EGU General Assembly 2020
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Non-monotonic relationship of sun-induced fluorescence to photosynthesis

Sebastian Wieneke1, Manuela Balzarolo2,3, Han Asard4, Hamada AbdElgawad4,5, Josep Peñuelas2,3, Uwe Rascher6, Arne Ven1, Melanie Verlinden1, Ivan Janssens1, and Sara Vicca1
Sebastian Wieneke et al.
  • 1Plants and Ecosystems (PLECO), Department of Biology, University of Antwerp, Wilrijk, Belgium (
  • 2Consejo Superior de Investigaciones Científicas (CSIC), Global Ecology Unit, CREAF-CSIC-UAB, Bellaterra, 08193 Barcelona, Catalonia, Spain
  • 3Centre de Recerca Ecològica i Aplicacions Forestals (CREAF), Cerdanyola del Vallès, 08193 Barcelona, Catalonia, Spain
  • 4Integrated Molecular Plant Physiology Research (IMPRES), Department of Biology, University of Antwerp, Antwerp, Belgium
  • 5Botany and Microbiology Department, Faculty of Science, Beni-Suef University, Beni-Suef 62511, Egypt
  • 6Institute of Bio- and Geosciences (IBG-2): Plant Sciences, Forschungszentrum Jülich GmbH, Leo-Brandt-Str., Jülich, Germany

Due to its close link to the photosynthetic process, sun-induced fluorescence (SIF) is one of the most promising signals to assess spatio-temporal variation in photosynthesis. Yet the positive linear relationship between SIF and photosynthesis, often reported from satellite and proximal remote sensing, contradicts findings from leaf-level studies, particularly under stress conditions. In two separate experiments, we grew Mays (Zea mays L.) under increasing phosphorus limitation and potato (Solanum tuberosum L.) under increasing drought stress to assess whether SIF can detect the phosphorus and drought induced reduction in photosynthesis. We demonstrate that the relationship between photosynthesis and APAR (absorbed photochemical active radiation) normalized SIF (FY) is non-monotonic under increasing environmental stress conditions, rendering the prediction of photosynthesis by FY alone unfeasible. The use of FY in combination with a pigment corrected photochemical reflectance index (PRI) as an indicator of the stress stage, allows the estimation of photosynthesis. However, this approach is strongly affected by uncertainties in PRI and we therefore propose the pigment-corrected ratio of the two SIF peaks (cFratio) as a precise and robust estimator of photosynthesis (R² = 0.90, rRMSE = 10%). Due to its independence on the absorbed photosynthetic active radiation, the cFratio is a promising novel estimator of spatio-temporal variation in photosynthesis.

How to cite: Wieneke, S., Balzarolo, M., Asard, H., AbdElgawad, H., Peñuelas, J., Rascher, U., Ven, A., Verlinden, M., Janssens, I., and Vicca, S.: Non-monotonic relationship of sun-induced fluorescence to photosynthesis, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-9759,, 2020.


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