Beetle assemblage distribution along edge–forest gradient in a managed oak forest

Abstract

Forest management practices creating small‐scale forest edge habitats in managed forests have substantial impacts on the formation of beetle assemblages. In 2021, we conducted research in a managed oak woodland in Central Slovakia using three flight interception traps (FITs) to study beetle assemblages. Two FITs were installed at the forest edge, facing both, the clearing and the closed‐stand forest, while the third FIT was positioned 100 m within the closed‐canopy forest. We employed a novel methodological approach, which involved separately collected subsamples within the ecotone using FITs differentiated as ‘ecotone inwards’ and ‘ecotone outwards’ to capture distinct directional movements at the edge. We recorded 5.997 beetle specimens, encompassing 417 species across 284 genera and 58 families. We found that the species diversity and abundance of beetles were not significantly different between the FITs. However, the species composition was significantly different. The partial detrended canonical correspondence analysis suggests that these compositional differences might be closely associated with the distribution of trophic guilds, indicating varied responses to habitat modifications induced by forest edge creation. The results of our study showed that phloephagous, saproxylophagous, xylomycetophagous, xylophagous and zoophagous beetles exhibited a positive association with the forest edge, while mycophagous, phytophagous and saprophagous groups were distinctly associated with the closed‐canopy forest. Our analyses indicated that the ‘ecotone outward’ part of forest edges of managed forest may attract higher number of trophic groups, while the ‘ecotone inward’ part of the forest edge hosted high abundances of phloephagous and xylomycetophagous species.