A simulation model of net photosynthesis rate of canopy was developed with the field measurement of individual leaf in a Cunninghamia lanceolata (Lamb.)Hook.Plantation combining the aero dynamical characteristics and the nonlinear response of photosynthesis to light,based on simplified models of radiation transmission and the photosynthesis photosynthetic active radiation curves ( A PAR)of needles of different ages in different layers of canopy.The results showed that the value adjusted is 10% high...