阿尔泰山主要针叶树种树木径向生长及其对气候变化的响应

Radial growth of dominant coniferous species and their responses to climate changes in the Altay Mountains,China

本研究以阿尔泰山富蕴地区的西伯利亚云杉和西伯利亚落叶松为对象,获取2个树种基部断面生长增量和树轮宽度年表与气候因子的相关系数,对比分析了相似生境下2个树种的径向生长特征及其对气候变化的响应。结果表明:西伯利亚云杉基部断面生长增量总体高于西伯利亚落叶松,但西伯利亚落叶松的径向生长增加趋势更为显著。近60年来,上年快速生长期的高温对研究区内西伯利亚云杉的径向生长有限制作用,而当年6月较高的气温则有利于西伯利亚落叶松生长。西伯利亚落叶松的径向生长与当年1月气温呈负相关。分段相关分析显示,这种情况在1980年代中期气候变暖以后表现得更为明显。滑动相关分析表明,在气候变化背景下研究区内西伯利亚云杉和西伯利亚落叶松径向生长对气温和降水量的响应在近年来均有所增强。

Based on the standard method of dendrochronology,we examined the tree-ring width index of two dominant tree species in the Altay Mountains,China,including Picea obovata and Larix sibirica.We analyzed the basal area increments(BAI)of those two species and the relationships between their radial growth and the climatic factors,which were compared in similar habitats.The results showed that the BAI of P.obovata was greater than L.sibirica,but the radial growth rate of L.sibirica was greater.In recent 60 years,the radial growth of P.obovata negatively correlated with high temperature in the fast growing stage of previous year,while the high temperature in June of current year promoted the radial growth of L.sibirica.There was a significantly negative correlation between radial growth of L.sibirica with temperature in January of current year.The sensitivity of tree growth to climate showed an obvious increase after an abrupt climate change under the background of recent warming and wetting trend in mid-1980 s.Results of the moving correlation analysis showed that the response of the radial growth of P.obovata and L.sibirica to temperature and precipitation were enhanced under the background of climate change in the study area.