Beyond Metal(loid) Immobilization: Redox-Stratified Biocrusts Shield Humid Mining Regions

, supporting a potential mechanism for metal(loid) sequestration via sulfide formation in underlying tailings, where sulfur occurred exclusively as sulfides at 5 cm depth. This barrier-mediated effect may outweigh metal(loid) immobilization within biocrusts. Our findings elucidate biocrust-mediated protection against metal(loid)s and provide theoretical support for remediation in humid mining regions.