Controls on suppression of methane flux from a peat bog subjected to simulated acid rain sulfate deposition
Gauci, Vincent; Dise, Nancy; Fowler, David. 2002 Controls on suppression of methane flux from a peat bog subjected to simulated acid rain sulfate deposition. Global Biogeochemical Cycles, 16 (1). 4-12. 10.1029/2000GB001370Full text not available from this repository.
The effect of acid rain SO42− deposition on peatland CH4 emissions was examined by manipulating SO42− inputs to a pristine raised peat bog in northern Scotland. Weekly pulses of dissolved Na2SO4 were applied to the bog over two years in doses of 25, 50, and 100 kg S ha−1 yr−1, reflecting the range of pollutant S deposition loads experienced in acid rain-impacted regions of the world. CH4 fluxes were measured at regular intervals using a static chamber/gas chromatographic flame ionization detector method. Total emissions of CH4 were reduced by between 21 and 42% relative to controls, although no significant differences were observed between treatments. Estimated total annual fluxes during the second year of the experiment were 16.6 g m−2 from the controls and (in order of increasing SO42− dose size) 10.7, 13.2, and 9.8 g m−2 from the three SO42− treatments, respectively. The relative extent of CH4 flux suppression varied with changes in both peat temperature and peat water table with the largest suppression during cool periods and episodes of falling water table. Our findings suggest that low doses of SO42− at deposition rates commonly experienced in areas impacted by acid rain, may significantly affect CH4 emissions from wetlands in affected areas. We propose that SO42− from acid rain can stimulate sulfate-reducing bacteria into a population capable of outcompeting methanogens for substrates. We further propose that this microbially mediated interaction may have a significant current and future effect on the contribution of northern peatlands to the global methane budget.
|Item Type:||Publication - Article|
|Digital Object Identifier (DOI):||10.1029/2000GB001370|
|Programmes:||CEH Programmes pre-2009 publications > Biogeochemistry > CC01B Land-surface Feedbacks in the Climate System|
|CEH Sections:||_ Pre-2000 sections|
|Additional Keywords:||Biosphere/atmosphere interactions, Pollution—urban and regional, Global Change, Wetlands|
|NORA Subject Terms:||Ecology and Environment
|Date made live:||27 Jul 2009 13:01|
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