| Abstract: |
A high-resolution pollen record derived from DG9603 core reveals vegetation and climate changes on the East China Sea Shelf (ECSS) during the past 30 000 years. From 29.8 to 26.6 cal ka BP, the ECSS was covered by warm temperate forest-steppe and wetland, indicating a relatively temperate and moist environment. During the period of 26.614.8 cal ka BP (including the Last Glacial Maximum), wetland and temperate forest-steppe developed around the ECSS. From 14.8 to 5.3 cal ka BP, sea-level continuously rose, and the ECSS was gradually submerged. In some exposed areas of the ECSS and lower reaches of the Yangtze River, northern subtropical forest (with plants of Quercus-evergreen, CastanopsisLithocarpus and Tsuga) developed instead of temperate forest-steppe and wetland. The pollen record shows that the rainfall and temperature increased continually during the period of 14.812.8 cal ka BP. At the end of this period, subtropical forest expanded and even reached the level of Holocene Optimum period (early-mid Holocene). IN the Younger Dryas period (12.811.1 cal ka BP), a rapid increase in the proportion of arboreal taxa especially Quercus-deciduous tree, and a slight decrease in Quercus-evergreen, Tsuga and herbs component indicates a mild climate with higher precipitation. From 11.1 to 5.3 cal ka BP, the northern subtropical forest was widely distributed around the ECSS region, suggesting a relative warm and humid condition in the early Holocene. The subtropical forest component declined slightly and herbaceous taxa increased, reflecting a relatively drier and cooler climate during the period of 9.07.0 cal ka BP. In the past 5.3 cal ka BP, forest vegetation in the lower reaches of the Yangtze River was deforested severely, possibly caused by human activity.
|
