Microbial contribution to continental wetland carbon budget

Continental wetlands are major carbon dioxide sinks but the second largest source of methane.

Monitoring of wetland methane emissions revealed large inter-site variability that is hard to explain in the framework of current biogeochemical theories.

Methane production in wetlands is an anaerobic microbial driven process involving a complex set of microbial metabolisms depending on the availability of (i) energy (via the presence of specific redox couples), (ii) organic substrates and (iii) specific microbial communities.

To understand the complexity of microbial drivers on wetland methane emissions and quantify their contribution, the MICADO project will set up a multidisciplinary approach linking isotope organic geochemistry and environmental microbiology to assess microbial functioning in situ.

As an organic geochemist I have developed an innovative approach to trace in situ microbial activity via compound specific carbon isotope analysis of microbe macromolecules and organic metabolites.

The host institution is a leader in France in environmental microbiology and biogeochemistry developing high-throughput metagenomics and microbial rate assessments, for which I will be trained during the MICADO project.

These techniques are highly complementary and combined they will provide a comprehensive knowledge on microbial metabolisms involved in organic matter degradation encompassing their complexity and interactions.

This will revisit the relationships between organic substrate availability and microbial communities and will contribute at estimating the impact of microbial activity on wetland methane emissions.

This project will give me the opportunity to acquire fundamental knowledge and to develop original lines of research that will consolidate my position as an independent scientist in biogeochemistry.