Late Holocene plants, Catavina, Baja California

Thirty-six plant taxa were identified from macrofossils and pollen in a lat e Holocene (1,770 years B.P.) woodrat (Neotoma) midden from a granite bould er field near Catavina, Baja California, Mexico. The fossils document the p resence of Sonoran Desert (Viscaino subdivision) vegetation and a relativel y modern climatic regime in the late Holocene. However, abundances and dist ributions of plants were different from today. Excluding rare Pinus pollen (long distance transport), only about 51% of the midden plants still occur within 100 m of the site. Another 8 species have moved into the area. Appar ently, greater moisture allowed soil development on boulders and the expans ion of plants, especially Prosopis glandulosa, away from the mesic washes. The modern climate is drier than 1,770 years ago.