Forest Bird Abundance Is Linked to the Interactions Between Forest Characteristics and Species Ecological Traits: Implications for Forest Management.

Majority of European forests are managed by intensive commercial forestry. At the same time, these forests are inhabited by numerous bird species expressing considerable diversity of ecological traits. From this perspective, it is important to learn how forest characteristics, resulting from modern forestry techniques, interact with ecological traits of forest bird species in shaping their abundance. To fill this knowledge gap, we used an extensive dataset on forest bird abundance collected within a national common bird monitoring scheme covering Czechia, a Central European country, supplemented by numerous variables describing forest stands collected within a national forest inventory and ecological traits of bird species extracted from literature. Our results show clear support for the interactions between bird traits and forest characteristics. Specifically, we found that migration distance emerged as the most important moderating bird trait interacting with all five forest characteristics, followed by habitat specialization, which interacted with four characteristics. From the management perspective, it is important to support forest stands with characteristics that are associated with the traits of species sharing unfavorable conservation status. This is the case for long-distance migrants preferring broad-leaved stands in lower growth phases and lower stem density, and habitat specialists preferring upland stands of higher growth phases and multiple vegetation layers. These two species groups can benefit from introducing specific management types, for example, coppicing in lowland areas for long-distance migrants or protection of old-growth stands in upland areas for habitat specialists.