In boreal regions of the northern hemisphere, peatlands cover up to 20% of the Canadian territory, and between 9 to 12% of the Quebec province. Considering that peat accumulation is thought to be largely a function of moisture and temperature, we developed a multidisciplinary approach in order to improve the understanding of peatland carbon dynamics in the James Bay Lowlands (…).

Between 2003 and 2006, we investigated from a local to a regional scale, different peatlands types representative of the ecogeomorphic areas from which they belong. The approach has been defined following three major axis of research and presents data from paleoecology, biogeochemistry, surface vegetation ecology, surface hydrology, geomorphology and remote sensing, integrated into a geographic information system (GIS).

Axis 1 of the project focuses on regional characterization and classification of present-day surface peatland types using satellite images and aerial photos. Axis 2 of the project set sights on assessing the local and regional variability of CO2 and CH4 exchanges to determine the relative sensitivity of the peatland carbon fluxes in relation with current climate conditions and nutrient context (bogs vs fens). Axis 3 of the project aims to understand and/or quantify: 1) isotopic fractionation (δ C13) of surface and subsurface vegetation, 2) peat and carbon accumulation reconstructed through the last centuries (ca 250 yrs) and dated with 210Pb and 3) holocene paleoenvironmental conditions related with peat and carbon accumulation since the beginning of peat inception in the region (ca 7000 BP). Sequential reconstructions are to be achieved using radiochronology (14C), carbon content (LOI and C/N), microfossils (pollen, spores and rhizopods) and plant macrofossils.

Models will be run to determine the relative sensitivity of CO2 and CH4 exchanges under past, current and future climate conditions using transfert functions and CGCM2 simulations. The integration of these data will allow a comprehensive spatial and temporal understanding of boreal peatlands dynamics from the time they first began accumulating carbon to their present day patterns and processes. This research is supported by a Natural Sciences and Engineering Research Council of Canada collaborative grant (NSERC-CRD) in partnership with Hydro-Québec (coordinator, Dr. Alain Tremblay) and CFCAS.

An integrated multiscale (spatial and temporal) approach for carbon dynamics comprehension of boreal peatlands, Québec, Canada