|
Based on the field investigation and analysis inside, the indexes of soil physical properties,soil chemical properties,soil microorganisms,the vegetal status of plants,the contents and the conformation of heavy metal have been studied.The main conclusions can be drawn as follows:(1)The mining wasteland been evegetated, the soil physical properties have been greatly improved, the soil becomes loose and porous, permeable good ventilation, suitable for plant growth.(2)As the precipitation leaching, soil enzyme, the transformation and absorption of animal and microbial factors, mining wasteland been evegetated,soil in 0-20cm ,20-40cm layer of organic matter, hydrolysable nitrogen, phosphorus, potassium content over time are reduced, but the difference was not significant. But the 40-60cm layer of soil content in all nutritional parameters gradually increase over time.(3)Mining wasteland been evegetated,the trend of soil enzyme activity and nutrition targets the same trend, but the number of three types of micro-organisms changes over time in each soil layer were increased.(4)Mining wasteland been evegetated,the plant species richness, Simpson index, Shannon - Wienner index and evenness index has reached a high level, especially in the herb layer, even higher than the forest plots. However, tree and shrub diversity is lower.(5)Mining wasteland been evegetated,the soil content of heavy metals have decreased over time, but Cd, Cu content higher than soil environmental quality standard Grade II; Zn, Pb content higher than soil environmental quality standard Grade I. In addition, migration of heavy metals in the order: Cd> Ni> Zn> Cu> Pb> Cr. Activity of the order: Ni> Zn> Cd> Cu> Pb> Cr.
|