The birds of Pasvik / E. I. Khlebosolov, O. A. Makarova, O. A. Khlebosolova [et al. ; English transl. Nikita Chernetsov]. - Ryazan : Golosgubernii, 2007. - 175 с. : ил., портр.

is lichen-subshrub and subshrub-lichen tund ra with rock ou tcrop s and pebble patches. Patches o f subshrub-grass tund ra, grass tund ra , peatbog subshrub tund ra (Ramenskaya 1972). In the subzone o f the tund ra forest the lower parts o f slopes are occupied by m oun tain birch forest. It is gradually replaced by crooked birch forest and then by m oun tain tundra and rock outcrops. Several features contribute to frequent occu rrence o f bogs: flat relief o f the Pasvik valley, th e presence o f depressions between the m oraine hills, a high level o f ground water and constant excess moisture. The source o f water is mainly a tm o s­ pheric and to a lesser extent subterranean. Wetlands are m ainly heterotrophic and mesotrophic, humm ock-ridge and tussock bogs, grass and grass-moss bogs occur. Shrub and shrub-m oss bogs occur locally. Typical eutrophic and oligotrophic bogs can be found. Most wetlands are situated along the banks o f the Pasvik river, along steams and on lake coasts. Raised bogs are less comm on , they are found on galleries and in depressions between the hills. The aforem entioned physical geographic features exert a considerable influ­ ence on the avifauna o f the Pasvik valley and adjacent areas.