2018 Volume 44 Issue 2 Pages 330-339
The vegetation in the Misen Mountains on the Shimane Peninsula has been strongly affected by sika deer, Cervus nippon. Therefore, we investigated the scars caused by browsing and debarking on every tree and the number of each species in the study forest and discuss the effects of sika deer on the survival of tree species. We examined five forest types: red pine (Pinus densiflora), hornbeam (Carpinus tschonoskii), oak (Quercus serrata), broad-leaved evergreen (Castanopsis sieboldii), and a forest of trees killed by pine wilt. Neolitsea sericea was the most abundant tree in our study forests. There were large numbers of Q. serrata, P. densiflora, C. tschonoskii, Ilex pedunculosa, and Eurya japonica var. japonica, which showed lower rates of browsing and debarking. TWINSPAN indicated that the species composition of adult trees (diameter at breast height DBH＞4 cm) could be separated into the five forest types according to the dominant species. By contrast, the species composition of young trees (DBH＜4 cm and height＞2 m) and saplings (height＜2 m) did not separate according to the dominant species. Although every forest type contained many N. sericea saplings and young trees, the greatest number of young trees was in the dead pine forest, while the greatest numbers of saplings were in the pine forest and dead pine forest. In our study forests, N. sericea germination was stimulated by two factors: long-term feeding of sika deer and death of canopy trees in the pine forest.
