青海圣雄煤矿煤矸石堆积对周边高寒湿地植被和土壤的影响

Effects of Coal Gangue Accumulation in Shengxiong Coal Mining of Qinghai on Vegetation and Soil of Surrounding Alpine Wetland

针对青海江仓圣雄煤矿开采产生的煤矸石堆积对多年冻土区高寒湿地的影响,本文通过地面调查、取样比较,研究分析了矿区周边高寒湿地植被和土壤特征对煤矸石山堆积的响应。结果表明,矿区煤矸石堆积的4 a时间已经对周边近、中、远不同距离(300、650、1000 m)高寒湿地植被和土壤产生了一定程度的影响,引起原生莎草类盖度和高度减小,靠近煤矸石山区域的牧草高度降低,中距离杂草平均高度比近距离高2.65 cm。矸石堆积造成周围土壤容重增加,全氮和有机质含量逐渐减少,远距离0~10 cm土层全氮和有机质平均含量分别是近距离的1.16倍和1.20倍。高寒湿地土壤真菌和放线菌数量减少,0~10 cm土层近距离样区真菌数量仅为中距离的51.8%,中距离样区放线菌数量分别是近距离和远距离的4.32倍和3.4倍。除Zn以外,煤矸石堆积没有显著影响土壤As、Cr、Ni、Cu、Hg、Pb、Cd等7种重金属元素含量。随机森林算法分析表明,杂草类高度、Zn含量、土壤容重、莎草盖度、有机质含量是煤矸石堆积对周围高寒湿地影响的主要因子。

Taking the coal gangue mountain in Shengxiong coal mining of Qinghai and the surrounding alpine wetland as the study objects,the responses of vegetation and soil characteristics of the wetland to gangue accumulation were studied and analyzed through ground investigation and sampling comparison in this paper.The results showed that the 4 a coal gangue accumulation had certain influences on the vegetation and soil of the wetland with different distances(300,650,1000 m),which decreased the coverage and height of native sedge and decreased the height of herbage near gangue mountain,the average height of herbage in the middle distance was 2.65 cm higher than that in the short distance.Coal gangue accumulation increased the bulk density and the contents of total nitrogen and organic matter of surrounding soil,average contents of total nitrogen and organic matter in the far distance were 1.16 and 1.20 times of those in the short distance in 0–10 cm soil,respectively.The quantities of soil fungi and actinomycetes in wetland decreased,the quantity of soil fungi in the short distance was only 51.8%of that in the middle distance in 0–10 cm soil,the quantity of soil actinomycetes in the middle distance was 4.32 and 3.4 times of those in the short and far distances,respectively.Except for Zn,coal gangue accumulation did not significantly affect the contents of other heavy metals in surrounding soil.The analysis of random forest algorithm showed that herbage height,Zn content,soil bulk density,sedge coverage and organic matter content were the main factors of coal gangue accumulation which affect the surrounding alpine wetland.