The Loss and Recovery Potential of Net Ecosystem Productivity in Mining Areas: A Global Assessment Based on Data for 2000–2020

Climate change control requires more land to increase ecosystem carbon sequestration. With the high-intensity development of mineral resources in past decades, massive mining areas have been generated worldwide. However, few studies have evaluated the carbon sequestration of these mining areas. In this study, we analyzed the net ecosystem productivity (NEP) changes and calculated the NEP losses in global terrestrial mining areas. We adopted the random forest model to evaluate the NEP recovery potential and its driving factors. The key findings are that (1) the NEP of global mining areas exhibited a relatively obvious decreasing trend from 2000 to 2020, with an overall reduction of 29.1% and a maximum decline of 35.7%. By 2020, the NEP loss in mining areas was 11.9 g C m⁻² year⁻¹, and the total loss reached 576.9 Gg C year⁻¹. (2) Global mining areas demonstrate significant NEP recovery potential, with an average of 12.0 g C m⁻² year⁻¹. Notably, Oceania and South America have significantly higher recovery potentials, with average mine site NEP recovery potentials of 15.9 g C m⁻² year⁻¹ and 16.1 g C m⁻² year⁻¹. In contrast, European mines have considerably lower recovery potentials of less than 10 g C m⁻² year⁻¹. In Asia, North America and Africa, the NEP recovery potential varies widely from mine to mine, but generally meets the global average. (3) The annual precipitation, population density, organic soil carbon, and average slope are important drivers of NEP recovery in mining areas and exhibit positive correlations with the NEP recovery potential. In contrast, mine area and minimum temperature exhibit a negative correlation. The dependency curves of the three drivers, standardized precipitation evapotranspiration index, average elevation, and annual maximum temperature, are U-shaped, indicating that the recovery potential was poorer in the tropical and frigid zones with less precipitation. The results of this study provide a scientific basis for ecological restoration and sustainable development of mining areas worldwide.