EN
The structural composition of the forest habitats is considered to be one of the most important factors affecting the breeding bird community composition. Structurally more homogenous forests are usually characterized by lower number of bird species and their densities. This study presents results of a comparison of the breeding bird communities in three Carpathian mountain forests, and the effect of the forest composition on breeding bird species richness and density. There are the bird communities occurring in semi-natural forests: natural mixed forest (NMF) – spruce-beech forest situated ca. 1000 m a.s.l. and UFZ-spruce forest in the upper forest zone (UFZ) up to 1510 m a.s.l., and the managed spruce forest (MSF) at altitude which is similar to NMF. The territory mapping method was used to estimate the number of breeding species and their densities during years 2004– 2006. The species richness as well as the density of breeding bird communities were found to be higher in the semi-natural habitats (33 breeding species; 64.6 breeding pairs 10–1 ha in NMF and 8 breeding species; 57.6 breeding pairs 10–1 ha in UFZ) than in the managed habitat (21 breeding species; 53.6 breeding pairs 10–1 ha). This was true even for the high-elevated study plot despite the fact that the altitude is usually negatively correlated with both the species richness and density.