Ebullition of methane from peatlands: Does peat act as a signal shredder?

Abstract

Bubbling (ebullition) of greenhouse gases, particularly methane, from peatlands has been attributed to environmental forcings, such as changes in atmospheric pressure. However, observations from peat soils suggest that ebullition and environmental forcing may not always be correlated and that interactions between bubbles and the peat structure may be the cause of such decoupling. To investigate this possibility, we used a simple computer model (Model of Ebullition and Gas storAge) to simulate methane ebullition from a model peat. We found that lower porosity peat can store methane bubbles for lengthy periods of time, effectively buffering or moderating ebullition so that it no longer reflects bubble production signals. Our results suggest that peat structure may act as a "signal shredder" and needs to be taken into account when measuring and modeling ebullition. Key Points Link between environmental forcing and CH4 ebullition depends on peat structure Storage and transport processes within peat can "shred" CH4 production signals Small differences in peat porosity produce large differences in CH4 gas storage