Forêts en crise et biodiversité : menaces et opportunités. Effets des dépérissements et de leur gestion sur la biodiversité forestière

Abstract:
The effects of declines on stand structure, the quantity and quality of resources, the composition of landscapes and biological communities have been analysed. In Bavarian spruce stands, specific richness generally increases in perturbed areas, where certain rare species are found again. In Pyrenean fir forests, the effects of decline at the stand and landscape scales are mutually dependent. In plain-located oak stands, contrasting responses of the insect guilds of tree crowns are found. Sanitary cuts alter the stand structure and modify the initial composition of communities through an additive effect to decline. The many uncertainties about the community dynamic highlight the importance of having long-term time series available. Operational reflection for a retention-type silviculture is ongoing to seize the opportunity of crises while maintaining economic and phytosanitary balances.

Highlights:
The effects of forest crises on biodiversity vary according to the context.
The effect of forest crises on biodiversity is enhanced by sanitary harvests.
Long-term monitoring is indispensable to decrease the uncertainty of predictions.