刺楸年轮中重金属含量动态变化及富集特性

为探索刺楸对受污染土壤重金属的富集和修复效应, 以南京栖霞山的乡土树种刺楸及其根际周边土壤为研究对象, 截取其根基部年轮盘及根际土壤样本, 采用ICP-AES法测定年轮及土壤样本中重金属(Cu、Cd、Cr、Mn、Ni、Pb、Zn)元素含量。结果表明: 栖霞山样地中的土壤受Mn、Pb和Zn污染最为严重, 存在Cu、Cd、Mn、Pb、Zn元素的高度复合污染, Cd、Cr、Cu、Ni、Zn在土壤和年轮中存在相关性, Mn和Pb则没有表现出明显的相关性; 刺楸修复受Cd、Mn、Pb、Zn污染的土壤效果并不显著, 更适用于Cr、Cu、Ni污染的土壤修复; 鉴于Cu元素含量变化特征, 刺楸也可以作为反映当地污染历史的记录载体; 刺楸年轮中的重金属元素之间存在交互作用, 其中Cd与Zn元素含量高度相关(r=0.984, p<0.01), 在刺楸年轮吸收重金属元素的过程中, Cu与Cd、Cr、Mn、Zn元素具有协同作用, Mn元素对其他元素有一定的拮抗作用。

Dynamic changes and accumulation characteristics of heavy metals in tree rings of Kalopanax septemlobus

The objects of this work were to reveal the ability of monitoring heavy metal and to explore the effects on rehabilitating the contaminated soil by Kalopanax septemlobus.By applying tree rings of Kalopanax septemlobus that was native in Qixia area,Nanjing,and soil samples around the roots as research materials,applying the methods of ICP-AES to measure the contents of metals(Cu,Cd,Cr,Mn,Ni,Pb,Zn)both in sample soil and tree rings.The results showed that Mn,Pb,and Zn seriously contaminated the soil in sample area.In addition,there was a combined contamination of Cu,Cd,Mn,Pb,Zn elements,Cd,Cr,Cu,Ni and Zn had correlations in soil and tree-rings,while Mn and Pb showed no significant correlation.Kalopanax septemlobus could be appropriate for restoring the soil contaminated by Cr,Cu and Ni,rather than Cd,Mn,Pb and Zn,Also,applied as a record carrier reflecting local pollution history in view of changes by the content of Cu.Also,there was an interaction among the heavy metals in tree ring of Kalopanax septemlobus;the content of Cd and Zn in tree rings was significantly correlated(r=0.984,p<0.01);in the process of absorbing heavy metals by the ring of Kalopanax septemlobus,Cu had synergistic effect with Cd,Cr,Mn and Zn,and Mn had an antagonistic effect in some sense.