Large hydraulic safety margins protect Neotropical canopy rainforest tree species against hydraulic failure during drought - Université de Montpellier Accéder directement au contenu
Article Dans Une Revue Annals of Forest Science Année : 2019

Large hydraulic safety margins protect Neotropical canopy rainforest tree species against hydraulic failure during drought

Camille Ziegler
  • Fonction : Auteur
  • PersonId : 1137364
Sabrina Coste
Clement Stahl
Sylvain Delzon
Sébastien Levionnois
  • Fonction : Auteur
  • PersonId : 1110304
Jean-Yves Goret
  • Fonction : Auteur
  • PersonId : 958728
Gaëlle Jaouen
Damien Bonal

Résumé

AbstractKey messageAbundant Neotropical canopy-tree species are more resistant to drought-induced branch embolism than what is currently admitted. Large hydraulic safety margins protect them from hydraulic failure under actual drought conditions.ContextXylem vulnerability to embolism, which is associated to survival under extreme drought conditions, is being increasingly studied in the tropics, but data on the risk of hydraulic failure for lowland Neotropical rainforest canopy-tree species, thought to be highly vulnerable, are lacking.AimsThe purpose of this study was to gain more knowledge on species drought-resistance characteristics in branches and leaves and the risk of hydraulic failure of abundant rainforest canopy-tree species during the dry season.MethodsWe first assessed the range of branch xylem vulnerability to embolism using the flow-centrifuge technique on 1-m-long sun-exposed branches and evaluated hydraulic safety margins with leaf turgor loss point and midday water potential during normal- and severe-intensity dry seasons for a large set of Amazonian rainforest canopy-tree species.ResultsTree species exhibited a broad range of embolism resistance, with the pressure threshold inducing 50% loss of branch hydraulic conductivity varying from − 1.86 to − 7.63 MPa. Conversely, we found low variability in leaf turgor loss point and dry season midday leaf water potential, and mostly large, positive hydraulic safety margins.ConclusionsRainforest canopy-tree species growing under elevated mean annual precipitation can have high resistance to embolism and are more resistant than what was previously thought. Thanks to early leaf turgor loss and high embolism resistance, most species have a low risk of hydraulic failure and are well able to withstand normal and even severe dry seasons.
Fichier principal
Vignette du fichier
13595_2019_Article_905.pdf (1.91 Mo) Télécharger le fichier
Origine : Publication financée par une institution

Dates et versions

hal-02432407 , version 1 (14-12-2020)

Identifiants

Citer

Camille Ziegler, Sabrina Coste, Clement Stahl, Sylvain Delzon, Sébastien Levionnois, et al.. Large hydraulic safety margins protect Neotropical canopy rainforest tree species against hydraulic failure during drought. Annals of Forest Science, 2019, 76 (4), pp.115. ⟨10.1007/s13595-019-0905-0⟩. ⟨hal-02432407⟩
278 Consultations
71 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More