Within crown variation in hydraulic architecture in beech (Fagus sylvatica L): evidence for a stomatal control of xylem embolism - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Annals of Forest Science Année : 2002

Within crown variation in hydraulic architecture in beech (Fagus sylvatica L): evidence for a stomatal control of xylem embolism

Damien Lemoine
  • Fonction : Auteur
  • PersonId : 758080
  • IdRef : 14520023X
Hervé H. Cochard

Résumé

The stomatal control of embolism in Fagus sylvatica L. was analysed in response to crown position and experimental changes of trunk hydraulic resistance. On one mature beech tree deep cuts were made in the trunk to increase the resistance to water transfert. We followed the changes in leaf and xylem water potential and stomatal conductance after the cuts at three levels within the canopy. We characterised vulnerability to cavitation for branches taken from two levels of irradiance (sun-exposed branches and shaded ones). Some differences appeared between shade and sun-exposed branches. When the leaf water potential dropped, stomatal conductances decreased earlier and faster in the shade branches. These results are well correlated with vulnerability to cavitation, shade branches being more vulnerable than sun-acclimated branches. Xylem water potential levels producing fifty percent loss of hydraulic conductivity were lower in sun-exposed branches than in shade grown ones (-3.1 MPa vs. -2.5 MPa on average). Xylem water potentials that induced stomatal closure were above the threshold-value inducing cavitation both for shade and sun-exposed branches. We confirmed that vulnerability to cavitation in Fagus sylvatica can acclimate to contrasting ambient light conditions, and we conclued that stomatal response to water stress occured early and sufficiently fast to protect xylem from dysfunction.
Fichier principal
Vignette du fichier
Lemoine_al_2002.pdf (100.88 Ko) Télécharger le fichier
Origine : Accord explicite pour ce dépôt
Loading...

Dates et versions

hal-01097901 , version 1 (08-01-2015)

Identifiants

Citer

Damien Lemoine, Hervé H. Cochard, André A. Granier. Within crown variation in hydraulic architecture in beech (Fagus sylvatica L): evidence for a stomatal control of xylem embolism. Annals of Forest Science, 2002, 59, pp.19-27. ⟨10.1051/forest:2001002⟩. ⟨hal-01097901⟩
90 Consultations
175 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More