贵州东南部喀斯特汞金矿带苔藓植物及其重金属富集特征

Bryophytes and its heavy metal accumulation in mercury-gold ore belt in the karst area of southeast Guizhou

贵州东南部的三(三都)—丹(丹寨)汞金矿带是以喀斯特地质为背景,以卡林型汞金矿为主的多金属矿带。长期汞矿的开采和冶炼,导致当地生态环境受到了严重的破坏。通过对矿带上各种典型生境苔藓植物标本的采集、整理及鉴定,共发现了苔藓植物13科26属58种,其中丛藓科和真藓科为优势科。对汞金矿带上占优势的南亚石灰藓Hydrogonium consanguineum、狭网真藓Bryum algovicum、小石藓Weisia controversa、刺叶真藓Bryum lonchocaulon、皱叶毛口藓Trichostomum crispulum、狭叶小羽藓Haplocladium angustifolium、亮叶绢藓Entodon aeruginosus和黑扭口藓Barbula nigrescens等8种苔藓及基质的Cd、Pb、Cu、Zn、Ca、Mg、As、Hg等8种金属元素进行了分析测定。结果表明,8种苔藓体内元素含量最高是Ca,其次是Mg,最低的是Cd。Hg-Zn(P<0.01)存在极显著正相关;Hg-Pb(P<0.05)存在显著正相关性;而As-Cd(P<0.05)则存在显著负相关。应用富集系数分析,表明了矿带上8种苔藓对Cu均有一定的富集作用,小石藓对Hg、Cd、Cu、Zn等4种重金属的富集系数均大于1,狭网真藓对Hg、As、Cu、Pb等4种重金属的富集系数大于1,表明这两个物种对汞金矿带上重金属污染具有良好的耐受性,是矿带上生态恢复、矿区综合治理的适宜物种。

The San-Dan （Sandu-Danzhai） Mercury-Gold Ore Belt in the karst area of southeast Guizhou belongs to the Carlin-type mercury-gold deposits. Long-term mercury ore and gold ore exploiting and smelting led to serious environmental pollution in San-Dan Mercury Belt. Based on extensive investigation of the bryophytes in the area, it is discovered that the bryoflora consists of 58 species and 26 genera in 13 families. The dominant families are Bryaceae and Pottiaceae. The concentration of Cd, Pb, Cu, Zn, Ca, Mg, As and Hg in bryophytes and their substrates are measured. Hydrogonium consanguineum, Bryum algovicum, Weisia controversa, Bryum lonchocaulon, Trichostomum crispulum, Haplocladium angustifolium, Entodon aeruginosus and Entodon aeruginosus are the dominant species in Mercury-Gold Belt. The results show that Ca concentration is the highest, Mg the second and the Cd the lowest in the plants of eight main species of bryophytes. Hg-Zn shows prefect correlation at 0.01 level, Hg-Pb shows coefficient at 0.05 leve1, but As-Cd shows negative correlation at 0.05 leve1. Based on the analysis on the accumulation coefficient, all the eight species have ability to accumulate Copper. Weisia controversa and Bryum algovicum could accumulate more than four types of heavy metals. It indicates that these two species have strong tolerance to contamination by Mercury-Gold ore belt and is good materials to be used for bioremediation and comprehensive treatment of abandoned mining site.