六盘山地区油松(Pinus tabulae formis)径向生长对气候因子的响应

RESPONSE OF PINUS TABULAEFORMIS RADIAL GROWTH TO CLIMATE FACTORS IN LIUPAN MOUNTAIN AREAS

基于建立的须弥山油松树轮宽度年表,分析了油松径向生长与该区气温、降水和帕尔默干旱指数(PDSI)等主要气候因子之间的关系.结果显示研究区油松径向生长与前一年9、11月和当年4、6、7月的气温呈极为显著负相关(P<0.01),与当年5月的气温呈显著的负相关(P<0.05),与前一年9月的降水呈极为显著正相关(P<0.01),与当年7月的降水呈显著正相关(P<0.05),与前一年9月至当年8月PDSI呈极为显著的正相关(P<0.01).分析表明,六盘山地区树木径向生长对气候因子具有明显的响应关系,与全年的气温呈负相关关系,与生长季的降水呈正相关关系,由气温和降水共同决定的干旱程度是限制油松径向生长的主要因子.

The relationships between radial tree growth and related climatic variables such as temperature, precipitation and PDSI were analyzed from established standard ring-width index series of Pinus tabulaeformis on Xumi Mountain. Radial Pinus tabulaeformis growth was negatively correlated with temperature in last September and November and this April, June and July （P%0.01）, negatively correlated with temperature in May （P〈0.05）, positively correlated with precipitation in last Septemhe （P〈0.01）, positively correlated with precipitation in July （P〈0. 05）, positively correlated with PDSI from last September to August （P〈0.01）. It is shown that radial tree growth in Liupan Mountains area was sensitive to and consistent with climate. Not low temperature but drought due to high temperature and low precipitation was the major limiting factor to radial tree growth.