Basal bending of Japanese cedar (Cryptomeria japonica) due to snow pressure is a type of damage that occurs in the juvenile stage. The purpose of this study is to clarify the effect of the microfibril angle (MFA) in the S₂ layer of the latewood tracheid of annual rings on the basal bending. We selected six highly resistant varieties from candidate trees for snow pressure damage as the resistance group. A total of six varieties were used as the control group: three candidate trees and one plus tree with low resistance, and one local tree and one tree from the natural population with unknown resistance. Increment cores were collected at breast height from these 12 varieties and counted the number of annual rings from the pith as the annual ring number. The MFA of the resistance group was smaller than that of the control group in all annual rings investigated. There were significant differences between the groups in the 3rd and 5th rings. We examined the relationship between the size of basal bending and MFA in each variety, and found a high correlation in the annual rings formed in the juvenile stage. Generally, wood with small MFA exhibits a high modulus of elasticity. Thus, the resistance group had a high modulus of elasticity in the juvenile stage. Therefore, we concluded that small MFA in the juvenile stage can contribute decreasing stem leaning from loading of the crown with snow, so the trees in the resistant group would maintain the small basal bending.

For genetic preservation (ex-situ preservation) at the population level for an endemic conifer in Shikoku, Abies veitchii var. shikokiana, the genetic diversity of both adult trees and seed pools collected from mother trees in two mast years (2011 and 2014) was evaluated using six nuclear microsatellite markers. Differences in the genetic diversity of seed pools among mother trees were examined. Increases in the genetic diversity of seed pools associated with an increased number of mother trees were also estimated by conducting a random resampling of mother trees using a seed genotype from 2014. Allelic diversity of seed pools was higher in families of mother trees with a smaller diameter at breast height in both mast years. The relationship between the number of mother trees sampled and the allelic diversity of seed pools, evaluated by drawing the rarefaction curve, differed among allelic diversity statistics. However, based on the effective number of alleles and the expected heterozygosity, seed pools collected from about 30 mother trees covered almost all of the genetic diversity observed in the adult tree population and whole seed pools combined. Findings of the present study provide important guidelines for the development of seed collection strategies for genetic preservation of rare forest tree populations.

Changings in educational goals and contents of subjects related to “forest civil engineering” at vocational high schools were analyzed using the “Education Ministry Guidelines” (1947-2017) and school textbooks. The subjects named “forest engineering” in 1947 were divided into three in 1970's: “felling and log hauling,” “forest machinery” and “sabo” (erosion control engineering). They were integrated into “forest civil engineering” in 1978. In the 1998 revision, the subjects were placed as two chapters under “forest science”. Until the 1990s, the educational purposes were to learn techniques and knowledge for restoration of devastated land and logging, including forest machinery and civil engineering. However, these were then changed into learning about forest conservation and its multiple utilizations. Educational contents were classified into four fields; 1) “general remarks,” including role and safety, 2) “timber production,” including operating plans, felling and bucking, yarding and log hauling, 3) “forest engineering,” including forest roads and forest machinery, and 4) “sabo,” including water and soil conservation and erosion control. The description in the textbooks has been changed by technology development. The contents of practical forestry works have been changed to forest conservation and utilization. The same trend was reported in “forest management” and “silviculture” in our previous studies. In conclusion, education has been affected by the change in educational goals from cultivation of specialized professional areas to specialized basic areas.

The purpose of this study was to clarify the status and problems of the management and stand structure of the Moso bamboo forests in Kagoshima Prefecture. We conducted an interview survey with 2 bamboo forest managers and investigated the stand structures in their bamboo forests, which are located in Aira City and Satsuma Town. It was revealed that density control, fertilization, and mowing in the bamboo forests are carried out regularly. As the result of this management, the stand structure of bamboo forests was revealed as: average culm density 3,917 / ha, average culm diameter at breast height 12.0 cm, 30.6％ of 1-2 years culm; the culm stand was close to regular distribution. However, due to the sluggish demand for bamboo products and the aging of forest labour, the production of bamboo raw materials, especially bamboo shoots, has decreased significantly compared to 10 years ago, which was also considered to be connected with the increase in the density of bamboo culm in the bamboo forests. We concluded from these results that it is necessary to organize and record the information and methods related to management and production accumulated in the long term of bamboo forest management to ensure the sustainability of production, especially if management passes to a new entity in the future. Developing and introducing forestry machines was also expected to be an effective way to save labor costs in a bamboo forest connected with its relative low culm density and regular culm distribution.

