Simultaneous inhibition of CH 4 efflux and stimulation of sulphate reduction in peat subject to simulated acid rain

• Published in: Soil biology & biochemistry Vol. 38; no. 12; pp. 3506 - 3510
• Main Authors: Gauci, Vincent, Chapman, Stephen J.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 2006
• Subjects: Acid rain; Atmosphere; Bacteria; Bogs; Competitive exclusion; Emissions; Methane; Methanogens; Peatlands; SRB; Sulfate; Sulphate; Sulphate reduction; Wetlands; Methane; SRB; Competitive exclusion; Bogs; Peatlands; Methanogens; Acid rain; Sulphate reduction; Wetlands; Emissions; Sulphate; Atmosphere; Bacteria; Sulfate
• ISSN: 0038-0717; 1879-3428
• DOI: 10.1016/j.soilbio.2006.05.011

Acid rain sulphate (SO 4 2−) deposition is a known suppressant of methane (CH 4) emission from wetlands. However, the hypothesised mechanism responsible for this important biogeochemical interaction, competitive exclusion of methanogens by dissimilatory SO 4 2− reducing bacteria (SRB), lacks supporting evidence. Here, we present data from an acid rain simulation experiment in the Moidach More peat bog of NE Scotland that strengthens this hypothesis. We report a tenfold increase in estimated SO 4 2− reduction during periods when measured CH 4 emission rates were suppressed relative to controls receiving only one-tenth the SO 4 2− of treated plots, but no treatment effect on potential methane oxidation. This tenfold increase in estimated SO 4 2− reduction indicates the presence of a more active population of SRB in plots where CH 4 emissions were reduced by over 30%.