Details zur Publikation |
| Kategorie | Textpublikation |
| Referenztyp | Zeitschriften |
| DOI | 10.1016/j.geoderma.2025.117658 |
Lizenz  |
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| Titel (primär) | Root organic exudate stimulation of greenhouse gases is offset by radial oxygen loss in mineral-dominated anoxic wetland soil |
| Autor | Mollenkopf, M.; Haas, I.L.; Kappler, A.; Muehe, E.M. |
| Quelle | Geoderma |
| Erscheinungsjahr | 2026 |
| Department | AME |
| Band/Volume | 465 |
| Seite von | art. 117658 |
| Sprache | englisch |
| Topic | T7 Bioeconomy |
| Supplements | Supplement 1 |
| Keywords | Root traits; Methane oxidation; Rusty carbon sink; Priming; Fermentation |
| Abstract | Wetlands are important contributors to global CH4 emissions, yet uncertainties remain regarding plant-mediated controls of greenhouse gas (GHG) fluxes. Wetland graminoids influence these emissions via multiple pathways. The study focuses on two key root traits: organic carbon exudation and radial oxygen loss (ROL). Their individual and combined impacts on soil organic carbon (SOC) dynamics and GHG emissions were investigated in 26-day-long incubations, using an anoxic mineral-rich permafrost fen soil as a wetland proxy. Organic exudation was imposed by repeated injection of an artificial organic compound mix mimicking real root exudate, and ROL by continuous ambient-air injection. Organic exudation enhanced CO2 and CH4 emissions 3- and 2.2-fold, respectively. This stimulated fermentation, methanogenesis, and Fe mineral dissolution, thereby co-mobilizing SOC from the ‘rusty carbon sink’. ROL promoted methanotrophs and aerobes reducing bioavailable carbon pools, so that 29% less CO2 and 47% less CH4 were emitted compared to the no-addition control. The combination of organic exudation and ROL increased CO2 by 70% and decreased CH4 by 20% relative to the no-addition control, indicating active methanotrophs. Thus, Fe-associated OC increased ∼4.6-fold with an OC:Fe ratio above 1, suggesting a persistent ‘rusty carbon sink’ with less bioavailable SOC. This study demonstrates that combined root traits can exert opposing effects on CO2 and CH4 emissions, which can improve prediction and management for natural, agricultural, and restored wetlands. |
| dauerhafte UFZ-Verlinkung | https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=31789 |
| Mollenkopf, M., Haas, I.L., Kappler, A., Muehe, E.M. (2026): Root organic exudate stimulation of greenhouse gases is offset by radial oxygen loss in mineral-dominated anoxic wetland soil Geoderma 465 , art. 117658 10.1016/j.geoderma.2025.117658 |
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