关键词: 新疆天山西部, 云杉树轮宽度, 不同采点, 不同去趋势方法, 气候信号

Abstract:

Based on the tree-ring width data of spruce from the upper tree lines on northern slope of western Tianshan Mountains in Yili and Bozhou region of Xinjiang, the tree-ring width chronologies were developed by using the three different detrending methods, i.e. regional curves, negative exponential curves (no positive slope) and 300-year fixed splines. Analyses on the effect of different sampling sites and different detrending methods on correlation between tree-ring width chronologies in different frequency domains and their climate signals showed: ①Distance between two sampling sites and whether chronologies are in the same climate area are import factors that influence the correlation between two tree-ring width chronologies. There are better similarity in the higher frequency domain and greater different in the lower frequency in the changes of tree-ring width at the three different sampling sites, which implies that the tree-ring width chronologies maybe possess large potential in application for disclosing and reconstructing the climate change of higher frequency domain on large scale. ②The tree ring width chronologies developed from Negative Exponent and Spline Detrending methods are similar, but that developed from Regional Curve Detrending Method can remain more information of tree ring width change on lower frequency domain. ③Precipitation is the first limiting factor that influences the tree ring width growth of spruce on upper tree line in the western Tianshan Mountains and the effect has obvious hysteresis. ④Regional curve detrending method can keep more moisture information in the tree ring width chronology of spruce on upper tree line in the western Tianshan Mountains of Xingjiang.

Key words: western Tianshan Mountains of Xinjiang, tree-ring width chronology of spruce, sampling site, detrending method, climate signal