Abstract
Competition between wetland species, Phragmites australis, and upland species, Misranthus sacchanflorus, in a river-wetland rehabilitation site was analyzed in relation to flood discharge, flood interval and their stem-breaking moment. River flow was analyzed by two-dimensional depth-averaged Reynolds equation to solve the moment acting on the stems. Regrowth dynamic model considering their stem-breaking, one of the damage types of the two species, was formulated. The decrease in biomass by flood discharge and interval were analyzed for monospecific stands and competitive stand. If their stem breaking is occurred every year, survival of the two species is difficult. However, if the interval is 2-5 years, they can survive but superiority of M. sacchariflorus is decreased. The analysis indicates that stem-breaking of both two species by flood every 2-5 years can delay the transition from wetland to upland species.
