关键词: 天山北坡西部, 树木年轮, 年最低气温, 响应, 气温重建

Abstract:

The Boertala Mongolia Autonomous Prefecture is located on the western Tianshan Mountains' north slope, belonging to the semi-arid area of Northwest China. Three tree-ring increment cores of Picea schrenkiana Var tiansclhanica were sampled from the upper tree lines in Boertala. Three standardized chronologies were developed by using a 100-year Spline Function. Single correlation analyzing result indicated that the relations were significant among the three tree-ring width chronologies and climate factors; the greatest coefficient (R=0.512) is relation with annual minimum temperature, and that with precipitation in July is 0.456, their significance are all greater than the 99.9 percent level. Response analysis proved the same correlation between tree-ring chronologies and annual minimum temperature and precipitation in July. On the basis of the three standardized chronologies the series of annual minimum temperature in Boertala from 1576 to 2002 was reconstructed. Considering the hysteresis of tree growth against temperature, a average annual minimum temperature series was well reconstructed and its explain variance was 60.7%. Tested by the Leave-One-Out Method it was verified that the reconstructed temperature series was reliable. The temperature change in the 427 years showed obvious vibration periods of 2~3 years and 40~50 years, and has experienced abrupt change in 1631,1832,1920,1961.

Key words: west of Tianshan Mountains north slope, tree-ring chronology, minimum temperature, response relationship, temperature reconstruction