Study On The Characteristics Of Plant Community,soil Seed Bank And Physicochemical Properties Of Longchang Coal Mine Dump In Wuhai City

The dump is an extreme ecosystem,which is prone to geological disasters such as soil erosion and landslide due to its large pile area and steep slope.The effective vegetation restoration in the dump in arid and semi-arid areas is conducive to regional ecological security and stability.Taking luotuoshan Coal Mine dump in Longchang,Wuhai City as the research area,the surface vegetation,soil seed bank and soil physical and chemical properties at the early stage of different vegetation restoration modes of the dump were studied in this thesis.Field vegetation investigation,seed bank germination and laboratory experiment methods were combined.Three types of shrub-grass restoration modes of slope Caragana korshinskii+Agropyron cristatum+Medicago sativa,Caragana korshinskii+Artemisia ordosica+Medicago sativa+Limonium sinense,Artemisia ordosica+Agropyron cristatum+Medicago sativa;Three kinds of herbal repair pattern alfalfa grass,Medicago sativa+gropyron cristatum,Astragalus adsurgens+Agropyron cristatum,Medicago sativa+Elymus sibiricus,natural slope repair CK,7 research sample plots of plant community,soil seed Banks,to study the characteristics of soil physical and chemical properties,using the principal component analysis,entropy value method and the TOPSIS model evaluation method to evaluate different vegetation restoration mode,In order to screen out the dominant vegetation in this area,and provide theoretical basis for the selection of vegetation species in this area.The results are as follows:(1)A total of 33 species of plants were found in the study area of Luotuoshan Coal Mine dump,longchang,belonging to 12 families and 32 genera.Gramineae,legumes,chenopodiaceae and compositae occupied the dominant position in the settlement community.The main life forms were perennial herbaceous,followed by one/biennial herbaceous.A total of 11 plants germinated in the soil seed bank,and the density of the soil seed bank ranged from 137 seeds/m2 to 1577 seeds/m~2.The dominant life type was one/two year herbaceous,followed by perennial herbaceous.The similarity index between surface vegetation and soil seed bank differed greatly among different configuration modes.(2)The soil bulk density,total porosity and field water capacity of the dump range from 1.36 g·cm-3 to 1.60g·cm-3,31.97%to 40.47%and 15.71%to 26.4%,respectively.Compared with the natural restored slope,the soil physical properties are improved.(3)the dump soil PH between 6.6～7.1,show neuter soil in the study area as a whole,is beneficial to vegetation growth,total phosphorus organic matter total potassium available phosphorus,available potassium,total nitrogen alkali-hydro nitrogen of soil chemical properties indexes such as compared with the natural repair of CK,got a higher improvement,surface soil repair effect is higher than the lower soil repair effect,in addition to the table on cohesion.(4)The aboveground vegetation diversity characteristics of sixdifferent configuration modes were as follows:the indexes of Artemisia ordosica+Agropyron cristatum+Medicago sativa(GC3)were better than those of other restoration modes and herbage,and the soil seed bank density was the highest and the soil physical and chemical properties were good.(5)According to TOPSIS score ranking,Artemisia ordosica+Agropyron cristatum+Medicago sativa(GC3),Medicago sativa+gropyron cristatum(C1),and Caragana korshinskii+Artemisia ordosica+Medicago sativa+Limonium sinense(GC2)ranked the third in the study area,and the ecological benefits of each restoration model in the study area were in the middle level.Based on TOPSIS ranking and evaluation indexes,the most suitable vegetation restoration model of Luotuoshan Coal Mine drainage site was Artemisia ordosica+Agropyron cristatum+Medicago sativa(GC3).It is suggested that the priority vegetation restoration mode of the dumping site in the study area should be shrub-grass Artemisia ordosica+Agropyron cristatum+Medicago sativa.The late succession plant species should be added through the study,and legumes,graminae and other plants that can improve soil properties and drought tolerance should be added.