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.

03 P- u о g 3 о о О Figure 3.7. Occurrence o f Eurasian Redstarts in different types o f forest in the 0v re Pasvik N ational Park (Norway). 1 —semifrutex and lichen pine forest; 2 —pine and birch forest w ith ground cover o f black crowberry, grass and ling; 3 —red bilberry pine forest; 4 —sem ifrutex and green moss birch forest; 5 — lichen pine forest w ith birch adm ixed; 6 - semifrutex and green moss pine forest. A reason for the low diversity o f forest vegetation on the Norwegian side is the technology o f lumbering that does not permit a change o f the main tree species. In the place o f a lumbered pine forest new pines are planted or grow naturally. It does not allow development o f the natural succession that normally includes a series o f mixed pine and birch stands from young birch forest to mixed pine and birch and pine forests with birch admixed (Khlebosolov et al. 2000). Statistical analysis shows a clear positive relationship between Redstart n um ­ bers and tree height in the first story and some negative correlation with forest d e n ­ sity (Tab. 3.2). Selection o f high sparse pine stands with loose understory is governed by the foraging behaviour o f this species. This species usually forages in the lower parts of Table 3.2. Relationship between the numbers o f Eurasian Redstarts w ith different biological characteristics o f the forest. Pairwise correlations Species Pine Birch Pine Birch Pine Birch Crown volume, m 3• m 2 Tree height in the first story, m N um b er o f tall trees per 500 m2 Eurasian Redstart 0,46 -0 ,5 1 0,93 0,08 -0 ,3 0 * * —data pooled for both tree species. 1 2 6