We elucidated cesium 137 (¹³⁷Cs) transfer from riparian forest to a headwater stream ecosystem through input of leaves contaminated by radionuclides due to the Fukushima Daiichi Nuclear Power Plant (NPP) Accident. In riparian zone of Kawamata-machi, Fukushima, living leaves of konara (Quercus serrata) were collected from crowns in 2013 and senescent leaves of that were collected from forest floor in November 2012 and 2013, respectively. In March 2013 and 2014, we collected senescent ones, which include konara leaves, deposited in a headwater stream running off the riparian zone. The comparison of ¹³⁷Cs concentration showed that living leaves of konara contained higher ¹³⁷Cs than fresh senescent ones. The ¹³⁷Cs concentrations of fresh senescent leaves in the forest floor were larger than those of senescent ones deposited in the headwater stream. Therefore, we consider that ¹³⁷Cs in the leaves was released to headwater stream while they were deposited in there. There was little change in ¹³⁷Cs concentration of senescent leaves on forest floor and in the stream between 2 and 3 years after the FDNPP Accident, suggesting that ¹³⁷Cs transfer from leaves to headwater stream ecosystems continues for a prolonged period.

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To prevent the spread of oak wilt, the population and dispersal of Platypus quercivorus must be reduced. Because this insect is an engraver of living Japanese oaks, freshly cut logs were used to collect the insects from 2010 to 2013 in 26 sites, and 47 examples were accumulated. These logs were then piled in the sides of the forest road and timber yards in the damaged areas or in the forests of Cryptomeria japonica around the damaged oak forests. Huge piles of logs do not dry for a long period and the favorable sites for their mating can be maintained. It is also known that kairomones that attract these insects are present in large quantities in the cross-section of these logs. We succeeded in inducing more than 10,000 insects / 1 m³ to the piled logs by attaching synthetic pheromones on them. With this method, insects could be collected from middle to heavily damaged areas. If logs are crushed before the emergence of new adults, this trapping method is effective not only for disinfestation but also for reutilizing the logs. The tips of the oaks can be used for fuel and in paper manufacture. Furthermore, we suggest the use of this method for forest regeneration, making stands younger by cutting old oaks. Thus, logging can be valuable for protecting from oak wilt, providing useful materials, and regenerating oak forests.

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The purpose of this study is to discuss the structure of effective forest environmental education by taking into account the personal developmental stage, and to analyze participants, educational aims, and implementation content in anecdotal reports (162 cases) of forest environmental education programs researched by the Forestry Agency of Japan related to the personal developmental stage. The participants, aims, implementation content, and challenges for forest environmental education are analyzed by means of a text mining approach. As a result, the intended participants of forest environmental education are mainly children, and the educational aims are related to knowledge, understanding, and awareness on forests and forestry. Implementation content is often based on the experience type such as nature and tree observation (73 cases), woodworking (71 cases), thinning (42 cases), tree planting (33 cases), and so on. Forest environment education may have been regarded as an experience for children to gain knowledge and understanding. In order to realize the final goal of actual“participation"by increasing the implementation amongst adolescents, there is a need for implementation of the objectives and content tailored to the personal developmental stage, because participants, implementation aims, and implementation content tend to be biased toward child participants.

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With the improvement of rural environment and national living standards, farmhouse touring which is a representative of green tourism in China has become popular in recent years. In order to make clear the reality and problems of farmhouse touring in China, this study investigated the managers and relevant departments of farmhouse touring in TongLu, ZheJiang Province. We found that the rate of success has increased in modern times in cases of farmhouse touring when tourist attractions have been developed in cooperation with districts and villages. The development of farmhouse touring in rural areas being far away from the city and offering no nearby attractions is difficult. Farmhouse touring as a solution method of agriculture, countryside and farmers issues is still currently a major challenge.

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To assist in decision-making related to the construction, maintenance, and management wooden check dams, interviews were conducted in all Japanese prefectures to obtain data regarding the construction of such structures in recent years, and to determine their current statuses. We found that in 2013, 1,166 wooden check dams were scheduled for construction across the nation, and that construction records had been set in 42 prefectures. As for construction materials, we found that Japanese cedar was, on the whole, the most popular main building material, accounting for approximately 60% of all such dams, while larch was used in about 20% of the total. It was also determined that the usage rate of antiseptic paint to prevent wood decay was less than 20% until 2009, but began increasing from 2010 and reached about 70% in 2013. Examinations of 358 wooden check dams, including 58 privately owned dams located in a national forest, were conducted, and area-based maintenance management plans were created. These plans included information on antiseptic paint application over an elapsed 10-year period, and were proposed for use as part of a prospective maintenance management index.

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An investigation was carried out into the extent of decay of up to nine-year-old wooden check dams at several sites in the Nagano region by determining their density (ρ) and moisture content using an increment borer. The results indicated that at Nakajo and Tokikubo, the dams contained many components for which ρ had decreased to below the fiber saturation point. Accordingly, it was likely that decay had occurred recently, when the moisture content had decreased. For both the dam body and wings, ρ was found to decrease linearly with increasing age, whereas standard deviation (σ) gradually increased with age. It was calculated that 20.0 and 25.5 years were required for ρ to reach zero for the dam wings and body, respectively. This difference of approximately five years arose on the dam wings and the dam bodies, and the difference in the years by a part appeared in them. Moreover, it was found that the relationship between σ and age tend varied depending on the installation environment and the structural condition of the dam. In addition, ρ was found to fluctuate markedly depending on the location of the dam.

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