滇西不同海拔云南松径向生长对气候水文要素的响应

Responses of radial growth of Pinus yunnanensis to climatic and hydrological factors at different altitudes in Western Yunnan,China

利用滇西地区两个不同海拔采样点的云南松树轮样本,建立树轮宽度标准化年表,研究其径向生长对气候和水文要素的响应。结果表明:滇西云南松径向生长主要受降水量、气温和径流量的影响,其中高海拔(2413.3 m)云南松径向生长受夏季高温的制约和季风季节径流量影响,而低海拔(1062.6 m)云南松径向生长受生长季的降水量和全年径流量影响。滇西高海拔云南松径向生长对气温变化的响应受温度阈值影响表现出不稳定性;低海拔云南松径向生长对降水量和径流量的响应,在20世纪80年代均受到东亚夏季风的减弱而出现波动。滇西不同海拔云南松径向生长与亚洲夏季风活动及厄尔尼诺存在联系。

A tree-ring width chronology(STD)was established using tree-ring cores of Pinus yunnanensis from two sites with different altitudes in Western Yunnan,to study the responses of radial growth to climatic and hydrological factors.The results showed that the radial growth of P.yunnanensis in Western Yunnan was mainly affected by precipitation,temperature and runoff.The radial growth of P.yunnanensis at high altitude(2413.3 m)was controlled primarily by high temperature in summer and runoff in the monsoon season.In contrast,the radial growth of P.yunnanensis at low altitude(1062.6 m)was mainly controlled by precipitation in the growing season and annual runoff.The responses of radial growth of P.yunnanensis at high altitude to temperature change was unstable due to the existence of the temperature threshold.Due to the weakening of the East Asian summer monsoon in the 1980 s,the temporal stability of tree growth response at low altitude to precipitation and runoff fluctuated.The radial growth of P.yunnanensis at different altitudes in Western Yunnan was related to the Asian summer monsoon and El Ni1 o-Southern Oscillation.