东北天然林针叶建群树种径向生长对区域气候响应的时空分异研究

上世纪60年代以来，北半球中高纬度气候暖干化地区广泛存在的"分异问题"对传统年轮气候学及森林气候演替模型的理论基础提出了挑战。这其中的关键问题是限制树木生长的某种或某几种气候因子超过了某一阈值，进而导致树木生长-气候关系的不稳定。然而，由于缺乏区域尺度上系统的树木年轮学研究，限制了对阈值问题的探究。本研究选择我国气候暖干化较为严重的东北地区为研究对象，利用年轮学方法，沿纬度梯度构建东北地主要天然针叶建群树种的年轮宽度数据库；分析各建群种径向生长的主要限制性气候因子，探讨其随纬度、海拔、坡向的空间变化规律及气候阈值，揭示建群种径向生长对区域气候响应稳定性及其形成机制；明晰东北地区建群种的区域气候响应特征，预测未来气候变化下森林群落类型和结构的变化趋势，为制定合理的气候变化应对措施，维护东北地区生态安全提供数据支持。

Diverenge Problems, which have been widely found in the area of the high latitude in the Northern Hemisphere since 1960s, challenged the basis of tradional denderchronology and climate-forest succession models. The key ploblem is that the limit climate factors exceeded the thesholds, and then caused the instability of relationship of tree radial growth and cliamte. However, lack of systemetic data of tree ring in the region of Northeast China restricted us to futher study. in this project, we will select Northeast China as research area, and chnorologically establish the tree ring width network data of dominated conifeous tree species in the natural forest; uncover the limit climatic factors in tree radial growth, and their variety along latitudinal, altitidinal and slope aspect gradients, and then explore the mechanism of stability in climate-radial growth; make clear that regional response characters of dominant coniferous species to climate change, predict forest structure change dynamic, provide the data support to decesion-maker for taking scientific measurements to deal with climate change, and protect ecological security of Northeast China.