Abstract
An individual based dynamic model describing Nitrogen cycles and vegetation growth and succession was developed. The model is composed of tree modules, where recruitment, self-thinning, growth, defoliation/decomposition processes were simulated, herbaceous plant modules, which provide the biomass given by the soil nitrogen content, soil particle size and shading effect by trees, and nitrogen budget modules, providing nitrogen budgets through the decomposition of herbs and tree leaves. The model was applied to the observed data at Aara and Kurobe rivers'sediment bars, showing the suitable agreement. Then, it was applied for the simulation of the 20-year succession, subjected to frequent floods to see the trend of vegetation biomass and nitrogen cycle.
