ANALYTICAL SOLUTION OF THE RECTANGULAR HYPERBOLA FOR ESTIMATING DAILY NET PHOTOSYNTHESIS

Simulation models require algorithms that are accurate yet efficient. Many simulation models use rectangular hyperbolas to express the light-response curve for net photosynthesis. The diurnal light-distribution function must be superimposed on that functional relation and numerically integrated to obtain daily net photosynthetic amounts. Usually, leaf and ambient temperature, soil moisture, leaf-water potential, and other controlling environmental data are not available for use in large, multi-species simulation models. In this paper a procedure is given for integrating the diurnal light-response curve. The model assumes that light is evenly distributed throughout the plant canopy. The algorithm is computationally more efficient than the iterative numerical solution and is most useful for open canopies or when investigators are not concerned about simulating light depletion in relation to canopy density.