HR: 0800h
AN: GC31A-0115    [Abstracts]
TI: The understanding of past and present-day carbon dynamics of boreal peatlands, James Bay Lowlands, Quebec, Canada
AU: * Garneau, M
EM: garneau.michelle@uqam.ca
AF: Departement de geographie et GEOTOP-UQAM-McGill, Universite du Quebec a Montreal, C.P. 8888, Succ. Centre-Ville, Montreal, QC H3C 3P8, Canada
AU: Turunen, J
EM: jukka.turunen@gtk.fi
AF: Geological Survey of Finland (GTK)Kuopio Unit, P.O.Box 1237 (Neulaniementie 5), Kuopio, FIN-70211, Finland
AU: Ali, A
EM: adam.ali@uqat.ca
AF: Departement de geographie et GEOTOP-UQAM-McGill, Universite du Quebec a Montreal, C.P. 8888, Succ. Centre-Ville, Montreal, QC H3C 3P8, Canada
AU: Asnong, H
EM: asnong@sca.uqam.ca
AF: Departement de geographie et GEOTOP-UQAM-McGill, Universite du Quebec a Montreal, C.P. 8888, Succ. Centre-Ville, Montreal, QC H3C 3P8, Canada
AU: Pelletier, L
EM: pelletier.luc@uqam.ca
AF: Departement de geographie et GEOTOP-UQAM-McGill, Universite du Quebec a Montreal, C.P. 8888, Succ. Centre-Ville, Montreal, QC H3C 3P8, Canada
AU: Loisel, J
EM: loisel.julie.2@courrier.uqam.ca
AF: Departement de geographie et GEOTOP-UQAM-McGill, Universite du Quebec a Montreal, C.P. 8888, Succ. Centre-Ville, Montreal, QC H3C 3P8, Canada
AU: Beaulieu-Audy, V
EM: verobeaulieu@gmail.com
AF: Departement de geographie et GEOTOP-UQAM-McGill, Universite du Quebec a Montreal, C.P. 8888, Succ. Centre-Ville, Montreal, QC H3C 3P8, Canada
AB: 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 region (51-54^oN; 73-78^oW). Ten peatlands representative of the ecogeomorphic areas from which they belong were investigated and provide data from paleoecology, biogeochemistry, surface fluxes and related vegetation. Local and regional variability of surface CO₂ and CH₄ exchanges were determined to detail the relative sensitivity of the peatland carbon fluxes in relation with current climate conditions (WTD) and nutrient context (bogs vs fens). Isotopic fractionation (δ C¹³) of surface and subsurface vegetation as well as peat and carbon accumulation reconstructed from the beginning of peat inception in the region ( ca 7000 BP) until the last centuries ( ca 250 yrs) were achieved using radiochronology (²¹⁰Pb and ¹⁴C), carbon content (LOI and C/N), microfossils (pollen, spores and testate amoebae) and plant macrofossils. Detailed analyses of the peatlands show that even the general peat accumulation models present relatively accurate estimates of LORCA and peat depths, the balance between C input and decay has changed considerably (LORCA range 11-59 g m^-2 yr^-1) during the development of the peatlands. These data provide spatial and temporal understanding of northeastern canadian boreal peatlands from the time they first began accumulating carbon to their present day patterns and processes. This research is supported by NSERC (Natural Sciences and Engineering Research Council of Canada) and Hydro- Québec.
DE: 0439 Ecosystems, structure and dynamics (4815)
DE: 0473 Paleoclimatology and paleoceanography (3344, 4900)
DE: 1630 Impacts of global change (1225)
SC: Global Environmental Change [GC]
MN: 2007 Fall Meeting