Non‐saproxylic beetles in beech forests: Larval habitat, trophic guild structure in a case study from the Czech Republic

Beech forests in Central Europe are frequently the focus of entomological studies targeting saproxylic beetle species that depend on deadwood. However, considerably less attention has been paid to non‐saproxylic beetle species. Our research aimed to address this gap by focusing on the diversity and abundance of functional guilds of non‐saproxylic beetles. General analyses based only on total species richness can be misleading, as they may overlook fundamental ecological processes. Thus, the primary objective was to evaluate species richness and abundance of non‐saproxylic beetles in relation to species' habitat types, larval habitat types, and larval trophic feeding guilds. Data were collected over a three‐year period using window traps placed on permanent monitoring plots. Regarding species habitat, the highest proportion of both species (46%) and individuals (61%) belonged to an opportunistic group that inhabits both open landscapes and forest habitats equally. The second largest group, in terms of species (23%) and individuals (32%), consisted of species preferring forest environments. When categorized by larval habitat—belowground, epigeic, and aboveground—the number of species was relatively balanced. However, the highest number of species had epigeic (41%) or belowground (34%) larval stages. In contrast, the majority of individuals (63%) belonged to species whose larvae develop belowground. From the perspective of trophic guilds, most species were classified as mycetophagous (35%) or carnivorous (21%). Other trophic groups (rhizophagous, phytophagous, and saprophagous) were evenly represented. In terms of abundance, carnivorous species were dominant, comprising 40% of all individuals recorded. The results indicate that the composition of mainly flying, non‐saproxylic beetles is derived largely from the soil and epigeic layers of pure beech stands, with a community structure dominated by opportunistic species primarily associated with carnivorous and mycetophagous trophic guilds. This study contributes new insights into beech forest beetle assemblages, expanding the focus beyond the frequently studied saproxylic species.