露天矿区植物多样性与土壤养分空间变异性特征

Characteristics of spatial variability of plant diversity and soil nutrients in open-pit mining area

为研究煤矿露天开采对自然植物与土壤因子的影响,以内蒙古胜利矿区为研究区,采用野外生态学调查方法对采矿区周边不同距离草地进行植物群落调查,采集距矿区不同距离土壤样品进行实验室分析。结果表明:①距矿区边界100 m处,草地自然植物群落以糙隐子草(Cleistogenessquarrosa)、寸草苔(Carex duriuscula)和小画眉草(Eragrostis minor)为主;距离煤矿400 m处植物群落以大针茅(Stipa grandis)、克氏针茅(S.krylovii)和冰草(Agropyron cristatum)为主,900 m处以大针茅、小画眉草和糙隐子草为主;距离煤矿1900 m处,以克氏针茅、糙隐子草和大针茅为主;②与对照区相比,距离矿区越近,植物多样性指数显著降低,群落相似性降低,土壤含水量、有机质(SOM)、硝态氮(NO3--N)和速效磷(AP)均显著减少;③远离矿区的位置土壤肥力要好于矿区附近,煤矿开采对一定范围内的土壤肥力产生影响,矿区周边土壤养分的空间异质性呈不同程度的变化趋势;④冗余分析(RDA)表明,植物多样性指数与土壤含水量、有机质、硝态氮、速效磷和速效钾呈正相关。矿区周边植被群落的演替对土壤养分的需求不同,群落物种的变化明显,土壤含水量、有机质在影响矿区周边植物群落特征的土壤因子中所占比重较大。矿区周边草地出现不同程度的退化趋势,可在自然恢复为主的前提下,实施适当的人工干预调控以促进矿区周边草地的恢复。

To study the effects of open-pit mining on natural plants and soil factors,We take the Inner Mongolia Nortel Shengli Mining Area as the study area.We use field ecological survey methods to carried out plant community surveys on grassland at different distances around the mining area.and collectted soil samples around the mining area for laboratory analysis.The study results show that:①the natural flora of the grassland is dominated by Cleistogenes squarrosa,Carex duriuscula and Eragrostis minor,at a distance of 100 m away from the coal mine which is relatively disturbed by coal mines;the plant community at a distance of 400 m from the coal mine is dominated by Stipa grandis,S.krylovii and Agropyron cristatum.Stipa grandis,Eragrostis minor and Cleistogenes squarrosa are mainly at a distance of 900 m;at a distance of 1900 m from the coal mine,the vegetation community has stabilized with S.krylovii,Cleistogenes squarrosa and Stipa grandis.②Compared with the control area,the closer to the mining area,the plant diversity index decreased significantly,the community similarity decreased,and the soil water content,organic matter,nitrate nitrogen,and available phosphorus all decreased significantly.③The soil fertility far from the mining area is better than that near the mining area.Coal mining has an impact on soil fertility within a certain range,and the spatial heterogeneity of soil nutrients around the mining area changes to varying degrees.④Redundancy analysis shows that plant diversity index was positively correlated with soil water content,organic matter,nitrate nitrogen,available phosphorus and available potassium.The soil and plants around the coal mining area are disturbed to a certain extent,and the soil nutrients are spatially heterogeneous.The succession of vegetation communities around the mining area has different needs for soil nutrients,and the changes of community species are obvious.Soil water content and organic matter account for a larger proportion of soil factors affecting plant community characteristics around the mining area.The grassland around the mining area is degraded to varying degrees.Under the premise of natural restoration,appropriate artificial interventions can be implemented to promote the restoration of grassland around the open-pit.