对湖北铜绿山古铜矿遗址区的木本植物种类组成及生长概况进行了调查,并采用原子吸收光谱法测定了木本植物地上部和地下部及其根际土壤中重金属含量;在此基础上,分析了各树种对Cu、Cd 和Pb 的富集作用,并对木本植物的生态修复意义进行了初步评价。结果表明:在该古铜矿遗址区共有木本植物13 科14 属14 种,其中乔木13 种、灌木1 种;木本植物的树龄4 ~25 a、株高3. 7 ~22. 6 m、胸径5. 3 ~29. 0 cm,长势均较好。木本植物根际土壤中Cu、Cd、Pb、Cr、Mn 和Zn 的平均含量分别为3 166. 73、3. 66、137. 06、31. 32、1 774. 43 和208. 32 mg·kg-1 ,其中,土壤中Cu、Cd 和Pb 的含量达到重度污染等级。各树种地上部和地下部的Cu、Cd 和Pb 的含量差异明显,且均为Cu 含量最高、Cd 含量最低;各树种的地上部和地下部对Cu、Cd 和Pb 的富集系数及综合富集系数也均有明显差异,但对Cd 的富集系数均最大。法国冬青[Viburnum odoratissimum var. awabuki (K. Koch) Zabel ex Rumpl.]、梧桐[Firmiana platanifolia (Linn. f.) Marsili]、桂花[Osmanthus fragrans (Thunb.) Lour.]和刺槐(Robinia pseudoacacia Linn.)地上部的综合富集系数较高,苦楝(Melia azedarach Linn.)、女贞(Ligustrum lucidum Ait.)、法国冬青和樟树[Cinnamomum camphora (Linn.) Presl]地下部的综合富集系数较高;总体上看,法国冬青、苦楝、女贞、梧桐和桂花对Cu、Cd 和Pb 的平均综合富集系数均大于1,具有较高的重金属富集能力。根据研究结果,建议在Pb 污染区域可选择栽植二球悬铃木[Platanus ×acerifolia (Ait.) Willd.]和构树[Broussonetia papyrifera (Linn.) L’Hert. ex Vent.]等树种,在Cd 污染区域可选择栽植法国冬青、梧桐、刺槐和苦楝等树种,而在Cu-Cd-Pb 复合污染区域应栽植法国冬青、苦楝、女贞、梧桐、桂花和刺槐等树种。

Species composition and growth status of woody plants at ancient copper mine site in Tonglushan of Hubei Province were surveyed and heavy metal contents in above-and under-ground parts of woody plants and in its rhizosphere soil were determined by atomic absorption spectrometry. On these bases, enrichment effect of all tree species on Cu, Cd and Pb was analyzed and significance of ecological restoration of woody plants was evaluated preliminarily. The results show that there are 14 species woody plants belonging to 14 genera in 13 families at ancient copper mine site in Tonglushan, in which includes 13 arbors and 1 shrub, and they grow better with tree age 4-25 a, height 3. 7-22. 6 m and diameter at breath height 5. 3-29. 0 cm. Average contents of Cu, Cd, Pb, Cr, Mn and Zn in rhizosphere soil of woody plants are 3 166. 73, 3. 66, 137. 06, 31. 32, 1 774. 43 and 208. 32 mg·kg-1, respectively, in which, Cu, Cd and Pb contents in soil reach the heavy pollution level. There are obvious differences in Cu, Cd and Pb contents in above-and under-ground parts of all tree species, and in all tree species, Cu content is the highest and Cd content is the lowest. Also, there are obvious differences in enrichment coefficients and complex enrichment coefficients of Cu, Cd and Pb in above-and under-ground parts of all tree species but enrichment coefficient of Cd is the highest. Complex enrichment coefficient of above-ground part of Viburnum odoratissimum var. awabuki (K. Koch) Zabel ex Rumpl., Firmiana platanifolia (Linn. f.) Marsili, Osmanthus fragrans (Thunb.) Lour. and Robinia pseudoacacia Linn. is higher, and that of under-ground part of Melia azedarach Linn., Ligustrum lucidum Ait., V. odoratissimum var. awabuki and Cinnamomum camphora (Linn.) Presl is higher. Generally, averages of complex enrichment coefficient of V. odoratissimum var. awabuki, M. azedarach, L. lucidum, F. platanifolia and O.fragrans on Cu, Cd and Pb all are more than 1, and they possess strong enrichment ability to heavy metals. According to these research results, it is suggested that Platanus ×acerifolia (Ait.) Willd. and Broussonetia papyrifera (Linn.) L’Hert. ex Vent. can be planted in Pb pollution area, V. odoratissimum var. awabuki, F. platanifolia, R. pseudoacacia and M. azedarach can be planted in Cd pollution area,and V. odoratissimum var. awabuki, M. azedarach, L. lucidum, F. platanifolia, O. fragrans and R.pseudoacacia should be planted in Cu-Cd-Pb complex pollution area.