Ecological Effects Of Planted Communities On Coal Gob Piles In The Yangquan Mining Area,Shanxi

Based on the investigation of planted vegetation on the two Coal Gob Piles(CGP)of different reclamation time(2003a and 2013 a,respectively)in the Yangquan mining area of Shanxi,the planted community types,interspecific relationship of dominant species,soil physical and chemical properties,and soil enzyme activities of the planted communities on the CGP were studied by using the methods of quantitative ecology and soil biochemistrical analysis.Ecological effects of the planted communities were evaluated by using subordinate function method.The aims of this research revealed the ecological relationship between the planted communities and soil environment and screened dominant plant community suitable for CGP ecological restoration.This research provided the sciencific basis and technical guidance for quickly building up self-sustaining planted vegetation-soil ecosystem on the CGP.The main research contents and results were as following:(i)Planted communities on the CGP in the Yangquan mining area were classified into 9 associations by TWINSPAN,which were in the early and middle stages of ecological restorationThe ecological relationships of planted communities on the CGP in the Yangquan mining area were studied by using two-way indicator species analysis(TWINSPAN)and detrended correspondence analysis(DCA).The results showed that the 63 quadrats were classified into 9 associations by TWINSPAN classification,the revegetation time of associations I-IV was shorter(3-year),and it was in the early stage of community succession.The revegetation time of associations V-IX was longer(13-year),and it was in the middle stage of community succession.The result of TWINSPAN classification well reflects the relationship between the types of planted communities and the distribution of dominant species and environmental factors.All results were confirmed by the two-dimensional ordination diagram of DCA.The first two axes of DCA reflected the gradient of revegetation time,content of soil organic matter and slope,indicating that revegetation time,content of soil organic matter and aspect are the main environmental factors that affecting the distribution and change of planted communities on the CGP.(ii)The degree of interspecific associations of dominant species in planted communities on the CGP in the Yangquan mining area were lower17 dominant species of the planted communities on the CGP in the Yangquan mining area,Shanxi were studied by using ?2-tests,Pearson correlation coefficients and Spearman rank correlation coefficients.The results revealed that: among 136 species-pairs,those pairs displayed negative correlation outnumbered those displaying positive correlation,and those pairs of significant correlation were far less than those pairs of no significant correlation,indicating that the 17 dominant species in painted communities on the CGP in the Yangquan mining aera had different ecological adaptability;compared with Pearson coeerlation coefficients,the sensitivity of the Spearman rank correlation test was higher,indicating that it could better indentify the inter-specific associations among plants;based on Spearman rank correlation coefficients,the 17 dominant species were devided into 2 ecological species groups.Species in the same ecological group had great relevance,On the contrary,the associations between the different ecological groups showed a distinct difference.(iii)Soil physical and chemical properties of different planted communities improved with the increase of revegetation time on the CGP in the Yangquan mining areaThe soil physical and chemical properties under different planted communities on the CGP in the Yangquan mining area,Shanxi were studied by using soil biochemical analysis method.The results showed that,except for soil bulk density,the contents of p H and available phosphorus reducing with the extension of revegetation time on the gob piles,while soil field capacity,soil water content,organic matter and available potassium increasing with the extension of revegetation time on the CGP.(iv)Soil enzyme activities of different planted communities improved with the increase of revegetation time on the CGP in the Yangquan mining areaSoil enzyme activities under different planted communities on the CGP in the Yangquan mining area,Shanxi were studied by using soil biochemical analysis method.The results showed that soil alkaline phosphatase activity,invertase activity and urease activity were increased with the extension of revegetation time.(v)Ecological effects of different planted communities on the CGP in the Yangquan mining area had significant differences,and the leguminous plants played important roles in the process of revegetation restorationThe ecological effects of the planted communities on the CGP in the Yangquan mining area,Shanxi were evaluated by using subordinate function method.The results showed that ecological effects of different species combination were significant different.The leguminous plants(Robinia pseudoacacia and Amorpha fruticosa)played obvious roles in the process of revegetation restoration on the CGP.On the CGP with 13-year revegetation,the ecological effect of Assoc.Robinia pseudoacacia-Lespedeza bicolor-Artemisia capillaris had the best ecological effect,followed by Assoc.Salix babylonica-Sophora viciifolia-Bothriochloa ischaemum;on the CGP with 3-year revegetation,the ecological effect of Assoc.Amorpha fruticosa-Festuca arundinacca was better than that of others.(vi)Strengthen the study of ecological restoration strategy on the CGP and its scientific management and protectionIn this study,it was found that the role of leguminous plants(Robinia pseudoacacia,Amorpha fruticosa)in the process of revegetation restoration was significant,and thus,the ecological effects of different restoration models and successional dynamics should be strengthened.The spontaneous combustion occurred at the CGP with 3-year restoration succession,which caused numerous deaths of the planted plants.Thus,the plant species with high temperature and flame retardant resistance should be selected as much as possible and the scientific management should be strengthened in the future CGP reclamation.