关键词：兴安落叶松；径向生长；NDVI；气候变暖；大兴安岭；快速升温期；升温间歇期 中图分类号：S716.3 文献标识码：A DOI： 10.7525/j.issn.1006-8023.2025.04.003

Abstract：Theforestcanopyfixes carbon dioxidein theatmosphere through photosynthesis，andthetre trunk uses the organic matter generated by thecanopy forcambium spliting and thickening.Whether the assmilation of tree canopy andtheradial growthof tree trunk changedsynchronouslyintheprocessof climatechange iscontroversial，and whether the synchronous ordiferential changes arerelatedtotheresponsecharacteristics ofthese two processes to climate factors isalsoahottopicofattention.Inparticular，thesametreespeciesindiffrentclimaticbackgroundisstilltobestudied. Larix gmelini as themain coniferous forest species incold temperate zoneof China，issensitive toclimate change. Therefore，this paper selected Greater Hinggan Mountains from south to north in the Arshan （AES），Kudur（KDE）and Daebaeksan（DBS）as the research objects.Normalized diference vegetation index（NDVI）and ring width index （RWI）wereused to represent the growthof tree canopy and trunk，respectively.Segmentation function and correlation analysis were used.Therelationship between treecanopyand trunk growth and thediferences indriving factors under diferent climate backgrounds were investigated.The mainresultswereas folows：therapid warming period significantly promoted the growth of tree canopy，mainly reflected in the early growing season （EGS）and the late growing season （LGS）.However，organic mater produced by photosynthesis may be more used forcanopyrespiration，thus inhibiting theradial growth oftres，resulting inan insignificantrelationship between tre trunk andcanopy growth during this period.Withthe slowing downof the temperature riserate，the growthoftree canopy was mainlyreflected inthe midleof the growing season（MGS）and the endof the growing season（LGS），and the relationship between treetrunk and canopy growth showed significant correlation（ Plt;0. 05 ）.The global temperature rise rate leads to the diference in response of foresttrunk and canopygrowth toclimate factors，which may be the rootcauseof the inconsistent relationship between tree trunk and canopy growth.Theaccelerationof global temperature rise increases the diffrence between trunk and canopy growth in response to climate，and on the contrary，greatly reduces the diffrence between the two.

Keywords： Larix gmelinii；radial growth；NDVI；climate warming；Greater Hinggan Mountains；rapid warming period；intermittent warming period

0 引言

在全球气候变暖的背景下，森林动态变化及其对气候的响应均对全球碳循环产生了重要的影响1。近年来，全球平均低温上升了约 1.5^∘C^[2] ，世界迅速变暖，特别是在北半球高纬度地区，包括中国东北地区[3]，这种升温自20世纪80年代以来尤其明显[4-5]，于20世纪末期出现停滞[6-7]。全球变暖影响了森林生态系统的结构与功能，以及树木的生长、开花和结果等[8]。树木个体也可以通过改变其结构和功能来适应气候变化，森林生长受到了气候变暖和干旱的胁迫[10-11]，北方针叶林已经出现了生长下降[12]，加剧了水分胁迫对树木造成的危害。但是，也有相关研究表明气候变暖促进了森林的生长，主要表现为二氧化碳含量升高、光合速率提高和生长季延长等[13-14]。因此，了解树木生长对气候变暖的响应对评估全球森林生态系统具有重要意义。

树木年轮宽度指数（ringwidthindex，RWI）和归一化植被指数（normalized differencevegetation，NDVI）都是研究森林生态系统及其对气候变化响应常用的有效指标。树木年轮记录了大量关于树木生长、物种行为等信息[15-16]，并且对研究森林生长及其与气候的关系具有重要价值[17]。NDVI与植被生长状况、光合作用、覆盖率以及叶面积指数有着密切的关系[18-19]，该指标能够有效地估算植被净初级生产力[20]。然而，树木年轮宽度指数只能代表局部地区森林植被生长状况，要想研究更大区域内森林植被的生长状况费时费力[21]，而NDVI时间序列较短，不适合做长期气候背景下森林生态系统的变化研究[17]。……