Impact of mining tailings on soil decomposition and carbon stabilisation in a riparian atlantic forest

Abstract This study examines the impacts of mining tailings on soil decomposition processes within a riparian Atlantic Forest ecosystem, centring on the Samarco dam disaster in Brazil. Understanding these impacts is essential for the restoration and management of contaminated environments. Using the Tea Bag Index method, supplemented with raw mass loss data analysis, we measured soil decomposition rates ( k ) and stabilisation factors ( S ) at contaminated and reference sites under varying seasonal conditions. Soil chemical and physical properties were analysed to determine their influence on decomposition processes. Results indicated significantly lower decomposition rates in contaminated soils compared to reference sites, particularly during wet conditions and at mid-incubation periods. The stabilisation factor was lower in contaminated soils, suggesting a reduced capacity for carbon sequestration. Seasonal variations significantly affected decomposition dynamics, highlighting the complex interactions between environmental conditions and soil contamination. The study underscores the profound impact of mining tailings on soil ecological functions, particularly on decomposition rates and carbon stabilisation. These findings are crucial for developing strategies to mitigate the effects of such disturbances and enhance the resilience and recovery of affected ecosystems.