Chang J. F. auteur aut IRD Ciais P. auteur aut IRD Viovy N. auteur aut IRD Vuichard N. auteur aut IRD Sultan Benjamin auteur aut IRD Soussana J. F. auteur aut IRD text journalArticle eng text/pdf born digital access The greenhouse gas (GHG) balance of European grasslands (EU-28 plus Norway and Switzerland), including CO2, CH4 and N2O, is estimated using the new process-based biogeochemical model ORCHIDEE-GM over the period 1961-2010. The model includes the following: (1) a mechanistic representation of the spatial distribution of management practice; (2) management intensity, going from intensively to extensively managed; (3) gridded simulation of the carbon balance at ecosystem and farm scale; and (4) gridded simulation of N2O and CH4 emissions by fertilized grassland soils and livestock. The external drivers of the model are changing animal numbers, nitrogen fertilization and deposition, land-use change, and variable CO2 and climate. The carbon balance of European grassland (NBP) is estimated to be a net sink of 15 +/- 7gCm(-2)year(-1) during 1961-2010, equivalent to a 50-year continental cumulative soil carbon sequestration of 1.0 +/- 0.4PgC. At the farm scale, which includes both ecosystem CO2 fluxes and CO2 emissions from the digestion of harvested forage, the net C balance is roughly halved, down to a small sink, or nearly neutral flux of 8gCm(-2)year(-1). Adding CH4 and N2O emissions to net ecosystem exchange to define the ecosystem-scale GHG balance, we found that grasslands remain a net GHG sink of 19 +/- 10g C-CO2 equiv. m(-2)year(-1), because the CO2 sink offsets N2O and grazing animal CH4 emissions. However, when considering the farm scale, the GHG balance (NGB) becomes a net GHG source of -50gC-CO2 equiv. m(-2)year(-1). ORCHIDEE-GM simulated an increase in European grassland NBP during the last five decades. This enhanced NBP reflects the combination of a positive trend of net primary production due to CO2, climate and nitrogen fertilization and the diminishing requirement for grass forage due to the Europe-wide reduction in livestock numbers. specialized European grassland grassland management greenhouse gases balance livestock ORCHIDEE EUROPE 082 021 21 10 3748-3761 2015 1354-1013 https://www.documentation.ird.fr/hor/fdi:010065272 10.1111/gcb.12998 1354-1013 [F B010065272] https://www.documentation.ird.fr/hor/fdi:010065272 https://www.documentation.ird.fr/intranet/publi/2015/10/010065272.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2015-11-06 2017-08-23 fdi:010065272 fre