赛里木湖流域雪岭云杉(Picea schrenkiana)树木径向生长对气候变化的响应

Response of Tree-ring Growth of Picea schrenkianato Climate Change in the Sayram Lake Basin,Xinjiang,China

选用赛里木湖流域海西沟雪岭云杉(Picea schrenkiana)树轮宽度标准化年表与温泉气象站历年逐月降水(月降水量,降水量≥0.1mm、≥1mm、≥2mm、≥5mm日数)、温度(月平均气温、月平均最高气温、月平均最低气温、平均地温)、积雪(积雪日数,积雪深度≥1cm、≥5cm、≥10cm日数)、月平均相对湿度、日照百分率及日照时数等主要气候因子,以相关函数法分析赛里木湖流域树轮宽度对气候变化的响应。结果表明:海西沟树轮宽度标准化年表与气候要素相关较好的月份集中在上年7月、上年8月、当年1月及当年7月,与降水、积雪、相对湿度正相关,而与温度、日照百分率、日照时数负相关。对器测资料上年1月到当年12月所有不同时段的顺序组合与海西沟树轮宽度标准化年表的年轮指数序列进行相关普查分析表明,在所有组合中上年8月至当年7月的降水量及降水≥5mm日数与树轮年表的相关性最好,相关系数分别为0.630和0.708,上年8月至当年7月的降水可能是该地区树轮径向生长的主要限制因子,海西沟树轮标准化宽度年表与周围的降水和PDSI均具有较好的相关性,该年表对天山北坡和中亚部分地区的降水及PDSI有较好的代表性。

In this study,we developed a tree-ring width chronology using the Schrenk spruce(Picea schrenkiana Fisch.et Mey)tree-ring samples.The samples was collected from the Sayram Lake Basin in western Tianshan Mountains.The tree-ring width chronology response to climate change was analyzed using monthly precipitation,temperature(average maximum temperature,mean minimum temperature and average temperature),relative humidity,sunshine,snow(snow depth and snow days)from Wenquan meteorological stations.Response function analysis shows that precipitation and moisture conditions are limiting factor for tree radial growth in Sayram Lake basin,there is a best correlation between tree-ring width chronology and precipitation(r=0.63,p<0.001),while precipitation from previous August to current July is a major limiting factor.The precipitation variability in the past several hundred years may be better reconstruction by tree-ring chronology.The spatial correlation analysis showed that the tree-ring width chronology have a good representative to precipitation variability from previous August to current July in Sayram Lake basin even most of the northern Xinjiang and the mountains of Central Asia.