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The species‐energy hypothesis predicts increasing biodiversity with increasing energy in ecosystems. Proxies for energy availability are often grouped into ambient energy (i.e., solar radiation) and substrate energy (i.e., non‐structural carbohydrates or nutritional content). The relative importance of substrate energy is thought to decrease with increasing trophic level from primary consumers to predators, with reciprocal effects of ambient energy. Yet, empirical tests are lacking. We compiled data on 332,557 deadwood‐inhabiting beetles of 901 species reared from wood of 49 tree species across Europe. Using host‐phylogeny‐controlled models, we show that the relative importance of substrate energy versus ambient energy decreases with increasing trophic levels: the diversity of zoophagous and mycetophagous beetles was determined by ambient energy, while non‐structural carbohydrate content in woody tissues determined that of xylophagous beetles. Our study thus overall supports the species‐energy hypothesis and specifies that the relative importance of ambient temperature increases with increasing trophic level with opposite effects for substrate energy. [ABSTRACT FROM AUTHOR]

Conservation of biodiversity requires in-depth knowledge of trait-environment interactions to understand the influence the environment has on species assemblages. Saproxylic beetles exhibit a wide range of traits and functions in the forest ecosystems. Understanding their responses to surrounding environment thus improves our capacity to identify habitats that should be restored or protected. We investigated potential interactions between ecological traits in saproxylic beetles (feeding guilds and habitat preferences) and environmental variables (deadwood, type and age of surrounding forest). We sampled beetles from 78 plots containing newly created high stumps of Scots pine and Silver birch in boreal forest landscapes in Sweden for three consecutive years. Using a model based approach, our aim was to explore potential interactions between ecological traits and the surrounding environment at close and distant scale (20 m and 500 m radius). We found that broadleaf-preferring beetle species are positively associated with the local broadleaf-originated deadwood and broadleaf-rich forests in the surrounding landscapes. Conifer-preferring species are positively associated with the local amount of coniferous deadwood and young and old forests in the surrounding landscape. Fungivorous and predatory beetles are positively associated with old forests in the surrounding landscapes. Our results indicate that both local amounts of deadwood and types of forests in the landscape are important in shaping saproxylic beetle communities. We particularly highlight the need to increase deadwood amounts of various qualities in the landscape, exempt older forests from production and to increase broadleaf-rich habitats in order to meet different beetle species' habitat requirements. Trait responses among saproxylic beetles provide insights into the significance of broadleaf forest and dead wood as essential attributes in boreal forest restoration, which helps conservation planning and management in forest landscapes. • Trait – environment interactions of saproxylic beetles are investigated. • Broadleaf-preferring beetles thrive with local broadleaved deadwood. • Broadleaf-rich forests contribute to the abundance of broadleaf-preferring beetles. • Fungivores and predators positively interact with old forests in the landscape. • Deadwood increase and a 'broadleafication' of boreal forests need to be implemented. [ABSTRACT FROM AUTHOR]

Uneven-aged silviculture may better maintain species assemblages associated with old-growth forests than clear felling in part due to habitat heterogeneity created by maintaining standing retention strips adjacent to harvest trails. Retention strips and harvest trails created at the time of tree removal will likely have different microclimate and may harbor different assemblages. In some cases, the resultant stand heterogeneity associated with uneven-aged silviculture may be similar to natural small-scale disturbances. For beetles, increased light and temperature as well as potential access to young vegetation and deadwood substrates present in harvset trails may harbor beetle assemblages similar to those found in natural gaps. We sampled saproxylic beetles using flight intercept traps placed in harvest corridors and retention strips in 9 replicated uneven-aged spruce stands in central Sweden. We compared abundance, species richness and composition between harvest corridors and retention strips using generalized linear models, rarefaction, permutational multivariate analysis of variance and indicator species analysis. Canopy openness doubled, mean temperature and variability in daily temperature increased and humidity decreased on harvest trails. Beetle richness and abundance were greater in harvests trails than in retention strips and the beetle species composition differed significantly between habitats. Twenty-five species were associated with harvest trails, including three old-growth specialists such as Agathidium discoideum (Erichson), currently red-listed. We observed only one species, Xylechinus pilosus (Ratzeburg) that strongly favored retention strips. Harvest trails foster both open habitat species and old-growth species while retention strips harbored forest interior specialists. The combination of closed canopy, stratified forest in the retention strips and gap-like conditions on the harvest trails thus increases overall species richness and maintains more diverse assemblages at the stand level than would otherwise be seen in less heterogeneous stand types. This suggests that uneven-aged silviculture may provide added conservation benefits for both open habitat and old-growth specialists than silvicultural approaches that reduce stand heterogeneity. [ABSTRACT FROM AUTHOR]

