桂西北有色金属矿区苔藓植物的主要类群及重金属富集特征

Main Groups and Heavy Metal Enrichment Characteristics of Bryophytes in Non-Ferrous Metal Mining Areas of Northwest Guangxi

摘要: 为了说明苔藓植物的重金属富集特征及其在土壤重金属污染修复中的作用，通过实地调查，采集了桂西北有色金属矿区苔藓植物的主要类群及其生长基质，用经典的形态学方法对其进行分类鉴定，用原子吸收光谱法对实验样品五种重金属元素Mn、Cu、Zn、Pb、Cd的含量进行测定，对苔藓植物的重金属富集系数及生长基质的重金属污染状况进行了比较分析。结果表明：1) 野外采集的7种苔藓植物隶属于2科4属，优势科为丛藓科和真藓科，优势属为真藓属和丝瓜藓属；不同重金属污染背景的调查区域，苔藓植物的种类差异较大。2) 苔藓植物具有较强的环境适应性，其生长基质的理化特性差异比较大，而且对重金属具有较强的耐性和一定的吸收能力，可以在有色金属矿区重度污染的环境中正常生长繁殖。3) 苔藓植物中的重金属含量与其生长基质的重金属含量具有明显的相关性，纤茎真藓对Cu和Zn的富集作用较强，Pohlia sp.对Cu、Zn、Pb相对富集，小石藓对Zn的富集系数最大，这些苔藓植物不仅可以作为环境监测的指示生物，也可作为重金属污染修复的先锋植物。由此可见，虽然有色金属矿区苔藓植物的种类数量相对较少，但重金属富集能力和耐性较强的苔藓植物优势种群，同样可以在土壤重金属污染生态修复中发挥积极的作用。

Abstract: In order to illustrate the heavy metal enrichment characteristics of bryophytes and their role in soil heavy metal pollution remediation, field survey was conducted to collect the main groups of bryophytes and their growth substrates in the non-ferrous metal mining area of northwest Guangxi. The classic morphological classification methods was used to classify and identify them, and atomic absorption spectroscopy was used to determine the content of five heavy metal elements Mn, Cu, Zn, Pb, and Cd in experimental samples. The heavy metal enrichment coefficients of bryophytes and the heavy metal pollution status of their growth substrates were compared and analyzed. The results showed that: 1) The 7 moss plants collected in the field belong to 2 families and 4 genera, with the dominant families being Pottiaceae and Bryaceae, and the dominant genera being Pohiia and Bryum. There are significant differences in the species of moss plants in the investigation areas with different heavy metal pollution backgrounds. 2) Bryophytes have strong environmental adaptability, with significant differences in the physicochemical properties of their growth substrates. They also have strong tolerance and absorption capacity for heavy metals, and can grow and reproduce normally in heavily polluted environments in non-ferrous metal mining areas. 3) The heavy metal content in moss plants is significantly correlated with the heavy metal content in their growth substrates. Bryum leptocaulon have a strong enrichment effect on Cu and Zn, Pohlia sp. relatively enriches Cu, Zn, and Pb, and Weissia controversa has the highest enrichment coefficient for Zn. These mosses can not only serve as indicator organisms for environmental monitoring, but also as pioneer plants for heavy metal pollution remediation. From this, it can be seen that although the number of species of moss plants in non-ferrous metal mining areas is relatively small, the dominant population of moss plants with strong heavy metal enrichment ability and tolerance can also play a positive role in the ecological restoration of soil heavy metal pollution.