气候变暖背景下云南西北部大果红杉径向生长衰退及其气候驱动因子分析

气候变化背景下森林生态系统的内部结构和功能发生转变，并减弱了其固碳能力，评估与预测森林生态系统对气候变化响应势在必行。基于采自云南西北部的大果红杉树木年轮样本，建立树轮宽度标准化年表，运用相关分析、空间相关、波谱分析等方法，探讨了滇西北大果红杉径向生长的主控因子及其对气候变化的响应。结果表明：(1)温度是限制滇西北大果红杉树轮径向生长的主要因素，季节性高低温变化交替影响大果红杉树轮径向生长。(2)相对湿度变化与滇西北大果红杉树轮的径向生长紧密关联，对滇西北大果红杉树轮的径向生长起促进作用。(3)波谱分析结果显示滇西北大果红杉径向生长呈周期性变化，受ENSO等外强迫影响显著。(4)气候变暖背景下，滇西北大果红杉的径向生长出现衰退趋势。研究结果为加强云南西北部天然林保护和构建西南绿色生态屏障提供了基础性资料。

The decline in radial growth of Larix potaninii in Northwestern Yunnan and its driving factors under the background of climate warming

Due to the change of carbon sequestration capacity and internal structure and function of forest ecosystems under global warming, it is imperative to assess and predict the response of forest ecosystems to climate change. Based on tree-ring samples collected from Northwestern Yunnan, some tree-ring width chronologies were developed. The main limiting factors of radial growth and the temporal stability of the tree growth response to climate change were analyzed by correlation analysis, spatial correlation, and spectral analysis. The results showed that (1) Temperature was the main factor limiting the radial growth of Larix potaninii in Northwestern Yunnan, and seasonal high and low temperatures alternately affected the radial growth of the Larix potaninii. (2) The relative humidity was closely positively related to the radial growth of Larix potaninii in Northwestern Yunnan. (3) The results of spectral analysis showed that the radial growth of Larix potaninii in Northwestern Yunnan periodically changed and was significantly affected by ENSO and other external forcing. (4) Under the background of climate warming, the growth of Larix potaninii in Northwestern Yunnan presented a decline trend. It provides a scientific decision basis for us to strengthen the protection of natural forest and construct green ecological barrier in Northwestern Yunnan.