To shake or not to shake: 13C-based evidence on anaerobic methane oxidation in paddy soil

摘要: The anaerobic oxidation of methane (AOM) removes most the biologically produced (CH 4 ) from marine ecosystems before it enters atmosphere and thus mitigates greenhouse gas emissions. As compared to environments, surprisingly little is known about role AOM in terrestrial ecosystems. Particularly, how controls CH budget paddy soils unexplored, partly reflecting analytical difficulties analyzing turnover. To date, commonly used method study vitro incubation microcosms with injection into headspace with/without shaking slurry. Shaking, however, introduces various errors disturbances. Here we measured rice soil using a new alternative approach that introduced 13 C-labelled directly slurry via silicone tube without shaking. results were those obtained by classical approaches (i.e., tubes and/or shaking). In all batches, C enrichment CO 2 after clearly confirmed occurrence soil. cumulative during 84 days reached 0.16–0.24 μg g −1 dry shaking, but was 33–80% lower Unexpectedly, effect on insignificant either or suggesting concentration water (slurry) not main limiting factor for AOM. Without addition revealed steady increase headspace/tube, whereas jars constantly low 59 days. This suggests inhibited methanogenesis. There strong linear correlation between amount oxidized (R = 0.91), this relationship followed power growth regression. Based current reported rates, rough upscale China showed recycling ca. 2.0 Tg each year, making crucial sink.