Brown bears digging up artificial forests

by University of Tokyo
March 01, 2024

Brown bears foraging for food in the Shiretoko Peninsula of Hokkaido, Japan, have been disrupting tree growth in artificial conifer forests, according to a new study. Researchers compared soil and tree samples from human-forested plots with samples from natural forests. They found that the bears’ digging for cicada nymphs damaged tree roots and altered the nitrogen content of the soil, which in turn limited the diameter growth of trees. The phenomena of bears digging for cicadas, an unusual food source, appears to be restricted to human-planted conifer forest; diversely vegetated natural forest was unaffected. Bears in Hokkaido sometimes suffer from sparse food supplies, but it is not known if this is the reason for their cicada search. These results are important for animal conservation and efforts to return used land to a wild state, highlighting the value of recreating diverse local ecosystems which can support natural wildlife behavior.

Keep reading: https://www.u-tokyo.ac.jp/focus/en/press/z0508_00338.html

Read the Ecology paper: https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecy.4266