气候变暖对西北山地树轮温度敏感性的影响及其机制分析

西北山地是树轮气候重建和全球变化响应研究的重要区域。本项目以西北山地森林主要树种为对象，基于树轮气候学和稳定碳同位素方法，使用滑动相关分析、响应函数分析、主成分分析等手段，研究升温突变前后主要树种树轮温度敏感性的变化；系统分析树种、树龄和年表类型等非环境因素和位点、温度变化、降水变化、干旱指数变化等环境因素对树轮温度敏感性的影响；揭示干旱诱导的气孔关闭是否温度敏感性下降或反转的原因，深入分析西北山地树轮温度敏感性变化的发生机制。本项目有助于促进西北山地树木生长对气候变化的响应和适应研究，并对区域树轮气候重建和生产力预测提供指导。

The mountains in northwestern China are the perfect places to reconstruct past climate using tree-ring and to study the response of terrestrial ecosystem to global change. By measuring δ13C and based on dendroclimatology methods such as moving correlation analysis, response function analysis and principal component analysis, temperature sensitivity of tree-ring will be analyzed before and after abrupt warming in the mountains, northwestern China. Meanwhile, the influences of non-environmental factors such as tree species, age, chronological type, and environmental factors such as site condition, temperature, precipitation and drought index on temperature sensitivity will also be identified. The role of the drought stress to stomata closure and the formation mechanism of temperature sensitivity change will be in-depth analyzed. In summary, this project can promote the study on response and adaptability of tree growth to climate change in the mountains of northwestern China and provide the guidance for regional climate reconstruction and productivity simulation.