Effects of an increase in population of sika deer on beetle communities in deciduous forests.
The overabundance of large herbivores is now recognized as a serious ecological problem. However, the resulting ecological consequences remain poorly understood. The ecological effects of an increase in sika deer,Cervus nipponTemminck (Cervidae), on three insect groups of beetles was investigated: ground beetles (Carabidae), carrion beetles (Silphidae), and dung beetles (Scarabaeidae and Geotrupidae) on Nakanoshima Island, Hokkaido, northern Japan. We collected beetles on Nakanoshima Island (experimental site) and lakeshore areas (control site) and compared the species richness, abundance, diversity index, and community composition of beetles between the sites. Results showed that although both species diversity and abundance of carabid beetles were significantly higher at the lakeshore site, those of dung and carrion beetles were higher at the island site. It was additionally observed that abundance of larger carabid beetles was higher at the lakeshore site, whereas that of small-sized carabid beetles did not differ between the lakeshore and island sites. For dung beetles, abundance of smaller species was higher at the island site, whereas that of large species did not differ between the lakeshore and island sites. Abundance of two body sizes (small and large) of carrion beetles were both higher at the island site. Overall, the findings of this study demonstrated that an increase in deer population altered the insect assemblages at an island scale, suggesting further changes in ecosystem functions and services in this region.
Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8, Saiwai, Fuchu 183-8509, Japan.
Taichi
T
Iida
School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo, Tokyo, 113-8656, Japan.
Masashi
M
Soga
Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8, Saiwai, Fuchu 183-8509, Japan.
Shinsuke
S
Koike
Ecosystem functions; ecosystem management; forest ecosystems; herbivores overgrazing; species traits