Screening of Suitable Species Combinations for Vegetation Restoration in Ecologically Damaged Areas of Representative Coal Mines on the South Slope of Tianshan Mountain

Coal mining has significantly degraded the ecological environment, and the ecosystem structure of the southern slopes of the Tianshan Mountains is complex, with drought, low rainfall, and ecological fragility increasing the difficulty of ecological restoration. There are few studies on the selection of suitable pioneer species for the restoration of mining areas on the south slope of Tianshan Mountain. In this study, we investigated the artificial restoration of vegetation in the damaged areas of nine representative coal mines on the south slope of the Tianshan Mountains. We categorized the coal mines into three classes based on elevation. Using a combination of the entropy weight method and the technique for order preference by similarity to ideal solution (TOPSIS), indicators such as the diversity index and vegetation cover were selected to compare the recovery of vegetation in the mining area and screen for suitable pioneer species in ecologically damaged areas. The results show the following: (1) Based on the entropy weight TOPSIS findings, Run Hua coal mine, Da Wanqi coal mine, and Ke Xing coal mine are the highest-scoring coal mines among different types of coal mines. (2) Based on the score results and species rankings, species combinations including Agropyron cristatum, Achnatherum splendens, Medicago sativa Linn, and Halogeton glomeratus are recommended for altitudes below 1500 m. For altitudes between 1500 m and 2000 m, combinations including Festuca elata Keng ex E, Agropyron cristatum, Halogeton glomeratus, and Artemisia sieversiana Ehrhart ex Willd are recommended; similarly, combinations including Agropyron cristatum, Achnatherum splendens, Seriphidium kaschgaricum, and Halogeton glomeratus are recommended for elevations above 2000 m. This study discusses the recovery of artificial vegetation communities within 2 years, with a view to providing a theoretical basis and data support for the recovery of the remaining ecologically damaged areas of the same types.