广西金钟山细叶云南松径向生长及其对气候因子的响应

为探究广西金钟山细叶云南松径向生长及其对气候的响应,该文建立了细叶云南松树木年轮标准年表,采用响应分析探讨了径向生长与气候因子的关系,并使用逐步回归和方差分解量化了不同气候因子对径向生长的影响。结果表明:(1)响应分析结果显示,上一年1月、8月、9月、11月的日照时数以及上一年10月的平均最低气温和平均气温与标准年表年轮宽度均呈显著正相关,而上一年6月降雨量>10 mm的天数与年轮宽度呈显著负相关; 当年2月的降雨量、3月的空气相对湿度和平均最低气温、6月的日照时数以及9月的平均气温和平均最高气温均与年轮宽度呈显著正相关。(2)逐步回归最终模型的方差分解结果显示,上一年10月的平均最低气温对细叶云南松径向生长的影响最大(方差解释量达23.35%),其次是当年9月的平均最高气温(方差解释量为10.39%); 上一年1月和11月的日照时数分别解释了径向生长变异的3.94%和6.58%。综上表明,秋季的温度和冬季的光照条件是限制细叶云南松径向生长最主要的气候因子,早春干旱和雨季大降雨量会降低细叶云南松的径向生长。

Radial growth of Pinus yunnanensis var. tenuifolia and its response to climatic factors in Jinzhongshan, Guangxi

In order to explore the radial growth of Pinus yunnanensis var. tenuifolia in Jinzhongshan of Guangxi and its response to climate, a standard tree-ring chronology of P. yunnanensis var. tenuifolia was established, response analysis was used to explore the relationship between radial growth and climatic factors, and stepwise regression and variance decomposition were used to quantify the effects of climatic factors on radial growth of P. yunnanensis var. tenuifolia. The results were as follows:(1)Sunshine duration in January, August, September and November, and the mean minimum temperature and the mean temperature in October of the previous year were significantly positively correlated with tree-ring width of standard chronology. By contrast, there was a significant negative correlation between the number of days with the amount of precipitation >10 mm in June of the previous year and tree-ring width. Precipitation in February, relative air humidity and the mean minimum temperature in March, sunshine duration in June, and the mean maximum temperature and mean temperature in September of the current year were positively correlated with tree-ring width.(2)The variance decomposition results of the final stepwise regression model revealed that the mean minimum temperature in October of the previous year had the greatest effect on the radial growth of P. yunnanensis var. tenuifolia(explaining 23.35% of the variance), followed by the mean maximum temperature in September of the current year(explaining 10.39% of the variance). Sunshine duration in January and November of the previous year explained 3.94% and 6.58% of the variation in radial growth of P. yunnanensis var. tenuifolia, respectively. In conclusion, autumn temperature and winter light condition are the main climatic factors limiting the radial growth of P. yunnanensis var. tenuifolia in Jinzhongshan. In addition, both drought in early spring and heavy rainfall in rainy season can reduce the radial growth of P. yunnanensis var. tenuifolia.