Intermediary ecosystem metabolism as a main driver of methanogenesis in acidic wetland soil

Methanogens have a very limited substrate range, and their in situ activities are thus linked to 'intermediary ecosystem metabolism', i.e. complex trophic interactions with other microorganisms catalysing essential intermediary processes that ultimately drive methanogenesis. However, information on intermediary ecosystem metabolism and associated biota is fragmented and often conceptualized rather than resolved. The main objective of this review is to evaluate the concept of intermediary ecosystem metabolism in context with recent work aimed at resolving the complex trophic interactions of a methaneemitting peatland.