Distribution of saproxylic beetles in a recently burnt landscape of the northern boreal forest of Québec

Towards a Better Understanding of Beta Diversity: Deconstructing Composition Patterns of Saproxylic Beetles Breeding in Recently Burnt Boreal Forest

“…The tree size classes were based on diameter at breast height (dbh); and burn severity classes were visually defined following criteria adopted by Ministère des Ressources naturelles de la Faune du Québec (MRNF) but with modifications of the classes. These habitat variables have been shown to differentially influence the distribution of saproxylic beetles in burned forests (Saint-Germain et al, 2004;Boulanger et al, 2010); and we expect them to also differentially contribute to the turnover and nestedness component of beta diversity. For example, different tree species might attract or host different beetle species and, consequently, might contribute more to the turnover than nestedness component of beta diversity.…”

“…For example, different tree species might attract or host different beetle species and, consequently, might contribute more to the turnover than nestedness component of beta diversity. The effects of burn severity and tree size class is to generally create a gradient of habitat suitability, the lowest suitability being in small trees and/or severe-burns and highest suitability being in large trees of low severity classes (Boulanger et al, 2010). Such a hierarchical suitability gradient would potentially contribute to the nestedness component of beta diversity.…”

“…Our study system is located in the western spruce-moss bioclimatic subdomain (northwestern Quebec, Canada) where fire is an important natural disturbance generating mosaics of stands with high structural and compositional heterogeneity in the forest landscape (Bergeron et al, 2004). The post-fire environment is characterised by huge amounts of freshly killed and stressed trees, which are very important habitat attributes that sustain saproxylic beetles that feed directly on the bark/wood of dead and dying trees, saprophagous, mycophagous and their predators (McCullough et al, 1998;Grove, 2002;SaintGermain et al, 2004;Boulanger et al, 2010). The early post-fire environments are characterised by a diversity/abundance of saproxylic beetles that rapidly attack or colonize burned forests.…”

Impact de la coupe de récupération après feu sur les coléoptères associés aux brûlis en forêt boréale :

“…We also estimated the proportion of salvaged area within the 7 ha scale (Sal.Area). Since the unburned continuous forest can be considered as a source habitat for species that colonize bums (Saint-Germain et al, 2008;Boulanger et al, 2010), we measured the shortest distance from the plot center to the interface between the burn edge and the unburned continuous (i.e. areas of more than hundreds of hectares) forest (Dis.GF), which is dependent of the burn shape.…”

“…Distance to burns edges seems to be an important factor in the colonization of the postfire habitat by beetles (Boulanger et al, 2010); it is thus not surprising that it is also an important factor explaining species turnovers of burn-associated beetles after salvage logging. Species turnover between years no.l and no.2 after salvage logging were greater the further from burns edges; i.e.…”