Abstract
A 2,500-year vegetation history was reconstructed by analyzing phytolith assemblages in sediments from Paitan Lake located in the Central Plain of Luzon, the Philippines. Five local zones of phytolith assemblage were established for the sediment sequence analyzed. Cogon (Imperata) dominated in Zone 5 (ca. 2,460–1,410 cal. yr BP), cogon and other Gramineae grasses and coniferous trees dominated in Zone 4 (ca. 1,410–1,240 cal. yr BP), non-cogon Gramineae grasses and trees dominated in Zone 3 (ca. 1,240–1,150 cal. yr BP), cogon and other Gramineae grasses and trees dominated in Zone 2 (ca. 1,150–350 cal. yr BP), and Oryza sativa (rice) increased while trees disappeared in Zone 1 (ca. 350–0 cal. yr BP). The results of this study indicate that trees were included in the component species of the vegetation at least until ca. 350 years ago, and that woodlands were replaced with rice fields and Gramineae grasslands. The development of cogon grasslands in Zone 5 may have been due to drier climatic conditions.
