This award supports collaborative research between teams of US and Chinese ecologists, geochemists, and palynologists on the study of sedimentary histories of selected lacustrine ecosystems of the Yunnan Plateau in southwest China. Cores collected from five Yunnan lakes will be studied to determine rates of ecosystem response to natural and anthropogenic stresses. Measurements will be made of changing rates of accumulation of aquatic and terrestrial, biological and chemical fossils between isotopically dated levels in lake sediments. This part of China is well known for its floristic similarity to the southeastern US. It is also one of the world's oldest centers of intensive agriculture. Through this cooperative project, it is hoped that our understanding of the environmental consequences of agricultural, industrial, and urban development will be improved.