Laboratory
in biooptics and microbial ecology of the INRS-ETE
Methane emissions from arctic ponds
Arctic
climate change accelerates permafrost thawing and the mobilisation of carbon
(C) stored in frozen soils of the tundra for millennia. This thaw generates
thousands of small aquatic systems with diverse limnological and
geomorphological properties. Some of these systems emit substantial amounts of
greenhouse gases and scientists estimate that these emissions could influence
the climate. However, the source and lability of the available organic C, and
the microbial communities of these systems influence C exchanges, which are quite
variable in space and time, leaving large uncertainties on their potential to
influence climate at the planetary scale. Notably, methane emissions through
ebullition have been overlooked. Moreover, gas exchange models used to estimate
diffusive emissions are inadequate for such small systems. Finally, the
emission of old C stored in peat deposits could have a determining influence on
climate through a positive feedback, by comparison to C recently fixed by
plants, urging for the identification of C sources used by microbes.
The project
consist in sampling a series of thaw ponds on Bylot Island, Nunavut, to
determine diffusion and ebullition flux, C sources with 14C dating, and the
factors influencing the emissions (geomorphology surrounding the ponds, physical
structure of the water column and sediment below, C characteristics, CH4
oxidation with stable isotopes, etc.). This multidisciplinary project will be
supervised by I. Laurion (limnology, microbial ecology, INRS-ETE) and D.
Fortier (geomorphology, U. of Montreal), and is financed by ArcticNet. The
student will be highly encouraged to apply to EnviroNorth scholarship program
(deadline 15 November,http://environord-environorth.ca).
Start:
as soon as possible (January 2014)
Contact: Isabelle.Laurion@ete.inrs.ca
The application needs to include a CV, a motivation letter, the university transcripts and 2 letters of recommendation.
A good knowledge of biology and biogeochemical cycles will be an asset.
The application needs to include a CV, a motivation letter, the university transcripts and 2 letters of recommendation.
A good knowledge of biology and biogeochemical cycles will be an asset.
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