The rates of starch depletion and hydraulic failure both play a role in drought-induced seedling mortality
TRUEBA, Santiago
Biodiversité, Gènes & Communautés [BioGeCo]
Botanique et Modélisation de l'Architecture des Plantes et des Végétations [UMR AMAP]
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Biodiversité, Gènes & Communautés [BioGeCo]
Botanique et Modélisation de l'Architecture des Plantes et des Végétations [UMR AMAP]
TRUEBA, Santiago
Biodiversité, Gènes & Communautés [BioGeCo]
Botanique et Modélisation de l'Architecture des Plantes et des Végétations [UMR AMAP]
Biodiversité, Gènes & Communautés [BioGeCo]
Botanique et Modélisation de l'Architecture des Plantes et des Végétations [UMR AMAP]
LAMARQUE, Laurent
Biodiversité, Gènes & Communautés [BioGeCo]
Université du Québec à Trois-Rivières [UQTR]
Biodiversité, Gènes & Communautés [BioGeCo]
Université du Québec à Trois-Rivières [UQTR]
GIMENO, Teresa
Interactions Sol Plante Atmosphère [UMR ISPA]
CREAF - Centre for Ecological Research and Applied Forestries
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Interactions Sol Plante Atmosphère [UMR ISPA]
CREAF - Centre for Ecological Research and Applied Forestries
Langue
en
Article de revue
Ce document a été publié dans
Annals of Forest Science. 2024-08-02, vol. 81, n° 1, p. 27
Springer Nature (since 2011)/EDP Science (until 2010)
Résumé en anglais
Key message: The elapsed times to deplete starch concentrations and to reach a null hydraulic safety margin were related to tree seedling mortality under experimental drought. Starch concentration showed an accelerated ...Lire la suite >
Key message: The elapsed times to deplete starch concentrations and to reach a null hydraulic safety margin were related to tree seedling mortality under experimental drought. Starch concentration showed an accelerated decline across all species during the early stages of dehydration, while the concentrations of soluble sugars and total nonstructural carbohydrates remained stable. Concomitant carbohydrate depletion and hydraulic failure drive seedling mortality under drought.Context: Current upsurges of drought events are provoking impacts on tree physiology, resulting in forest mortality. Hydraulic dysfunction and nonstructural carbohydrate (NSC) depletion have been posited as the main mechanisms leading to plant mortality under drought.Aims: This study explores the dynamics of the two mortality-inducing processes during drought stress using an experimental approach with 12 evergreen tree species.Methods: Seedlings were subjected to drought until 100% mortality was observed. Midday (ΨMD) and predawn (ΨPD) water potentials, xylem pressure leading to a 50% loss of hydraulic conductivity (Ψ50), along with NSC concentrations in different organs (leaves, stems, and roots) were measured regularly during drought.Results: Total NSC concentrations and soluble sugar pools did not decline during drought. However, starch pools showed strong reductions early during drought stress as ΨPD decreased, and the time leading to starch depletion emerged as a strong mortality predictor. Ψ50 alone did not provide an accurate estimate of mortality, while the elapsed time to reach a null hydraulic safety margin (ΨMD—Ψ50 = 0) was related to seedling mortality.Conclusion: Adopting a dynamic approach by estimating the times to consume both starch reserves and hydraulic safety margins is highly relevant to improve predictions of tree mortality under the current context of increasing global drought.< Réduire
Mots clés en anglais
Embolism vulnerability
Fructose
Nonstructural carbohydrates
Hydraulic safety margin
Light environment
Sucrose
Ecophysiology
Origine
Importé de halUnités de recherche