Influence of temperature and oxygen availability on the flux of volatile sulphur compounds from wetlands: A comparison of peat and paddy soils

The fluxes of volatile sulphur compounds (VSCs) from two Scottish peat soils and two Japanese paddy soils were compared using both closed and open (dynamic) incubations. Dimethyl sulphide (DMS) was the main VSC emitted rom the peat soils,with the flux from a forested peat being x 100 that from an indigenous bog peat. It also showed a strong temperature dependence. The exclusion of oxygen stimulated the flux of other VSCs, particularly methyl mercaptan (MeSH) and hydrogen sulphide (H2S). The dynamic system demonstrated carbonyl sulphide (COS) uptake by the forested peat. VSC emission from the paddy soils was generally much lower than that from the peat soils except that the addition of glucose greatly stimulated carbon disulphide (CS2) emission. A novel observation was the trace emission of MeSH under aerobic conditions from the paddy soils. Extrapolation of the results to field conditions indicates that VSC fluxes do not play an important role in the overall sulphur cycle either in cool northern peatlands or in warm temperate paddy fields