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

Résumé

1. Fire-killed timber is considered as a loss of potential revenues andis thus increasingly salvaged, though not without concerns for biodiversity con-servation. Indeed, a large diversity of burn-associated saproxylic beetles userecently burned trees. 2. This study intends to reduce potential impacts of salvage logging on biodi-versity by identifying high conservation value forests (HCVFs) for burn-associated beetles, which are considered the most at risk. 3. In five burns ignited naturally in 2010 in the eastern Canadian boreal for-est, we selected 31 and 29 stands of black spruce and jack pine respectively.Three 50-cm bole segments were retrieved from each stand and placed inemergence cages to measure tree utilisation by saproxylic beetles. This yielded7235 beetles from 103 taxa, of which 67 were considered rare (<5% occurrencein logs) and 36 as common taxa (>5% occurrence in logs). 4. Among the common taxa, we identified six groups of ecologically relatedspecies using co-occurrence-based hierarchical clustering, among which threewere mainly formed by opportunistic species that are currently of little concernin a post-fire logging context. The three other groups were formed by burn-associated species that could be affected by salvage logging. 5. HCVFs include jack pine stands and large trees of either tree species oflow- to mid-range burn severity. We also recommend retaining the periphery ofburned stands, as ecotones are rich habitats used by several burn-associatedspecies that are found in low numbers in green forests but they benefit fromburned habitats by increasing their populations significantly.