Ecological Effects Of Typical Vegetation-soil System On Reclaimed Dumps In Antaibao Surface Mining Area Of Shanxi

The Antaibao surface coal mine(ATB),one of the largest surface coal mines in China,is located in the Pingshuo mining district of northern Shanxi Province.It is located in the steppe-forest transition zone of the Loess Plateau,which enjoy a typical semi-arid continental monsoon climate and barren soil.In this region,the process of coal waste dump revegetation with different planting combinations and different revegetated ages has significant ecological effects on the vegetation-soil system.In this thesis,field plant and soil plot sampling on the reclaimed dumps of ATB,with a focus on the planted vegetation-soil system,which investigated the planted community composition,species diversity,interspecific relationship of dominant species,soil physicochemical properties,enzyme activity and bacterial community diversity of eight typical planting combinations with different revegetated ages.Studied by using the methods of quantitative ecology,soil biochemical analysis and high-throughput sequencing,and evaluated the ecological effects of the eight typical planting combinations by using principal component analysis.The aim was to elucidate planted vegetation-soil relationships in order to determine the most suitable planting combinations and to help quickly establishment a self-sustaining planted vegetation-soil ecosystem adapted the unique coal waste dumps environment.This would further support scientific management strategies for future ecological restoration of abandoned coal waste dumps in Shanxi mining areas and similar areas in China.The main research findings were as follows:(1)The species diversity of the typical planting combinations on the reclaimed dumps in ATB significantly increased with the increase in revegetation age.The results of the plant plot sampling showed that there were 78 species of vascular plants from 22 genera and 56 families in the eight typical planting combinations on the reclaimed dumps in ATB.Among them,the planted trees,shrubs and herbaceous plants(18 species),natural colonized plants(60species),and perennial herbaceous plant species(33 species)respectively accounted for 23.1%,76.9% and 42.3% of the total species.The dominant species were the planted species of Robinia pseudoacacia,Pinus tabulaeformi,Ulmus pumila,Caragana korshinskii,Hippophae rhamnoides,Medicago sativa,Agropyron desertorum and Agropyron cristatum.The planted community composition was mainly composed of Compositae(12 species),Gramineae(9 species)and Leguminosae(7 species).Mesophyte,xero-mesophyte and mesoxerophytes plants accounted for 55.1%,21.8% and 12.8% of the total species,respectively,indicating that with the increase in revegetation age,the habitats of the planted communities on the reclaimed dumps in ATB have been significantly improved,the species diversity(Pa?H??DS?IP)of the communities has significant increased(p<0.05),and the planted communities tended to develop steadily.(2)The interspecific correlation of dominant species in the typical planting combinations on the reclaimed dumps in ATB was relatively low.Results of the interspecific relationship analysis showed that among 78species-pairs from 13 dominant species of the planted communities in the eight planting combinations on the reclaimed dumps in ATB,most species-pairs had no significant interspecific association,and their interspecific associations were loose,which indicated that the planted vegetation on the reclaimed dumps was still in the process of succession to zonal vegetation.Based on Spearman's rank correlation coefficients,the 13 dominant species fell into two ecological species groups,with soil moisture being the key environmental factor responsible for the differentiation of these species groups.(3)Soil quality of the typical planting combinations on the reclaimed dumps in ATB significantly improved with the increase of revegetated age.Analysis of soil physicochemical properties showed that,compared with the control(CK),the soil nutrients(organic matter,total nitrogen,available nitrogen and potassium)of the eight typical planting combinations on thereclaimed dumps in ATB significantly increased with the increase of revegetated age(p<0.05).Furthermore,soil bulk density and pH values decreased,which indicated that the soil quality of of the eight typical eight planting combinations on the reclaimed dumps in ATB had improved.(4)Soil enzyme activity of the typical planting combinations on the reclaimed dumps in ATB significantly increased with the increase of revegetated age.The results of soil enzyme activity analysis showed that,compared with CK,soil enzyme activity(urease,alkaline phosphatase,invertase and catalase)of the eight typical planting combinations on the reclaimed dumps in ATB significantly increased with increase of revegetated age(p<0.05).In addition,soil enzyme activity of mixed forest vegetation was higher than that of pure forest,shrubs and grasslands;soil enzyme activity of R.pseudoacacia + P.tabulaeformis forest was the highest of those tested.Overall,soil enzyme activity was strongly correlated with soil physicochemical properties.(5)Soil microbial diversity of the typical planting combinations on the reclaimed dumps in ATB significantly increased with increase in revegetation age.The soil bacterial community structure was less different.The results of high-throughput sequencing analysis showed that the soil bacterial communities of the eight planting combinations on the reclaimed dumps in ATB belonged to 44 Phylum,80 Classes,113 Orders,259 Families,and 977 Genera.There were differences in the community structure of soil bacteria at different taxonomic levels among the eight typical planting combinations.Compared with CK,the diversity of soil bacteria in the eight typical the eight planting combinations significantly increased with the increase of revegetation age.The richness and diversity of soil bacteria in the three planting combinations of R.pseudoacacia + P.tabulaeformis,Caragana korshinskii and U.pumila + R.pseudoacacia were the highest of those evaluated.Soil enzymes,organic matter,and total nitrogen were the key factors affecting soil bacterial diversity.(6)The ecological effects of the typical planting combinations with elderrevegetated age on the reclaimed dumps in ATB were significant,and the most prominent ones were the planting combinations of R.pseudoacacia + P.tabulaeformis.The ecological effects evaluation by principal component analysis(PCA)showed that,compared with CK,the ecological effects of the vegetation-soil system of the eight planting combinations on the reclaimed dumps in ATB were significantly different.The planted vegetation-soil system of R.pseudoacacia + P.tabulaeformis had the best ecological effect and significantly improved soil quality on the reclaimed dumps.