Relationship between plant species diversity and soil chemical properties in coal gangue dump：early stage of ecological restoration in Lingwu Mining Area

In order to obtain the optimal vegetation configuration model in the early stage of Zaoquan coal gangue dump ecological restoration in Lingwu Mining Area and the soil chemical factors that affect the plant species diversity.Combined field investigation with the important value， alpha diversity index and community similarity coefficient， meanwhile，took the vegetation on the natural landform surrounding the gangue mountains as the control， this paper studied the changes of plant species composition， community structure and alpha diversity index of planting configuration types in the artificial reconstruction of arboreal forest， mixed forest of trees and shrub， shrubbery on Zaoquan coal gangue dump， as well as the correlation between each index and soil chemical factors.The tests results revealed：①According to the three typical area of vegetation configuration types on Zaoquan coal gangue dump， there are totally 24 species of plants in eight families， 22 genera， including seven species of compositae， which accounting for 29.17% of the total species.Six species of Chenopodiace-ae accounting for 25%； and each four of Leguminosae and gramineae accounting for 16.67% respectively.②Among the three vegetation configuration types， the proportions of undergrowth perennial herbs to the total herb layer amounts are in the order of arboreal forest(50.00%)＞shrubbery (46.67%)＞mixed forest of shrubs and tree (38.48%)， and in natural landform， the proportion of perennials in herbaceous layer is 68.75%.③Among the three vegetation configuration types， Shannon-wiener diversity index and Simpson diversity index， Patrick richness index and Pielou evenness index of herbaceous layer plant species in shrubbery are the highest.④The correlation between the soil alkaline nitrogen and each index is the most significant， indicating that soil alkaline nitrogen content has a great influence on plant species diversity.⑤Among the three vegetation configuration types， the composition of herbaceous species in arbor woodlands is the most similar to that of natural landform herbaceous plants at the levels of family， genus and species.The coverage， density， biomass，soil moisture， soil organic matter and total nitrogen content of herbaceous plants in understory forests are all higher than that in mixed of tree ＆ shrubs and shrubbery.In the early stage of ecological restoration of the Zaoquan Gangue Mountain， among the three planting configuration types，the arbor woodland configuration mode is more suitable， and the soil chemical factors affecting plant species diversity are mainly soil alkali-hydrolyzable nitrogen.