普达措国家公园海拔上限3个针叶树种径向生长对气候变化的响应

Response of radial growth of three conifer trees to climate change at their upper distribution limits in Potatso National Park,Shangri-La,southwestern China

本文利用树木年轮学方法研究普达措国家公园海拔上限麦吊云杉、大果红杉和长苞冷杉的生长特征,构建差值年表并分析其与气候因子的关系,以揭示影响该区域3个主要树种径向生长的气候因子及对气候变化响应的种间差异。结果表明:1)生长后期的气候因子对该地区树木生长起着重要作用,但不同树种的响应方式存在差异;2)麦吊云杉生长主要受限于生长季的气候条件,与上年生长后期(上年9—10月)平均温度呈显著负相关,且当年生长盛期(6—8月)温度的升高有利于其径向生长;3)大果红杉生长主要受限于生长后期的水分条件,主要表现为与上年10月以及上年生长后期(9—10月)降水呈显著负相关;4)长苞冷杉生长主要受限于生长季的气候条件,主要表现为对当年生长季盛期(6—8月)以及当年生长季后期(9—10月)平均温度的显著正相关。本研究为香格里拉地区的气候重建提供基础数据。

In order to detect the response of tree growth to climate change in the northwestern Yunnan Plateau,we used residual chronologies of three major conifers,i. e. Picea brachytyla,Larix potaninii and Abies georgei at their upper distribution limits in Potatso National Park,to study the characteristics of the residual chronologies and the relationships between radial growth and climatic factors（ temperature and precipitation）. We aimed to find out the main climatic factors affecting tree growth in the area and to detect differences of growth responses to climates among the studied species. The results showed that： 1）The climatic factors（ temperature and precipitation） of post growing season were the main factors affecting tree growth at the upper distribution limits in Potatso National Park,but varied with tree species. 2） The radial growth of P. brachytyla was mainly limited by temperature condition during the post growing season（ September- October of previous year）,and was negatively correlated with meantemperature of post growing season in previous year（ September-October of previous year）,meanwhile higher temperature during the growing season（ June- August） of current year positively affected its radial growth. 3） Precipitation in October and the post growing season of previous year（ September- October）was the main factor limiting the radial growth of L. potaninii,with a significant and negative correlation between the residual chronology and precipitation. 4） The radial growth of A. georgei was mainly limited by climatic factors of the growing season,presented by a significant and positive correlation between radial growth and mean temperature of growing season（ June- August） and post growing season（ September-October） in current year. This study can provide basic data for climate reconstruction in Shangri-La,northwestern Yunnan of southwestern China.