Community And Soil Characteristic During The Process Of Vegetation Restoration In Zijinshan Gold Tailing Wasteland

For the purpose of exploring the succession law of vegetation and soil,interaction mechanism and the effects of different vegetation types on soil properties and plant community characteristics,Zijinshan gold tailings was selected as research object and the method of spatial sequence instead of time successional sequence was used to investigate plant community structural characteristics,quantity component and soil physical-chemical properties and heavy metals at different vegetation restoration stages and patterns,compared with lands under natural plant conmunity and bared tailings without vegetation restoration,revealing the succession law of vegetation and soil,and the relationship between species diversity and soil properties,analysing species diversity and improvement effect on soil properties of plant community under different vegetation patterns.The main results were as follows:(1)Vegetation restoration could significantly improve species diversity,which increased gradually with restored years,species richness increased by 11 to 56 from first year to tenth year.The species richness of tree and shrub layer increased,herb layer increased at first and then decreased gradually at different vegetation restoration stages,the species diversity was higher in shrub and herb layer than in tree layer.(2)Vegetation restoration could significantly improve soil physical-chemical properties,soil bulk density and pH decreased gradually with restored years at different vegetation restoration stages,while soil organic matter and nutrient content increased,and the contents of total and available phosphorus increased at first and then decreased gradually.There was a remarkable correlation between species diversity and soil physical-chemical properties.(3)Vegetation types have significantly effect on community characteristics.The species and structure of plant community were different among different vegetation restoration patterns,6 types of artificial vegetation restoration communities and natural community similarity was very low and showed extremely dissimilar,Artificial undisturbed community can accelerate species diversity.The species diversity of Pinus massoniana-Liquidambar formosana-local floodplain grass and Pinus massoniana-Eucalyptus dnmii-local floodplain grass were higher,and community structure was more complex.Pinus massoniana-Cinnamomum camphora-Lespedeza bicotor-loeal floodplain grass was lower.(4)The type of vegetation has effect on soil property,and the characteristics of soil properties were different among different vegetation restoration patterns.The content of different vegetation restoration patterns on soil organic matter increased by 12.23 to 27.74 times after vegetation restoration which showed that mode F>mode E>mode A>mode B>mode C>mode D.The soil nutrient and physical characteristics of the vegetation restoration community are consistent,and the good nutrient cycling and accumulation need to be based on the good physical properties.Compared with natural community,the soil quality of artificial undisturbed community still maintained at low level.(5)The result of a principal component analysis(PCA)and technique for order preference by similarity to an ideal solution(TOPSIS)indicated that Pinus massoniana-Liquidambar formosana-local floodplain grass and Pinus massoniana-Eucalyptus dunnii-local floodplain grass had better comprehensive improvement of the ecological restoration.The species diversity of different vegetation restoration stages and patterns was higher in shrub and herb layer than in tree layer.The herbaceous plants were the dominant life forms in artificial vegetation community,and Gramineae and Compositae occupied the dominant position,Miscanthus floridulus,Ageratum conyzoides,Artemisia argyi,Bidens pilosa and Isachne globosa can serve as pioneer species during vegetation at Preliminary Succession.