五大连池火山蒙古栎和紫椴径向生长对气候变化的响应

研究不同气候因子利用策略的蒙古栎和紫椴径向生长与气候变化的关系,进而为气候变暖后,该区域火山森林生态系统管理和利用提供基础数据。以蒙古栎和紫椴为研究对象,采用树木年代学方法分析了蒙古栎和紫椴径向生长对气候变化的响应,揭示蒙古栎和紫椴径向生长-气候的关系对气温突变的响应差异。结果表明:1)五大连池火山6-7月的月平均最高气温和干燥指数与蒙古栎和紫椴年轮指数均呈显著负相关(P<0.05),这表明同一区域树木生长-气候关系具有一定的相似性,也表明6-7月的月平均最高气温和干燥指数是该地区蒙古栎和紫椴径向生长的主要限制因子。2)蒙古栎和紫椴年轮指数在突变增温(1981年)前后与气候的响应关系呈现明显的变化,气温明显变暖后与气侯的响应更加敏感; 突变增温后,南北坡向蒙古栎和紫椴树木生长-气候响应差异显著,南坡蒙古栎径向生长的趋势与温度升高的趋势相同,而北坡紫椴径向生长则呈现出随着温度升高而降低的现象。升温造成的干旱胁迫可能是2树种生长响应差异及北坡紫椴出现生长对温度变化响应的“分离现象”的重要原因。如果未来增温趋势持续或者加重,紫椴的生长可能会因干旱胁迫加剧而衰退,蒙古栎生长增长的趋势快速下降或也出现生长对温度变化响应的“分离现象”。

Response of Radial Growth for Quercus mongolica and Tilia amurensis in Wudalianchi Volcano,China to Climate Changes

Quercus mongolica and Tilia amurensis are the main broad-leaved tree species occurring on the southern and northern slopes of Wudalianchi volcanoe.The study of the relationship between the radial growth of broad-leaved tree species with utilization strategies of different climatic factors and climate changes can provide basic data for the management and utilization of the volcanic forest ecosystem under climate warming.In this work,Q.mongolica and T.amurensis were used as research objects to analyze the response of radial growth to climate change using dendrochronology,to reveal the difference in response two species.The results showed that 1) the tree-ring width indexes of two species were significantly and negatively correlated with the monthly mean maximum temperature (MMMT) and dryness index during June to July (P<0.05),indicating that the tree growth-climate relationship in the same region had a certain similarity.Meanwhile,the MMMT and dryness index during June to July were the main limiting factors for the radial growth of the two species.2) The response between climate and tree-ring width indexes showed obvious changes before and after the abrupt warming (1981),and the response became more sensitive after significant warming.The growth-climate response on the southern and northern slopes varied significantly after the abrupt warming.The radial growth of Q.mongolica had a consistent trend with the increasing temperature on the southern slope,however,the radial growth of T.amurensis decreased with the increasing temperature on the northern slope.Drought stress caused by warming was likely to cause difference in the growth response of the two species.And the drought stress may be an important reason for the “separation phenomenon” of T.amurensis growth in response to temperature changes on the northern slope.The growth of T.amurensis may decline with increased drought stress if warming trends persist or worsen in the future.In addition,the growth trend of Q.mongolica will decline rapidly,or the growth of Q.mongolica will also show the “separation phenomenon” in response to temperature changes.