Mechanistic modelling of gross primary production from sun-induced fluorescence measurements on a wheat canopy in Belgium
Pezzetti, Natacha
Promoteur(s) : Longdoz, Bernard ; Beauclaire, Quentin
Date de soutenance : 23-aoû-2022 • URL permanente : http://hdl.handle.net/2268.2/15704
Détails
Titre : | Mechanistic modelling of gross primary production from sun-induced fluorescence measurements on a wheat canopy in Belgium |
Titre traduit : | [fr] Modélisation mécaniste de la production primaire brute à partir de mesures de fluorescence induite par le soleil sur une canopée de blé d'hiver en Belgique |
Auteur : | Pezzetti, Natacha |
Date de soutenance : | 23-aoû-2022 |
Promoteur(s) : | Longdoz, Bernard
Beauclaire, Quentin |
Membre(s) du jury : | Jonard, François
Delaplace, Pierre Charles, Catherine Le Dantec, Valérie |
Langue : | Anglais |
Nombre de pages : | 55 |
Mots-clés : | [en] Photosynthesis [en] Sun-Induced Fluorescence [en] Gross Primary Production [en] Winter Wheat [en] Edaphic Drought |
Discipline(s) : | Sciences du vivant > Sciences de l'environnement & écologie |
Institution(s) : | Université de Liège, Liège, Belgique |
Diplôme : | Master en bioingénieur : sciences et technologies de l'environnement, à finalité spécialisée |
Faculté : | Mémoires de la Gembloux Agro-Bio Tech (GxABT) |
Résumé
[en] In the context of global climate change, extreme weather events are expected to intensify, threatening agricultural systems. Meanwhile, food demand is likely to grow due to increas-
ing human population. Accordingly, being able to assess and predict dynamic behaviours of
crops under changing climatic conditions is crucial to ensure food security. For that purpose,
photosynthesis is the key process to characterise. According to the literature, sun-induced flu-
orescence (SIF) represents a potential indicator of photosynthesis. Recently, the mechanistic
light response model (MLR) estimating gross primary production (GPP) from SIF has been
established. Firstly, this study aims to assess the relationship between SIF and GPP from the
MLR model perspective for a winter wheat canopy in Belgium. Secondly, the dynamics of the
main model parameters depending on environmental conditions have been studied. Continuous
measurements of micro-meteorological, flux and SIF data have been carried out for five months
by an ICOS station. Moreover, leaf-level gas exchange and fluorescence parameters have been
measured manually using a portable photosynthesis system. Similar temporal evolutions of SIF
and GPP in response to light have been observed, supporting the use of SIF as an indicator
of photosynthesis. The model provides a relatively moderate performance at half-hourly scale
which improved at daily scale. In particular, the model seems to correctly reproduce the SIF-
GPP relationship only under low light intensities and high soil moisture which is in agreement
with the main model assumption. Overall, these results point out the need for more accurate
characterization of the model underlying processes and parameters dynamics regarding envi- ronmental conditions.
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