Do factors describing forest naturalness predict the occurrence and abundance of middle spotted woodpecker in different forest landscapes?

Conservation biologists often use some specialized species as surrogates for communicating conservation needs, e.g. to signal states and changes in ecosystem. This requires a detailed knowledge of a species' habitat demands and relationship between its occurrence and abundance, and certain environmental conditions. This paper explores the relationship between the occurrence and abundance of middle spotted woodpecker (Leiopicus medius) and structural, compositional, and functional elements of forest naturalness in three different forest landscapes in Poland, which encompass a wide spectrum of species' habitats. Neither compositional nor functional elements of forest naturalness seemed to affect species' distribution. In all studied areas, environmental variables related to the structural elements of forest naturalness, e.g. the share of old and uneven-aged stands, number of large living trees, positively influenced the occurrence and abundance of middle spotted woodpecker. Mature, unevenly structured forests might occur as a result of sustainable forest management, aimed at preserving the continuity of old stands and the maintenance of diverse age and species' structure, providing suitable habitat condition for the species. Therefore, both presence and abundance of middle spotted woodpeckers can serve as indicators of wildlife-friendly forest management in deciduous forests.