Assessment of the effect of beaver foraging activities on the alteration of waterside forests in northern and middle taiga of Russian Karelia

  • Fyodor Fyodorov Institute of Biology of the Karelian Research Centre of the Russian Academy of Sciences

Abstract

The territory of the Republic of Karelia is elongated latitudinally, traversing two boreal subzones – northern and middle taiga. Pine and spruce stands predominate in northern taiga, while forests in middle taiga are more diverse, represented by secondary stands, often dominated by deciduous species. These factors define the foraging behaviour of beavers and their role in riparian forest alteration. Dispersing in northern taiga, beavers tend to choose waterside areas with a higher proportion of deciduous species. Such habitats, however, occupy less than 1% of the forested area in this subzone, so the overall effect of beaver foraging on forest stands would be minor. Inside beaver colonies, on the other hand, stand alteration is far more pronounced than changes in colonies in middle taiga, and the effects are the following: 1) waterside forests in northern taiga lose 2.5 times more deciduous trees than those in middle taiga (61.4 and 26.3 %, respectively); 2) in waterside stands, aspen is totally removed, the share of conifers is doubled, and the share of birch is reduced (in middle taiga, the share of birch around beaver colonies slightly increases, and the share of aspen is reduced 1.5 times); 3) beavers in the north of Karelia consume thick birch trees oftener than in the south; 4) the regeneration capacity of damaged trees in the north is lower than in the south of Karelia. Key words: beavers, foraging activities, waterside forests, northern and middle taiga, tree stand
Published
2020-07-25
Section
Forest Ecology