Simulating seasonal and inter-annual variations in energy and carbon exchanges and forest dynamics using a process-based atmosphere-vegetation dynamics model

The present paper shows simulated results of seasonal and inter-annual variations in energy and carbon exchanges and forest dynamics in a sub-boreal deciduous forest using a fully coupled atmosphere-vegetation interaction model [multilayered integrated numerical model of surface physics-growing plants interaction (MINoSGI)]. With careful adjustment of site-specific eco-physiological parameters, MINoSGI reproduced successfully stand biomass-tree density relationship based on the forest inventory data for 7 years (1999-2005) and seasonal and inter-annual variations in energy and CO₂ fluxes measured by means of eddy covariance technique for 3 years (2003-2005) in the sub-boreal forest, northern Japan. In addition, MINoSGI estimated annual evapotranspiration (E_vt) at 328.6 ± 25.8 mm year^-1, net primary production (NPP) at 372.1 ± 31.5 gC m^-2year^-1 and net ecosystem exchange (NEE) at -224.2 ± 32.2 gC m^-2year^-1. We found the estimate of annual NEE in our site lies among the estimates at other forest stands with the almost same climatic conditions in northern Japan, although the tree species and stand age of these forests are different from those of our site. Overall, MINoSGI was found useful to present simultaneous simulations of forest dynamics, surface energy, and carbon exchanges of a forest stand in the future from micro-meteorological and ecophysiological points of view.