Large live and dead trees promote saproxylic beetle diversity and White‐backed Woodpecker breeding territories

Effective forest management to promote biodiversity requires understanding the intricate relationship between forest characteristics and species occurrence. Given that more than 25% of forest taxa are associated with dead wood, this resource has gained attention as key component of closer-to-nature forest management. The White-backed Woodpecker ( Dendrocopos leucotos ) is one of Europe’s rarest woodpeckers, and observational studies often report the species preferentially foraging on dead standing trees (i.e. snags) in deciduous forests. Despite the lack of systematic assessment of the importance of dead wood for the woodpecker and its associated saproxylic beetle community, conservation plans typically focus on snag enrichment when restoring forest patches for the target bird species. Here, we used confirmatory path analysis to compare the direct and indirect effects of structural characteristics of beech-dominated extensively managed forests on saproxylic beetle communities and on the White-backed Woodpecker activity. Using in situ eclectors, we sampled saproxylic beetle communities emerging from 87 European beech snags distributed in forests with and without the woodpecker, over a period of two years, yielding 6519 specimens represented by 156 saproxylic beetle species. While our study did not provide evidence that saproxylic beetle communities emerging from snags serve as a reliable predictor of White-backed Woodpecker activity, several habitat variables proved to be good predictors for saproxylic diversity. In addition to the positive effect of ambient temperature on saproxylic beetle richness, we identified that communities of saproxylic beetles were correlated with the diameter and the bark coverage of the snags, as well as indirectly with the diameter of the surrounding live trees. Taken together, our results emphasize the importance of promoting large live trees, benefiting subsequent late-successional dead wood resources to foster biodiversity in temperate deciduous forests. Independently of White-backed Woodpeckers known occurrence, practitioners and stakeholders should take on every opportunity of actively enhancing habitat quality where dead-wood dependent organisms occur. From retaining large live trees and snags in managed forests to focusing targeted conservation measures in forest stands where White-backed Woodpeckers occur, every measure increasing forest naturalness would ultimately benefit the fraction of biodiversity found in Central European forests.