To clarify the water retention characteristics of forest soils in the Kyushu-Okinawa region, we applied the van Genuchten model to 513 pore distribution analyses from the appendix of Hotta's 1997 Ph. D thesis, extracting four water retention property values (m, ψ₀, gravitational water content, readily available water content). We then compared these values among eight soil types. The results indicated that the Reddish/Yellowish Brown and Red and Yellow soil types exhibited low gravitational and readily available water contents, while the Black soil type showed high readily available water content but low gravitational water content and a dispersed pore size distribution. The Immature soil type consisting of coastal dune sand, had a smaller peak pore size and a more concentrated pore size distribution. Comparing the Dry and Moist Brown forest soil types revealed that the latter had a higher readily available water content and a more dispersed pore size distribution. To enhance the accuracy of models predicting the effects of climate change on catchment runoff, tree growth using forest soil water retention data, ongoing collection and development of such data across various regions, parent materials, and soil types are essential.

In October 2023, a road-killed raccoon was collected near the Forestry and Forest Products Research Institute in Tsukuba, Ibaraki Prefecture, Japan, and external parasites were collected from its entire body surface. Haemaphysalis flava, H. longicornis, Ctenocephalides felis, and species of Trichodectids were collected. Two species of tick are known as vectors of Japanese spotted fever and severe fever with thrombocytopenia syndrome, while the cat flea harbors Bartonella henserae. These results indicate that the urban wildlife such as raccoons, carries multiple ectoparasites that can bite humans, and transmit vector-borne pathogens. It is recommended that workers in wildlife management should take precautions against zoonoses.

We report that Rymosia placida Winnertz, 1863 (Diptera: Myceotphilidae) infests fruit bodies of Ascomycota, Trichoderma cornudamae (Hypocreales: Hypocreaceae). A Japanese name of this fungus gnat species was proposed after its species epithet. This is the first report of animal infestation on Trichoderma cornudamae which is one of the toxic fungi in Japan and of host fungi of R. placida. This fungus gnat was recorded from Honshu in addition to Hokkaido. Trichoderma cornudamae broadly occurs in Japanese forests infected by Japanese oak wilt. We expect that the host-parasite association between T. corunudamae and R. placida is generally observed in Hokkaido and Honshu.

Bamboo species, known for their longevity and monocarpic life cycles, require extensive long-term experiments to gain a comprehensive understanding of their biology. In Japan, since the 1930s, one cultivation experiment has specifically targeted moso bamboo (Phyllostachys edulis, also known as Ph. pubescens). This study presents a comprehensive compilation of nearly a century's worth of cultivation records and ecological data derived from literature reviews, interviews, and field investigations. Conducted across 11 different sites, field trials revealed that the first generation of seedlings flowered simultaneously approximately 67 years after germination. The second generation is currently maintained in nine locations, and some with significantly shortened flowering timings have also been observed. The study also addresses key future challenges such as lineage preservation, updating and sharing information, and re-considering research questions.

To clarify the spread of pine wilt disease to unaffected area of the Tohoku region of northern Japan, researchers of six Tohoku prefectures (Fukushima, Miyagi, Yamagata, Akita, Iwate and Aomori) surveyed the distributions of dead Pinus thunbergii and P. densiflora trees killed by the pinewood nematode, Bursaphelenchus xylophilus and the vector beetle, Monochamus alternatus. Following on from the previous report from 2007 to 2011, the distributions of pine wilt disease and the vector beetle was surveyed from 2012 to 2022 by the researchers from each prefecture. These data were combined to yield the annual figures for the Tohoku region. During these 11 years, the distribution area newly infected with pine wilt disease has expanded to 11 districts and the insect’s distribution was also found in nine new districts.

This study examined which broadleaf tree species could be retained trees and whether retention of about 10 trees per hectare would be feasible, if the retention forestry were applied to Cryptomeria japonica (cedar) or Chamaecyparis obtusa (cypress) plantations in Shikoku, Japan. The selection criterion was to retain large, healthy hardwood trees at 10 trees per hectare. Selections were made at two post-harvest plantations. We also gathered feedback from forestry operators on their impressions and experiences of retention forestry. At one site, s saplings, damaged individuals and coppice regeneration individuals were also selected. in some forests, selecting only broadleaf trees that have grown to a certain size may make it difficult to achieve even low retention densities. Forestry operators were positive about retention forestry, but the difficulty of communicating the details of operations between work teams was noted.

In this study, we investigated fire frequency in grassland sites dominated by Imperata cylindrica along the Balikpapan–Samarinda Road in East Kalimantan, Indonesia from July 1991 to October 1998 (7.3 years). Imperata cylindrica continued to dominate grasslands under average fire intervals of 1.2 and 1.9 years. Fires were more likely to occur during periods of low precipitation. Repeated fires removed plants taller than I. cylindrica, maintaining its dominance through an increase in sunlight exposure. However, using the history function of Google Earth, we found that almost all I. cylindrica grasslands in our study plots were lost by 2024. Between 1998 and 2024, the number of pepper plantations decreased, and land conversion to oil palm plantations and coal mining areas progressed in regions between Samarinda and Balikpapan, including the study area. These conversions fragmented the grasslands and prevented fires. Small tree species, Acacia mangium, and pyrophytic tree species that coexist with I. cylindrica growing in the fragmented grasslands may have suppressed I. cylindrica.

The Tohkamachi Experimental Station of the Forestry and Forest Products Research Institute has been conducting meteorological observations since 1918 and snow profile observations since the winter of 1939–40. This report aims to provide fundamental data on snow phenomena observed at the Tohkamachi Experimental Station. The report summarizes the results of meteorological and snow profile observations during five winter periods from 2019–20 to 2023–24. The meteorological observations include weather, air temperature, daily precipitation, snow depth, daily snowfall depth, and snow water equivalent, measured daily at 09:00. Snow profile observations were conducted approximately every ten days to measure the snow layer structure and the vertical distribution of physical characteristics such as grain shape, grain size, snow temperature, snow density, snow hardness, and water content.