塔里木盆地西南缘表土碳同位素组成特征分析  

Composition characteristics of surface soil δ^(13)C_(org) in the southwest margin of Tarim Basin

作　　者：琚立 冉敏 杨运鹏 王馨 JU Li;RAN Min;YANG Yunpeng;WANG Xin(College of Geography and Environmental Science,Henan University,Kaifeng 475004,Henan,China;National Demonstration Center for Environmental and Planning,Henan University,Kaifeng 475004,Henan,China;Henan Key Laboratory of Earth System Observation and Modeling,Henan University,Kaifeng 475004,Henan,China)

机构地区：[1]河南大学地理与环境学院,河南开封475004 [2]河南大学环境规划国家级实验教学示范中心,河南开封475004 [3]河南大学地球系统观测与建模河南省重点实验室,河南开封475004

出　　处：《干旱区地理》2022年第6期1805-1813,共9页Arid Land Geography

基　　金：国家自然科学基金(41502168,41771234)资助。

摘　　要：土壤碳同位素可以反映生长植被的同位素组成,从而进一步反映当时的植被类型以及气候环境状况。已有的研究显示,不同地区碳同位素与气候因子的关系存在显著差异,因此在不同区域开展土壤碳同位素与气候因子之间相关性关系分析对古气候的重建至关重要。通过采集塔里木盆地西缘帕米尔地区和盆地南缘和田地区策勒县的表土沉积物,分析测定后获得其有机碳同位素,并将该表土有机碳同位素数据与气候因子进行相关性分析,以探明研究区有机碳同位素组成特征及其潜在的气候意义。结果表明:帕米尔地区和策勒地区的表土碳同位素变化对气候因子的响应存在明显差异。气温方面,帕米尔地区与气温呈正相关,其中与冷季气温相关性最好(r=0.598,P<0.01);策勒地区与气温呈负相关,其中与暖季气温相关性最好(r=-0.684,P<0.01)。降水方面,帕米尔地区与降水量的相关性不显著;策勒地区与年均降水量呈弱负相关,与暖季降水量呈弱正相关,与冷季降水量呈显著的负相关关系(r=-0.632,P<0.01)。上述分析表明基于沉积物有机碳同位素来重建古气候时应充分考虑区域差异的影响。Soil organic carbon isotopes(δ^(13)C_(org)) can reflect the isotopic composition of growing vegetation and thus further reflect the vegetation type and the related climate. Previous studies have demonstrated that there are significant differences in the relationship between δ^(13)C_(org) and climate factors in different regions. Therefore, it is essential to analyze the correlation between soil δ^(13)C_(org) and climate factors in different regions for paleoclimate reconstruction. In our research, two transects of the Pamir Plateau and Qira County, located in the core of the arid region of Central Asia, are selected to analyze the carbon isotopic composition of surface soil and its relationship with climate factors to provide a scientific basis for paleoclimate reconstruction. In this paper, we first obtained 50 topsoil sediment samples and analyzed their organic carbon isotopic composition characteristics. Second, the relationship between soil organic carbon isotopes and climate factors was analyzed in detail. Finally, its potential driving mechanism was preliminarily explored. The results show that there are obvious differences in the relationship between surface soil δ^(13)C_(org) and climate factors in the Pamir Plateau and Qira County: In terms of temperature, the Pamir region is positively correlated with annual average temperature(r=0.594, P<0.01), warm season temperature(r=0.593, P<0.01), and cold season temperature(r=0.598, P<0.01);the Qira County is negatively correlated with annual average temperature(r=-0.675, P<0.01), warm season temperature(r=-0.684,P<0.01), and cold season temperature(r=-0.646, P<0.01). In terms of precipitation, the correlation between the Pamir region and precipitation is insignificant;the Qira County has a weak negative correlation with the average annual precipitation(r=-0.485, P<0.05), a weak positive correlation with the warm season precipitation(r=0.483,P<0.05), and a significant negative correlation with the cold season precipitation(r=-0.632, P<0.01). Further mechanism

关 键 词：表土δ^(13)C_(org) 气温 降水量 相关性分析 干旱区 

分 类 号：P597[天文地球—地球化学]