Elevated temperatures drive abiotic and biotic degradation of organic matter in a peat bog under oxic conditions
Affiliation
Department of Environmental Science, The University of ArizonaIssue Date
2022-01Keywords
Biotic and abiotic processesHigh resolution mass spectrometry
Peatlands
Soil organic matter
Temperature
Metadata
Show full item recordPublisher
Elsevier BVCitation
AminiTabrizi, R., Dontsova, K., Graf Grachet, N., & Tfaily, M. M. (2022). Elevated temperatures drive abiotic and biotic degradation of organic matter in a peat bog under oxic conditions. Science of the Total Environment, 804.Journal
Science of the Total EnvironmentRights
© 2021 Elsevier B.V. All rights reserved.Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
Understanding the effects of elevated temperatures on soil organic matter (SOM) decomposition pathways in northern peatlands is central to predicting their fate under future warming. Peatlands role as carbon (C) sink is dependent on both anoxic conditions and low temperatures that limit SOM decomposition. Previous studies have shown that elevated temperatures due to climate change can disrupt peatland's C balance by enhancing SOM decomposition and increasing CO2 emissions. However, little is known about how SOM decomposition pathways change at higher temperatures. Here, we used an integrated research approach to investigate the mechanisms behind enhanced CO2 emissions and SOM decomposition under elevated temperatures of surface peat soil collected from a raised and Sphagnum dominated mid-continental bog (S1 bog) peatland at the Marcel Experimental Forest in Minnesota, USA, incubated under oxic conditions at three different temperatures (4, 21, and 35 °C). Our results indicated that elevated temperatures could destabilize peatland's C pool via a combination of abiotic and biotic processes. In particular, temperature-driven changes in redox conditions can lead to abiotic destabilization of Fe-organic matter (phenol) complexes, previously an underestimated decomposition pathway in peatlands, leading to increased CO2 production and accumulation of polyphenol-like compounds that could further inhibit extracellular enzyme activities and/or fuel the microbial communities with labile compounds. Further, increased temperatures can alter strategies of microbial communities for nutrient acquisition via changes in the activities of extracellular enzymes by priming SOM decomposition, leading to enhanced CO2 emission from peatlands. Therefore, coupled biotic and abiotic processes need to be incorporated into process-based climate models to predict the fate of SOM under elevated temperatures and to project the likely impacts of environmental change on northern peatlands and CO2 emissions.Note
24 month embargo; available online: 01 September 2021ISSN
0048-9697Version
Final accepted manuscriptSponsors
US Department of Energy Office of Scienceae974a485f413a2113503eed53cd6c53
10.1016/j.scitotenv.2021.150045