We surveyed a stand of patchwork-like mixed planting 30 years after its planting, and discussed whether this method is useful for the creation of mixed forests. In each patch 25 trees of the same species were planted in 5 rows by 5 columns. There were 3 plots with planting densities of 5,000, 10,000, and 40,000/ha. The sizes of patches were 7.0 by 7.0 m square, 5.0 by 5.0 m, and 2.5 by 2.5 m, respectively. Nine species of hardwoods were planted. Average heights of Betula platyphylla var. japonica were the highest, followed by B. maximowicziana, Prunus sargentii, Kalopanax pictus, Cercidiphyllum japonicum, Quercus crispula, Tilia japonica, Maackia amurensis var. buergeri, and Phellodendron amurense. All patches of birches, K. pictus, and C. japonicum survived, but some patches of P. sargentii, M. amurensis var. buergeri, Q. crispula, and T. japonica, in either the 10,000 or 40,000/ha plot, and all patches of P. amurense in all plots disappeared. Crown canopies above patches of birches consisted of those of trees planted in the plots. Crowns of birches intruded into patches of other species with slower initial growth. Although patchwork-like mixed planting is effective for creation of mixed forests, some improvement is necessary to allow all patches to survive; either making patches bigger than 49 m² or creating strips of un-planted areas between patches needs to be tested.

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A decrease in student numbers has led to a reorganization of forest-related courses in senior high schools, sometimes leading to integration or abolition. To secure entrants and to correspond to various prospective courses of students, educational reform that includes review of educational objectives and curricula is now being pursued in senior high schools. In this study, the value of teaching forest-related subjects was examined from the viewpoint of systematically understanding regional revitalization and school reform. Based on the findings, a direction for school revitalization was proposed. Analysis of school reform in Tottori Prefectural Chizu Agriculture and Forestry Senior High School and of regional revitalization of Chizu-cho in Tottori Prefecture indicated that cooperation had been built between the school and the region with respect to regional revitalization. The relationship between the school and the region had apparently deepened due to personnel developments such as internship and social education. Thus, forest-related courses in senior high schools can be revitalized under the following conditions: the education is practiced based on a partnership with various local bodies; and school reform is pursued with a positive participation in regional revitalization.

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We analyzed data of about 30-year-old Japanese larch (Larix kaempferi) grown in four provenance test sites in Nagano Prefecture that were produced at 25 provenances in 9 natural distribution areas (1 to 6 provenances per area) and conducted analysis of variance and principal component analysis to verify the classification of larch provenances and their regions. In all test sites, there were significant differences among provenances in tree height, diameter at breast height, branch thickness, branch length, and spontaneous fall of branches, but the differences in stem crookedness and branch angle were significant only in some test sites. The percentages of variance among provenances to total variance in tree height and diameter, which are major characteristics, were 25 to 60% and 39 to 61%, respectively, suggesting that it is important to select an appropriate provenance for increasing stem volume. Interactions between provenance and test site were observed in many characteristics, but the effect of the provenance was prominent as there was one provenance that resulted in good growth in several test sites. In the principal component analysis, which was conducted for each test site by using two or more characteristics as factors, three provenances in Nikko were similar to each other, three provenances near Mt. Fuji were similar, and two provenances in the Japanese northern Alps were similar. The six provenances in Yatsugatake were relatively similar, and so were the three provenances in Kiso. Rengedake provenance was found to be isolated from the rest of the provenances in the Japanese northern Alps. The two provenances in the Japanese southern Alps were not similar in the principal component analysis. The provenances in Mt. Asama were divided into two groups, showing that the lower Mizunoto forms a new group with Kusatsu Manza.

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This study improves one of the stand growth prediction systems: Local Yield table Construction System (LYCS), in order to satisfy the demands of its end users including local government, forestry institutes and staff in forestry cooperatives. The parameters of LYCS were determined to predict stand growth of planted forests throughout Japan. It was imported into a Microsoft Excel macro program designed to improve the usefulness and applicability of LYCS to more tree species and local regions compared to the original system. Modeling various thinning methods including self-thinning, line-thinning and thinning from above enabled to predict stand growth after practice of various thinning methods reflecting the present situation. Also linking LYCS with the wood conversion algorithm, which incorporates timber price and stand condition, enabled to estimate the income derived from harvesting. Estimates by LYCS were compared to observed values under several conditions, and results of the comparisons confirm that the improved LYCS can predict timber harvests under various thinning strategies.

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Fatal root rot caused by Armillaria tabescens is common on cherry trees planted in parks and on streets in Japan. Inoculation experiments using Japanese isolates of A. tabescens and A. gallica were conducted on 3-year-old cherry seedlings. Four years after inoculation, one of four seedlings inoculated with A. tabescens was dead, and all seedlings had mycelial fans of A. tabescens beneath the bark. No rhizomorphs were observed on tree root systems or inocula. All seedlings inoculated with A. gallica were still alive at the end of the experiment, despite having many rhizomorphs on the root systems and inocula. Mycelial fans of A. gallica were found in the periderm of some fine root of one inoculated seedling. Each isolate was reisolated from the inoculated seedling. Neither mycelial fan nor rhizomorphs were formed in all non-inoculated seedlings and they did not die. These results clearly show that A. tabescens is pathogenic to cherry seedlings.

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NdhF gene and trnL-F region chloroplast DNA sequences of Toxicodendron succedaneum (L.) Kuntze derived from local cultivars and candidates for superior trees in Japan, and wild individuals from the Asian Continent and Okinawa Island were compared. Nine single-nucleotide polymorphisms were observed in the overall aligned sequences (2,403 bp), and 10 chloroplast haplotypes were detected. One haplotype (designated A) was observed only in the local cultivars and the candidates for superior trees, while two (B and C) were detected only in individuals from Japan, including Okinawa. Haplotype A differed from some haplotypes in the Asian Continent by only a single nucleotide, while B and C differed more. The findings suggest that the local cultivars and the candidates for superior trees in Japan comprise several lineages derived from the Asian Continent or the south-western islands of Japan.

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