Distribution of endemic bark beetle attacks and their physiological consequences on Pinus halepensis
ROZENBERG, Philippe
Biologie intégrée pour la valorisation de la diversité des Arbres et de la Forêt [BioForA]
Biologie intégrée pour la valorisation de la diversité des Arbres et de la Forêt [BioForA]
SABATIER, Sylvie-Annabel
Botanique et Modélisation de l'Architecture des Plantes et des Végétations [UMR AMAP]
Département Systèmes Biologiques [Cirad-BIOS]
< Réduire
Botanique et Modélisation de l'Architecture des Plantes et des Végétations [UMR AMAP]
Département Systèmes Biologiques [Cirad-BIOS]
Langue
en
Article de revue
Ce document a été publié dans
Forest Ecology and Management. 2020-08-01, vol. 469, p. 118187
Elsevier
Résumé en anglais
One factor that determines a tree’s resilience capacity to drought is its level of interaction with aggravating biotic factors, such as bark beetles, which in turn depends on whether insect populations are at an endemic ...Lire la suite >
One factor that determines a tree’s resilience capacity to drought is its level of interaction with aggravating biotic factors, such as bark beetles, which in turn depends on whether insect populations are at an endemic or epidemic stage. In a Mediterranean natural forest ecosystem, we investigated the ecophysiological characteristics of trees which (i) predispose Pinus halepensis to attacks of endemic populations of bark beetles (Tomicus destruens) and (ii) that arise as a result of these attacks. The annual life cycle of Tomicus destruens features an initial dispersal phase of sexually mature adults towards pine trunks for the purposes of brood production, and a second dispersal phase of callow adults from trunks to pine shoots for sexual maturation. During a three-year survey of endemic bark beetle attacks in a stand of 178 trees, we found that trees targeted for trunk attacks showed a more aggregated distribution pattern than those targeted for shoot attacks. Moreover, shoot-attacked trees were clearly larger and taller, had lower wood density, and were less exposed to competition than non-attacked trees. No differences were found between the characteristics of trunk-attacked trees and non-attacked ones. We found crown defoliation, lower primary growth and alteration of trunk non-structural carbon in phloem in the year following trunk attacks, although this did not affect vulnerability to cavitation of the vascular system, secondary growth, wood density, and xylem starch. Conversely, the health status and physiological variables of the shoot-attacked trees were not altered, which may be explained by their initial vigor. We conclude that the distribution of Tomicus destruens attacks at the plot level was independent of the ecophysiological traits of the host trees. It was mainly determined by the dispersal strategy of the endemic bark beetle population especially during brood production as only trunk attacks significantly weakened the trees.< Réduire
Mots clés en anglais
Bark beetle
Mediterranean
Endemic
Pinus halepensis
Tree physiology
Sucrose
Project ANR
Objectif Terre : Bassin Méditerranéen
Origine
Importé de halUnités de recherche