INVESTIGADORES
LAGORIO MarÍa Gabriela
congresos y reuniones científicas
Título:
Modeling chlorophyll fluorescence at canopy level for different species
Autor/es:
JUAN MANUEL ROMERO; GABRIELA B. CORDON; MARÍA GABRIELA LAGORIO
Reunión:
Congreso; XIII ELAFOT 2017; 2017
Resumen:
Chlorophyll fluorescence is used as an indicator physiological state of plants. Remote acquisition of fluorescence allows the diagnosis of large field extensions, even from satellite measurements [1]. However, fluorescence emerging from chloroplasts, the one directly connected to plant physiology, undergoes reabsorption proccesses both inside the leaf and the canopy, which completely distort the observed emission spectra [2,3]. Therefore, to draw accurate inferences about plant health, it is necessary to correct the observed canopy fluorescence taking into account these two reabsorption proccesses [4]. In a previous work, we have shown the theoretical development and experimental validation of a biophysical model that allows retrieving leaf fluorescence from that of the canopy using a correction factor which is a function of canopy and soil reflectance and canopy transmittance [5].In this work, we apply our fluorescence correction model to canopies of different species and, mainly, different canopy structures. Plants used were: ficus (Ficus benjamina, planophile), maize (Zea mays, erectophile), oats (Avena sativa, erectophile), pea (Pisum Sativum, planophile) and ryegrass (Lolium multiflorum, erectophile). Canopy and leaf fluorescence spectra were registered for each species and corrected canopy fluorescence spectra were obtained and compared with the leaf spectra. The model showed a higher accuracy at predicting leaf spectra of planophile plant covers than of erectophile ones. Moreover, a reasonable dependence on the amount of biomass was found. The performance of the fluorescence reabsorption model will be discussed in terms of the photophysical assumptions and model equations.(A) Canopy photophysical model, with photon fluxes taken into account by the model.(B) Chlorophyll fluorescence corrected from canopy to chloroplasts.Acknowledgments: UBA (UBACyT 20020130100166BA) and to the ANPCyT (PICT 2012-2357) provided the financial support. M.G.L. and G.B.C. are researcher scientists of CONICET. J.M.R. developed this work with a fellowship from CONICET.[1] K Maxwell, GN Johnson. Chlorophyll fluorescence - a practical guide. J. Exp. Bot. 2000, 51(345), 659.[2] G Agati, F Fusi, P Mazzinghi. A simple approach to evaluation of the reabsorption of chlorophyll fluorescence spectra in intact leaves. J. Photochem. Photobiol. B. 1993, 17:163.[3] ME Ramos, MG Lagorio. True fluorescence spectra of leaves. J. Photochem. Photobiol. Sci. 2004, 3:1063.[4] A Porcar-Castell, et al. Linking chlorophyll a fluorescence to photosynthesis for remote sensing applications: mechanisms and challenges. J. Exp. Botany. 2014, Eru191.[5] JM Romero, GB Cordon, MG Lagorio. Modeling re-absorption of fluorescence from the chloroplast to the canopy level. Rem. Sens. Env. Work still under review.