气候变化背景下的树木生长动态一直是生态学关注热点,探索树木生长与气候因子的关系具有重要意义。为研究滇西北高原树木生长的气候响应规律,选取云南西北部玉龙雪山及老君山2个典型区域,进行典型样木采样,采用树轮年代学方法,建立云南铁杉差值年表,分析年轮指数与气候因子的时空关联。结果表明:1)云南铁杉径向生长受气温和降水量共同影响。其中,玉龙雪山云南铁杉径向生长在上一年11月和当年6月与气温显著正相关,在当年6月和10月与降水分别表现为显著负相关和显著正相关;老君山云南铁杉径向生长主要受5月水热条件影响,表现为与气温的显著负相关及与降水的显著正相关,同时在10月与气温和降水均显著正相关。2)降水的动态响应较气温更为稳定,表明水分条件在年际尺度上的决定性作用,其中,老君山云南铁杉径向生长与上一年10月及当年5月降水呈显著相关性的年份最多,而玉龙雪山云南铁杉与降水相关性最多的年份为当年6月。滇西北云南铁杉径向生长对气候因子的响应规律,主要表现为对上年度生长季末气候条件的“记忆效应”,以及对本年度春末夏初水热组合的“即时响应”。

The growth dynamics of trees under the background of climate change have been a hot topic of ecological concern,therefore exploring the relationship between tree growth and climate is of great significance.In order to study the climate response laws of tree growth in northwest Yunnan Plateau,we selected Yulong Snow Mountain and Laojun Mountain as two typical areas,and studied the relationship between radial growth and climatic factors of Tsuga dumosa,by using the method of tree ring chronology.Two residual chronologies of T.dumosa were established by using data from tree ring widths and the spatiotemporal correlation between the annual ring index and climate factors was further analyzed.The results showed that T.dumosa growth was influenced by both precipitation and temperature.The radial growth of T.dumosa in Yulong Snow Mountain was significantly and positively correlated with the temperature in previous November and current June,and its growth was negatively and positively correlated with the precipitation in June and October of the current year,respectively.T.dumosa growth in Laojun Mountain was mainly affected by the water and heat conditions in May,showing a significantly negative correlation with temperature and a significantly positive correlation with precipitation,while showing a significantly positive correlation with temperature and precipitation in October.In the sliding analysis,the dynamic response of precipitation is more stable than temperature,confirming the decisive role of moisture conditions on an interannual scale.The growth of T.dumosa in Laojun Mountain presented the most significant correlations with precipitation of previous October and current May,while in Yulong Snow Mountain,significant correlations with precipitation of current June appeared in most years.The research results reveal the climate "memory effect" of the radial growth of T.dumosa on the late growing-season of the previous year,and the "immediate response" effect on the water and heat combination at the end of spring and beginning of summer in current year.