ESTIMATION OF THE OPTICAL PARAMETERS AND LIGHT GRADIENTS IN LEAVES: MULTI-FLUX versus TWO-FLUX TREATMENT

Abstract— Parameters of light propagation in plant leaves—absorption and scattering coefficients, asymmetry of scattering—have been estimated on the basis of measured transmission and remission as well as internal fluxes. This estimation has been carried through by solving the inverse problem of the 4-flux radiative transfer—a theory considering forward and backward diffuse as well as directed components of the overall radiation in a multiply scattering sample. Using the gained parameters, light flux gradients in a two-layered model leaf have been calculated at different wavelengths. Monte Carlo simulation of absorption spectra performed with the parameters obtained with this treatment is in a good agreement with experimental spectra, thus substantiating the theory. Parallel calculations with the two-flux (Kubelka-Munk) theory provide an estimation of the accuracy and applicability of this more simple treatment. Calculations have been performed for two different plants.