西藏亚东地区铁杉树轮样本稳定氧同位素的气候响应  

Climate responses of tree-ring stable oxygen isotopes from Yadong County, Tibetan Plateau

作　　者：李强[1,2] 刘禹[1,2,3] Takeshi Nakatsuka 宋慧明[1,2] 王丽丽[5] 他维媛[1] 

机构地区：[1]中国科学院地球环境研究所黄土与第四纪地质国家重点实验室,西安710061 [2]全球变化研究协同创新中心,北京100875 [3]西安交通大学人居环境与建筑工程学院,西安710049 [4]Research Institute for Humanity and Nature,Kyoto 603-8047,Japan [5]中国科学院地理科学与资源研究所,北京100101

出　　处：《地球环境学报》2017年第1期6-14,共9页Journal of Earth Environment

基　　金：黄土与第四纪地质国家重点实验室开放基金;中国科学院西部博士;中国科学院青年创新促进会(2017451)~~

摘　　要：为调查树轮稳定氧同位素在西藏南部的气候应用潜力,选择了西藏亚东县三个铁杉(Tsuga chinesis Pritz.)样本进行分析。其中两个样本表现出长期的稳定氧同位素下降趋势,而另一个表现出增高趋势,且三者相关性很低。当对三条稳定氧同位素序列进行一阶差处理之后,它们的相关关系有了非常显著的提高,表现出很好的一致性(p<0.0001)。无论是原始还是一阶差树轮稳定氧同位素序列,它们都与夏季相对湿度和降水反相关,而与温度正相关,然而方差解释量未能达到古气候重建的最低要求。周期分析发现亚东树轮稳定氧同位素序列仅存在4.657年的显著周期,可能与ENSO活动有关,进一步研究显示1978年之前上年冬天到当年夏天的赤道中东太平洋海表温度对亚东树轮稳定氧同位素有显著影响(p<0.01),而在1978年之后则无任何影响,20世纪70年代末期的全球气候突变改变了ENSO对该地树轮稳定氧同位素的影响。Background, aim, and scope Dendroclimatology is one of the important approaches in paleoclimate studies because of tree-ring＇s high temporal resolution and accuracy of dating. Traditional dendrcoalimatology employed tree-ring width to investigate climate variations. To obtain more climate signals, other tree-ring parameters such as density, stable isotope ratios are employed during recently years. Tree-ring stable oxygen isotope ratios have the advantage that the physiological controls are well understood and relatively simple in comparison to many factors controlling tree-ring width. The tree-ring stable oxygen isotope ratios may keep the memory of past changes in the stable oxygen isotope ratio of precipitation because tree roots absorb soil water that are from precipitation. In addition, relative humidity is known as the other factor impacting the tree-ring stable oxygen isotope ratios by affecting the enrichment of stable oxygen isotope ratios in leaf water. Generally, it is a necessary step to remove age-related trend in tree-ring widths studies. However, time series of tree-ring stable oxygen isotope are not necessary to carry out the detrending process because of rarely juvenile effect, consequently tree-ring stable oxygen isotope series could preserve more low-frequency climate signals. In Europe and North America, tree-ring stable oxygen isotope study has developed over the past half century. Comparing with tree-ring widths studies, tree-ring stable oxygen isotope studies are very rare in China, especially in some ecologically fragile regions such as Tibetan Plateau, where climate variations are very important to global climate change. To investigate the climate potential of tree-ring stable oxygen isotope in southern Tibetan Plateau, we employed three tree-ring samples of growing Tsuga chinesis Pritz from Yadong County, Tibetan Plateau to carry out the analysis of climate responses in this study. Materials and methods There are missing rings or false rings in most trees in Tibetan Plateau because of c

关 键 词：西藏亚东 铁杉 树轮稳定氧同位素 气候响应 海表温度 

分 类 号：S791.17[农业科学—林木遗传育种] P532[农业科学—林学]