Spatial distribution of damage induced by a resinous disease of the hinoki was surveyed in a ca. 30 year old hinoki artificial stand located in Hanawa Town, Fukushima Prefecture. All 142 hinoki trees within a ca. 0.12 ha survey area were mapped. Their heights and diameters at breast height were measured, and the degree of damage was evaluated for each tree. The rate of damaged trees and the rate of trees having flat stem and / or sunken stem were 96.5% and 78.9%, respectively. The damage was more severe at lower slopes than at upper slopes in unit level analysis. The degree of damage differed depending on height from ground level. The most severely damaged parts were less than two meters from the ground. Moran's I values were calculated and the results showed that a clustered distribution of damage existed within the stand. The results also indicated that the severely - damaged area within the stand was ellipsoidal, and it's axis parallel to the slope was longer than the vertical axis.

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This report shows the relationships between flow regime and precipitation, air temperature & forest volume at the forest watershed. (1) The relationship between flow regime and precipitation is clearly noticed from large to small dischage. Flow regime is in proportion to precipitation. (2) The relationship between flow regime and air temperature forest volume is little in comparison with that of flow regime and precipitation. (3) Flow regime is inversely proportional to air temperature in cases of large discharge. Conversely,flow regime is proportional to air temperature in cases of small discharge. (4) Flow regime is inversely proportional to forest volume.

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As a case study of small scale forestry, we investigated the stability and surface drainage of a low-structure road for small forest vehicles in Akita Prefecture, Japan. In the section constructed 20 years ago (section A), the upper sub-base contained more fine grained soils than the section constructed 4 years ago (section B). The average angle of the cutting slope was 48° in section A and 81° in section B. The average rate of the natural vegetation covering the cutting slope was 59% in section A and 14% in section B. The cutting slope has become more gentle and has been covered with natural vegetation over a long period (more than 20 years). The one-way grade which heightened the cutting side of the road was 3.4-10.3 % in section A and 0.2-4.3 % in section B. These values did not exceed the safety limit allowing forest vehicles to run at 10 km/hr. It seems that the one-way grade, together with simple open culverts, had a positive effect on distributing drainage. The conclusion which may be drawn from this study is that both the stage construction and simple drainage by a one-way grade can contribute to low-cost road construction.

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