覆土处理对高寒矿区露天煤矿排土场植被和土壤特征的影响

目的]探讨高寒矿区覆土处理对露天煤矿排土场植被恢复的影响,以评估覆土措施在露天煤矿排土场所达到的植被恢复效果,为高寒矿区生态保护和恢复提供技术依据。方法]调查分析青海省木里煤田不同年限5个覆土处理和3个不覆土处理矿区排土场植被群落特征和土壤理化性质。结果]在覆土处理下,随着建植年限的增加,木里煤矿排土场植被和幼苗盖度显著增加(p<0.05),土壤速效磷、全钾、速效钾和有机质含量呈增加趋势,但未达显著水平;煤矿区排土场不覆土和覆土处理,植被特征和土壤理化性质主要指标差异不显著;非度量多维尺度分析结果表明:影响高寒煤矿区排土场植被生长的主要土壤养分是全氮、速效氮、速效钾和有机质。结论]高寒矿区露天煤矿排土场植被恢复的关键措施不是覆土处理,可通过施足有机肥和化肥的方式代替覆土处理达到植被恢复的目的。

Effects of Replacing Topsoil Treatment on Vegetation and Soil Characteristics of Open-pit Coal Mine Dump in Alpine Mining Area

Objective] The influence of replacing topsoil treatment on vegetation restoration of open-pit coal dumps in alpine mining area was investigated to evaluate the vegetation restoration effect of replacing topsoil treatment in open-pit coal mine dumps and to provide a technical basis for ecological protection and restoration in an mining area.Methods] The vegetation community characteristics and soil physicochemical properties of five topsoil replaced and three topsoil unreplaced treatments in mining areas in the Muli coalfield of Qinghai Province were investigated and analyzed.Results] Vegetation and seedling coverage significantly increased (p<0.05) as the planting period increased, and the available phosphorus, total potassium, available potassium, and organic matter content in the soil showed an increasing trend, but it was not significant. There was no significant difference between replacing and not replacing topsoil treatments in vegetation characteristics and soil physical and chemical properties. The results of nonmetric multidimensional scaling analysis showed that the soil nutrients, including total nitrogen, available nitrogen, available potassium, and organic matter, were the main factors affecting the vegetation growth.Conclusion] The key measure of vegetation restoration in open-pit coal mine dumps in alpine grasslands is not the replacement of topsoil treatment but the addition of organic and chemical fertilizers.