On the Application of Photoacoustic Absorption Spectral Data to the Modeling of Leaf Optical Properties

Abstract

Due to the importance of plants in the Earth's ecosystem, their photobiological responses have become the subject of extensive research in life sciences. Leaf optical models have been developed to assist in the analysis of remotely sensed data to derive information on leaf biochemistry and anatomy from foliar spectral curves (transmittance and reflectance). In this paper, we investigate the implications of using in vitro pigment absorption spectra to model foliar optical properties in the visible domain. Typically pigment absorption spectra have been determined using light absorption spectroscopy or by applying a data fitting approach. Alternatively, we propose the use of photoacoustic absorption spectroscopy, which despite being available in the literature has not been used in the modeling of foliar optical properties before. We also perform computational experiments in which foliar modeled reflectance and transmittance spectral curves generated using these different absorption data sets are compared with actual measured data. Our findings indicate that the proposed alternative not only allows key pigments to be individually incorporated into the models, which, in turn, increases the predictability of the simulations, but also enables the generation of modeled leaf spectra that are closer approximations to measured leaf spectra than those obtained using absorption data derived from standard absorption spectroscopy procedures.