General patterns of beavers’ selective foraging: how to evaluate the effects of a re-emerging driver of vegetation change along Central European small watercourses
Along small watercourses, the growth and renewal of native willows and poplars (Salicaceae species) are hindered by the effects of past and recent man-made landscape alteration and climate change, while the selective foraging of the beaver (Castor fiber) is also becoming an increasingly important driver. Knowledge about foraging decisions can refine predictions about vegetational processes and help to develop better nature conservation and forest management strategies. We surveyed the woody plant supply (13,304 units) and its utilization by the beaver at 11 study sites along Central European small watercourses, at two fixed distances from the water. We collected information about the taxon, trunk diameter, and type of utilization (cutting, carving, debarking) of each unit. We built (generalized) linear mixed models aimed at answering questions regarding taxon and diameter preference, their interrelatedness, and their importance in foraging decisions. All of the factors examined had a significant effect on foraging decisions. Utilization was mostly explained by the taxon, with Salicaceae species being generally preferred and utilized in all diameter classes with a high ratio. Several further genera were frequently utilized (mainly Cornus and Ulmus), while others were almost completely avoided (including invasive Amorpha and Robinia). The beavers preferred units with a diameter of 5–9 cm. The type of utilization depended primarily on diameter class. Because native softwoods are the most affected by beaver impact, regardless of trunk diameter, their survival and regrowth should be consciously supported by increasing the water table and improving hydrological conditions.
© The Author(s) 2023. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Version of Scholarly Record of this Article is published in Biodiversity and Conservation, 2023, available online at: https://link.springer.com/article/10.1007/s10531-023-02598-8 . Keywords: browsing impact; Castor fiber; ecosystem engineer species; forest management; optimal foraging strategy; riparian woodland.
Juhász, E., Molnár, Z., Bede-Fazekas, Á. et al. General patterns of beavers’ selective foraging: how to evaluate the effects of a re-emerging driver of vegetation change along Central European small watercourses. Biodivers Conserv (2023). https://doi.org/10.1007/s10531-023-02598-8