College of Geography and Environment Science, Northwest Normal University, No.967, Anning East Road, Lanzhou, 730070, China.
State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, No.19, Xinjiekouwai Street, Haidian District, Beijing, 100875, China.
Int J Biometeorol. 2020 Dec;64(12):2127-2139. doi: 10.1007/s00484-020-02003-x. Epub 2020 Sep 5.
The increasing frequency and intensity of extreme climate events have caused serious impacts on the service functions of terrestrial ecosystems and the production and life of human society in recent years. The warm nights (TN90p) variable of the 26 extreme climate indicators was the main factor controlling the tree radial growth of Schrenk spruce (Picea schrenkiana) in the Tianshan Mountains region based on the responses of tree-ring width in the 5 sample sites. Therefore, TN90p in the growth season from May to September (TN90p) during 1735-2016 was reconstructed on the basis of the time stability of the growth-climate relationships. The interpretation rate of variance of the reconstructed equation was 45.4% (R = 44.4%, F = 45.7). The reconstruction showed four relatively high TN90p historic intervals (1747-1798, 1856-1872, 1906-1951, and 2002-2016) and four low intervals (1735-1747, 1798-1856, 1872-1900, and 1951-2002). The occurrence frequency of extreme high values was higher than that of extreme low values during the reconstruction period of 1735-2016. The extreme values of reconstruction were consistent with historical droughts and large-scale volcanic eruptions, indicating that the reconstruction series had high accuracy. Multi-window spectral periodic analysis and spatial correlation analysis revealed that TN90p variation in the study area was affected by large-scale sea-air stress factors. In particular, the TN90p obtained by using R/S analysis (rescaled range analysis) will continue to show an upward trend in the relative period of time in the future. This trend will lead to a further decrease in the radial growth of trees and even trigger forest death events.
近年来，极端气候事件的发生频率和强度不断增加，对陆地生态系统的服务功能以及人类社会的生产和生活造成了严重影响。基于 5 个样点树木年轮宽度的响应，26 个极端气候指标中的暖夜（TN90p）变量是控制天山地区云杉径向生长的主要因素。因此，基于生长-气候关系的时间稳定性，重建了 1735-2016 年生长季 5 月至 9 月的 TN90p（TN90p）。重建方程的方差解释率为 45.4%（R=44.4%，F=45.7%）。重建结果显示了四个相对较高的 TN90p 历史区间（1747-1798、1856-1872、1906-1951 和 2002-2016）和四个较低的区间（1735-1747、1798-1856、1872-1900 和 1951-2002）。在 1735-2016 年的重建期间，极端高值的出现频率高于极端低值。重建的极值与历史干旱和大规模火山爆发一致，表明重建序列具有较高的精度。多窗口谱周期分析和空间相关分析表明，研究区 TN90p 的变化受大规模海气应力因素的影响。特别是，使用 R/S 分析（重标极差分析）获得的 TN90p 在未来的相对时间内将继续呈现上升趋势。这种趋势将导致树木的径向生长进一步下降，甚至引发森林死亡事件。
