Pollen Records Of Vegetation,climate Changes And Human Activities During The Mid

Climate and environmental changes have changed human's way of life and have a profound impact on human activities,especially for the abrupt changes in the climate since the Holocene.The study of climate and environmental changes and its influence on human activities during the Holocene,providing reference and basis for prediciting the future environmental change,human social adaptation and other scientific issues.Ningshao plain is the coastal plain on the south bank of Hangzhou Bay which significantly affected by monsoon climate.Extreme weather and environmental events such as floods and storm surge occurred frequently in this area during the Holocene.The relationship between vegetation,environmental change and human activies in the middle-late Holcene of Ningshao plain was analyzed based on AMS14C?pollen sediments from JTS1501 in Jingtoushan area of Zhejiang province.The vegetation changes in this region are as follows:between the 7900?7700cal.a B.P.,vegetation is subtropical deciduous subtropical fallen and broad-leaved forest;During the 7700-7300cal.a B.R,the content of evergreen trees increased and the climate became warmer and wetter.From 7300 to 6300cal.a B.P.,the content of drought-living herbs increased,and the climate of this stage was cold and dry,and the vegetation type was subtropical broad-leaved forest.From 6300 to 6200cal.a B.P.,the content of Quercus(E)and Liquidambar increased,the climate was warm and wet,and the vegetation was mainly subtropical evergreen forest.From 6200 to 6000cal.a B.P.,vegetation is subtropical fallen and broad-leaved forest.From 6000cal.a B.P.to now,the main vegetation types are evergreen broad-leaved forest.During 7800-6500cal.a B.P.period,and the sea level was in an upward phase until about 6200cal.a B.P.,the sea level gradually stabilized.Human activities also affected the vegetation development in this region,from about 7900 to 7300cal.a B.P.,showing trace of human activities.About 7300?6800cal.a B.P.,human activity interference has an impact on trees and shrubs,human activities had interrupted during 6800?6200cal.a B.P.;From 6200 to 5800cal.a B.P.,the content of Poaceae has increased,and human activities gradually increased.