Regulation of methane oxidation: contrasts between anoxic sediments and oxic soils

Abstract

Although the majority of organic matter mineralization occurs under oxic conditions, significant rates of mineralization occur in the anoxic guts of herbivores, and in the anoxic sediments and water columns of freshwater and marine ecosystems (Henrichs, Reeburgh 1987). Anaerobic metabolism in these systems is often coupled to methane production, with variations in the extent of methanogenesis among systems a function of organic matter, nitrate, ferric iron, and sulfate availability. Controls of anaerobic metabolism and methanogenesis have been reviewed extensively elsewhere (e.g., Henrichs, Reeburgh 1987; Oremland 1988), and will not be considered further here. Instead, I will illustrate the controls of methane oxidation by comparing two very different: anaerobic methane oxidation in marine systems and methane consumption in terrestrial systems.