伊犁山区雪岭云杉(Picea schrenkiana)不同树干高度树木径向生长特征及其对气候响应

采集新疆伊犁地区雪岭云杉（Picea schrenkiana）1.3 m、5 m、10 m、15 m、20 m和25 m树干高度树轮样本并研制其树轮宽度年表。通过相关分析得出不同树干高度树木径向生长对气候要素的响应关系及其稳定性,并计算出不同气象因子的相对贡献率和绝对贡献率。结果表明：（1） 不同树干高度具有相似的径向生长变化特征,且平均气温和降水量的影响主要表现为各树干高度树轮宽度与当年9月降水量的显著负相关,与上年11月平均气温的显著正相关,并且5 m至25 m树干高度处还受当年7月降水量的影响。（2） 通过贡献率量化各树干高度气象因子影响情况,1.3 m和5 m树干高度的主要影响因子是平均气温,而10 m、15 m、20 m和25 m树干高度的主要影响因子则是降水量。（3） 滑动相关分析得到各树干高度对气候变化响应的稳定性存在差异,主要表现为各树干高度处与上年12月平均气温相关性减弱,与当年6月平均气温相关性先增强后减弱,与上年9月平均气温负相关性增强;1.3 m至15 m树干高度与当年9月降水量负相关性增强,10 m至25 m树干高度与当年1月降水量相关性减弱。通过分析不同树干高度树木径向生长与气候要素的关系,有助于了解各树干高度树木径向生长与气候响应的差异,为开展更精确的气候重建提供参考。

Characteristics of radial growth at different trunk heights of Picea schrenkiana and its climate response in the mountainous area of the Ili Region

To analyze the radial growth characteristics at different trunk heights of Picea schrenkiana and the influence of meteorological elements on radial growth at each trunk height and the stability to combat climate change, we collected tree ring samples from different trunk heights (1.3 m, 5 m, 10 m, 15 m, 20 m, and 25 m) of Picea schrenkiana and examined the development of tree ring width chronologies in Ili Region, Xinjiang. Based on the correlation analysis, we conclude that the response relationship of radial growth at different trunk heights and its stability. Then, we computed the relative and absolute contribution rates of meteorological elements. The findings show the following. (1) The radial growth patterns are similar at different trunk heights, and it is jointly influenced by temperature and precipitation. All tree trunk heights had a significantly positive correlation with the September precipitation of the current year and the November temperature of the previous year. Simultaneously, the tree trunk height of 5-25 m had a significantly positive correlation with July precipitation of the current year. (2) Quantification of the meteorological elements’ influence on each tree trunk height through contribution rate shows that temperature is the primary element for tree trunk heights of 1.3 m and 5 m, and precipitation is the primary element for tree trunk heights of 10 m, 15 m, 20 m, and 25 m. (3) Moving average analysis showed a variation between the stable response to climate change at each tree trunk height, predominantly expressing that the correlation with the December temperature of the previous year was attenuated at each tree trunk height. The correlation with the June temperature of the current year was enhanced first and then attenuated. The negative correlation with the September temperature of the previous year was enhanced and that with September precipitation of the current year was also enhanced at tree trunk heights of 1.3 m, 5 m, 10 m, and 15 m. Furthermore, the correlation with January precipitation was attenuated at tree trunk heights of 10 m, 15 m, 20 m, and 25 m. By analyzing the relationship between radial growth and climate factors at different trunk heights, it is helpful to understand the difference between radial growth and climate response of trees at different trunk height, which provide reference for more accurate climate reconstruction.