Decline in biodiversity have increased the interest in alternative forest management approaches. Uneven-aged silviculture has been proposed as a mean to maintain continuity of forest canopy cover, mimic small-scale disturbances and provide a stratified forest structure similar to that of old-growth forests and therefore better maintain species associated with unmanaged forest. We used a large-scale chronosequence study spanning 50 years to study beetle diversity in uneven-aged silviculture compared with both short-term impacts and the longer-term legacy of even-aged silviculture. We compared: (1) even-aged recently clear-felled stand, (2) even-aged recently thinned stand, (3) uneven-aged stands subjected to selective felling with (4) uneven-aged reference stands to evaluate whether abundance, species richness and composition of beetles (Coleoptera) were affected differently by even-aged than by uneven-aged management. We collected 15,147 beetles from 461 species using flight interception traps in 30 stands. Beetle composition was maintained in uneven-aged managed stands; composition did not differ from unmanaged reference stands, the exception being cambium consumers. Both even-aged silviculture treatments (clear-felling and thinning) had different beetle composition compared to the reference stands, indicating that assemblages had yet to recover even 50 years into the rotation. However, beetle composition did not differ between uneven-aged managed and thinned stands. The result supports our prediction that uneven-aged silviculture better maintains beetles assemblages associated with semi-natural mature forest than even-aged silviculture. The greater temporal continuity in selectively felled stands could benefit species dependent of mature or old growth forest since some of the needed habitat qualities are continuously available. Uneven-aged silviculture could therefore serve as an important tool for landscape planning to benefit biodiversity and thus help fulfil environmental commitments. However, uneven-aged silviculture may still alter the forest and should therefore be viewed as an alternative to even-aged silviculture, rather than to set-asides. [ABSTRACT FROM AUTHOR]

The article presents a study regarding the effect of clear-cutting forestry practices on boreal organisms and on saproxylic and non- saproxylic beetle. The study compared group of beetles using three successional phases of boreal spruce forests and evaluated whether saproxylic and non- saproxylic beetle shows biodiversity patterns. The study reveals that not only forest is affected but also the group compositions of beetles and other site aspects such as altitude and management history.

Abstract: The aim of this study was to evaluate how future harvesting of spruce low stumps as a renewable energy source, might influence the saproxylic (wood living) beetle fauna. Species richness, abundance and assemblages of saproxylic beetles were compared on low stumps, high stumps and logs of spruce on 10 clear-cuts in northern Sweden. The sampling was conducted with emergence traps and a total of 929 individuals and 120 species were collected. No significant differences in beetle abundance or species richness were detected between substrate types. However, there were clear differences in assemblage composition between all substrate types. Our results suggest that low stumps created at final felling support as many species and individuals per volume dead wood as other dead wood substrates and that they are therefore overlooked as substrates for wood living organisms. Consequently, harvesting of low stumps might have negative effects on the diversity of saproxylic beetles, as up to 80% of the dead wood remaining on clear-cuts is in the form of low stumps. Future studies should evaluate if compensatory measures can be performed to minimize negative impacts. [ABSTRACT FROM AUTHOR]