天山北坡东部地区树轮宽度年表特征分析

Analysis of Tree-ring Width Chronology Characteristics from Eastern Area on North Slope of Tianshan Mountains

通过对天山北坡东部地区8个树轮宽度标准化年表的有关参数的对比，证明苏巴什沟与白杨河沟年表包含有较多的气候信息，8个树轮宽度标准化年表的互相关系数平均值达0．530，其中白杨河沟与苏巴什沟年表的相关系数高达0．725。说明所采样本对该区域的气候具有较好的代表性。再将8个树轮宽度标准化年表与附近的奇台县、木垒县两个气象站1961—2007年逐月降水和平均最低气温，及单月降水和单月气温进行相关分析。结果表明，天山东部地区白杨河沟的树轮宽度生长与上年7月至当年6月的降水呈正相关，其相关系数为0．597，显著性水平达0．000006，与当年6月平均最低气温呈负相关，相关系数为-0．437，显著性水平达0．001，上述均具有明确的树木生理学意义。研究还发现，在0．05显著性水平上，8个年表的树轮宽度指数变化以2～3a的变化准周期最为多见，苏巴什沟、大东沟及白杨河沟年表以11a准周期多见。就整个地区而言，天山北坡东部地区8个年表中低频气候信息一般多于高频气候信息。

Comparison of some parameters of the eight tree-ring standardized chronologies from eastern Tianshan Mountains area indicated that the Subashigou and Baiyanghegou tree-ring standardized chronologies have recorded more climatic information. The mean value of correlation coefficients between the eight tree- ring standardized chronologies is 0. 530, and the highest （0. 725） is between Subashigou and Baiyanghegou. The correlation between tree-ring width index and monthly precipitation, mean lowest temperature, and in- dividual monthly precipitation and temperature of Qitai and Mulei stations showed that there is positive cor- relation between Baiyanghegou tree-ring width chronology and precipitation from last July to current June （ R = 0.597, Sig. level= 0.000006）, and a negative correlation between Baiyanghegou tree-ring width chro- nology and mean lowest temperature of current June （R = -0. 437, Sig. level=0. 001）. At 0.05 significant level, the periods of 2 to 3 years is the most common in the eight tree-ring width chronologies, the periods of 11 years is clear in chronologies of Subashigou, Dadonggou and Baiyanghegou. Generally, the low fre- quency information is more than the high frequency information in the eight tree-ring standardized chronolo- gies from eastern Tianshan Mountains area.