不同生境和去趋势方法下的祁连圆柏径向生长对气候的响应

利用青海不同生境祁连圆柏树木年轮样本，采用3种不同去趋势方法建立树轮年表，结合青海30个气象站的气象资料，分析不同生境和去趋势方法下祁连圆柏径向生长对气候的响应差异。结果表明，祁连山区，生长季前期的平均气温是祁连圆柏树木径向生长的主要限制性因子，NEP树轮标准化宽度年表与生长季前期冬季平均气温相关最好；在柴达木盆地，生长季降水量是该地区树木径向生长的限制性因子，SPL树轮年表对生长季降水量相关较好；在青南高原，祁连圆柏径向生长对春季温度响应最为敏感，而SPL年表与春季温度呈现明显的负相关关系，相关系数达-0.606；而在青海东部地区，祁连圆柏树木径向生长对气候的响应总体不显著。位于青海西部和北部的柴达木盆地和祁连山区祁连圆柏径向生长受西风气候的影响显著，尤其是柴达木盆地，其气候受西风主导；而青南高原受西南季风影响更为显著，该地区祁连圆柏径向生长同时受西南季风气候和海拔高度两方面影响；在青海东部，祁连圆柏径向生长受东亚季风影响更为显著。

Responses of Qilian junipers radial growth of different ecological environment and detrending method to climate change in Qinghai Province

In this paper, more Qilian juniper (Sabina przewalskii Kom.) tree ring samples in 12 sites from different ecological environment in Qinghai Province are collected, and the 12 tree ring chronologies are developed using three different detrending methods, contain spline function detrending method(SPL), negative exponential fitting detrending method(NEP) and regional curve detrending method(RCS). Combined temperature and precipitation data from 30 Meteorological stations in Qinghai, the Qilian juniper radial growth responses to climate in the different ecological environment and detrending method were analyzed using correlation function and the response function method. The results showed that the average temperature before trees growing season is a major limiting factor on Qinlian Mountains, and there have a good correlation between the NEP tree-ring width chronologies and the average temperature in last winter. In the Qaidam Basin, The precipitation in growing season is the limiting factor for tree radial growth, there have a better correlation between the SPL tree-ring width chronologies and the precipitation. On the southern Qinghai, the Qilian juniper radial growth response to average temperature in May, there is most sensitive, while the SPL tree-ring width chronologies and temperature in May showed a significant negative correlation, and the correlation coefficient exceed -0.606. In the eastern region of Qinghai, Qilian juniper tree radial growth response to climate generally not sensitive. There have a good correlation between Qilian juniper radial growth and North Atlantic Oscillation Index(NAO)/Arctic Oscillation Index (AO) in Qaidam Basin, and there also have some relationship on Qilian Mountains. There have a good correlation between Qilian juniper radial growth and India-Burma trough Index(IBT) on southern Qinghai Plateau, and tree-ring chronologies correlates better with the Pacific Decadal Oscillation(PDO) in the eastern region of Qinghai. The results showed that the tree-ring chronologies significantly affected by the westerly climate in Qaidam Basin and Qilian Mountains, and the Indian monsoon dominate to Qilian juniper radial growth on southern Qinghai Plateau. In the eastern Qinghai, Qilian juniper radial growth affected by the East Asian monsoon.