About 10 years have passed since the practical production of container-grown conifer species began in Japan. In order to investigate the whole method of raising plants (seedlings/cuttings) in multi-cavity containers and clarify the current standard cultivation method and problems, we conducted a questionnaire survey on container cultivation methods for Cryptomeria japonica, Chamaecyparis obtusa, and Larix spp., targeting containerized plant producers nationwide. The cultivation method that producers employed was almost the same as the official manuals issued by the related organizations. As a result of analyzing the relationship between the production scale of containerized plants and production style, the introduction of production infrastructure for labor saving and efficient production and the expertise of bare-root plant production or long experiences of containerized plant production seemed to contribute to mass production of containerized plants. A problem with the production of containerized plants was a poor yield ratio due to substandard (e.g. small size, uneven growth, insufficient diameter, poor formation of root ball) plants. These results reveal that it is necessary to establish a method to efficiently produce containerized plants that reach the standard size by the time of shipment and to construct a stable supply and demand system for sustainable production of containerized conifer plants.

A total of 287 thousand m³ local Sugi logs from Miyazaki and Kagoshima Prefectures are exported from Shibushi port to China annually. This study measured the economic ripple effects of log exports by creating a Miyazaki-Kagoshima-other 45 prefecture interregional input-output table. Supposing final demand for log export is 3,566 million yen, which was the annual log export from Shibushi port in 2017, induced production values are 2,936 million yen in Miyazaki Prefecture, 2,507 million yen in Kagoshima Prefecture, and 1,425 million yen in other prefectures. Induced added-values are 1,817 million yen in Miyazaki Prefecture, 1,417 million yen in Kagoshima Prefecture, and 611 million yen in other prefectures. The number of gross induced jobs is 81.4 in Miyazaki Prefecture, and 79.4 in Kagoshima Prefecture. Additionally, business model transfer from Sugi log exports to Sugi product exports would make the gross regional production 2.9 times larger in Miyazaki Prefecture and 2.0 times larger in Kagoshima Prefecture. As a future wood export strategy, we suggest the importance of transforming to Sugi product exports.

We measured subjective well-being related to forests and examined the results as well as the factors influencing these. We conducted a questionnaire survey in 2018 targeting households in the upper Yasu River watershed, Shiga Prefecture, Japan. Using factor analysis, we divided subjective well-being related to forests into four categories: satisfaction, fulfillment, positive affect, and negative affect. We conducted regression analyses using these categories as explained variables and forest-related activities and other variables as explanatory variables. Working in agriculture or forestry has a positive correlation with satisfaction and fulfillment. Forest management activities conducted for respondents' household forests or those done as a volunteer activity have a positive influence on satisfaction and fulfillment, whereas such activities conducted for their community forests have a negative correlation with positive affect. The proportions of forest in residential areas are not related to subjective well-being. Forest ownership lowers all four categories of subjective well-being. This may indicate that the low asset value of forests increases the psychological burden of forest management activities. Currently, forest restoration in Japan has been conducted in terms of quantity; the qualitative improvement of forests now requires deeper involvement from people. Given these conditions, forest-related subjective well-being should be studied in a structured manner, such as by measuring various types of subjective well-being separately, to consider how people should engage with forests and simultaneously improve their subjective well-being.

Forest environment transfer tax at the national level and the accompanying implementations of forest management schemes were introduced in Japan in 2019. Local governments of both prefectures and municipalities receive the tax revenue and need to disclose how the revenue was used annually. There are existing forest tax schemes in 37 prefectures, and prefectural governments are in need to demarcate and elucidate the uses of their prefectural taxes and the national-level tax. In this study, surveys were conducted to detect (1) demarcation of uses of the prefectural taxes and national-level tax in individual prefectures, (2) information exchange meetings of municipalities in individual prefectures and supporting bodies, (3) exchange of staff members and (4) guidelines for new management systems. Although there is a general limitation of comparing prefectures with different contexts and prefectural tax schemes, it was identified for (1), demarcation methods of uses of the prefectural taxes and national-level tax in forest management such as thinning differ among prefectures. There was diversity in patterns for (2) and six prefectures established new permanent bodies for supporting municipalities. For (4), exchanges of staff members between prefectural and municipalities were identified. In Ehime Prefecture, prefectural staff were serving as extension workers of both prefectures and municipalities simultaneously, as a newly introduced system in the prefecture. For (4), guidelines were developed in 17 prefectures. Furthermore, implementation of information exchange meetings correlates with the number of municipalities and ratio of private forest, and exchanging of staff members and developing guidelines correlate with the amount of the allocated forest environment transfer tax.

