西南高山林区树木生长对气候响应的分异及其驱动机制

西南高山林区树木生长对气候响应的分异规律研究，对于该区树木生长及生产力模拟、区域碳循环和树轮气候重建都具有极其重要的意义。温度是影响高山林区树木生长的重要气候因子，但水分条件在其中可能也起着至关重要的作用。本研究以西南高山林区主要建群树种为对象，根据年均降水量设定区域环境梯度，基于树木年轮气候学方法，在建立量化响应分异特征指标体系的基础上，使用响应函数分析、主成分分析、冗余分析等方法，研究树木生长对气候响应的分异特征及其空间分布格局；分析树种、树龄和年表类型等非环境因素对响应分异的影响；揭示区域降水梯度和位点环境差异对响应分异的作用机制；利用纵向数据分析的固定效应和随机效应模型，全面分析西南高山林区响应分异的驱动机制，探讨响应分异现象成因。该研究可促进对响应分异现象的深入分析，为寒冷区域树木生长对气候变化的响应和适应性研究提供科学依据，并为区域森林生长模拟和气候重建提供指导。

It is critical to better understand the divergent tree growth responses to climate change for simulating tree growth, productivity change and regional carbon cycle and reconstructing past climate with tree rings in alpine areas, southwestern China. Temperature is an important climatic factor affecting tree growth in alpine areas, while moisture condition may also plays a crucial role. Under the average annual precipitation environmental gradients and based on dendrochronology methods, such as response function analysis, principal component analysis and redundancy analysis, divergent growth responses of the main tree species to climate change will be studied in alpine areas, southwestern China. Some indexes will be defined to quantify the divergence degree. Meanwhile, the influences of species, age, chronological type, and precipitation and site environmental conditions on tree growth divergence will also be identified. Finally, the comprehensive mechanism of divergent tree growth response to climate change will be investigated with the fixed and random effects model in Longitudinal Data Analysis, and the causes of divergence phenomenon will be discussed in alpine areas of southwestern China. In summary, this project can promote the in-depth analysis of divergence phenomenon, lay a scientific basis for exploring response and adaptability of tree growth to climate change in cold areas, and provide a guidance for regional forest growth simulation and climate reconstruction.