Deciduous forest restoration alters but does not restore functional and phylogenetic diversity of saproxylic beetles

Abstract Introduction Restoring ecological function and stability is crucial amid anthropogenic biodiversity loss. Yet, taxonomic diversity alone provides an incomplete picture, requiring incorporation of functional and phylogenetic diversity. Objectives We evaluated how boreal deciduous forest restoration influences functional and phylogenetic diversity of saproxylic beetle communities. Methods We compared non‐restored forests, forests restored 12–21 years earlier by removing conifers to benefit deciduous trees, and restoration target forests. Restoration targeted the deciduous umbrella species, the White‐backed woodpecker ( Dendrocopos leucotos ). Results Restored forests supported less phylogenetic richness than target forests. Their functional composition was closer to that of non‐restored forests while phylogenetic composition differed among all forest types. These differences were associated with lower relative abundances of large‐bodied and deciduous‐associated species in restored forests compared to target forests. The target forests also had greater functional divergence, indicating that abundance was distributed toward more extreme traits. At landscape scale, we found no differences in phylogenetic or functional richness between forest types, suggesting that restoration altered local diversity, while many species and traits occurred across restored stands collectively. However, target forests supported greater functional diversity when frequent and dominant species were given more weight, showing landscape‐scale differences remained in trait‐abundance distributions. Conclusions Restoration altered saproxylic beetle communities but, after 12–21 years, had not recreated the functional and phylogenetic structure of target forests. Restored communities were distinct rather than consistently intermediate between non‐restored and target conditions.