The dwarf bamboo species have been considered to repeat flowering and seedling regeneration at long intervals ranging from several decades to 120 years. However, the flowering of dwarf bamboo species varies from large-scale mass flowering of several hundred hectares to small-scale sporadic flowering of a few square meters, depending on the species, region and year. The objectives of this study are 1) to document the flowering phenomena in Sasa borealis communities, 2) to clarify the difference in sound seed rate between mass and sporadic flowerings, and 3) to examine the dormancy and germination of Sasa borealis seeds. In the Ogawa Forest Reserve, we could observe various types of flowering of Sasa borealis at six locations over a 33-year period (1990–2023). These were three small mass flowerings of 0.45 ha or more area in 2017, and three sporadic flowerings of a few square meters in 1991, 2020, and 2023. During small-scale mass flowering, inflorescence of different sizes emerged from buds of culms and rhizomes, but sound seeds occurred only on inflorescence branched off from culms. The sound seed rate was 7.9–10.2% in the one mass flowering patch, but no sound seeds were observed in the low-density patches in mass flowering. On the other hand, sound seed was not found in all of three sporadic flowerings. Mass flowering produced 1176 ± 945 seeds/m² in 2017, and an average of 0.63 seedlings/m² were present in 2018 and 2.46 seedlings/m² in 2020. These results indicate that Sasa borealis can produce seeds even in small-scale mass flowering of about 0.45 ha, and that the seeds are dormant and likely to germinate within two years after fruiting. Future research will focus on the competition and survival between Sasa borealis, tree seedlings and other dwarf bamboos at the site after the simultaneous flowering and death of the former.

The essential oil components derived from wood possess several functional properties and are used in various products in daily life. This study aimed to elucidate the flavor characteristics of a newly developed wood-derived alcoholic beverage using human sensory evaluation. The Check-All-That-Apply method was used to assess the sensory profiles of alcohols produced from five wood species: Japanese cedar, Japanese white birch, Japanese oak, Kuromoji, and Japanese mountain cherry. Consumer panel surveys identified key flavor characteristics associated with each species. Japanese cedar was characterized by a “woody aroma” and “bitterness/pungency.” Japanese white birch exhibited a “grassy or fruity aroma” and “sweetness.” Japanese oak was characterized by a “barrel-aged aroma” and a “heavy taste,” whereas Kuromoji was characterized by a “floral/fruity aroma” and “bitterness/pungency.” The survey results also revealed significant differences in flavor harmony and overall preference across the wood species. Although challenges remain including the optimization of evaluation terminology and the correlation of sensory findings with chemical analysis the study suggests that sensory evaluation is a viable approach for characterizing the distinctive flavors of wood-derived alcohols. Further data collection is required to enhance the appeal and utilization of forest resources.

On April 15, 2025, a Yoshino cherry tree fell in the Second Arboretum of Forestry and Forest Products Research Institute. The fallen tree was one of thirteen planted trees along Norin-Sakura Avenue. Owing to concerns regarding potential failures among the remaining trees, visual and instrument-based decay assessments were conducted on the twelve remaining trees. The cause of the tree fall was also investigated through a detailed examination of the affected specimen. Diagnostic results indicated that six of the twelve remaining trees exhibited notable abnormalities, confirmed via visual inspection and diagnostic instruments. Notably, two trees showed cavity rations of 60% or more, prompting recommendations for immediate risk mitigation, including possible removal. The tree fall was attributed to a combination of root deterioration and strong wind conditions.

Temporal changes in tree mortality and stem growth were studied for Pinus thunbergii and Cinnamomum camphora using nine-year tree census data from a coastal forest. The census was conducted at Ozato-Matsubara coastal forest, Tokushima Prefecture, Shikoku Island, from February 2016 to January 2025, during which storm surge flooding occurred in October 2019. Mortality rates surveyed six months after the flooding were higher for C. camphora than for P. thunbergii. Mortality rates of both species remained elevated two years after the flooding compared to those in non-flood areas. Relative growth rates of stem diameter for both species were lower for two years after the flooding than before and showed a gradual recovery, although still below pre-flooding levels five years after the flooding. These findings suggest that the impact of storm surge flooding persists for at least five years, with C. camphora being more sensitive to saltwater immersion than P. thunbergii.

Species distribution models play a crucial role in understanding shifts in vegetation composition driven by climate change, estimating the probabilities of plant species distributions. However, existing studies have concentrated on large-scale assessments of the distributions and are not well-equipped to analyze temporal changes in distribution probabilities of multiple species at specific sites. This study addresses this gap by estimating the distribution probabilities of 45 major tree species in Japan’s forested areas across four time periods: the Last Glacial Maximum, the Mid-Holocene, the present, and the future. We developed the Species Composition Change Estimation Map system, which calculates the probability of each species at specified latitude and longitude coordinates. Here, we present Species Composition Change Estimation Maps for the summit areas of Japan’s 100 most famous mountains. This system serves as a valuable tool for understanding shifts in species composition in response to climate change and for predicting future vegetation dynamics.