Electrochemical Properties of Peat Particulate Organic Matter on a Global Scale: Relation to Peat Chemistry and Degree of Decomposition

Methane production in peatlands is controlled by the availability of electron acceptors for microbial respiration, including peat dissolved organic matter (DOM) and particulate (POM). Despite much larger mass POM peat, knowledge on ranges its transfer capacities—electron accepting capacity (EAC), donating (EDC)—is scarce comparison to DOM humic fulvic acids. Moreover, it unclear how chemistry decomposition relate EAC EDC. To address these gaps, we compiled samples with varying carbon contents from mid high latitude analyzed their EACPOM EDCPOM, element ratios, indicators, relative amounts molecular structures as derived infrared spectra. Peat EDCPOM are smaller (per gram carbon) than EDC terrestrial aquatic acids highly variable within between sites. Both small decomposed unless has quinones phenols. Element ratio-based models failed predict while spectra-based can a large extent, but not EDCPOM. We suggest conceptual model that describes vegetation control polymeric phenol quinone drivers EACPOM. The implies need mechanistic or spatially resolved measurements understand variability thus role controlling methane formation.