莽山不同海拔华南五针松径向生长对气候因子的响应

Response of Radial Growth of Pinus kwangtungensis at Different Elevations to Climate Factors in Mangsha

为了解全球升温背景下我国亚热带地区树木生长对气候变化的响应,基于树木年轮学方法,在湖南莽山建立不同海拔(1 400、1 200、1 000 m)华南五针松(Pinus kwangtungensis)标准年表,利用响应分析和单年分析研究其径向生长与气候因子的相关关系。结果表明,海拔1 400 m处华南五针松的径向生长与当年6月均温和最高温显著负相关,与当年4月的降水量呈显著正相关关系;海拔1 200 m处的径向生长与当年3月均温及上年和当年10月均温、最低温显著正相关,与当年7月的最低温显著负相关,与上年11月降水量呈显著正相关关系;海拔1 000 m处的径向生长与当年6月均温、最高温和当年1月的平均温、最低温以及上年10月的最低温显著负相关,与当年3月、上年10月和当年10月的降水呈显著正相关关系。温度和降水共同影响着该地区华南五针松的径向生长,生长季初期的温度和降水以及夏季温度是影响其生长的关键气候因子。

Under the background of global warming, to achieve a better understanding about tree growth-climate association in subtropical China, tree-ring width chronologies of Pinus kwangtungensis at different elevations were established based on the standard method of dendrochronology. The relationship between radial growth and climatic factors was studied by response analysis and single-year analysis. The results showed that radial growth of P. kwangtungensis at the altitude of 1 400 m was negatively related to the averaged and maximum temperature in June of the current year, and positively related to precipitation in April of current year. The radial growth at the altitude of 1 200 m was significantly positively correlated with the temperature in March, the average temperature and the lowest temperature in October of last year and current year, negatively correlated with the lowest temperature in July of current year, and significantly positively correlated with the precipitation in November of last year. The redial growth at the altitude of 1 000 m was significantly negatively correlated with the average and maximum temperature in June of current year, the average temperature in January and the lowest temperature in October of last year. Additionally, the precipitation in March, October of last year and current year was positively correlated with radial growth. Temperature and precipitation together affect the growth of P. kwangtungensis in Mangshan. Therefore, the temperature and precipitation at the beginning of the growing season as well as the maximum temperature in summer should be the major climatic factors affecting the radial growth of trees.