Evaluating the potential of large-scale simulations to predict carbon fluxes of terrestrial ecosystems over a European Eddy Covariance network

[摘要] This paper reports a comparison between large-scale simulations of threedifferent land surface models (LSMs), ORCHIDEE, ISBA-A-gs and CTESSEL, forcedwith the same meteorological data, and compared with the carbon fluxesmeasured at 32 eddy covariance (EC) flux tower sites in Europe. The resultsshow that the three simulations have the best performance for forest sitesand the poorest performance for cropland and grassland sites. In addition,the three simulations have difficulties capturing the seasonality ofMediterranean and sub-tropical biomes, characterized by dry summers. Thisreduced simulation performance is also reflected in deficiencies in diagnosedlight-use efficiency (LUE) and vapour pressure deficit (VPD) dependenciescompared to observations. Shortcomings in the forcing data may also play arole. These results indicate that more research is needed on the LUE and VPDfunctions for Mediterranean and sub-tropical biomes. Finally, this studyhighlights the importance of correctly representing phenology (i.e. leaf areaevolution) and management (i.e. rotation–irrigation for cropland, andgrazing–harvesting for grassland) to simulate the carbon dynamics of Europeanecosystems and the importance of ecosystem-level observations in modeldevelopment and validation.

[学科分类] 地球化学与岩石