Improved estimates of the terrestrial carbon cycle by coupling of a process-based global vegetation model (LPJ-DGVM) with a 17-year time series of satellite-observed fPAR data (AVHRR)

Coupling of a state-of-the-art Dynamic Global Vegetation Model (LPJ-DGVM) with a 17-year time series of fPAR data (AVHRR) allows improved derivation of important global carbon cycle parameters such as global net primary production (NPP), heterotrophic respiration (Rh) and net ecosystem exchange (NEE) by combining satellite observations with the process knowledge encoded in the model. Global net primary production is estimated to be a 9 GtC/yr lower than from the unconstrained model, partially due to human agricultural activity. The estimated current size of the global carbon sink is reduced from 1.3 to 0.9 GtC/yr. Current global biomass is predicted to be 223 GtC less than that of potential natural vegetation.