Research Progress in Technological Pathways and Accounting Methods for Carbon Sequestration and Sink Enhancement in Mine Ecological Restoration

The ecological restoration of mines has become critical for achieving carbon neutrality. This review focuses on extreme site conditions, namely heavy metal contamination, extreme pH, and substrate depletion, as well as systematically synthesized technological pathways and accounting methods for carbon sequestration and sink enhancement in abandoned mines. Unlike previous studies, which merely describe isolated components like vegetation recovery or soil carbon, this study constructs a problem-oriented, full-chain integration framework that links carbon source transformation mechanisms, site-specific sink enhancement technologies, monitoring methods, and accounting systems. Our findings indicate that existing carbon sink accounting frameworks, largely derived from forest or agricultural ecosystems, are poorly suited for mine sites, resulting in low accuracy, significant uncertainty, and broad incompatibility with carbon trading mechanisms. Key findings include: (1) multi-layer vegetation configuration and microbe-plant synergy can significantly enhance carbon density, though their effectiveness heavily depends on substrate conditions; (2) an integrated “satellite-airborne-ground” monitoring approach improves spatial coverage but is limited by NDVI insensitivity in sparse vegetation and significant soil carbon inversion errors; (3) current methodological standards lack localized parameters for organic carbon turnover, carbon leakage risk, and long-term permanence assessment. Additionally, this study highlights critical controversies and proposes that microbial-driven carbon-nitrogen coupling mechanisms, multi-source remote sensing fusion, and locally calibrated accounting frameworks should be tested in future research. This review provides actionable guidance for advancing mine restoration from descriptive case studies toward verifiable, tradeable carbon sinks using a “dual-carbon” strategy.