Agritrop
Accueil

Potassium nutrition and water availability affect phloem transport of photosynthetic carbon in eucalypt trees

Epron Daniel, Cabral Osvaldo Machado Rodrigues, Laclau Jean-Paul, Dannoura Masako, Packer Ana Paula, Plain Caroline, Battie Laclau Patricia, Moreira Marcelo, Trivelin Paulo, Bouillet Jean-Pierre, Gérant Dominique, Nouvellon Yann. 2015. Potassium nutrition and water availability affect phloem transport of photosynthetic carbon in eucalypt trees. In : Geophysical Research Abstracts. EGU. Göttingen : Copernicus Publications, 1 p. (Geophysical Research Abstracts, 17) European Geosciences Union General Assembly 2015, Vienne, Autriche, 12 Avril 2015/17 Avril 2015.

Communication par affiche
[img]
Prévisualisation
Version publiée - Anglais
Sous licence Licence Creative Commons.
EGU2015-3504-1.pdf

Télécharger (38kB) | Prévisualisation
[img] Version publiée - Anglais
Accès réservé aux personnels Cirad
Utilisation soumise à autorisation de l'auteur ou du Cirad.
Poster_EGU_2015-.pdf

Télécharger (336kB) | Demander une copie

Url - éditeur : http://meetingorganizer.copernicus.org/EGU2015/posters/17109

Matériel d'accompagnement : 1 poster

Résumé : Potassium fertilisation strongly affects growth and carbon partitioning of eucalypt on tropical soil that are strongly weathered. In addition, potassium fertilization could be of great interest in mitigating the adverse consequences of drought in planted forests, as foliar K concentrations influence osmotic adjustment, stomatal regulation and phloem loading. Phloem is the main pathway for transferring photosynthate from source leaves to sink organs, thus controlling growth partitioning among the different tree compartments. But little is known about the effect of potassium nutrition on phloem transport of photosynthetic carbon and on the interaction between K nutrition and water availability. In situ 13C pulse labelling was conducted on tropical eucalypt trees (Eucalyptus grandis L.) grown in atrial plantation with plots in which 37% of through fall were excluded (about 500 mm/yr) using home-made transparent gutters (-W) or not (+W) and plots that received 0.45 mol K m-2 applied as KCl three months after planting (+K) or not (-K). Three trees were labelled in each of the four treatments (+K+W, +K-W, -K+W and–K-W). Trees were labelled for one hour by injecting pure 13CO2in a 27 m3 whole crown chamber. We estimated the velocity of carbon transfer in the trunk by comparing time lags between the uptake of13CO2and its recovery in trunk CO2efflux recorded by off axis integrated cavity output spectroscopy (Los Gatos Research) in two chambers per tree, one just under the crown and one at the base of the trunk. We analyzed the dynamics of the label recovered in the foliage and in the phloem sap by analysing carbon isotope composition of bulk leaf organic matter and phloem extracts using an isotope ratio mass spectrometer. The velocity of carbon transfer in the trunk and the initial rate 13C disappearance from the foliage were much higher in +K trees than in –K trees with no significant effect of rainfall. The volumetric flow of phloem, roughly estimated by multiplying the velocity of C transfer with the bark cross-section area of tree at 1.30m high, was also higher in +K trees than in –K trees and well-correlated with crown photosynthesis and with the xylem sapflow density.

Classification Agris : K10 - Production forestière
F04 - Fertilisation
F61 - Physiologie végétale - Nutrition

Auteurs et affiliations

  • Epron Daniel, CIRAD-PERSYST-UMR Eco&Sols (FRA)
  • Cabral Osvaldo Machado Rodrigues, EMBRAPA (BRA)
  • Laclau Jean-Paul, CIRAD-PERSYST-UMR Eco&Sols (FRA) ORCID: 0000-0002-2506-214X
  • Dannoura Masako, Kyoto University (JPN)
  • Packer Ana Paula, EMBRAPA (BRA)
  • Plain Caroline, Université de Lorraine (FRA)
  • Battie Laclau Patricia, USP (BRA)
  • Moreira Marcelo, USP (BRA)
  • Trivelin Paulo, USP (BRA)
  • Bouillet Jean-Pierre, CIRAD-PERSYST-UMR Eco&Sols (BRA)
  • Gérant Dominique, INRA (FRA)
  • Nouvellon Yann, CIRAD-PERSYST-UMR Eco&Sols (BRA)

Source : Cirad-Agritrop (https://agritrop.cirad.fr/579792/)

Voir la notice (accès réservé à la Dist) Voir la notice (accès réservé à la Dist)

[ Page générée et mise en cache le 2022-07-13 ]