Abstract: A simulation model of canopy radiation was developed for the calculation of within-and between-tree shading. The model accounts for the canopy structure of an even-aged plantation on a sloping site and heterogeneity of leaf area density within tree crowns. It can be used to simulate instantaneous radiation at any point within crowns, the direct, diffuse and scattered fractions as well as daily radiation within 1 hour time steps. Canopy photosynthetic productivity can also be simulated with the radiation model