The Eurasian beaver returned after a few centuries of absence and spread across most rivers in Slovenia. Unfortunately, no much is known about beavers in our environment, though their activity and impact on riparian ecosystems already begun to result in conflicts with humans. The main task of this work was to find out where in their territory beavers cuts down trees and whether the selection of a certain tree species depends on its availability. We chose nine locations on the Krka River and its tributaries, determined the territory boundaries, counted all trees that were cut down or gnawed on by beaver and recorded the number of all available trees per species in a parameter of 5 meters from the river banks. We found that beavers cut trees throughout their territory and the number is decreasing with the distance from the beaver lodge. Secondary structures, such as natural, artificial and beaver dams, probably have a great impact on spatial distribution of cut down trees. Beavers prefer stems with less than 10 cm in diameter, depending on the size and thickness of trees. Although in most cases beavers choose hazel (Corylus avellana) and willow trees (Salix sp.), they prefer other species such as alder (Alnus sp.), hawthorn (Crataefus oxyacantha) and oak (Quercus sp.) if available. Surprisingly they also included elder (Sambucus nigra).
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