Duration of O₂ Exposure Determines Dominance of Fe^II vs CH₄ Production in Tropical Forest Soils.

ABSTRACT: Temporal fluctuations in redox conditions influence the availability of Fe^III and greenhouse gas emissions in humid upland soils. However, the impact of fluctuation duration on biogeochemical processes remains unclear. We hypothesized that rates of Fe^III reduction and CH₄ production are sensitive to the duration of soil oxygenation. To test this, surface soil from the Luquillo Forest, Puerto Rico, was subjected to fluctuating redox conditions with an anoxic interval of 6 days followed by oxic intervals of either 8, 24, or 72 h. Shorter oxic intervals enhanced Fe reduction, while longer oxic intervals enhanced CH₄ emissions. As O₂ exposure decreased from 72 to 8 h, Fe reduction rates increased from 0.12 ± 0.02 to 0.26 ± 0.05 mmol kg

SUBMITTER: Barcellos D 

PROVIDER: S-EPMC11912342 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature