SIMULATION OF LIGHT INTERCEPTION FROM A MAIZE CANOPY MODEL CONSTRUCTED BY STEREO PLOTTING

Three-dimensional (3-D) computer models of vegetation represent a mean s to analyse the interactions between light and canopy structure, with out requiring the turbid medium analogy used in transport theory. Howe ver, no field validations of such models have been presented until now . In this paper, we evaluate the ability of a computer model of maize constructed in earlier work from stereo-plotting to reproduce the prop erties of actual vegetation relevant to light interception. We compare d the directional and bi-directional gap fraction distributions calcul ated from real and simulated hemispherical photographs. A good agreeme nt was found between measurements and simulation, although the model s lightly overestimated the gap fraction for zenith angles higher than 4 0 degrees. Finally, stereovision appears to be able to provide realist ic 3-D description of vegetation structure. Some directions for improv ing the method and possible applications are presented.