中国西南典型山地地区重金属时空分布特征:基于树木年轮反演解析  

Temporal and Spatial Distribution of Heavy Metals in Typical Mountainous Areas of Southwest China:Based on Tree Rings Inversion and Analysis

作　　者：高源 贺春露 雷浩然 刘旭 王训 王永敏[1] 王定勇[1] GAO Yuan;HE Chunlu;LEI Haoran;LIU Xu;WANG Xun;WANG Yongmin;WANG Dingyong(College of Resources and Environment,Southwest University,Chongqing 400715,China;Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China)

机构地区：[1]西南大学资源环境学院,重庆400715 [2]中国科学院地球化学研究所环境地球化学国家重点实验室,贵阳550081

出　　处：《地球与环境》2023年第3期308-317,共10页Earth and Environment

基　　金：中央高校基本科研业务费专项基金项目(XDJK2017B035);西南大学大学生创新创业训练计划项目(X202110635326)。

摘　　要：为探究中国西南部年轮重金属的时空变化特征与主要影响因素,本文测定了沿印度西南季风传播路径上的西双版纳番龙眼、哀牢山滇木荷、大理苍山云杉、白马雪山冷杉和贡嘎山冷杉年轮中12种重金属的含量,重点探讨了铅(Pb)、铬(Cr)、镉(Cd)和砷(As)4种元素的时空变化特征。结果表明:人为活动导致树木年轮中Pb、Cr、Cd和As含量年际变化波动较大。1950年前,中国西南部树木年轮中的Pb、Cr、Cd和As含量变化主要受控于欧美发达国家工业排放重金属的远距离传输,而改革开放以来,西南区域工业化快速发展导致的人为源排放急剧增加是引起年轮中Pb、Cr、Cd和As含量变化的主要原因。树轮中Pb和As含量沿季风传播路径逐渐降低,其中Pb的降低趋势最为明显,这种空间变化特征主要受树种差异、沿季风重金属沉降及土壤背景的综合影响。本研究可为近两百年来中国西南部重金属的时空变化提供数据佐证,为认识偏远地区重金属的累积提供了新视角。To explore the spatio-temporal variations and its primary influencing factors of heavy metals in tree rings of Southwest China,the concentrations of 12 heavy metals in tree rings of Xishuangbanna pometia pinnata,Ailao Mountains schima superba,Dali Cangshan spruce,Baima snow mountain fir and Mount Gongga fir along the propagation path of the Southwest Indian monsoon were determined,and 4 heavy metals(Pb,Cr,Cd and As)were mainly discussed.The results showed that the annual concentrations of Pb,Cr,Cd and As in tree rings fluctuated greatly due to the influence of human activities.Besides,the variations of Pb,Cr,Cd and As in tree rings of Southwest China were mainly controlled by the long-distance transport of heavy metals emitted by industry in Europe and America before 1950,while the rapid increase of anthropogenic emissions caused by rapid industrialization in southwest China was the dominant reason for the variations of tree-ring Pb,Cr,Cd and As.In addition,the average contents of Pb and As in tree rings decreased gradually along the monsoon propagation path,with the more obvious decrease trend of Pb.This spatial variation was mainly affected by the differences of tree species,heavy metal deposition along the monsoon and soil background.This study can provide evidence for the spatio-temporal variations of heavy metals in Southwest China in the past two hundred years,as well as a new perspective for understanding the accumulation of heavy metals in remote areas.

关 键 词：年轮 重金属 中国西南部 时空分布 

分 类 号：X142[环境科学与工程—环境科学] P593[天文地球—地球化学]