Study On The Natural Vegetation Succession And Land Suitability Evaluation Of Gangue Pile

This paper takes the Sunjiawan coal gangue pile of Fuxin mine area as the research object, through field investigation and lab analysis to research the vegetation succession under different dumping years and with different slope aspects, and evaluate the land suitability for vegetation restoration in the coal gangue pile. The results show as following:(1) Succession of the natural vegetation. With the increase of dumping years, the vegetation species changes from infertility-resistant annuals like Zygophyllaceae and Chenopodiaceae, to perennial herbs like Compllsitae and Gramineae with various kinds.The succession order is about, in the shady slope, Cynanchum chinense + Salsola collinacommunity →|(8a) Dracocephalum moldavica + Artemisia lavandulaefolia + Setaria viridiscommunity →|(15a) Setaria viridis + Bidens parviflora + Heteropappus altaicu community →|(25a)Ulmaceae community, in the sunny slope, Cynanchum chinense + Salsola collinacommunity →|(8a) Artemisia siversiana + Setaria viridis community + Heteropappus altaicuscommunity →|(15a) Setaria viridis + Artemisia capillaries + Cleistogenes polyphyllacommunity →|(25a) Aristida adscensionis + Setaria viridis + Cleistogenes polyphyllacommunity. Species diversity indexes, richness indexes and Pielou evenness index are getting more with the increase of dumping years, ecological dominance indexes and Alatalo evenness index are getting smaller with the increase of dumping years, and under the same dumping years the species diversity indexes of shady slope are more than that of sunny slope.(2) Relationship between the vegetation succession and the soil development. The weathering layer, soil little particle content and smaller-gravel content, soil moisture parameters, total porosity and capillary porosity, soil nutrient content increase with the increase of dumping years, stone content and bigger-gravel content, soil bulk density, soil electrical conductivity (EC) , soil infiltration rate decrease with the increase of dumping years, soil pH value decreases first and then increases with the increase of the dumping years, and under the same dumping years the soil of shady slope is better than that of sunny slope. The relationship between the thickness of weathering layer, particle content with diameter less than 1mm, capillary porosity, organic matter content, soil EC and the Patrick richness are according with exponential positive correlation, and the relationship between the soil bulk density, initial infiltration rate and the Patrick richness are according with negative correlation, under the same dumping years, the relativity of shady slope is better than that of sunny slope.(3) Impact about vegetation restoration to local climatic. The plots with long dumping years has better vegetation, and the day air temperature, soil temperature, water evaporation, wind velocity in plant growing months about these plots are lower than those about shot dumping years plots with worse vegetation, but the relative humidity of long dumping years is evidence higher than that of shot dumping years.(4) Land suitability evaluation for vegetation restoration. According to the comprehensive evaluated indexes, combing with the field situation, divide the research object into four vegetation restoration as very suitable, suitable, reluctantly suitable and unsuitable, corresponding plots are, shady slop of 25～40 dumping years, shady slop of 15～25 and sunny slop of 25～40 dumping years, shady slop of 8～15 and sunny slop of 8～25 dumping years, and less than 8 dumping years.