合肥环城高速公路防护林带土壤重金属污染及主要树种富集能力  

Heavy metal contamination in soils and enrichment capacity of typical tree species in shelterbelt along Hefei Loop Expressway

作　　者：张前进[1] 陈永生[1] 刘华[1] 王嘉楠[1] ZHANG Qian-jin;CHEN Yong-sheng;LIU Hua;WANG Jia-nan(Institute of Forestry and Landscape Gardening,Anhui Agricultural University,Hefei 230036,China)

机构地区：[1]安徽农业大学林学与园林学院,合肥230036

出　　处：《生态学杂志》2021年第6期1775-1782,共8页Chinese Journal of Ecology

基　　金：安徽省教育厅自然科学基金重点项目(KJ2020A0131)资助。

摘　　要：为了解合肥环城高速公路防护林带土壤重金属污染状况和防护林主要树种加杨(Populus canadensis)、栾树(Koelreuteria paniculata)、女贞(Ligustrum lucidum)、夹竹桃(Nerium oleander)和垂柳(Salix babylonica)富集重金属能力,在环城高速防护林带中设置12条采样带,共60个取样点,分别收集土壤和树木枝干木质部样品,用电感耦合等离子体发射光谱法(ICP-AES)测定样品中Pb、Cd、Hg、Cr、As 5种重金属元素含量,探讨了土壤重金属含量变化特征以及5种树木重金属富集能力。结果表明:防护林带内土壤5种重金属元素含量均高于土壤背景值,Cd的平均含量为背景值的15.3倍。随着距公路距离增加,土壤重金属含量呈现减少趋势,在距离公路35 m以内土壤综合潜在生态风险随距离的增加显著下降,35 m以外,综合潜在生态风险指数趋于平稳,并降低到轻微潜在生态风险水平。5种树木对土壤重金属元素综合富集能力大小顺序为:夹竹桃>女贞>栾树>垂柳>加杨。To understand the heavy metal pollution in soils of the shelterbelt along the Hefei Loop Expressway and the heavy metal accumulation ability of typical tree species( Populus canadensis,Koelreuteria paniculata,Ligustrum lucidum,Nerium oleander,and Salix babylonica) in the shelterbelt,we collected xylem samples from trunks and branches and soil samples from 60 sampling points in 12 sampling strips perpendicular to the shelterbelt. The concentrations of five kinds of heavy metals( Pb,Cd,Hg,Cr,and As) were measured by inductively coupled plasma emission spectrometry( ICP-AES). The results showed that the concentrations of those five kinds of heavy metals in the soils all exceed the background values. The average concentration of Cd in the soil was 15.3 times of the background value. The concentrations of heavy metals in the soil tended to decrease with increasing distance from the expressway. Within the range of 35 m from the expressway,the comprehensive potential ecological risk of soil decreased significantly with increasing distance,but tended to be stable beyond 35 m from the expressway and was reduced to a slight level. The comprehensive enrichment ability of the five tree species to heavy metals was declining with an order of Nerium oleander,Ligustrum lucidum,Koelreuteria paniculata,Salix babylonica,and Populus canadensis.

关 键 词：重金属污染 土壤 植物富集 公路交通 

分 类 号：X173[环境科学与工程—环境科学] X53