A modeling approach to estimate the gross and net primary production of forest ecosystems as a function of the fraction of absorbed photosynthetically active radiation

A simple non-linear model allowing to calculate daily and monthly GPP and NPP of forests using parameters characterizing the light-use efficiencies for GPP and NPP, and integral values of absorbed photosynthetically active radiation, obtained using field measurements and remotes sensing data was suggested. Daily and monthly GPP, NPP of the forest ecosystems were derived from the field measurements of the net eco-system exchange of $\rm CO_2$ in the spruce and tropical rain forests using a process-based Mixfor-SVAT model.