普达措国家公园2个针叶树种径向生长对温度和降水的响应

Response of radial growth of two conifers to temperature and precipitation in Potatso National Park,Southwest China

基于树轮年代学方法,利用普达措国家公园海拔上、下限丽江云杉(Picea likiangensis)和长苞冷杉(Abies georgei)树轮宽度资料,构建差值年表并分析其与温度和降水的关系,阐明影响该区域2个主要针叶树种径向生长的主要气候要素。结果表明:(1)海拔下限丽江云杉径向生长同时受到温度和降水的影响:与上年11月平均温、当年生长季后期(9—10月)平均温和上年7月降水呈显著正相关;(2)海拔上限丽江云杉径向生长只受温度影响,与上年生长季后期平均温呈显著负相关,与当年生长季盛期(6—8月)平均温呈显著正相关;(3)长苞冷杉径向生长只与温度表现出显著相关性,海拔下限的生长与上年11月平均温呈显著正相关,海拔上限的生长与当年生长季盛期平均温呈显著正相关。结果可为气候变化对滇西北高原树木生长影响研究提供参考,为滇西北高原森林生态系统管理与保护提供理论依据。

The Hengduan Mountain is located to the southeastern margin of the Qinghai-Tibet Plateau, which is sensitive to climate change and a hot spot for tree-ring research; it has rich biodiversity and significant climate changes, so it plays an important role in climate change research. Up to now, tree-ring research in this area concentrated on the upper distributional limits, however the systematic study of both the upper and lower distributional limits was out of focus. Based on the dendrochronological method, we established the residual chronologies of Picea likiangensis and Abies georgei at their upper and lower distributional limits by using tree-ring width data, and studied the relationship between the residual chronologies, temperature and precipitation. The study can identify the key climatic factors that affect the radial growth of two conifers. The results showed that ： （ 1 ） The radial growth of Picea likiangensis was affected by both temperature and precipitation at its lower limits; there were significant and positive correlations between its growth and November mean temperature （T ） in the previous year, T of post growing season （September-October） in the current year and July precipitation in previous year. （2） The radial growth of Picea likiangensis was only affected by temperature at its upper limits, by showing a negative correlation with T of post growing season in the previous year, and a significantly positive correlation with T of growing season （June-August） in the current year. （3） The radial growth of Abies georgei was only correlated with temperature. November T in the previous year and growing season T in the current year positively affected its growth at lower and upper distributional limits respectively. The results of this paper can offer a reference for the study in effects of climate change on tree growth in Northwest Yunnan Plateau, and provide a theoretical basis for the management and protection of forest ecosystems in the area.