高寒矿区人工种草对露天排土场渣山表层基质的影响

Effects of Artificial Grass planting on Surface Matrix Substrate on Open-pit Slag Hill in Alpine Mining Area

露天煤矿开采引起了祁连山区高寒湿地生态环境的部分破坏,本文通过调查7个矿区植被恢复状况,研究了青海木里煤田矿区人工种草对排土场渣山表层基质理化性质的影响,为高寒矿区植被复绿提供参考。结果表明:人工种草可以有效改善排土场渣山表层基质含水量,增加土壤微生物的数量,影响排土场渣山表层基质有机质含量。种草区域细菌、真菌、放线菌平均数量分别是不种草区域的4.20,4.05和2.29倍。7个矿区排土场渣山表层基质速效氮分布极不均衡,差异显著(P<0.05),种草区域明显高于非种草区域。人工种草后绝大多数矿区全氮、速效磷和速效钾含量明显增加,全钾含量降低。除汞元素外,种草对其它7种重金属(砷、铬、镉、铜、铅、镍、锌)含量产生不同程度的影响,7个矿区砷含量平均值从4.61 mg·kg^-1增加到6.06 mg·kg^-1。

Open-pit coal mining has caused some destruction of alpine wetland ecological environment in Qilian Mountains.Based on investigation of vegetation restoration in seven mining areas,the effects of artificial grass planting on physical and chemical properties of the surface soil of slag hill in the dumping area of the Muli coalfield,Qinghai province,were studied to provide reference for vegetation restoration in alpine mining area.The results showed that the artificial grass planting could effectively improve moisture content,increase the number of soil microorganisms and affect the organic matter content of slag mountain matrix.The average number of bacteria,fungi and actinomycetes in vegetation restoration regions was 4.20,4.05 and 2.29 times higher than those in non-restoration regions,respectively.The distribution of available nitrogen in the surface matrix of slag mountain was extremely uneven in seven mining areas(P<0.05).The planted area was significantly higher than that in non-planted area.The contents of total nitrogen,available phosphorus and available potassium in most mining areas increased significantly after artificial grass planting,but the total potassium content decreased.Except for mercury,the grass planting has different effects on the other seven heavy metals(As、Cr、Cd、Cu、Pd、Ni、Zn).The average arsenic content in seven mining areas increased from 4.61 mg·kg^-1 to 6.06 mg·kg^-1.