431-12 13CPLFA Analysis of the Microbial Community Composition within Peat Depth Profiles in Response to Seasonal Changes and Warming.
Poster Number 1319
In this study, 13CPLFA analysis was used to characterize the microbial community along peat depth profiles taken from the SPRUCE Project, as well as to provide isotopic information about the carbon being used by the microbes. The SPRUCE Project is an extensive study of the response of peatlands to climatic manipulation in the Marcell Experimental Forest in northern Minnesota. Heating rods were installed in peatland plots where peat is being warmed to temperatures ranging from ambient to +9 degrees Celsius, to a depth of 1 meter. The effects of natural environmental fluctuation over time to the microbial community will be evaluated based on peat samples taken from ambient plots from June 2014, September of 2014, and June of 2015, throughout the depth profile. The effects of warming on the microbial community composition and their use of 13C will be evaluated based on peat samples from September 2014 and June 2015.
This study will result in useful information about the influence of environmental fluctuation over time and different depths on the microbial community composition within the peatland. This study will also provide insight into the influence of warming on the microbial community composition and on how the microbes are using the carbon present at these different levels of warming.
Preliminary isotopic data at both sampling dates appears to show that microbial biomass has a higher d13C lower in the peat profile, indicating as expected that microbes at depth utilize older carbon or carbon more enriched in 13C. The increase over depth in the δ13C coefficient may also reflect the increasing dominance of pre-industrial carbon which is more enriched in 13C.