PONTON, Stéphane; DUPOUEY, Jean-Luc; BRÉDA, Nathalie; FEUILLAT, F; BODENES-BREZARD, Catherine

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PONTON, Stéphane
Ecologie et Ecophysiologie Forestières [devient SILVA en 2018] [EEF]

DUPOUEY, Jean-Luc
Ecologie et Ecophysiologie Forestières [devient SILVA en 2018] [EEF]

BRÉDA, Nathalie
Ecologie et Ecophysiologie Forestières [devient SILVA en 2018] [EEF]

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Article de revue

Ce document a été publié dans

Plant, Cell and Environment. 2001, vol. 24, n° 8, p. 861-868

Wiley

Résumé en anglais

The two most common oak species in western Europe, Quercus robur and Quercus petraea, display different ecological behaviours, particularly with respect to their responses to drought. The ecophysiological basis of this niche difference is not understood well. Here we test the hypothesis that these two species present distinct water use efficiencies (WUEs), using the carbon isotope discrimination approach. Leaves and 13 dated ring sequences were sampled in 10 pairs of adult trees growing side by side. Carbon isotope composition was measured on cellulose extracts. In addition, relationships between carbon isotope discrimination and wood anatomy were assessed at the tree level. Quercus robur displayed a 1·0‰ larger isotopic discrimination than Q. petraea, and therefore a lower intrinsic WUE (- 13%). This interspecific difference of isotopic discrimination was quite stable with time and independent of tree radial growth and climate fluctuations. A strong positive correlation was observed between average tree values of earlywood vessel surface area and 13 C isotopic discrimination. This correlation was even higher with 13 C of the 1976 dry year (r = 0·86). These observations led to the hypothesis that hydraulic properties of xylem could exert a constraint on leaf gas exchange, resulting in a larger WUE for individuals with smaller vessel cross-section area.< Réduire

Mots clés

EFFICACITE DE L'UTILISATION DE L'EAU

Mots clés en anglais

INTERSPECIFIC VARIABILITY

OAK

TREE RING

VESSEL AREA

WATER USE EFFICIENCY

CHENE

CARBONE ISOTOPE

Origine

Importé de hal

Unités de recherche

BioGeCo (Biodiversité Gènes & Communautés) - UMR 1202