The effects of anthropogenic and natural disturbances on breeding birds of managed Scots pine forests in northern Poland

Anthropogenic disturbance of habitats associated with clear-cut harvesting has replaced natural disturbances, such as wildfire and wind-throw, as initiators of succession in most European forests. Recently, however, forest management has begun to adopt techniques that better mimic natural disturbances, following the documentation of the negative effects of forestry activities, but less information exists on the relative similarity between man-caused and natural disturbances. This study aimed at comparing the bird faunas of windstorm, clear-cut and closed-forest areas in northern Poland. Following the two disturbances, species inhabiting open areas and edge habitats increased (e.g., Yellowhammer Emberiza citrinella and Woodlark Lullula arborea) while closed-forest specialists decreased (Wood Warbler Phylloscopus sibilatrix, Crested Tit Parus cristatus and Goldcrest Regulus regulus). Community density, rarefied diversity and estimated species richness were higher in the disturbed than in the intact, closed-canopy forests. The species-specific responses to windstorm and clear-cutting were positively correlated, i.e., a given species that increased in response to one disturbance regime also increased in response to the other. This finding indicates that man-made disturbances, such as logging, may act as substitutes for natural disturbances for some species.