Effects of Composite Reclamation Models of Sea Buckthorn, A Pioneer Species in Semi‐Arid Regions, on Soil Quality and Microbial Communities

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Open‐pit coal mining severely degrades soil and ecosystem functions, constraining regional sustainability. Vegetation‐based reclamation has therefore been widely adopted as an effective approach to promote soil recovery and ecosystem restoration. In this study, eight reclamation models were established at the Antaibao Open‐Pit Coal Mine, all dominated by sea buckthorn ( Hippophae rhamnoides L.) and combined with Chinese pine ( Pinus tabulaeformis Carr.), black locust ( Robinia pseudoacacia L.) and littleleaf peashrub ( Caragana microphylla Lam.). Soil physicochemical properties and microbial community characteristics were systematically investigated in 2019 and 2022 to evaluate reclamation effectiveness. The results showed that the H. rhamnoides + C. microphylla model (SJ_NT) significantly increased soil available phosphorus (AP) (mean difference = 9.467 mg/kg, p < 0.001) and total nitrogen (TN) contents (mean difference = 211.333 mg/kg, p = 0.002), and was the only configuration that achieved sustained improvement in AP over time. Soil microbial communities exhibited clear temporal dynamics during reclamation. In 2022, the SJ_NT model displayed the highest fungal operational taxonomic unit (OTU) richness (439). At the bacterial phylum level, community dominance shifted from Actinobacteriota to Proteobacteria , with Cyanobacteria emerging as an additional dominant group. Functional prediction further indicated enhanced microbial metabolic potential, particularly for carbon metabolism–related and amino acid metabolism functional genes. Core microbial taxa were significantly correlated with soil nutrient availability, suggesting their role in stabilizing community structure through complementary metabolic functions. The SJ_NT reclamation model promotes ecological recovery through a positive feedback pathway involving improved soil nutrient status, optimized microbial community structure, and enhanced functional activity. This study provides practical guidance for vegetation configuration and ecological reclamation of open‐pit coal mines in semi‐arid regions.