Brown bear digging decreases tree growth: Implication for ecological role of top predators in anthropogenic landscapes.

Autor: Tomita KM; Faculty of Agriculture and Marine Science Kochi University, Nankoku, Japan., Hiura T; Department of Ecosystem Studies, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan.
Jazyk: angličtina
Zdroj: Ecology [Ecology] 2024 Apr; Vol. 105 (4), pp. e4266. Date of Electronic Publication: 2024 Feb 29.
DOI: 10.1002/ecy.4266
Abstrakt: Large carnivores have recently increased in number and recolonized in human-dominated landscapes; however, their ecological roles in these landscapes have not been well studied. In the Shiretoko World Heritage (SWH) site, brown bears have recolonized a previously abandoned mosaic landscape of natural forests and conifer plantations after land abandonment. We previously reported that the bears had recently begun to dig for cicada nymphs in association with the creation of larch plantations. As a result, this digging activity decreased soil nutrients. To deepen the understanding of the novel ecological role of brown bears within human-modified landscapes, we examined the impacts of brown bear digging on the growth of larch trees. We found that brown bear digging decreased fine root biomass of larch, soil water, and nitrogen availability. Brown bear digging negatively affected needle nitrogen content, but not carbon isotope ratios, a water stress index of trees. Tree ring data suggest that digging negatively affected the radial growth of larches. The results imply that digging decreases tree growth due to limited soil nitrogen uptake. Our findings indicate that the ecological roles of large carnivores may differ between natural and anthropogenic landscapes.
(© 2024 The Ecological Society of America.)
Databáze: MEDLINE
Externí odkaz: