PARENT SESSION
Poster Session 3: Aquatic Ecology
Monday, August 8, 5:00 PM - 6:30 PM, Exhibit Hall 210 D, Level 2, Palais des congrès de Montréal

Impact of elevated CO₂ and temperature on the structure of microbial communities in a peatland.

Kim, Seon-Young^*,1, Lee, Seung-Hoon^*,1, Kang, Hojeong ^*,1, Fenner, Nathalie ^*,2, Freeman, Chris ^*,2, ¹ Dep. of Environmental Science & Engineering, Ewha Womans University, Seoul, South Korea² School of Biological Sciences, University of Wales, Bangor, UK

ABSTRACT- The effects of elevated CO₂ and temperature on soil microbial community will have important implications for nutrient cycling and an accumulation of soil carbon. We hypothesized the structure of microbial communities would be different as a result of the qualitative and quantitative changes in dissolved organic carbon. We investigated the structure of bacterial community in soil of a peat mire that had been exposed to elevated CO₂ (235 ppm above ambient, ca 605ppm) and/or elevated temperature (3°C above ambient) for 3 growing seasons. We analyzed the bacterial community structure by using Terminal-Restriction Fragment Length Polymorphism (T-RFLP) of 16S rDNA fragments amplified by Polymerase Chain Reaction (PCR). Structure of the bacterial community, as assessed by distribution of T-RF in each sample, was affected by elevated CO₂ (p<0.05, n=5) significantly, but not by the elevated temperature treatment. This result is likely to have been due to significantly increased DOC and phenolic compounds concentrations in peat cores growing at CO₂ enrichment. This finding is of considerable importance since it suggests that elevated atmospheric CO₂ may lead to a change of bacterial community structure in wetlands and may feedback into bacterial functions such as organic carbon decomposition, nutrient cycling, and greenhouse gas emissions.

Key words: elevated CO2, bacterial community structure, peatland, 16S rDNA