干旱区生态环境知识资源中心

Two key-periods, the Last Glacial Maximum (LGM) and the Holocene Optimum represent respectively the coldest and warmest episodes that were testified in China by a great number of paleoenvironment evidences. At the LGM, the climate was colder and drier with the mean annual temperature 7-10 degrees C lower than today in the North and 4-6 degrees C in the South. The multidisciplinary data are consistent with global changes, such as the depression of snowline, southward advancing of permafrost limit, expansion of loess deposition, lowering of the lake level, invasion to the eastern China of desertic vegetation, displacement to the South of zonal vegetation, many discoveries in temperate climate zone of the northern cold mammals, and the remarkable sea regression resulting in the Eastward shift of the Chinese coastal line. The data of Holocene recognized a warm period (ca. 9,000-6,000 yr BP) that the temperature estimates were generally 2-4 degrees C higher than nowadays. The rise of sea level resulted in great changes of the coastal environment in eastern China. Doe to the warm climate, glaciers largely retreated and even disappeared in the eastern part. The permafrost was located to the North of the current limit. Desert and loess greatly reduced and the highest lake level was found mostly during 9,000-5,000 yr BP. The boreal conifers were to the north of the present locations, and many steppe areas were covered with forested formations. The above past climate and ecological pattern of the key-periods in China helps to better understand the future changes and their results.