LiveZilla Live Chat Software

Constellation, le dépôt institutionnel de l'Université du Québec à Chicoutimi

How do drought and warming influence survival and wood traits of Picea mariana saplings?

Balducci Lorena, Deslauriers Annie, Giovannelli Alessio, Beaulieu Marilène, Delzon Sylvain, Rossi Sergio et Rathgeber Cyrille B. K.. (2015). How do drought and warming influence survival and wood traits of Picea mariana saplings? Journal of Experimental Botany, 66, (1), p. 377-389.

[img]
Prévisualisation
PDF - Version publiée
Disponible sous licence Creative Commons Attribution.

2MB

URL officielle: http://dx.doi.org/doi:10.1093/jxb/eru431

Résumé

Warming and drought will occur with increased frequency and intensity at high latitudes in the future. How heat and water stress can influence tree mortality is incompletely understood. The aim of this study was to evaluate how carbon resources, stem hydraulics, and wood anatomy and density determine the ability of black spruce saplings to survive daytime or night-time warming (+ 6 °C in comparison with control) in combination with a drought period. Plant water relations, the dynamics of non-structural carbohydrates and starch, mortality rate, and wood anatomy and density of saplings were monitored. Warming, in conjunction with 25 d of water deficit, increased sapling mortality (10% and 20% in night-time and daytime warming, respectively) compared with the control conditions (0.8%). Drought substantially decreased gas exchange, and also pre-dawn and mid-day leaf water potential to values close to -3MPa which probably induced xylem embolism (xylem air entry point, P 12, being on average around -3MPa for this species). In addition, the recovery of gas exchange never reached the initial pre-stress levels, suggesting a possible loss of xylem hydraulic conductivity associated with cavitation. Consequently, mortality may be due to xylem hydraulic failure. Warmer temperatures limited the replenishment of starch reserves after their seasonal minimum. Lighter wood was formed during the drought period, reflecting a lower carbon allocation to cell wall formation, preventing the adaptation of the hydraulic system to drought. Saplings of black spruce experienced difficulty in adapting under climate change conditions, which might compromise their survival in the future.

Type de document:Article publié dans une revue avec comité d'évaluation
ISSN:00220957 (ISSN)
Volume:66
Numéro:1
Pages:p. 377-389
Version évaluée par les pairs:Oui
Date:2015
Sujets:Sciences naturelles et génie > Sciences appliquées > Foresterie et sciences du bois
Sciences naturelles et génie > Sciences naturelles > Biologie et autres sciences connexes
Département, module, service et unité de recherche:Départements et modules > Département des sciences fondamentales
Mots-clés:Carbon balance, climate change, drought, survival, warming, wood anatomy, wood density, Picea mariana
Déposé le:19 janv. 2017 01:18
Dernière modification:19 janv. 2017 01:18
Afficher les statistiques de telechargements

Éditer le document (administrateurs uniquement)

Creative Commons LicenseSauf indication contraire, les documents archivés dans Constellation sont rendus disponibles selon les termes de la licence Creative Commons "Paternité, pas d'utilisation commerciale, pas de modification" 2.5 Canada.

Bibliothèque Paul-Émile-Boulet, UQAC
555, boulevard de l'Université
Chicoutimi (Québec)  CANADA G7H 2B1
418 545-5011, poste 5630