Late-Glacial and Early Holocene vegetation and climate change near Owens Lake, eastern California

Pollen and algae from Owens Lake in eastern California provide evidence for a series of climatic oscillations late in the last glaciation. Juniper woo dland, which dominated the Owens Valley from 16,200 to 15,500 cal yr B.P., suggests much wetter conditions than today. Although still wetter and coole r than today, the area then became fairly warm and dry, with woodland being replaced by shrubs (mainly sagebrush) from 15,500 to 13,100 cal yr B.P. Ne xt, Chenopodiaceae (shadscale) increased, woody species declined, and lake levels fell-all evidence for a brief(ca. 100-200 yr) drought about 13,000 c al yr B.P. The climate continued to oscillate between wet and dry from 13,0 00 to 11,000 cal yr B.P. After 11,000 cal yr B.P., low lake levels and the increased dominance of desert shrubs indicate the beginning of warm, dry Ho locene conditions. The region's climate was unstable during the Younger Dry as but uncertainities in dating prevent identification of the Younger Dryas interval in the Owens Lake record. Comparison of the Owens Lake record wit h studies in the Sierra Nevada and Great Basin suggest that the climate was generally wetter between 13,000 and 11,000 cal yr B.P., with warmer summer s, although no consistent pattern of climate change emerges. (C) 2001 Unive rsity of Washington.