Lake Tahoe Ecology: Vegetation in the basin is dominated by a mixed conifer forest of Jeffrey pine (Pinus jeffreyi), lodgepole pine (P. contorta), white fir (Abies concolor), and red fir (A. magnifica). The basin also contains significant areas of wet meadows and riparian areas, dry meadows, brush fields (with Arctostaphylos and Ceanothus) and rock outcrop areas, especially at higher elevations. Ceanothus is capable of fixing nitrogen, but mountain alder (Alnus tenuifolia), which grows along many of the basin’s streams, springs and seeps, fixes far greater quantities, and contributes measurably to nitrate-N concentrations in some small streams. The beaches of Lake Tahoe are the only known habitat for the rare Lake Tahoe yellowcress (Rorippa subumbellata), a plant which grows in the wet sand between low- and high-water marks.
Each autumn, from late September through mid-October, mature kokanee salmon (Oncorhyncus nerka), transform from silver-blue color to a fiery vermilion, and run up Taylor Creek, near South Lake Tahoe. As spawning season approaches the fish acquire a humpback and protuberant jaw. After spawning they die and their carcasses provide a feast for gatherings of mink (Neovison vison), bears (Ursus americanus), and Bald eagles (Haliaeetus leucocephalus). These salmon were transplanted from the North Pacific to Lake Tahoe in 1944.
North American Beaver (Castor canadensis) were re-introduced to the Tahoe Basin by the California Department of Fish and Game (CDFG) and the U. S. Forest Service between 1934 and 1949. Descended from no more than nine individuals, 1987 beaver populations on the upper and lower Truckee River had reached a density of 0.72 colonies (3.5 beavers) per kilometer. At the present time beaver have been seen in Tahoe Keys, Meeks Creek at Meeks Bay on the western shore, and King's Beach on the north shore, so the descendants of the original nine beavers have apparently migrated around most of Lake Tahoe. That beaver were once native to the area is supported by the fact that the Washo have a word for beaver, c'imhélhel and the northern Paiute of Walker Lake, Honey Lake and Pyramid Lake have a word for beaver su-i'-tu-ti-kut'-teh. When Stephen Powers visited the northern Paiute to collect Indian materials for the Smithsonian Institution in preparation for the Centennial Exhibition of 1876, he reported that the northern Paiute wrapped their hair in strips of beaver fur, made medicine from parts of beaver and that their creation legend included beaver.
