Influence Study Of Soil And Topography Factors On Vegetation Restoration In An Opencast Coal-mine Dump In A Loess Area

Vegetation plays an important role in improving and restoring fragile ecological environments. The eco-environment of the Antaibao opencast coal mine has been substantially disturbed by mining activities, and the relationship between the vegetation and environmental factors is not very clear. Therefore, it is crucial to understand the effects of soil and topographic factors on vegetation restoration to improve the fragile ecosystems of damaged land. An investigation on soil, topography and vegetation were performed in 27 reclamation sample plots of two transects in the Shanxi Pingshuo Antaibao Opencast Coal Mine dump to analyze the response law of vegetation restoration on different site conditions. This study used one-way ANOVA and significance test form SPSS 20.0, multivariate techniques of detrended correspondence analysis(DCA) and redundancy analysis(RDA) based on the CANOCO 4.5 to analyze. The results indicated that:i) The result of One-way ANOVA indicated that the impact of different soil,topographic factors on vegetation changes had great difference. The influence of clay and available K on vegetation changes was significant, followed by total nitrogen and soil bulk density. However, the contribution of topographic factors was not significantii) The results of DCA analysis indicated that the gradient length of the first axis was lower than 3 SD. Therefore, the linear model with RDA was viewed to be the appropriate ordination method to perform the direct gradient analysis. The cumulative percentage variance of species–environment relation of the first axis was 75.3% and the second axis was 20.1%, namely, the first axis and the second axis explained 94.8%of the relationship between the species and the environment. And there was a strong correlation between vegetation and environmental factors with species–environment correlations of 0.839 on the first axis and 0.79 on the second axis.iii) Slope aspect showed a higher amount of explanation to vegetation changes.Available K in soil was the best explanatory variable, followed by rock content, clay,silt, sand, soil bulk density and total N. The explanations of other factors wererelatively small.iv) Slope determined the herbage coverage; slope aspect and soil organic matter had a positive relationship, the same to the slope aspect and rapidly available phosphorus. Soil nutrient was the main factor affecting the vegetation development and reconstruction in the process of vegetation restoration in the study area.v) So in order to improve and restore the degraded ecosystems of study area, the co-evolution of vegetation and soil should be conducted and natural succession also should be considered. A key strategy for ecological restoration is to improve soil condition and increase the area of artificial vegetation, and the protection of artificial and natural vegetation under local environmental conditions also should be strengthened.