秦岭南坡佛坪1789年以来1～4月平均温度重建

RECONSTRUCTION OF JANUARY TO APRIL MEAN TEMPERATURE AT QINLING MTS FROM 1789 TO 1992 USING TREE RING CHRONOLOGIES

采用秦岭南坡陕西佛坪龙草坪、光头山、三个包及三官庙建立的秦岭冷杉、油松和铁杉树轮宽度、密度年表 ,分析树木生长对气候要素变化的响应关系 ,重建了佛坪 1 789年以来 1～ 4月平均温度变化 ,并对其进行了变化特征分析。结果表明 ,各样点的树木生长明显受生长季前期温度影响 ,呈较为显著的正相关关系。利用多个样点的年表并引入主分量分析方法建立回归方程 ,显著地提高了回归方程的稳定性和显著性 ,进而提高了重建结果的可信度。功率谱分析结果表明 ,佛坪 1～ 4月平均温度变化具有显著的 3～ 4年周期。而滑动t检验、滑动F检验和Lepage检验结果表明 ,1 8世纪后期以来于 1 896年前后发生了 1 0年时间尺度的方差突变 ,表现为温度波动幅度的变化。

The mean temperature of January to April was reconstructed for the period of 1789 to 1992 using standard tree ring chronologies of Foping, Qinling, Shaanxi Province. The growth of Pinus tabulaeformis Carr., Abies chensiensis Van Tieghem and Tsuga chinensis Beisen at Muwangping, Guangtoushan, Sangebao and Sanguanmiao, whose altitudes are from 1500 to 2850 meters (a.s.l.), is significantly affected by the local January to April mean temperature. The correlation coefficient between the temperature series reconstructed by the regression and the observation data is up to 0.60, with an equation confidence level of 0.01 and highly significant cross verification testing parameters. A period of three to four years is found significant in the reconstructed series by the power spectrum method. The abrupt changes of standard deviation, in ten years scale, are detected around 1896 by means of the smoothing t Test, smoothing F Test and Lepage Test, apparing as the amplitude variation of temperature fluctuation.