太白山芳香寺剖面孢粉记录的古气候重建

PALAEOCLIMATIC RECONSTRUCTION OF SPOROPOLLON RECORDED IN FANGXIANGSI PROFILE, TAIBAISHAN MOUNTAIN

本文利用秦岭太白山表土孢粉建立的孢粉 -气候模型 ,对芳香寺剖面孢粉数据进行了气候重建 ,取得了近千年的气候序列 (包括年均温、 1月均温、 7月均温及年降水量 )。认为小冰期开始于 1 2 0 0aAD ,结束于 1 92 0aAD ,其中冰盛期为1 3 50aAD～ 1 70 0aAD。这与史料、古湖泊、树轮、冰川研究的结果基本相近。本区的气候变化与太白山南坡佛爷池地区气候的变化基本一致。由于本区位置较低 ,且位于北坡 ,所以气温数值较高 ,波动幅度大 ,降温幅值较大及年降水量稍大。本区升温时年较差增大 ,降温时相反 ,标志着 7月均温对气候变化极为敏感 ,从而显示夏季风的兴衰不容忽视。

In this paper climatic reconstruction of sporopollen data from Fangxiangsi profile was studied,through the sporopollen-climatic model created by sporopollen from surface soil in Taibaishan,Qinling Mountains.Furthermore,the climatic sequence of past one thousand years was obtained (including annual mean temperature,January mean temperature,July mean temperature and annual precipitaion).The results show that the small ice age started at 1200a AD and ended at 1920a AD,in which the grand ice age was 1350～1700a AD,coincided with results of historical data,ancient lakes,tree rings and glaciers.The climatic changes of study area are closed to Foyechi area located in south slope of Taibaishan Mountain.Because the heigth above sea level of Fangxiangsi located at the north slope of Taibaishan Mountain,is lower than Foyechi's,the value,fluctuate range and dropping range of air temperature in Fangxiangsi area turn higher,and annual precipitation is a little greater.When the value of air temperature turns higher,the annual range turns higher;however it turns lower,the opposition.This indicated that July mean temperature is sensitive for climatic changes,showing that the rise and decline of summer monsoon can't be ignored.