Iron mineral dissolution releases iron and associated organic carbon during permafrost thaw

• DOI: 10.1038/s41467-020-20102-6
• Publication Date: 2020-12-10T11:05:38Z
• Authors: Monique S. Patzner; Carsten W. Mueller; Miroslava Malusova; Moritz Baur; Verena Nikeleit; Thomas Scholten; Carmen Hoeschen; James M. Byrne; Thomas Borch; Andreas Kappler; Casey Bryce
• Keywords: Carbon fibers; Soil carbon; Carbon sink

Abstract It has been shown that reactive soil minerals, specifically iron(III) (oxyhydr)oxides, can trap organic carbon in soils overlying intact permafrost, and may limit mobilization degradation as it is observed other environments. However, the use of iron(III)-bearing minerals terminal electron acceptors permafrost environments, thus their stability capacity to prevent during thaw, poorly understood. We have followed dynamic interactions between iron using a space-for-time approach across thaw gradient Abisko (Sweden), where wetlands are expanding rapidly due thaw. show through bulk (selective extractions, EXAFS) nanoscale analysis (correlative SEM nanoSIMS) bound Fe primarily transition mineral horizons palsa underlain by (41.8 ± 10.8 mg per g soil, 9.9 14.8% total carbon). During water-logging O 2 limitation lead reducing conditions an increase abundance Fe(III)-reducing bacteria which favor dissolution drive both along gradient. By providing acceptor, this rusty sink effectively destroyed cannot release with