Near-natural ecological restoration in open-pit mine area

Ecological restoration in open-pit mining areas faces some problems such as low self-sustaining capacity and high maintenance costs, especially obvious mining traces after restoration. It is urgent to coordinate the relationship between artificial restoration and natural restoration, upgrade and develop traditional ecological restoration models, and promote harmonious coexistence between humans and nature in open-pit mining areas. ① Based on long-term theoretical research and practical experience, this article proposes the necessity, theoretical connotation, and technical framework of near-natural ecological restoration in open-pit mining areas. Near-natural mining ecological restoration is a restoration model that refers to the local natural landforms, hydrology, soil, vegetation, landscape and their evolution laws, so that the repaired mining patches reach a structural and functional state similar to the surrounding natural ecosystem, and integrate with the surrounding natural landforms, water systems, and landscape. It is an upgrade to the traditional ecological restoration model, approaching the ideal state of “mining without trace”. ② Near-natural ecological restoration is an important component of ecological design in open-pit mines, and its technical aspects mainly include learning from ecosystems, reshaping near-natural landforms, hydrological connection and regulation, reconstruction of active soil layers, vegetation reconstruction and diversity recombination, etc. Ecosystem learning can provide restoration objectives and parameters for subsequent restoration processes. The reshaping of near-natural landforms is the core and foundation of near-natural ecological restoration, including the reshaping of near-natural landforms throughout the entire life cycle of the inner dumping site, the reshaping of near-natural landforms of the outer dumping site, and the collaborative reshaping of adjacent natural problem landforms. The hydrological connection and regulation need to solve the optimization layout of river channels, the connection of upstream and downstream water systems in mining areas, and the regulation of using storage to replace runoff. The reconstruction of active soil layers in mines includes the physical structure reorganization of mining soil, the reconstruction of microbial and nutrient cycling processes, and other related contents. Vegetation reconstruction and diversity recombination include near-natural plant communities and diversity configuration, as well as near-natural plant spatial layout. ③ Practical analysis shows that the near-natural ecological restoration of open-pit mines helps to reduce soil erosion, improve geomorphic stability, enhance the self-sustaining ability of the reconstructed ecosystem, promote seamless mining in open-pit mining areas, and harmonious coexistence between humans and nature.