The effects of the artificial spraying of seawater on a Quercus acutissirna forest were investigated in order to evaluate the direct use of seawater in the aerial extinction of forest fires. Electric conductivity (EC) and the concentrations of Na+ and in throughfall abruptly rose just following seawater spraying. They decreased gradually and a full recovery required a period of two months. However, the soil EC peaked one week after spraying and gradually decreased in subsequent months. It was suggested that the salinity in the soil did not cause stress to vegetation, even at the peak of soil EC. Evidence of leaf necrosis first appeared two days following spraying and after eleven days was widespread. The measurement of water potentials suggested that leaf necrosis may be a result of the direct influence of salinity on leaves, not from the wilt induced as a result of water stress. The effect of seawater spraying on litter fall, growth of Q. acutissirna (diameter and height) and the yield of Q. acutissirna nuts, was not found to be significant. From our results, we suggest that the growth of Q. acutissirna is not influenced by seawater spraying, when the amount of seawater is less than 16 mm (16 L m^-2, 10 min).

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The appropriateness of Forest Fire Emergency Measure Simulation, which was developed for planning fire prevention measures, was examined based on a sensitivity analysis conducted on a forest fire which occurred in Kagamihara City. For the sensitivity analysis, one-way analysis of variance, Bonferroni multiple comparison and L16 (2¹⁵) orthogonal array variance analysis were applied to each factor. An examination of the area consumed by the fire, the rate and direction in which the fire spread and spotting numbers revealed that the most effective factors were as follows : the rate of fuel fire spread, wind direction, wind velocity, and mean stand height. This suggests that the data of spotting position was quite important for calculations related to the forest fire. An examination of appropriateness revealed that the utilization of average observed values for the calculations were the cause of error increment. Utilizing observed maximum values for the calculations was appropriate to a certain degree, but it was plagued with delays in spotting occurrence and undervaluation of the fire spread rate. To improve its compatibility, the following measures were suggested : re-examination of spotting parameters, incorporating the effect of intense heat on changing wind patterns, and examining of the rate of fuel fire spread. As it currently stands, this simulation can only be utilized for suggesting fire brigade allocations and locations for forest roads and fire breaks.

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Concentrations of total fine solids (TFS) and organic fine solids (OFS) in the stream water were measured from June to November in 2001 and 2002, in a forested catchment of 9.2 ha where selective-cutting had been carried out in the winter of 2001. TFS and OFS concentrations from the selective-cutting catchment were significantly higher after cutting as compared with those before cutting (1997). The significant difference in TFS concentrations between selective-cutting and control catchments was observed during the first year following the logging; average TFS concentration was higher in the selective-cutting catchment than that in the control. Ratio of OFS to TFS (=OFS concentration/TFS concentration), which reached a constant value as the stream discharge increased over a critical value were significantly lower during the period after logging as compared with that prior to logging. According to the observation at the disturbed area in the selective-cut catchment, the increase of inorganic component of TFS after logging seemed to result from sediment deposition below the skid trails adjacent to the stream.

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We surveyed the germination and survival rates, morphological characteristics, spatial pattern of root extension, and the mass distribution into each organ of current and 1-year-old Picea jezoensis seedlings growing on fallen logs with no moss (FL_B), short moss (FL_S), and tall moss (FL_T) in a natural coniferous forest in central Hokkaido, northern Japan, in order to estimate the in FL_Uence of moss height on the establishment of P. jezoensis seedlings on fallen logs. The germination rate was significantly lower on FL_T than on the others. The survival rate of seedlings did not differ among the logs. Almost all parts of the tap roots of living and dead seedlings were distributed in the humus and wood layers of the logs, irrespective of moss height. Seedlings on FL_T had longer stems and greater stem masses than seedlings on the other logs, which indicated their morphologic and allometric acclimation to shading from the tall moss. The masses of individual current-year seedlings were lower on FL_T than on the others. The masses of individual 1-year-old seedlings were lower on FL_B than on FL_S. The root extension of 1-year-old seedlings on FL_B was inhibited and resulted in shorter roots and a higher T/R ratio. Consequently, the growth of 1-year-old seedlings on FL_B was inhibited. Therefore, FL_S is the most suitable for the establishment of P. jezoensis seedlings.

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To quantify the amount of surface erosion from landslides in the weathered granite area of central Japan, a soil trap was installed at the base of a landslide site in Matsukawa watershed, Nagano Prefecture for a 2-yr period. The average surface erosion from the landslide site was 1, 200 ton/ha/yr with no difference between the two years. This value is a bit larger than previously believed. Both rain and frost heaving had significant influences on the amount of surface erosion; rain produced 59% of total surface erosion. Erosion by frost heaving varied widely between the two years of monitoring. The rainfall factor of USLE and some rainfall indices for surface erosion are estimated with a high confidence level when comparing the rainfall factor with known rainfall indices for surface erosion. The soil erodibility factor used in the USLE calculations is half the value of immature soil. By using this value of soil erodibility, the USLE provides an effective estimate of surface erosion from landslide sites during rainfall periods.

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The bark of 9 Morus alba L. trees was separated into the outer bark and the inner bark by hands with the use of a pocket knife. After that, we performed a quantitative analysis of six components : contents of moisture, ashes, resins, total sugar, essential oils, and condensed tannins. The resin contents were measured using the Tappi method. The total sugar analyses were conducted using the phenol-sulfuric acid method. The essential oils were measured using the steam distilling method. Condensed tannins were tested using the vanillin-HC1 method. The outer bark contained 68% moisture, 914% ashes, 710% resins, 46% total sugars, 0.20.9% essential oils, and 1.03.5% condensed tannins, while the inner bark contained 810% moisture, 619% ashes, 410% resins, 811% total sugars, about 0.13% essential oils, and 0.30.8% condensed tannins. As a result, the analyses clearly showed that there was a significant quantitative difference between the outer bark and the inner bark for all components except ashes and resins contents based on a t-test.

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The influence of two forest declines caused by forest fire and pine wilt disease on the discharge duration curve was estimated with a paired catchments experiment in Tatsunokuchi-yama Experi-mental Forest (34° 42' N, 133° 58' E). The regression lines between the discharge duration curves from Kitatani and Minamitani catchments were calculated during the control period (36 years). The observed discharge and calculated discharge with this regression line during the treatment period (19 years) were compared. Except for a few dozen days, the daily discharge was judged to be increased by disturbance on almost all days. The increased ratio on the observed discharge was around 15, 35 and 43% on the 140th, 140320th, and 320thday, respectively, in the discharge duration curve.

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