云阳马尾松树轮宽度年表特征研究

Analysis of the Tree-ring Width Chronology of Pinus massoniana in Yunyang County

利用采自重庆市云阳县马尾松分布上限和下限的树轮样芯材料,分别建立了树轮宽度年表。结果表明:分布上限的马尾松树轮宽度指数变化幅度大于下限,且上限树轮样本的信噪比、样本总体代表性均比下限的高;总体来讲,上限树木的生长对环境的敏感性比下限的高。进一步分析表明:上限马尾松的生长受前一年气温和降水的影响,而下限马尾松的生长只与当年降水量有关,这表明云阳分布在上限的马尾松和分布在下限的马尾松生长与气候因子之间的关系不同;气候因子对分布在上限的马尾松生长的影响存在滞后效应。

Tree-ring cores were collected from the low and upper altitude limits of Pinus massoniana in Yunyang county of Chongqing. Two tree-ring width chronologies were established using standardized dendrochronological methods, respectively. The two sampling sites are located close to each other but at different elevations. Results indicated that the chronology fluctuation of the upper altitude limit was higher than that of the low limit. The statistical character of the chronology showed that signal to noise ratio （SNR.）, express population signal（EPS） of upper limit were high than that of the low limit. Therefore, the sensitivity of tree＇s response to climatic changes increased with increasing altitude. In order to understand the differing response of tress at different elevations to the environment changes , the correlations between the chronology indices and precipitation and between air temperature in different seasons and different months were calculated. The results showed that the growth of upper limit of Pinus massoniana was affected by temperature and precipitation of previous year, and that of low limit was only affected by precipitation of current year. It showed that there was lag-effect of the growth response to climate force of upper limit.