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Methane and Reduced Sulfur Gas Production by Fresh and Dried Wetland Soils
Author(s) -
Crozier C. R.,
Devai I.,
DeLaune R. D.
Publication year - 1995
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1995.03615995005900010044x
Subject(s) - soil water , chemistry , wetland , salinity , environmental chemistry , swamp , organic matter , incubation , sulfur , methane , zoology , environmental science , ecology , soil science , biology , biochemistry , organic chemistry
Wetland soil microorganisms are probably influenced by fluctuating water levels and by longer‐term climatic change. This study investigated production of CH 4 and reduced S gases [H 2 S, CH 3 SH, (CH 3 ) 2 S, COS, and CS 2 ] by both freshly collected and air‐dried, rewet soils from four wetlands in the Mississippi deltaic plain. Soils from three depth intervals (0–10, 10–20, and 20–30 cm) from a swamp forest (Typic Hydraquent), a freshwater marsh (Terric Medisaprist), an intermediate salinity marsh (Typic Medisaprist), and a salt marsh (Typic Medisaprist) were incubated under anaerobic conditions. At repeated time intervals, the headspace gas was analyzed and then purged with N 2 . Peak production rates of both CH 4 and H 2 S occurred earlier in the fresh soils than in the dried soils in almost all cases. Presumably, this time lag associated with drying was caused by an increase in potentially reducible Mn and Fe. Nevertheless, drying increased labile C levels, thus total CH 4 production was similar during the entire 69‐d incubation. Production of CH 4 was positively correlated with organic matter content (fresh, R 2 = 0.52; dried, R 2 = 0.64) and labile C (fresh, R 2 = 0.83; dried, R 2 = 0.89). Due to their relatively low concentrations, inclusion of soil oxidants in a model did not significantly improve the fit of a model that already contained a term for labile C. Production of S gases was positively correlated with initial SO 2− 4 concentrations (fresh, R 2 = 0.75; dried, R 2 = 0.42). Drying significantly decreased total H 2 S production only for the salt marsh soils. In contrast, the drying treatment increased CH 3 SH production; only these soils produced (CH 3 ) 2 S, COS, and CS 2 .