江西大岗山地区7-9月降水量的重建与分析

根据江西大岗山地区4个采样点的马尾松年轮样本，建立了本地区的综合年轮年表，分析了马尾松径向生长与气候因子变化的相关及响应关系，发现大岗山地区树木径向生长受生长季7—9月降水量影响较显著，呈负相关关系。在响应分析的基础上，首次重建了大岗山地区1892年以来7—9月的降水量，交叉检验表明重建序列是可靠的。重建结果表明，大岗山地区7—9月份降水变化在过去的117年中总体经历了3个偏干时期：1895—1902年，1908—1926年和1944—1985年，和3个偏湿阶段：1903—1907年，1927—1943年及1986—2008年。重建的降水量序列在1921年，1937年及1977年发生明显的方差突变，表明百年以来该地区降水量变化趋势存在阶段性变化。

Reconstruction and analysis of July-September precipitation in Mt.Dagangshan, China

Tree ring chronologies have been used as a very good replaced reference for the climate flux in the research. Many academicians have already studied the climate change in the dry area of west and north China by using tree rings. Only a few works have been done in tropical and subtropical regions due to relative low sensitivity there.There are many ecological researches in Dagangshan State Forest Ecosystem Research Station in Jiangxi Province, it's very important to rebuild the history climate for the study in this area. So we selected the area for the study object.According to tree-ring samples of Pinus massoniana from four sampling points in Dagang Mountain area, we have established a comprehensive tree-ring chronology in this region. The tree-ring width series were measured with LINTAN5 and its software TSAP (time series analysis presentations), and the measured tree-ring series were crossdated and quality-controlled with the software COFECHA. Using the ARSTAR software to get off the growing trend of trees, and then develop tree-ring width chronology. There are three different kinds of chronology were established, including standard chronology (STD), residual chronology (RES) and arstan chronology (ARS). Comparison of chronology statidtics among these chronologies indicates that STD contains more climatic signal.Statistical analysis of STD showed mean series inter-correlation of 0.52, mean sensitivity of 0.27, and signal-to-noise of 25.70. And the tree-ring chronology was fit for the dendroclimatologic study.After conducting an analysis to the related and response relationship between radial growth of Pinus massoniana and climate change-related factors, we found that the tree radial growth in Dagang Mountain area was significantly affected by the precipitation during the growing season from July to September, which showed a negative correlation.On the basis of response analysis, we have reconstructed the precipitation data which was proved to be reliable by the cross validation in July-September of every year since 1892 in Dagang Mountain area for the first time. The reconstructing results showed that the precipitation changes of July-September in past 117 years had been experienced generally 3 partial dry periods and 3 partial wet periods in Dagang Mountain area: 1895-1902, 1908-1926 and 1944-1985; 1903-1907, 1927-1943 and 1986-2008. In addition, the apparent mutation variance of the reconstructing precipitation sequence in 1921, 1977 and 1937, shows that there is a phase change existing in the precipitation change trend in the region for hundreds of years.