| Qinghai Lake locates at the western side of Gaoligong Mountain in TengchongCounty, Which is influenced by southwest monsoon directly in Summar. And, it couldbe sensitive to record the information on shifts in southwest monsoon andenvironment. In order to understand the dynamic process of paleoenvironment andpaleoclimate in this area, a high resolution sediment core record was systematicallystudied by using the14C method, grain size, total organic carbon content, magneticsusceptibility, pollen analysis, and so on. The results show that:(1)The paleoenvironmental history since the late glacial epoch around theQinghai Lake is reconstructed. And it could be divisible into four stages: From15.68cal.kaBP to12.39cal. kaBP, a broadleaved deciduous forest occupied the landscape,and mixed some conifer tree species. The climate was cool and moderately dry. From12.29cal.kaBP to4.73cal.kaBP, the vegetation changed to a mixed deciduous andevergreen broadleaved forest, and the climate was warm and moist. The vegetationchanged to an Alnus-dominated forest from4.73cal.kaBP to0.37cal.kaBP, and theclimate became dry gradually in this stage. It was that human activities havenoteworthy affected the vegetation’s components since0.37cal.kaBP, and the climatewas cool and dry.(2)The multi-proxy records also reveal that there were several climate abruptevents in Qinghai Lake. From15.68cal.kaBP to12.39cal.kaBP, the area witnesseddry-wet oscillations which responded to B lling-Aller d interstadial and YoungerDryas clod event. And there several obviously intervals of hundreds-scale in Holocene,such as7.88-7.43cal.kaBP,5.46-5.24cal.kaBP、3.13-3.05cal.kaBP and1.4-1.00cal.kaBP.In conclusion, these results indicate that the climatic variation in Qinghai Lake,Tengchong County is probably mainly driven by solar activity, and also influenced by North Atlantic climate and sea surface temperature. |
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