祁连山青海云杉树轮δ^(13)C的时空变化及其气候意义  

Spatio-Temporal Variability and Climatic Significance of Tree Ring's δ^(13)C of Picea crassifolia on the Qilian Mountains

作　　者：刘晓宏[1] 安文玲[1] 梁尔源[2] 王文志[1] 邵雪梅[3] 黄磊[4] 秦大河[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所冰冻圈科学国家重点实验室,甘肃兰州730000 [2]中国科学院青藏高原研究所,北京100085 [3]中国科学院地理科学与资源研究所,北京100101 [4]中国气象局国家气候中心,北京100081

出　　处：《冰川冻土》2010年第4期666-676,共11页Journal of Glaciology and Geocryology

基　　金：中国科学院国际合作伙伴计划项目(CXTD-Z2005-2);中国科学院知识创新项目(KZCX2-YW-QN308);冰冻圈科学国家重点实验室自主课题(SKLCS09-03);国家自然科学基金项目(4087100240501076)资助

摘　　要：通过分析祁连山自东向西5个样点青海云杉年分辨率的树轮碳同位素比率(δ13 C),评价在大气CO2浓度日益增加的背景下青海云杉长期水分利用效率的变化及其对气候变化的响应.最长树轮δ13 C年表为189a,最短112a(1891-2003年).选择了5个样点的公共区间进行分析(1891-2003年).结果表明:祁连山青海云杉δ13 C序列之间显著相关,但是远离山脉主体的两条δ13 C序列与其余序列相关关系较弱.随着大气CO2浓度的持续增加,所有样点青海云杉水分利用效率均表现出显著的提高,但在祁连山腹地的青海云杉水分利用效率提高的幅度低于其它样点.以树轮碳同位素分馏(Δ13 C)和干旱指数之间的相关关系为基础,重建了研究区域1891-2003年期间的干旱历史.其中,20世纪20年代末30年代初和最近10a的两次最严重的干旱分别是由降水减少和气候变暖引起的.The carbon isotopic composition（δ13C）of tree rings was used to assess the changes in intrinsic water-use efficiency（Wi）and climate change on the background of increasing atmospheric CO2 during the period of 1891-2003.Five Qinghai spruce（Picea crassifolia）standing in the Qilian Mountains and growing with a precipitation gradient were selected.All five δ13C were correlated each other,but there were two sites（DDS CLS）far away from the main body of mountains,which showed relative weakly connections to other sites.The Wi of all sampling trees were enhanced in response to the increasing atmospheric CO2 concentration,while the spruce growing in the hinterland of the mountains had enhanced Wi less than those in other sites.Based on the correlation between carbon isotope discrimination（Δ）and Palmer drought severity index（PDSI）,the drought history covering the period of 1891-2003 was reconstructed in the study region.There were two most severe drought phases in the late 1920s to the early 1930s and the last ten years,caused by less precipitation and warming,respectively.This study will be useful in assessing further spatial climate-related bioclimatic information.

关 键 词：祁连山 青海云杉 树轮δ13C 水分利用效率 干旱历史 

分 类 号：Q945.17[生物学—植物学]