DESCRIPTION AND VALIDATION OF AN ARRAY MODEL - MAESTRO

An array model, MAESTRO, was developed to predict radiation absorption, photosynthesis and transpiration by the individual crowns of trees in a stand and by the stand as a whole. The fluxes of radiation are treated in the photosynthetic (PAR), near infrared (NIR) and thermal wavebands; beam and diffuse radiation are considered separately. The spatial heterogeneity of the leaf area density distribution within the tree crown has been incorporated into MAESTRO, which can be used to study the spatial distribution of the radiation regime, and of the water vapour and carbon dioxide exchanges of leaves within the tree crown, in relation to stand structure. This model has been tested by comparing the calculated hourly and daily fluxes of PAR with measurements made by quantum sensors at locations below the tree crowns using three different submodels of leaf area density distribution. Good agreement between measurements and predictions was obtained. © 1990.