Abstract
Dry ravel and soil creep caused by the gravity acting on soil particles are the typical soil movements in steep mountain area. Since these sediment movements result in loss of regolith as well as damage of standing woods, countermeasures are needed for forestry in mountain area. We, therefore, tried to clarify characteristics of sediment movement in steep mountain forests based on field observations. We also investigated effect of wood fences made of thinned woods on the check of sediment movement. Our observations conducted in Akaishi Mountains, central Japan, showed that the freeze-thawing in winter induces active soil movements as the dry ravel and the soil creep. Without influence of active sediment source on upper slopes, wood fences can check soil movement in arterial forests. The area stabilized by the wood fence is considered to depend on the angle of repose as well as the slope gradient.
