Holocene Lake Sediments and Environmental Changes in Daihai

The Daihai Lake is located in the east margin of semiarid region and the north margin of East Asian summer monsoon. Being fragile in ecological environment system and sensitive to changes in climate and environment, it is an ideal location for environmental evolution study. Since Holocene, the frequent migration of climate zone boundaries due to climate change and intensity of monsoon has transferred this area into a climate-sensitive region. Based on characteristics like strong continuity of inland lake sediments, high resolution and climate-sensitive, this paper restored the environmental evolution process since Holocene, by using single water chemical weathering record. Moreover, the process is discussed in details according to the granular changes of core sediments, pollen sources and distribution, organic carbon and its isotopic index sequence analysis, as well as the deposition rate determinated by Pb-210 data. Finally, the major findings of Daihai Lake sediments and environmental evolution since Holocene were summarized on the basis of a comparison analysis with other researches from the perspectives of spatial scales and different time scales, and on the relationship study between climate proxy index and climatic factors.