GDRI Car-Wet-Sib

Document présentant les axes de recherche du GDRI Car-Wet-Sib dédié à l'étude du cycle de l'eau, du carbone et des éléments associés dans les zones humides sibériennes. Le GDRI est actuellement en renouvellement pour 4 années: résumé.
Résumé :
Due to the fragility of boreal ecosystems with respect to human activity and their high vulnerability to climate change, studies of arctic regions have been in the centre of scientific research for the last decade. The main reason for this interest is the high uncertainty on the prediction of the evolution of carbon and nutrients fluxes from the land to the Arctic Ocean under progressive climate warming scenario. These fluxes are among the major controlling factors of primary productivity and CO2 exchange with the atmosphere of the Arctic Ocean basin which affects, in turn the overall ocean water and nutrients circulation (Holmes et al., 2012). Recent economic interest to these regions is linked to 1) the possibility of summer ice-free Arctic in the next several decades and 2) significant natural resources that become progressively available both on the shelf zone and on the continents. Among different regions of high latitude, Siberia seems to be most affected by these global climate changes, because of the presence of permafrost and important stocks of organic carbon in forest soils, tundra and swamp zones. Siberia represents 60% of the permafrost covered surface (Permafrost International Association) and is of major interest for the whole Earth system. A recent estimate (Schuur et al., 2008) indicates that the below-ground stock of carbon in permafrost-dominated regions is around 1650 gigatonnes of carbon (Gt C), an amount that greatly exceeds the carbon content of the atmosphere (around 750 Gt C). In the context of climate warming and permafrost thaw, these regions may be considered as a real “time bomb” capable doubling pCO2 of the atmosphere in a short period of time.