Study On The Characteristics Of Natural Restoration And Artifciail Ecological Restoration Of Quarry In East China

With economic development and modernization,the exploration and utilization of mineral resources is also increasing greatly.On the one hand,The quarry lets people meet their demand for material production,on the other hand,it results in serious damage of natural landscape and ecosystem. Restoration and reconstruction of abandoned mining areas has become an important research topic of ecology.The study is based on ecological theory.Through field investigation,pot experiments and field monitoring,this study have got an access to a large number of experimental data which mainly dedicated to the following four aspects:①the characteristics of soil and vegetation evolution during the process of the restoration period of abandoned mining quarry;②evaluation of the potential of the artificial vegetation restoration;③the eco-environmental effects of vegetation recovery mechanism and the process of vegetation restoration in the artificial vegetation restoration areas;④the choice of artificial vegetation for the quarry and the evaluation of the drought resistance of typical native plants;⑤the technical measures for artificial vegetation restoration in different types of abandoned quarries. The main findings are as follows:(1) The characteristics of soil and vegetation during the process of the restoration period of abandoned mining quarry shows:with the conduct of ecological restoration,soil thickness,soil organic accumulation,soil particle size,soil density and soil hardness gradually decrease;soil moisture,soil available nitrogen,available phosphorus and available kalium gradually increase while the physical and chemical properties of soil gradually improves.(2) With the increase in number of years,the species has increased from the initial 5 families 9species to the later 17 families 47 species and the species has experienced the enrichment.Order of community evolution:Herba Eleusines Indicae) + Setaria viridis + Salsola collina Community→Setaria viridis + Eragrostis pilosa + Chloris virgata Community Lespedeza→Lespedez abicolor + Setaria viridis + Chloris virgata + Phytolacca acinosa→Vitex negundo Linn.var.heterophylla + Ipperata cylindrica + Miscanthus floridulu→Vitex negundo Linn.var.heterophylla + Campylotropis macrocarpa + Miscanthus floridulu→Vitex negundo Linn.var.heterophylla + Campylotropis macrocarpa + Mallotus tenuifolius + Miscanthus floridulu mixedtrees+shrubs+grass community.a andβdiversity index has been taken to analyze characteristics of the plant community.As time passes by, the vegetation communities of abandoned quarry and the species have increased while the compositions of community species become similar to the surrounding plant communities.The overall species diversity of plant communities shows that the longer the nature recovery years last,the lower Simpson (D) and Pielou(C) predominace indexes become and there is a significant negative correlation between the predominace indexes and the number of recovery years.Patrick(Pa) and Margalef richness index (Ma) shows a trend from increase to decrease while Simpson and Shannon-Wiener diversity index shows a growing trend.(3) The initial study on the restoration of the natural ecology of the soil and plant communities in 4 different types of quarry sites shows:soil physical structure and nutrient status of 4 different types of quarry sites are very poor,but there are difference between different types.stone-soil stack and terrace for crush has the best and the worst ecological environments respectively and soil is the major factor affects the natural recovery of abandoned vegetation..(4) The use of fuzzy comprehensive evaluation - gray correlation advantages analysis method has established an evaluation model for artificial vegetation restoration potential of abandoned quarry.This model not only evaluates the level of the vegetation recovery potential of the abandoned quarry,but also compares the recovery potential between abandoned quarries on the same level.This model provides support for making decisions on how to evaluate the recovery potential,difficulty and propriety among different abandoned mining areas.(5) The environmental effects of artificial vegetation restoration areas are mainly to improve micro-climate environment of the quarry,lower air and soil temperature and increase air humidity, improve physical and chemical properties of soil,reduce soil density,increase soil porosity and improve soil moisture and stability infiltration rate accordingly.With the improvement physical properties of the soil,organic matters and nutrients in the soil have also significantly improved.Different plant matching modes have a different impact on physical and chemical properties of the soil.(6) On the basis of field investigation and exploration,according to 5 basic rules of choosing vegetation types,plants suitable for ecological restoration of quarries have been screened out,17 kinds of herbs,21 kinds of shrubs,13 kinds of trees and 6 kinds of vines.By employing the membership function evaluation method to analyze and assess the drought tolerance of 5 kinds of native trees,the findings show that the drought tolerance capacity is on the decrease from Vitex negundo Linn.var. heterophylla,Indigofera pseudotinctoria Matsum.,Rhus chinensis Mill,Lespedez abicolor to Amorpha fruticosa L..(7) According to the topographical features of the quarries,the abandoned quarries in Zhoushan area are divided into 6 types,and ecological management measures have been provided for each type. By introducing a variety of new materials,a reference has been provided for ecological management of the abandoned areas of the same type.