农田-泥炭藓系统重金属富集特征与生态风险评价

为了解贵州省都匀市毛尖镇高寨水库附近土壤重金属污染现状和农田泥炭藓对重金属的富集能力和重金属的污染来源，选取了该区域附近的农田泥炭藓为研究对象，测定了泥炭藓及表层土壤中重金属含量；采用空间分析和多元统计分析方法对重金属进行污染评价及来源分析.结果表明，表层土壤和农田泥炭藓中的重金属含量排序分别为：V>Zn>Cr>Pb>Cu>Ni>As>Cd>Hg和Zn>Cr>Ni>Cu>Pb>V>As>Cd>Hg.研究区域内的泥炭藓优势种为卵叶泥炭藓（Sphagnum ovatum Hamp.C.Muell）和泥炭藓原亚种（Sphagnum palustre L. ssp.palustre）,二者对土壤Cd、 Ni、 Cu和Zn均具有较强的富集能力，但卵叶泥炭藓（S.ovatum）对土壤重金属的富集能力总体高于后者.单项污染指数（C_f）和地累积指数(I_geo)均表明土壤Cd和Hg的含量水平最高，综合污染指数RI的平均值为87.75,处于轻微生态风险.土壤和泥炭藓的...

Concentration Characteristics of Heavy Metals in Farmland-Sphagnum System and Ecological Risk Assessment

In order to study the current status of heavy metal pollution, the accumulation capacity of farmland Sphagnum for heavy metals and the source of heavy metal pollution in the soil near Gaozhai Reservoir in Maojian Tea Town, Duyun City, Guizhou Province were assessed. Sphagnum and topsoil near this area were selected as the research object to measure the content of heavy metals. Spatial analysis and multivariate statistical analysis methods were used to conduct pollution evaluation and source analysis of heavy metals. The results showed that the heavy metal content in topsoil and farmland Sphagnum were V>Zn>Cr>Pb>Cu>Ni>As>Cd>Hg and Zn>Cr>Ni>Cu>Pb>V>As>Cd>Hg, respectively. The dominant species of Sphagnum in the study area were Sphagnum palustre L. ssp. palustre and Sphagnum ovatum Hamp.C.Muell, both of which had a strong ability to accumulate soil Cd, Ni, Cu, and Zn; however, the S. ovatum enrichment capacity of soil heavy metals was generally higher than that of the latter. Both the single pollution index (C_f) and the geo-accumulation index (I_geo) indicated that the Cd and Hg content in soil were at the highest levels, and the average comprehensive pollution index RI was 87.75, which indicates a slight ecological risk. The sources of heavy metals in soil and Sphagnum included transportation, domestic sewage, agricultural activities, and natural soil-forming processes.