Effects of climate on radial growth of Norway spruce and interactions with attacks by the bark beetle Dendroctonus micans (Kug., Coleoptera : Scolytidae): a dendroecological study in the French Massif Central

• Published in: Forest Ecology and Management
• Main Authors: Rolland, C., Lemperiere, G.
• Other Authors: Laboratoire d'Ecologie Alpine (LECA), Université Joseph Fourier - Grenoble 1 (UJF)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2004
• Subjects: Dendroctonus micans; Picea abies; dendroecology; drought; growth; tree-ring; Sub-arctic quebec; white-pine weevil; fir abies-alba; picea-abies; budworm outbreaks; mountain pine; choristoneura-occidentalis; tree-growth; scots pine; l karst; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDV.BID]Life Sciences [q-bio]/Biodiversity; [SDV.EE]Life Sciences [q-bio]/Ecology; environment; Arctic; Norway
• Online Access: https://hal.science/halsde-00294771; https://doi.org/10.1016/j.foreco.2004.05.059

International audience Samples of Norway spruce (Picea abies [L.] Karst) were dendrochronologically investigated in order to detect infestations by Dendroctonus micans (Kug.), the great spruce bark beetle (Col. Scolytidae), a relatively recent introduction to France. Uninfested natural forests located in the north-eastern French Alps and heavily infested plantations in the Ardeche region (Massif Central) were compared. The penetration holes bored in trunks by the bark beetle induced visible marks on wood, such as extreme ring width reductions, locally missing rings and crescent-shaped resin patches between consecutive rings that make possible a post-infestation dating. The outbreak began in 1979, 5 years prior to first insect visual detection by foresters. In the infested forest, tree basal area growth was not as sustained as in uninfested natural stands, but showed an inflection point at an unusually young tree age (from 30 to 40 years). Ring widths showing extreme synchronous radial growth reductions were caused either by excessively cold periods (e.g. in 1948, 1980, 1984, 1992) or by summer drought (as in 1986). Most of these weak growth years were shared with uninfested sites. In healthy forests, the consequences of extremely cold years were usually recorded only in high elevation stands, especially near the timberline, whereas summer drought effects were mostly visible in low altitude forests. By contrast, both phenomena were recorded in the infected Ardeche plantation. An analysis of tree-rings and monthly climate confirmed that Norway spruce growth in Ardeche plantations was reduced by excessively low minimum temperature during most parts of the year prior to ring formation, by higher than average maximum temperature during current spring and summer, and by drought in winter, spring and summer. Thus, the regional Ardeche climate with both cold winters and dry summers (especially in July) seems to weaken spruce trees planted there. Moreover, tree sensitivity to climate was found to be greatly enhanced by ...