show Abstracthide AbstractTriplicates of Molinia caerulea (spring) root-free soil and soil-free root anoxic microcosms were prepared. H2 supplementation in Molinia caerulea (spring) root-free soil anoxic microcosms led to an increase in acetate and CH4 concentration during incubation. H2-dependent acetogenesis was more stimulated than hydrogenotrophic methanogenesis in Molinia caerulea (spring) root-free soil anoxic microcosms. Fermentations, H2-dependent, and H2-independent acetogenesis are still possible ongoing processes in Molinia caerulea (spring) soil-free root anoxic microcosms during incubation. In contrast to the root-free soil H2-supplemented microcosms, CH4 concentration was of minor importance in H2-supplemented soil-free root anoxic microcosms.