Mountains are a source of water; thus information about water balance is important for water resources management. However, there is a lack of information, especially for high elevation areas, because it is often difficult to conduct measurement in high elevations. Here we report water balance at Kawamata catchment in the Chichibu Mountains (elevation 628-2,475 m, catchment area 94 km²) that consist of montane and subalpine forest. Because this catchment is relatively large, we need to consider spatial variation in precipitation. We tested the accuracy of 1 km mesh radar-raingauge analyzed precipitation, using measured point precipitation data within and near the Kawamata catchment and found that both monthly and annual precipitation measured by radar-raingauge and tipping bucket rain gauges showed almost 1:1 correspondence. We calculated water balance for years 2009-2018 using catchment mean annual precipitation obtained by 1 km mesh radar-raingauge analyzed precipitation and measured annual discharge. On average, annual precipitation, discharge and loss were 1,747±245 mm y^－1, 1,375±220 mm y^－1 and 372±78 mm y^－1, respectively. This annual loss was considered equal to the annual evapotranspiration at Kawamata catchment. Our data and previous reports suggest that even in forested catchment in the same Kanto Region, annual evapotranspiration in a higher elevation catchment covered with montane and subalpine forest can be a few hundred millimeters smaller than that of forested catchment in a low mountain range and is also comparable to that of cool temperate and subalpine forests in the higher latitudes, such as Hokkaido and the Tohoku region.

We performed an environmental control operation in a 1-ha Tricholoma matsutake test site established in Kyotamba Town, Kyoto Prefecture. We aimed to improve matsutake mushroom generation and spread through vegetation management. The study was conducted in a 25-year-old natural Japanese Red Pine forest and spanned 35 years, from 1963 to 1998. During that time, we investigated the distribution of the fungal colony of T. matsutake, along with the generation and dispersal of its sporocarps. By 1964, 12 fungal colonies were confirmed, and they were concentrated on the ridgeline and its periphery. Subsequently, fungal colonies began to form from the upper part to the middle part of the hillside. The fungal colonies continued to form on the lower part of the hillside, and all nine fungal colonies formed between 1983 and 1988 formed in the mid-to-lower part of the hillside. New fungal colonies often formed below the slope of the existing fungal colonies; therefore, it appears to be effective to carry out the environmental control operation below the slope of the existing fungal colonies to improve T. matsutake generation.

In this study, to select trees with various male-sterile genes from breeding materials in Niigata Prefecture, we observed male strobili or pollen dispersal for 6,240 seedlings obtained from 179 pairs of artificial-crossing between male-sterile trees (Shindai3 (ms1/ms1), Toyama1 (ms1/ms1), Shindai1 (ms2/ms2), Shindai5 (ms3/ms3), and Shindai8 (ms4/ms4))and 137 clones of breeding materials in Niigata Prefecture. The results showed that “Gosenshi-1” was heterozygous for the ms2 allele, “Kamikiri Niigata-15”, “Sado-102” and “Sado-119” were heterozygous for the ms3 allele, and “Kamikiri Niigata-58” was heterozygous for the ms4 allele. In addition, Shindai3 and “Higashikanbara-7” might have an unknown heterozygous male-sterility gene which is different from MS1, MS2, MS3 and MS4, since the segregation rates of male-fertile and male-sterile trees in two families (the self-fertilization of “Higashikanbara-7” and the artificial-crossing between Shindai3 and “Higashikanbara-7”) were followed to 3:1. Trees with ms2 to ms4 selected in this study were valuable. It is expected that these trees will contribute to future study and breeding.

Tree height-diameter allometry is fundamental in estimating growth and biomass, analyzing community structure, and simulating forest dynamics. In this study, we formulated the relationships based on the Chapman-Richards (von Bertalanffy) equation for 75 major species in Japan from data on about 26,000 individuals. Results for each species are shown in the main text, and sources of data and scatter plots of tree height and diameter are shown in the electronic material. We hope that this report will be widely used for forest management and research.