天山中部北坡头屯河流域树轮宽度年表特征分析及其与气候要素的相关性初探

The Tree-ring Width Chronological Characteristics and Correlation Between Tree-ring Widths and Climatic Factors from Toutun River Basin on the North Slope of Mid-Tianshan Mountains

利用天山中部北坡头屯河流域8个天山云杉树轮采点的树轮样本,建立树轮宽度指数年表,并分析树轮标准化年表与气候的相关性。结果发现:(1)树轮年表统计特征指示庙尔沟煤矿与三屯河树轮宽度标准化年表可能包含有较多的气候信息;(2)森林上限年表互相关平均系数为最大,森林下部林缘年表互相关平均系数居中,森林上树线附近的小渠子年表与处于下树线附近的庙尔沟煤矿年表间的相关系数最小;(3)位于森林下部林缘年表的连续显著的正自相关系数的阶数少于森林上限的年表,反映该区域森林下部林缘树轮中的气候信息较为清晰,上限年表中的气候信息较为模糊;(4)温度是影响森林上限树轮宽度年表树轮生长的的主要气候限制因子,而降水则是影响森林下部林缘树轮宽度年表树轮生长的主要气候限制因子,区域森林下部林缘年表当年轮宽指数与小渠子气象站上年7月至当年6月的降水呈显著正相关,区域森林上限年表与大西沟气象站当年2—3月的月平均气温呈正相关,这些相关具有明确的树木生理学意义;(5)区域森林上限年表经历了9个轮宽指数偏高时段和9个偏低时段,偏高时段反映当年2—3月的气温偏高,反之指示当年2—3月的气温偏低;区域森林下部林缘年表大致有5个轮宽指数偏高时段和5个偏低时段,偏高时段指示上年7月至当年6月降水偏多,反之表征上年7月至当年的降水偏少。

Based on the tree-ring width data of spruce from 8 sampling place in Toutun River Basin on the North Slope of Mid-Tianshan Mountains,the correlation between tree-ring width chronologies and their climate signals were studied.The resultes showed that： （1）Miaoergou Mine and Santun River chronology contain more climatic information; （2）the correlation coefficient of chronologies was maximal in upper limit of the forest, second in the lower limit and minimal in Xiaoquzi and Miaoergou Mine;（3）the obviously positive autocorrelation coefficients of the upper limit of regional forest chronology is less than the lower limit ,which reflected that the climatic information contained in the chronologies of the lower limit of forest was clearer than that in the upper limit; （4） precipitation was the first limiting factor on the lower limit of regional forest chronology, and temperature was the first limiting factor on the upper limit of the forest chronology. There is positive correlation between the chronologies from lower limit of regional forest and precipitation from last July to current June, and between the chronologies from upper limit of regional forest and temperature from February to March of current year. This result has distinct physiological significance;（5）the chronologies from thelower limit of regional forest had 9 higher phase and 9 lower phase. Higher phase indicated that temperature was higher from February to March of current year, vice versa. The chronologies from lower limit of regional forest had 5 higher phase and 5 lower phase. Higher phase indicated that precipitation was more from last July to current June, but lower phase indicated that precipitation was less from last July to current June.