Short-term response of coleopteran assemblages to thinning-induced differences in dead wood volumes

• Thinning entries could be used to improve animal conservation in plantations.
• We examined whether commercial thinning strategies could be used to promote beetles.
• Thinning increased beetle species richness and abundance.
• Thinning was associated with an increase in beetle abundance per feeding guild.
• Woody biomass harvesting threatened the beetle conservation gains from thinning.

Recent studies have commonly demonstrated the sensitivity of beetles (order Coleoptera) to forest management practices, managed forests generally supporting fewer beetles, fewer species, and a different community than unmanaged forests. In this study, we examine whether commercial thinning strategies that produce different dead wood volumes in plantations could be used to promote beetle diversity, abundance, and abundance across feeding guilds. To this end, we sampled beetles in the first two summers following thinning using flight intercept traps distributed in intensively-managed white spruce plantations and unmanaged, old coniferous forests. 60,385 beetles representing 48 families and 219 species were collected in the study. During both summers that followed thinning treatments, beetle abundance, richness, and abundance per feeding guild were similar to those observed in old forests. However, these effects began to fade during the second summer in plantations where woody debris had been removed. These results suggest that strategies of commercial thinning could be used to create resource pulses for beetles and favor their conservation in plantation landscapes, as long as woody debris are not harvested.