工业污染地6种乔木树种重金属累积特征研究

Accumulation of heavy metals in six trees in industrial pollution area

黄埔区是广州市工业污染较严重的地区,其中龟山是由污染导致土壤严重退化的典型地段。该地段植被退化,土壤重金属质量分数较高。为了探讨在这种工业污染区生存的植物对重金属的吸收能力以及不同树种吸收能力间的差异,选择该地段的台湾相思(Acacia confusa)、刺竹(Blumeana schult)、尾叶桉(Eucalypt urophylla)、高山榕(Ficus altissima)、小叶榕(Ficus microcarpa)和潺槁树(Litsea glutinosa)等6种乔木树种,采集其根、枝、叶等部位,测定Pb、Zn、Cu和Cd的质量分数。结果表明:4种重金属在乔木中累积量大小依次是:Zn>Pb>Cu>Cd,Zn累积量最大,为664.98mg·kg-1,Cd最小,仅为4.42mg·kg-1;各种重金属在乔木不同部位的累积量大小是:细根>粗根>叶子>枝条,细根中各重金属累积量最大,为368.15mg·kg-1;6种乔木树种抗重金属能力比较,小叶榕重金属累积量均为455.60mg·kg-1,抗性最好;尾叶桉和潺槁树重金属累积量较多,均为179.86和221.63mg·kg-1,抗性较好;高山榕重金属累积量均为114.41mg·kg-1,抗性中等;台湾相思和刺竹分别为78.04和96.41mg·kg-1,抗性较差。

The Huangpu District is a serious polluted area in Guangzhou city.Guishan is a district where degraded soil by pollution is typical.The heavy metal contents of soil was much more and vegetation degradated seriously.In order to investigate the ability and difference of plants which survived in industrial pollution area in heavy metal absorpting,six tree species were studied in this paper.The contents of heavy metals（Cu,Zn,Pb and Cd） in 6 plant samples and organs of root,branch and leaf were measured.The results indicate：The accumulation of four metals in arbors was in the order of ZnPbCuCd,Zn was in the largest 664.98 mg·kg-1,Cd was the smallest,only 4.42 mg·kg-1.The accumulation in every organs of different species varied apparently,and the rule was in an order：fine root coarse root leaf branch,fine root was in the largest,368.15 mg·kg-1.Ficus microcarpa had a higher capability of absorbing and accumulating heavy metals than others,with a cumulative amount of 455.60mg/kg.Eucalyptus urophylla and Litsea glutinosa had a high ability of anti-heavy metal,the accumulation were 179.86 and 221.63 mg·kg-1.Ficus altissima was medium,114.41 mg·kg-1.Blumeana schult and Acacia confusa had less resistance,78.04 mg·kg-1 and 96.41 mg·kg-1.