Heating-Induced Redox Property Dynamics of Peat Soil Dissolved Organic Matter in a Simulated Peat Fire: Electron Exchange Capacity and Molecular Characteristics

Environmental Science & Technology, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 2, 2025

Peatlands store one-third of the world's soil organic carbon. Globally increased fires altered peat matter chemistry, yet redox property and molecular dynamics peat-dissolved (PDOM) during remain poorly characterized, limiting our understanding postfire biogeochemical processes. Clarifying these dynamic changes is essential for effective peatland fire management. This study demonstrates temperature-dependent in electron exchange capacity (EEC) PDOM by simulating burning, significantly affecting microbial iron reduction. At low temperatures (200-250 °C), EEC remains constant releasing more phenolic moieties to enhance electron-donating (EDC). Higher (500 °C) diminish 90% consuming phenolic-quinone moieties. Pyrolytic (pyPDOM) contributes 40% soil, with this contribution declining at higher temperatures. Phenolic-quinone primary redox-active pyPDOM. Fourier transform ion cyclotron resonance mass spectrometry analysis shows that EDC depends on types than abundance, monophenol-like molecules (

Language: Английский

Enhanced Release and Reactivity of Soil Water-Extractable Organic Matter Following Wildfire in a Subtropical Forest

Environmental Science & Technology, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 21, 2025

Climate-driven increases in wildfire frequency may disrupt soil carbon dynamics, potentially creating positive feedback within global cycle. However, the release and lability of following remain unclear, limiting our ability to predict fire impacts on cycling. Here, we investigated chemical alterations water-extractable organic matter (WEOM) a subtropical forest by comparing burned soils an adjacent unburned site. The consensus is that fire-altered DOM aromatic less reactive. found 10 months postfire, contained nearly three times more (WEOC) than control Reactomics analysis further revealed overall 8-fold increase potential reactivity this carbon, identified higher abundances molecular formulas involved microbial reaction pathways. Specifically, exhibited elevated oxidative enzyme reactions, linked nominal oxidation state (NOSC) WEOM. Metagenomic enrichment taxa specialized degrading compounds areas, supporting occurrence pathways acting WEOM postfire soils. These findings highlight wildfires accelerate loss through reactive mobilization response, with implications for long-term carbon-climate projections.

Language: Английский

Molecular shifts in dissolved organic matter along a burn severity continuum for common land cover types in the Pacific Northwest, USA

The Science of The Total Environment, Journal Year: 2024, Volume and Issue: 958, P. 178040 - 178040

Published: Dec. 14, 2024

Language: Английский