Vegetation characteristics and soil properties of artificially remediated grasslands: The case study of the Shimenhe mining area in Qilian Mountains, northwest China

Abstract

The mining of limestone mines plays a crucial role in societal and economic advancement. However, mining activities have led to destructive variations in grassland ecology and soil, causing numerous environmental problems, and effective artificial restoration measures have been used to restore grasslands in the Shimenhe mining areas to different degrees. In this study, we investigated, examined and analyzed plant community structure and its correlation with soil properties across varying degrees of alpine grassland restoration in Qilian Mountains Shimenhe restoration mines using the sample method, and studied the changes in species diversity using five diversity indexes (Simpson index, Shannon index, Margalef index, Dominance index and Evenness index). This study showed that the plant community characteristics with high recovered degree (HRD)> middle recovered degree (MRD)> low recovered degree (LRD)> very low recovered degree (VLRD), 11 plant genera comprising 11 species across 10 families were identified. Dominant families with robust ecological adaptability included Leguminosae, Rosaceae, Gramineae, Asteraceae, and Salicaceae. The highest Simpson, Shannon, Margalef and Evenness index of HRD grassland community species were 0.82, 1.96, 1.66 and 0.89, respectively. The highest Dominance index of VLRD grassland community species was 0.34, which required several restoration methods such as spraying and mulching. Soil pH and EC tended to decrease with increasing restoration, SOC, SMC, TP, AP, NH4-N, TN, AN and NO3-N tended to increase and the content of soil environmental factors contributed to vegetation growth across various restoration levels the mine grassland. In conclusion, our study indicated that the community structure gradually diversified and soil properties changed positively with the increase of restoration degrees in the Qilian Mountains Shimenhe mine, and the best results of HRD restoration were obtained. This study provides the theoretical basis for the restoration and conservation of grasslands in mining areas by demonstrating examined the correlation between plant characteristics and soil properties in restored grasslands in alpine mining areas.