128-3
Linking Greenhouse Gas Production to Microbial Communities in High Arctic Polar Desert Soils.

Monday, November 4, 2013: 3:05 PM
Marriott Tampa Waterside, Room 10, Third Level

Martin Earl Brummell1, Stan Robert2, Levente Bodrossy2 and Steven Siciliano1, (1)Department of Soil Science, University of Saskatchewan, Saskatoon, SK, Canada
(2)Marine and Atmospheric Research, CSIRO, Hobart, Australia
The greenhouse gases CO2, CH4, and N2O are produced and consumed by soil microorganisms.  Production and consumption of one GHG may occur within the same soil profile, for example oxidation of CH4 in near-surface aerobic soil overlying a deeper, anaerobic soil layer where CH4 is released. Understanding these processes requires knowledge of microbial community ecology, because the organisms responsible for both production and consumption respond to both abiotic (soil water, oxygen, pH, nutrient availability) and biotic (competition, symbiosis, predation) factors. Within functional guilds such as ammonia-oxidizers, different phylotypes will be more or less represented in different environments, with consequences for overall rates of GHG production or consumption and thus consequences for total GHG flux to overlying atmosphere.

I have employed DNA-microarrays to survey the community composition of soils of the Canadian High Arctic, polar desert soils that have previously been shown to be active in GHG production, consumption, and efflux to atmosphere. These cold, nutrient-poor soils include a number of unusual features, including production/consumption overlying structures for CH4 and highly variable N2O productions. Community composition of ammonia-oxidizers and methane-oxidizers reveals dominance of ammonia-oxidation by Archaea, rather than Bacteria, and considerable diversity of high-affinity methane-oxidizing Bacteria.

See more from this Division: SSSA Division: Soil Biology & Biochemistry
See more from this Session: Biogeochemistry of Soil Microbial Communities

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