南京紫金山马尾松树轮δ13C对气候变化响应敏感性的研究

树木年轮宽度指标在气候重建中发挥了重要的作用，可是在温暖湿润的地区，利用树木年轮宽度重建古气候遇到了困难。因此寻找其他代用指标就成为一项急迫而重要的任务。一些研究发现，树轮稳定碳同位素可以发挥重要的作用。但是，是否所有的树种的树轮碳同位素对气候的响应都同样的敏感，还需要通过大量的研究分析工作来验证。为了了解温暖湿润的亚热带季风区马尾松树轮δ13C对气候响应的敏感性，选取了南京紫金山的两个马尾松树盘，进行了树轮δ13C的分析，建立了1939~2002和1955~2002年两个树轮δ13C变化序列。与降水、温度、相对湿度、光照时数、风速等气候指标进行了相关分析。结果表明：（1）马尾松树轮δ13C对于气候的响应是敏感的，可以作为气候变化的代用指标；（2）坡向对于马尾松树轮δ13C对气候的响应敏感性也有一定的影响，树轮δ13C平均值西南坡比东南坡高，西南坡比东南坡对月平均最低和最高温度的响应更敏感；（3）紫金山马尾松树轮δ13C与该地区生长季（尤其是夏、秋季）的月平均气温、月平均最高气温和日照时数呈正相关，而与月平均最低气温、降水量、空气相对湿度呈负相关

SENSITIVITY OF THE PINE TREE δ13C ON MT. ZIJIN AT NANJING TO CLIMATIC CHANGE

Tree ring width is sensitive to the changes of climate in the cold or arid regions and less sensitive in the humid and warm climatic regions.However,some studies show that the tree ring δ13C of some species of trees in the humid and warm subtropical region of China is sensitive to the climate changes.Whether the Pinus massoniana Lamb,as the widest distributed tree in the region,its δ13C is also sensitive to climate changes and to which climatic indicators,is still not clear.Two trees of Pinus massoniana Lamb on Mt.Zijin at Nanjing are selected and analyzed,in order to detect the sensitivity of its δ13C to climatic change.The relationship of the tree δ13C with the local temperature,precipitation,air humidity,and sunshine time,is analyzed.The results suggest that,the δ13C has closer correlation with the climatic indicators of the same year than that of the year before.The tree from the southwestern slop of the mountain has a higher value of δ13C,and the δ13C is better correlated with monthly mean lower or high temperature than from the southeastern slop.The pine tree δ13C is positively correlated with the monthly mean temperature,monthly mean high temperature and sunshine time,and negatively correlated with monthly mean lower temperature,precipitation,and air humidity.