부산대학교 도서관

Fallen tree, stand structure of black locust plantation and the site condition were examined on a degraded slope at Ashio mountains, Tochigi, Japan. The tree size was larger on lower slope and smaller on upper slope. Tree fall size distribution was different in the position of slope, middle to lower slope and retaining wall work, on larger tree falls occur on upper slope or non-retaining wall work area. Density dependent mortality, and unbalanced ratio of above and below ground parts of tree are main causes for small and large tree fall, respectively. Eight to ten meter in tree height is the limit for tree fall. Forest regeneration by indigenous species is more susceptible to site condition than black locust trees, and tend to be worse growth. Then, maintaining black locust plantation by protecting the tree falls in terms of pollading and proper density management is prior management option