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The objective of this study was to select individuals which has the highest resistance for pine wilt disease from black pine seedlings and to propagate them by the cutting. So we compare to the rooting ability of 2 year-old seedlings population which selected by virulent and avirulent isolate nematodes. Analyze of variance, family variance and family X isolate of nematodes interaction on rooting percentage were significant, but nematodes isolate variance was nonsignificant.

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We tried to measure the genetic diversity of the nematode resistance individuals and the plus trees in Japanese black pine (Pinus thunbergii) using DNA markers. First, we observed that the genetic similarity and the geographic distance between the selection points had the correlation relationships. Second, we observed that the genetic similarities among the plus trees are comparatively higher than among the nematode resistance individuals. This result suggested that the genetic diversity of the plus trees in Kyushu region have comparatively same than the nematode resistance individuals.

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Pollen allergies of Sugi is a serious social problem.Therefore, Paclobutrazol, an inhibitor of biosynthesis of gibberellin, treatments on inhibition of male flower setting were studied. In this study, 5 plus tree clones in seed orchard were used as experimental materials. Stem buried treatments were carried out in June, 2000.Branch buried treatments were carried out in June, 2001. Male flower setting was observed in February, 2001 and 2002.Branch buried treatment of paclobutrazol is effective to inhibition of male flower setting.

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Neutron radiography was applied to trace the development of discolored tissue in the wood of Cryptomeria japonica after the inoculation with a canker fungus, Guignardia cryptomeriae. Three, 7, 13 and 22 days after the inoculation, the seedlings were irradiated with thermal neutron beam. The image on the X-ray film was obtained. Discolored tissue and surrounding dry zone induced by the fungal inoculation was detected as dark area, indicating water deficient part, with high resolution. Dry zone was detected as early as 3 days after inoculation, whereas no obvious change in wood color was observed until later stage. Neutron images also showed the difference in the size of water deficient part due to the tissue damage among the treatment. Expansion rate of damaged tissue was most rapid in the seedlings inoculated with a virulent isolate. Neutron beam used in this experiment had no effect on the growth rate of the fungus on a medium, showing that this method an effective method for pathological research of trees.

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In the present study, the Japanese larch (Larix kaempferi) (L), the Kurile larch (L. gmelinii var. japonica) (G), and their F₁ hybrid (GL) were examined for their resistance to bark stripping by deer in the forest through cafeteria tests. Several sets of logs prepared from the trunks of L, G, and GL were fed to deer at test sites. The stripped area of log's bark significantly differed between the L/G set and the L/GL set (p <0.05). G and GL were shown to have a stronger resistance to bark stripping by deer when compared to L.

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To clarify vegetation use of Japanese hare(Lepus brachyurus) in snow season, We traced hare's tracks on the snow, investigated vegetation type, floor vegetation, feeding sign, facal pellet of hares. Tracks were abundant in open field, Cryptomeria japonica forest and Castanea crenata & Quercus serrata forest. Densities of feeding sign were the highest in forest edge, secondaly Pinus densiflora forest, Deciduous broad-leaved forest, low in C. japonica forest and open field. Densities of facal pellet were high in salix forest and Deciduous broad-leaved forest, low in forest edge. Feeding sign is directry shows feeding habitat. Feeding sign was abundant in forest edge, often in C. japonica forest and open field(Chi-square test). Forest edge is important habitat for feeding in snow season.

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Change of interception loss due to the vegetation succession has been made clear based on the comparison between previous and present observations conducted in the same forest, whose conditions were pure forest of Japanese red pine, and mixed forest of that and some oak species, respectively. Since stemflow increased from 14.6 mm (1.2% of gross rainfall) to 105.9 mm (8.5%) and throughfall did not change significantly, interception loss decreased from 208.7 mm (17.2%) to 114.7 mm (9.2%). Estimated rainfall storage capacity of forest decreased, but interception loss during events did not change significantly. It is concluded that decrease in storage capacity determined the change of interception loss.

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The major components contributing to the ride quality of forestry vehicle are tire, suspension, and seat. The seat dynamics may become significant in the ride quality since the seat directly transmits the vibration to operator. Also, most of off-road vehicles are not equipped the suspension system. Therefore, the purpose of this study was to specify the vibration characteristics of forestry vehicle seat and their interaction to human bodyThe fundamental mode is observed at 3.7-4.0 Hz for seat transmissbilities, and the head transmissibility shows two modes at 3.7 and 8.2Hz. The head response magnitude at the fundamental frequency is 29% larger than the hip response magnitude

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We developed a pin-sticking implement for fixing mulch-sheet in 2002. This implement is prototype. We introduce result when we tested it.

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We estimated rainfall interception using simple model consists of two continuous tanks correspond to canopy and litter interception processes. This model predicts the effect of these two interception processes separately. The canopy tank model calculates the amount of throughfall, stemflow and canopy interception from the gross rainfall data. On the other hand, the litter interception model calculates the litter interception from the throughfall data estimated by the canopy tank model, and also evaporation ratio from the litter layer estimated by the relative water content of the litter layer. We applied this model to coniferous C. japonica (Cryptomeria japonica D. don) and broad - leaved L. edulis (Lithocarpus edulis Nakai)plantation forest. Estimated annual interception loss showed good response to various rainfall conditions.

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The Forest and Forestry Basic Law was amended in 2001, and today the revision of forest and forestry policies is ongoing according to the policies presented in the amended law. One of the newly developed policy measures is the forest zoning system for private and public forests, which can play an important part in the forest improvement policy in the future. Kochi Prefecture launched the system with clearer objectives of forest management in each zone and more substantial differentiation of subsidy policies between zones than any other prefectures did. I followed up its process in Kochi Prefecture and examined the problems that the zoning system and the forest improvement policy based on it will have in the future. Firstly, the forest owners' response in the process revealed that many of them are not willing to abandon their timber production on their forests while on the other hand they are also unwilling to or incapable of intensive timber management. One of the objectives of the zoning system is to clarify the goals of forest management in each zone, but the above observation indicates that many forest owners are reluctant to do so. Secondly, the silvicultural methods for transforming single layer plantation forests into multiple layer and mixed forests in the zone of water nursing and land conservation forest have not established yet. In particular, the methods that are generally acceptable by private forest owners need to be developed.

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