| In recent years,a series of ecological and environmental problems caused by the development and utilization of coal resources have attracted people’s attention.Waste deposits have seriously affected the ecosystem of mining areas,especially the rapid development of open-pit coal mines in recent years,which has brought hidden dangers to ecological security.In order to further improve the ecological environment of the mining area,this study selects the open-pit coal mine in the alpine area of Inner Mongolia for in-depth field investigation.The sample method was used to carry out a random test in the mining area.According to the principle of scientificity and typicality,different restoration years(1 year,2 years,3 years and 4 years)were selected respectively.Different restored terrain(platform,slope and field grid);Different recovery gradients(0-10°,11-20°,21-30° and 31-40°);The artificially restored plots in different recovery seasons(May,July and September).The four restoration measures were used to study the vegetation community in mining area.Through the research of this paper,the main conclusions are as follows:(1)The species composition of open-pit coal mine vegetation in Inner Mongolia is relatively rich,but it is mainly composed of Gramineae,Compositae and Leguminosae.Gramineae account for 22% of the total,Compositae and leguminosae account for 17%.In addition,Linales,Euphorbiaceae,Equisetaceae,Gentianaceae,Boraginaceae,Lamiaceae,Scrophulariaceae,Cyperaceae,Amaryllidaceae and other families have only 1 species.Among them,artificial planting is less,and most of them are non-artificial planting from the surrounding grassland.Dominant species of quadrat include the Gramineous(Elymus dahuricus),(Bromus inermis),Leguminosae(Medicago sativa),(Melilotus officinalis),(Astragalus adsurgens),(Caragana sinica),Compositae(Artemisia sieversiana),Brassicaceae(Brassica napus),Elaeagnaceae(Hippophae rhamnoides).(2)Different restoration measures had different effects on plant communities.The Shannon-Wiener diversity index of the platform and slope was significantly higher than that of the field,and the Shannon-Wiener diversity index and Pielou evenness index were significantly different when the slope was restored to 11-20°.Shannon-Wiener diversity index and Pielou evenness index were significantly higher in September than in July and May,while Simpson dominance index was on the contrary.Different recovery years were the main factors affecting Shannon-Wiener diversity index,Simpson dominance index and Pielou evenness index.Increases with the number of years of recovery;Different restoration terrain and different restoration seasons were the main factors affecting plant importance value.Platform and slope were significantly larger than field grid,September > July > May.Different recovery years and seasons were the main factors affecting plant elements,the content of N and P increased,and the content of K decreased.(3)Different restoration measures had different degrees of effects on the growth of individual plants,and different restoration seasons had the most significant effects on plant biomass,plant height and plant cover,with September > July > May,and the growth of gramineous plants was obviously affected.(4)The dominant species,Gramineous(Elymus dahuricus),(Bromus inermis),Leguminosae(Medicago sativa),(Melilotus officinalis),(Astragalus adsurgens),(Caragana sinica),Compositae(Artemisia sieversiana),Brassicaceae(Brassica napus),Elaeagnaceae(Hippophae rhamnoides),conduct elemental analysis.The absorption of mineral elements by different organs of different plants was different.Legumes and Compositae were significantly higher than gramineae,and the absorption of nutrients by shrub seabuckthorn was higher than caragana.(5)The species distribution of plants in opencast coal mine was different,but the dominant plants included 9 species,including lymphora,Brome without awning,alfalfa,Mignonette,catagonia,Caragana,Artemisia macroseed,rapeseed and sea buckthorn.It is suggested to choose gramineae,Compositae and legume as the pioneer plants for vegetation restoration,mainly by grass irrigation complex planting,adjust the mixture ratio of gramineae and legume,and increase the proportion of legume.It is better to plant species with perennial herbs as the main,annual or biennial herbs as the auxiliary combination. |
