Evolution of Soil Health in Suburban Wetlands Under Urbanization and Innovation of Ecological Remediation Technologies: A Global Comparative Study

Abstract:

Urbanization-induced degradation of suburban wetlands threatens soil health via hydrological alteration, nutrient enrichment, and heavy metal (HM) accumulation. This study assessed soil health indicators (hydrological properties, nutrient cycling, microbial functional diversity) across 60 suburban wetlands in 5 countries (UK, China, Spain, Japan, USA). A novel ecological remediation technology (submerged macrophyte-biochar composite) was developed and validated. Results showed urbanized wetlands had 45% lower saturated hydraulic conductivity (Ksat), 3.8-fold higher total nitrogen (TN) content, 2.5-fold higher HM (Cd, Pb) concentrations, and 32% lower microbial functional diversity than non-urbanized wetlands. The proposed technology increased Ksat by 62%, reduced TN by 48% and HM bioavailability by 71%, while enhancing microbial diversity by 38%. This study provides an ecosystem-specific framework for suburban wetland soil health preservation amid urbanization.