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Selective Foraging on Tree and Shrub Species by the European Beaver Castor fiber in Lowland and Highland Habitats in Western Poland

Ważna A., Cichocki J., Bojarski J., Gabryś G.

Polish Journal of Ecology

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2018

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Vol. 66, nr 3

286--300

EN

In this study, generic composition of food and foraging preferences of the European beaver were determined on sites where the beavers were reintroduced after more than 200 years of absence. Research area was located on lowland (Silesian Lowland) and highland habitats (Bystrzyckie Mountains, Wałbrzyskie Mountains) in western Poland. During the study period, 17,418 trees and shrubs growing within the feeding area of the beavers were marked, out of which 4,669 were found to be cut by beavers. The results showed that the foraging preferences of beavers depend on the availability and diversity of the local food sources. In the lowlands beavers preferred the following species of trees and shrubs as their primary food source: Salix cinerea, S. fragilis, S. caprea, Cornus sanguinea and Populus tremula. In the highlands, beavers preferred Corylus avellana, Sorbus aucuparia, and Fagus sylvatica due to the low availability of Salix and Populus species. Moreover, in the highlands, beavers had to cover longer distances to reach the feeding sites and had to cut trees with larger diameter than in the lowlands.

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Impact of the European Beaver Castor fiber on Deadwood Resources in Lowland River Valley – A Case Study in Wigry National Park (NE Poland)

Misiukiewicz W., Piętka S., Bielinis E.

Polish Journal of Ecology

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2018

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Vol. 66, nr 3

270--285

EN

The impact of the European beaver Castor fiber on deadwood resources near dams on the rivers of Wigry National Park (northeastern Poland) has been analyzed. The river sampling area was subdivided into the flooded zone, scarp and upland. We found that beaver feeding was limited to the flooded zone and the scarp. Within a distance of 40 m of the river, beavers browsed 75% of all deadwood pieces (wood debris, stumps, dead trees). The wood generated via direct browsing by beavers made up 5% (3.29 m3/ha) of the total wood volume and 35% (641 pieces/ha) of the total number of wood pieces in this region. The beavers mostly left small pieces of wood (with a mean diameter of about 4 cm) at an area after feeding. The deadwood volume and number of pieces were significantly different in front and behind the dam only in the flooded zone. The volume of deadwood in front of the dam in the flooded zone was higher by 65% than behind the dam (102 and 62 m3/ha, respectively), and the number of pieces was higher by 75% (2200 and 1200 pieces/ha, respectively). We prove that beavers generate the majority of dead wood indirectly – by flooding a part of the area. This results leads to conclusion that frequent flooding of a given area may lead to limiting the source of deadwood in the long term. We also confirm that through direct browsing, beavers produce small amounts of thin dead wood with less usefulness for other groups of animals, thus in this way beavers are not able to provide high-quality deadwood resources.

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Dyskusja możliwych losów dwóch rodzin bobra europejskiego z Czarnej Rzeczki zagrożonych budową autostrady A4

Mundała P., Szwalec A., Guzdek A.

Problemy Ekologii

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2008

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R. 12, nr 5

255-259

PL

Praca przedstawia dyskusję możliwych rozwiązań sytuacji dwóch rodzin bobrowych bytujących w Czarnej Rzeczce (zlewnia Wisłoka) w powiecie Ropczycko-Sędziszowskim. Ich siedliska przecina planowana autostrada A4. Pomimo sporych trudności autorzy postulują przeniesienie koryta Czarnej Rzeczki łącznie z oczkami wodnymi. Stworzy to szansę na przeniesienie się tam opisywanych zwierząt. Planowany odcinek autostrady A4 trzeba bezzwłocznie budować. Kompensacja przyrodnicza powinna być szerzej wykorzystywana w praktyce ochrony przyrody.

EN

Due local human settlement the motorway can not be placed in other position. The author discussed possible solution of the problem. They recommend moving the beaver habitats. The new Czarna Rzeczka River bed could be made (including two small water bodies). In this case, there would be change, the animals colonize them.