Two strains ("Tohoku S 10" and "Mori 121") of Shiitake mushroom (Lentinula edodes), an entomogenous fungus (Beauveria bassiana), and a mycophagous fungus (Trichoderma sp.) were inoculated on the stems of Quercus crispula trees killed by Platypus quercivorus in order to clarify the effects of these fungi preventing the emergence of P. quercivorus. Untreated killed trees and killed trees which had only been drilled without inoculation of fungi were also prepared as controls. The relative lower number of P. quercivorus emerged from the trees inoculated "TogokuS 10" and Trichoderma sp. suggested that these fungi prevented the emergence. The result also suggested the difference between strains of Shiitake mushroom on the effect preventing the emergence. The relative lower number of the emergence was also observed on the trees drilled without inoculation of fungi. This might be caused by the evaporation from the drilled holes on the trees reducing the reproduction of P. quercivorus that need high water content. The similar numbers of the emerged P. quercivorus between the trees inoculated B. bassiana and the untreated trees might be caused that the fungi did not reach the galleries of P. quercivorus. We also counted the numbers of insects other than P. quercivorus. There were no species that emerged in lower number from the trees inoculated the fungi. In addition, some fruit bodies were harvested from the trees inoculated "Tohoku S 10", suggesting that the inoculation of "Tohoku S 10" can be an effective use of the killed trees.

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An application of logistic regression model to estimate a suitable logging operation system among classified patterns, such as traditional/high-performance forestry machines and wheel logging/cable yarding, was studied to improve the estimation precision. Noda et al. developed a final cutting cost estimation model based on site conditions, involving a suitable logging operation system estimation model of binary table type. Data set, the classified logging operation system patterns, and other conditions were matched to compare estimation performances of the logistic regression type model and the binary table type model. As the results, the logistic regression type model estimated correctly 90.9% in traditional forestry machines group, and 75.0% in high-performance forestry machines group. As for the high-performance machines group, the correct estimation rate of the logistic regression type model was not different from ones of the binary table type model (Chi-square test, p=0.429). However, as for the traditional machines group, the rate of the logistic regression type model was significantly better than ones of the binary table type model (p<0.05). It was concluded that the logistic regression model is more available than the binary table type for the suitable logging operation system estimation.

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[in Japanese]

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[in Japanese]

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Recently, the Japanese government has been promoting the replacement of conifer plantations with mixed forests and broad-leaved forests in Japan. In order to introduce broad-leaved trees into conifer plantations, it is necessary to understand the seed dispersal methods of broad-leaved tree species. In temperate forests, it is known that endozoochory by birds is important for the seed dispersal of broad-leaved tree species. The brown-eared bulbul, the Japanese white-eye and thrushes are major dispersal agents of berry species in temperate forests, while woodpeckers, flycatchers and Parus spp. also play important roles in the seed dispersal of dry fruit species. The density of these frugivorous birds increases in the season when the fruits of most tree species ripen, not only in natural forests but also in conifer plantations. Most endozoochrous species make seed banks which undergo an extended diapause in the forest soil. The soil seed banks in conifer plantations contain many pioneer tree species that are absent in the floor vegetation. A number of seedlings, including many pioneer species, emerge in clear-cut areas. It appears that dominance of the seedlings established after clear-cutting depends on the germination of buried seeds. Because few frugivorous birds inhabit clear-cut areas, the soil seed banks which were dispersed by frugivorous birds before clear-cuttings contribute to the recovery of vegetation after clear-cutting.

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