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

Low non-structural carbon accumulation in spring reduces growth and increases mortality in conifers defoliated by spruce budworm

Fierravanti Angelo, Rossi Sergio, Kneeshaw Daniel, De Grandpré Louis et Deslauriers Annie. (2019). Low non-structural carbon accumulation in spring reduces growth and increases mortality in conifers defoliated by spruce budworm. Frontiers in Forests and Global Change, 2, e15.

[thumbnail of ffgc.2019.00015.pdf]
Prévisualisation
PDF - Version publiée
Disponible sous licence Creative Commons (CC-BY 2.5).

5MB

URL officielle: http://dx.doi.org/doi:10.3389/ffgc.2019.00015

Résumé

Spruce budworm (Choristoneura fumiferana) outbreaks are important disturbance events in the boreal forests of northeastern North America, causing major growth loss and widespread tree mortality. The physiological mechanisms leading to tree mortality remain poorly understood and two important functional traits, tree-ring width and concentration of stored carbohydrate, can serve as indicators of tree vitality during defoliation. This study aims to test the hypothesis that storage starch is an indicator of tree vitality by (1) exploring the link among reductions in storage, growth and mortality, and (2) identifying starch or sugar threshold to predict the risk of mortality. We use balsam fir and black spruce, two main host species of spruce budworm. We sampled 81 trees across seven experimental sites in eastern Quebec, Canada, and assessed defoliation intensity, tree-ring growth, and tree vitality. Soluble sugar and starch concentrations in needles, twigs, and roots were measured from spring to autumn. Under conditions of increased defoliation, carbon allocation to reserves and radial growth decreased in a similar manner for both species. Starch concentration within twigs and needles in May and June was the best indicator of carbon status in defoliated trees. We observed the highest reductions in growth two to 3 years prior to mortality concurrently with reductions in starch in May and June. When starch concentrations were lower than 28 mg· (Formula presented.) in needles, the probability of balsam fir mortality exceeded 50%. At this level of starch, reserves and newly produced carbon are insufficient to support tree growth and vitality.

Type de document:Article publié dans une revue avec comité d'évaluation
ISSN:2624-893X
Volume:2
Pages:e15
Version évaluée par les pairs:Oui
Date:26 Avril 2019
Identifiant unique:10.3389/ffgc.2019.00015
Sujets:Sciences naturelles et génie > Sciences appliquées > Climatologie et météorologie
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
Unités de recherche > Centre de recherche sur la Boréalie (CREB)
Mots-clés:balsam fir, black spruce, carbon allocation, defoliation, starch, tree vitality, tree-ring growth
Déposé le:24 mai 2023 14:18
Dernière modification:24 mai 2023 14:18
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