Marten Habitat Preferences in the Northern Sierra Nevada

Abstract

Marten were studied in the 40-km2 Sagehen Creek Basin in Tahoe National Forest, Nevada County, California. Elevations range from 1,880 to 2,620 m. Summers are short and dry with great diurnal temperature variations; winters are long and nocturnally cold, but with midday temperatures often above 0 C. Most of the 91 cm of annual precipitation falls as snow. Average winter snow pack is 112 cm at 1,950 m elevation and may be substantially deeper at higher elevations. Xeric areas are dominated by Jeffrey pine (Pinus jeffreyi) and mixed Jeffrey pine-white fir (Abies concolor) (Jeffrey pine associations). Mixtures of lodgepole pine (P. contorta) and white fir (mixed conifer associations) dominate below 2,050 m elevation (lower basin). Above 2,050 m elevation (upper basin), red fir (A. magifica) dominates, with admixtures of mountain hemlock (Tsuga mertensiana) and western white pine (P. monticola) (red fir associations). Moist areas, comprising about 5% of the drainage, are dominated by lodgepole pine and a dense cover of sedges, forbs, and willow shrubs (Salix spp.) (riparian lodgepole associations). Large brushfields resulting from wildfire cover one-third of the study area.