Soil Health Restoration and Sustainable Vegetation Reconstruction in Mining-Affected Areas Under Urbanization: A Cross-Continent Study

Abstract:

Urbanization-driven expansion into mining-affected areas exacerbates soil health degradation via heavy metal (HM) mobilization, soil erosion, and vegetation loss. This study assessed soil health indicators (physicochemical properties, microbial activity, vegetation coverage) across 54 mining-affected sites in 5 countries (USA, China, Portugal, Germany, Australia). A novel integrated remediation technology (biochar-compost-metal-resistant microbe composite) was developed and validated. Results showed urbanized mining soils had 42% lower soil organic carbon (SOC), 3.6-fold higher HM (As, Pb, Zn) concentrations, 58% lower microbial biomass, and 65% lower vegetation coverage than non-urbanized mining soils. The proposed technology increased SOC by 45%, reduced HM bioavailability by 73%, restored microbial biomass by 62%, and achieved 82% vegetation coverage. This study provides a sustainable framework for soil-vegetation system restoration in urbanizing mining areas.