矿山废弃地生态修复区土壤特性 与物种多样性分析

Soil characteristics and species diversity analysis in ecological restoration area of mining abandoned land

为探求矿山废弃地生态修复区植被与土壤的演化特征及二者之间的相互关系,文中以祁连山中部金川矿山废弃地为研究对象,通过野外调查和实验检测分析,对区域内土壤理化特征及不同植被物种多样性进行了深入分析。结果表明:(1)植被恢复有效地增加了区域内物种多样性,现有物种20种,隶属15个科,但不同物种的多度和群落多样性具有明显的差异,其中,旱柳的多度值和重要值分别为29.67%和28.83%,在乔木层中占据重要位置,草本层植物种类繁多,丰富度较好,其中,早熟禾多度和重要值分别为46.66%和24.88%,显著高于其他植物,为草本植物的优势种。总体来说,草本层的丰富度指数、均匀度指数、多样性指数和优势度指数均高于灌木层和乔木层,在群落中占据主导地位;(2)研究区内植被的恢复有效地改善了土壤的理化性质,相比对照点,不同植被土壤电导率下降了约75.41%~83.40%,有机质含量和相对含水率分别增加了55.76%~180.24%和81.89%~362.53%,土壤pH值明显下降且未酸化,速效钾、硝态氮等养分显著增高;(3)相关分析显示,研究区物种多样性与土壤pH值和电导率显著负相关,与土壤有机质、含水率、速效钾、全磷、全氮、全钾呈极显著正相关。植被的恢复与土壤的改善相互作用、相互影响,选择合适的物种进行合理配置,能够有效地促进矿山废弃地植被的恢复和重建。

In order to explore the evolution characteristics and the relationships of the vegetation and the soil in the ecological restoration area of mining abandoned land,in this paper,taking the mining abandoned land of Jinchuan mine in the middle of Qilian mountain as the research object,and the soil physical and chemical characteristics and the diversity of the different vegetation species were analyzed deeply by the field investigation and the experimental detection and analysis in the region.Results showed that:(1)the species diversity had effectively increased by the vegetation restoration,there were 20 existing species belonging to 15 families,but the abundance and the community diversity of the different species had obvious differences,the abundance value and the importance value of the salix matsudana were 29.67%and 28.83%respectively,which occupied an important position in the arbor,the herbaceous plant had a wide variety of species with good abundance,the abundance and the importance value of the poa were 46.66%and 24.88%respectively,which were higher than other plants significantly and were the dominant species of the herbaceous plants.In general,the richness index,the uniformity index,the diversity index and the dominance index of the herb layer were higher than those of the shrub layer and the tree layer,occupying a dominant position in the community.(2)Restoration of vegetation in the study area effectively improved the physical and chemical properties of the soil,comparing with the comparison point,the conductivity of the different vegetation and the soil decreased by about 75.41%~83.40%,the content of the organic matter and the relative moisture content increased by 55.76%~180.24%and 81.89%~362.53%respectively.PH value of the soil had decreased significantly and had not been acidified,and the nutrients such as the available potassium and the nitrate nitrogen had increased significantly.(3)Correlation analysis showed that the species diversity in the study area was negatively correlated with the soil pH and the conductivity,and positively correlated with the soil organic matter,the water content,the available potassium,the total phosphorus,the total nitrogen and the total potassium.Vegetation restoration and the soil improvement interacted with each other and influenced each other.Selection of the appropriate species for the reasonable allocation could promote effectively the recovery and reconstruction of the mining abandoned land.