. U.S. Geological Survey, Fort Collins, Science Center, 2150 Centre Ave., Bldg C, Fort Collins, CO 80526. E-mail: tasha_kotliar@ usgs.gov. U.S. Forest Service, Rocky Mountain Research Station, 1648 South 7th Avenue, MSU Campus, Bozeman, MT 597...