新疆西天山不同海拔雪岭云杉树轮宽度年表特征及其气候响应分析

摘要

利用西天山新源林场卡勒克玛林区5个采样点(按海拔从高到低依次将采样点编号为KL1、KL2、KL3、KL4、KL5)的雪岭云杉树木样芯,建立宽度年表,并分析树木年轮标准化年表与气候的相关性,以及这种相关性随海拔梯度的变化情况.结果表明:(1)样本对总体均有较高代表性,KL3的各项指标在5个标准化年表中最高,包含的气候信息最多,受到气候的影响最明显;(2)高海拔的KL1和KL2与新源上年4—8月以及当年4月的降水量呈正相关,中、低海拔的KL3~KL5则与上年4月—当年4月降水量正相关,除KL5与当年4月的降水量正相关不显著外,其余标准化年表均与新源上年及当年4月降水量相关显著;(3)各标准化年表与新源站上年4—10月以及当年9月的平均温度和平均最高温度呈负相关,而与上年12月的温度要素呈正相关;(4)各采样点树木径向生长受气候的"滞后性"影响明显,森林上线采样点(KL1、KL2)的树木径向生长主要受制于温度,中、下线(KL3~KL5)主要受制于降水量.%Along an altitude gradient, tree-ring samples of Picea schrenkiana are collected and ring-width chronologies are developed from 5 sites (named KL1~KL5 along high altitude gradient to low) in Kalekema of Xinyuan , West Tianshan Montains. It is mainly focus on the response character of standard chronologies to local climate and the change of correlation coefficient along with altitudinal gradient. The main results showed that:(1)Comparing the five chronology characteristic parameters, chronology of KL3 at mid-altitude has the highest index, contain more climatic information than others and influenced by the climate most obviously.(2)KL1 and KL2 positively correlated with Xinyuan precipitation in last April to last August which at high altitude, but KL3~KL5 positively correlated with last till this April rainfall which at mid and lower altitude , all of the tree-ring standard chronologies have significant positive correlation with this and last April precipitation, except KL5 is not significant with this April.(3)All of the standard chronologies are negatively correlated with monthly mean temperature of last April to last October and this September, but positively correlated with last December.(4) the lay of climate influenced it obviously, temperature played a more important role than precipitation on radial growth of the high-forest boder sites (KL1、KL2), but the mid and low-forest boder sites (KL3~KL5) are just the opposite.