Bird communities in European taiga forest: A comparison between a large forest block in Archangelsk, Russia, and some small-grained old-growth fragments in central Norway

Abstract

The large intact areas of old-growth forest of the Archangelsk oblast represent today a possibility of studying taiga ecology in ecosystems that we do not find in Fennoscandia. They are to be regarded as the sources for the taiga-elements in our own coniferous forests. This study of bird communities was done in the core of one of the old remaining, intact forests of Archangelsk, alongside the Yula river in Pinega and Vinogradovsky rayons («regions»). Bird communities in mature spruce and pine dominated forests were studied in spring 2005. These communities from the core area of the taiga are compared with coniferous forest in the rural municipality of Lierne in eastern central Norway, studied in 2004. This latter area should be representative for the westernmost parts of the taiga. Due to extensive forestry exploitation and natural heterogeneity it is heavily fragmented, leaving behind only smaller fragments of more or less coherent old-growth stands. Findings in our comparison: • Species dependent on sufficient amount of dead wood, e.g. woodpeckers, comprise far less of the bird communities within the small-grained old-growth fragments in Lierne compared with the situation in the virgin taiga at Yula. • The abundance of all hole-nesters (including those using snags and cracks in the trunks) is considerably diluted in the bird community within the old-growth forest in Lierne compared with those found in the coniferous forests at Yula. • The assemblage forming the old-growth bird guild (predominately passerines) is still almost as abundant in the remaining fragments in Lierne as in the large block of taiga at Yula. As high abundance of hole-nesters might reflect the occurrence of several other vulnerable forest species among insects, vascular plants, bryophytes and lichens, our findings from the bird survey should also indicate a more general high conservation value of this large block of taiga at Yula.