Response of soil micro-food web and nutrient transfer efficiency to reclamation strategies in mining area

Background & Aims: The soil micro-food web plays a crucial role in facilitating ecological restoration and maintaining ecosystem functionality in post-mining environments. However, the specific influence of reclamation patterns on the structure of soil micro-food web and their trophic transfer efficiency in mining soils remains unclear. Therefore, this study aimed to analyse the specific impacts of reclamation models on the soil micro-food web and elucidate the underlying mechanisms that restores ecosystem functions. Methods: We conducted a field experiment at 15 sites across three reclamation patterns—coniferous plantation (CP), broad-leaved plantation (BP), and mixed coniferous-broadleaved plantation (MP)—within the Pingshuo Open-pit Coal Mine in China. Using metagenomic sequencing, we analysed soil micro-food web structures and nutrient transfer efficiencies across various reclamation strategies. Results: MP exhibited greater microbial network complexity and higher nutrient transfer efficiency than those of CP and BP. Specifically, MP ecosystems demonstrated considerably enhanced nutrient transfer efficiency among higher trophic-level microorganisms such as protists and metazoans, indicating improved trophic energy flow and resource utilisation within the soil micro-food web. Moreover, reclamation patterns influenced soil nutrient transfer efficiency by modifying soil physicochemical properties, ultimately shaping soil carbon and nitrogen metabolic processes. Conclusion: The mixed coniferous-broadleaved plantation enhanced nutrient transfer efficiency within the soil micro-food web, thereby optimising trophic interactions and ecosystem nutrient cycling. Reclamation models can influence C/N metabolism processes via the soil microbial network. Our findings provide a comprehensive understanding of optimizing reclamation strategies and improving ecosystem functions in mining areas.