洛坝铅锌矿废弃不同时间渣地植被恢复演替动态

对甘肃省徽县洛坝铅锌矿不同废弃时间的废渣地进行的化学分析表明，其主要污染物为重金属Pb和Zn，其w(Pb)和w(Zn)最大值分别为6 298和480 800 mg/kg. 重金属在废渣地中的质量分数随废弃时间的增长而减少；对废渣地恢复植被演替调查发现，Pb和Zn是影响植物自然演替的限制因子. 在现场考察的基础上对洛坝废渣地进行了植被恢复演替调查. 结果表明:从废弃时间序列上看，废渣地植物种类在增加、荒漠化在逆转，3，6和11 a的废渣地植物数分别为12，17和40种；从废渣地植被恢复演替序列上看，各时期植物都在更替，3 a废渣地以野艾蒿(Artemisia vulgaris)+升马塘(Digitaria sanguinalis)+车前草(Plantago asiatica)群落为主；6 a废渣地以野艾蒿+针叶蒿(Tripolium vulgare)+商陆(Phytolacca acinosa)+小蓬草(Erigeron annuu)群落为主；11 a废渣地又增加有固氮植物三叶草(Trifolium pratense)、苜蓿(Medicago lupulina)及紫薇(Lagerstroemia indica)、臭椿(Ailanthus altissima)的成功定居，已形成草-灌-乔简单植被结构. 

Succession Dynamics of Restored Vegetation in Lead-Zinc Mine Wastelands in Luoba over Different Time Periods

Chemical analysis of Luoba lead-zinc mine wastelands after being abandoned for different times indicated that the main pollutant types were some heavy metals such as Pb, Zn and others. The soils of the wastelands contained high concentrations of Pb and Zn; the highest content of Zn was 480,800 mg/kg, and the highest content of Pb was 6,298 mg/kg. The heavy metal mass fraction in the wastelands decreased with amount of time growing after abandonment. The restoration vegetation succession investigation discovered that the phytotoxicity of Pb and Zn may be the major obstacles for plant succession on the wastelands. From the time of abandonment on, the number of species of plants was increasing, and desertification was reversing. 12, 17, and 40 species of plants were found growing on 3, 6, and 11 year wastelands, respectively. From the time of vegetation succession on, the plant species change with various periods. There were major communities of Artemisia vulgaris, Digitaria sanguinalis and Plantago asiatica on the three year wasteland, and there were major communities of Artemisia vulgaris, Tripolium vulgare, Phytolacca acinosa and Erigeron annuu on the six year wasteland. On the 11 year wasteland, the nitrogen-fixing plants of Trifolium pratense and Medicago lupulina, Lagerstroemia indica and Ailanthus altissima were growing successfully, and simple grass-shrubs-arbor vegetation structures had formed.