Plant hydraulic modelling of leaf and canopy fuel moisture content reveals increasing vulnerability of a Mediterranean forest to wildfires under extreme drought
2023
Ruffault, Julien | Limousin, Jean‐marc | Pimont, François | Dupuy, Jean‐luc | de Càceres, Miquel | Cochard, Hervé | Mouillot, Florent | Blackman, Chris | Torres-Ruiz, José | Parsons, Russell | Moreno, Myriam | Delzon, Sylvain | Jansen, Steven | Olioso, Albert | Choat, Brendan | Martin-StPaul, Nicolas | Ecologie des Forêts Méditerranéennes (URFM) ; Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | Université de Montpellier (UM) | Centre d’Ecologie Fonctionnelle et Evolutive (CEFE) ; Université Paul-Valéry - Montpellier 3 (UPVM)-École Pratique des Hautes Études (EPHE) ; Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [Occitanie])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro Montpellier ; Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Université de Montpellier (UM) | Centre for Ecological Research and Applied Forestries = Centre de Recerca Ecologica i Aplicacions Forestals (CREAF) ; Consejo Superior de Investigaciones Cientificas [España] = Spanish National Research Council [Spain] (CSIC) | Laboratoire de Physique et Physiologie Intégratives de l’Arbre en environnement Fluctuant (PIAF) ; Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Clermont Auvergne (UCA) | University of Tasmania [Hobart] (UTAS) | US Forest Service | Biodiversité, Gènes & Communautés (BioGeCo) ; Université de Bordeaux (UB)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | Universität Ulm - Ulm University [Ulm, Allemagne] | Western Sydney University | ANR-18-CE20-0005,HydrauLeaks,Comprendre les effets combinés des stress hydriques et thermiques sur la mortalité des arbres(2018) | ANR-11-INBS-0001,ANAEE-FR,ANAEE-Services(2011)
International audience
显示更多 [+] 显示较少 [-]英语. Fuel moisture content (FMC) is a crucial driver of forest fires in many regions world-wide. Yet, the dynamics of FMC in forest canopies as well as their physiological and environmental determinants remain poorly understood, especially under extreme drought.We embedded a FMC module in the trait-based, plant-hydraulic SurEau-Ecos model to provide innovative process-based predictions of leaf live fuel moisture content (LFMC) and canopy fuel moisture content (CFMC) based on leaf water potential (psi Leaf$$ {\psi}_{\mathrm{Leaf}} $$). SurEau-Ecos-FMC relies on pressure-volume (p-v) curves to simulate LFMC and vulnerability curves to cavitation to simulate foliage mortality.SurEau-Ecos-FMC accurately reproduced psi Leaf$$ {\psi}_{\mathrm{Leaf}} $$ and LFMC dynamics as well as the occurrence of foliage mortality in a Mediterranean Quercus ilex forest. Several traits related to water use (leaf area index, available soil water, and transpiration regulation), vulnerability to cavitation, and p-v curves (full turgor osmotic potential) had the greatest influence on LFMC and CFMC dynamics. As the climate gets drier, our results showed that drought-induced foliage mortality is expected to increase, thereby significantly decreasing CFMC.Our results represent an important advance in our capacity to understand and predict the sensitivity of forests to wildfires.
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