Study On Characteristics And Relationship Between Eroded Microhabitat And Vegetation In Weathered Gangue Dump

Due to the poor matrix structure and poor habitat of weathered coal gangue dumps in western Liaoning,there are difficult vegetation settlement and restoration,as well as serious soil erosion,thus forming a mass of erosion micro-landforms.Micro-landform can usually provide safe habitats for vegetation in harsh ecosystems.In order to explore how erosion micro-landform affects vegetation settlement in gangue dumps,two typical gangue dumps were selected in this study,and bare slope,rill,shallow ditch and accumulation as research objects.By using field investigation,monitoring and indoor determination,this paper systematically studied the spatial and temporal pattern and relationship between matrix characteristics and hydrothermal characteristics of erosion micro-landform and vegetation regeneration pool and community characteristics in weathered coal gangue dumps in western Liaoning,so as to reveal the effects of different erosion microhabitats on vegetation,and provided theoretical basis and technical ideas for the practice of artificially promoting natural restoration of vegetation.The main achievements are as follows:(1)The sand content in accumulation and rill was higher than that in bare slope and shallow ditch,but the sand content in the two types of gangue dumps significantly decreased after rainy season,while the medium-coarse grain and coarse grain increased;the bulk density and capillary porosity of matrix showed that bare slope and rill were better than shallow ditch.There was no significant difference in p H value among different erosion microhabitats,and the overall conductivity of rills was lower than that of other microhabitats.(2)The microclimate and matrix hydrothermal characteristics in the two types of gangue dumps varied in the shape of "V" and "M" with the seasons.There was no significant difference in the microclimate characteristics of different erosive microhabitats,while the hydrothermal characteristics of the substrate showed that bare slope temperature was generally relatively high,the moisture content of substrate was relatively low,and the difference between different erosive microhabitats of gangue dumps in sunny slope was more obvious.(3)Gramineae and Chenopodiaceae are the main vegetation communities under different erosion microhabitats,and most of them are annual herbs.The species number,vegetation density and biomass were higher in shallow ditch and accumulation than in rill,and the bare slope was the lowest,while the coverage was better in shallow ditch and rill.Shallow ditch is beneficial to improve species diversity,and accumulation is conducive to improving species richness.There were obvious seasonal differences in the species composition of soil seeds in the two types of gangue dumps in the study area,and the density of soil seed bank in rills and accumulations was higher in autumn than in spring;seedlings in different erosion microhabitats were mainly annual herbs,and the number of species in bare slope seedlings was the least in any period;except shallow ditch,the seedling density of different eroded microhabitats reached the highest after rainfall.(4)The bare slope vegetation in the study area was related to the matrix mechanical composition,structure and hydrothermal characteristics,the furrow vegetation was related to the matrix structure and microclimate characteristics,and the shallow furrow vegetation was related to the matrix mechanical composition,structure and hydrothermal characteristics The vegetation of the accumulation is only related to the hydrothermal characteristics.In conclusion,when vegetation restoration is carried out in gangue dumps of semi-arid mining areas,the advantages of microhabitats in vegetation regeneration and restoration can be used to perform the practice of artificial promotion of natural vegetation restoration.According to the matrix characteristics,fertility characteristics,water and heat characteristics,regeneration characteristics and spatial-temporal pattern of different erosion microhabitats,suitable opportunities and sites can be selected to build similar favorable microhabitats.There are 28 pictures,13 tables and 110 references.