Radiocesium (¹³⁷Cs) migration from the environment to wild tree species that produce edible sprouts was examined following the accident at the Tokyo Electric Power Company’s Fukushima Daiichi Nuclear Power Station in March 2011. Compared to available data on edible herbaceous species, little is known about edible tree sprouts. The ¹³⁷Cs released into the environment following the accident has not yet reached equilibrium in the ecosystem, unlike naturally occurring cesium 133 (¹³³Cs), and its distribution is still changing. The current distribution of ¹³⁷Cs in the ecosystem, including that in plants, is thought to be approaching that of ¹³³Cs. By clarifying the present distribution and metabolic characteristics of ¹³³Cs, the future state of ¹³⁷Cs can be estimated. Therefore, in 2015–2017, the current status of radioactive ¹³³Cs and ¹³⁷Cs in Eleutherococcus sciadophylloides and its environment were examined in six municipalities in Fukushima Prefecture. The average ¹³³Cs concentration in current-year shoots (leaves and branches) was not correlated with ¹³³Cs concentrations in litter (P = 0.425) or soil (P = 0.751) but was negatively correlated with soil K⁺ concentration (R² = 0.2756, P = 0.025) and deposition (R² = 0.3390, P = 0.011). The ¹³⁷Cs current-year shoot concentration/litter deposition ratio (T_ag) was positively correlated with ¹³³Cs T_ag (R² = 0.5748, P < 0.001). Thus, ¹³⁷Cs transfer appeared to accompany ¹³³Cs transfer. Comparing organ-specific concentrations in trees, the current ¹³⁷Cs/¹³³Cs concentration ratios were occasionally smaller in leaves and roots than in other organs, e.g., bark and wood. Concentrations in the former will rise to those of the latter as ¹³⁷Cs approaches equilibrium in the ecosystem. In addition, ¹³⁷Cs concentrations in sprouts may decline in forestland with high soil K⁺ concentrations and increase in forestland with low soil K⁺ concentrations. Further studies of edible wild tree sprouts are required to verify the findings and assumptions of this study.

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Soil scarification is a natural regeneration practice that has been developed as a low-cost birch reforestation technique on Hokkaido, the northernmost main island of Japan. Scarification removes forest floor organic matter and surface soil. Contrary to our expectations, some stands had regenerated along control (non-scarified) lines. To clarify the effects of soil disturbance due to scarification on the locations of regenerated birch trees, we investigated the physicochemical properties of surface soils (depth: 0–5 cm) at 25 scarification-regenerated birch forests treated from the 1970s to the 1990s. In the strip-scarified stands examined in this study, the locations of regenerated birch trees on treatment and control lines were not explained by soil properties. The results of this study show that the various patterns in distribution of regenerated birch trees observed in these stands might be due to combinations of various factors that are not limited to soil properties.

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Seventy-five species of Orthopteroid insects (terrestrial Polyneoptera, including Grillobrattera, Dermaptera, Phasmatodea, Mantodea, Blattodea, Isoptera and Orthoptera) so far collected and one species of Orthoptera whose chirping sound was recorded in the Tama Forest Science Garden, the Forestry and Forest Products Research Institute, Hachioji City, Tokyo Metropolis, were reported. They were predominantly those preferring forest habitats, whereas those preferring grassland habitats were fewer. Four “Data Deficient” species, one “Vulnerable” species, one “Critically Endangered” species and one “Unrecorded” species of the South Tama Region in the Red List of Tokyo Metropolis and three alien species were recorded, and their present status was discussed.

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As part of a growth and yield study, the Forestry and Forest Products Research Institute and Regional Forest Offices have conducted long-term monitoring in more than 180 permanent experimental sites installed in national forests all over Japan. The present article reports the time-series growth data of 76 plots at 39 sites of Cryptomeria japonica, Chamaecyparis obtusa, Larix kaempferi, and Abies sachalinensis planted forests and 3 plots at one site of Pinus densiflora natural forest, for which the most recent measurement was conducted between FY2011 and FY2015. To obtain precise growth data, the trees in each plot were measured in detail: every individual tree was, in principle, identified by a unique number, and its condition (damaged, thinned, or dead) was recorded; the breast height was permanently marked with paint for measurement of the diameter at the same position at every data collection session; and the heights of all individuals were measured using a hypsometer. Moderate qualitative thinning has been performed in most plots. Some sites include plots with different planting densities or thinning intensities, including an unthinned plot. Time-series growth data of these plots were successfully used to construct and verify yield tables, to analyze thinning effects and the long-term growth dynamics of planted forests, and to determine the parameters of several forest growth models, indicating that these experimental sites are useful in terms of valuable data sources. Further well-planned, continuous measurements will enhance the value of the growth data.

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