【タイトル】 Under the Paris Agreement of the United Nations Framework Convention on Climate Change, Japan aims to achieve carbon neutrality (net zero emissions) by 2050. This research aims to identify the challenges in the policy rationale and logic of the Japanese government's forest carbon sinks programs to achieve this goal, and to propose corrective measures. Using logic models, we organized the causal and interrelated relationships among the measures in the Plan for Global Warming Countermeasures (both the Cabinet-approved version and the version announced by the Ministry of Agriculture, Forestry and Fisheries) and the Basic Plan for Forests and Forestry. In the Plan for Global Warming Countermeasures, the forest removals target (approximately 31.2 million t-CO₂) and the carbon storage effect target from Harvested Wood Products (HWP) (approximately 6.8 million t-CO₂) for FY2030 are set as proximal outcomes, and the progress of some measures is tracked in policy evaluations. The Basic Plan for Forests and Forestry incorporates a multi-layered logic for achieving its targets; while the relationships between specific measures are clear, the relationships between the logic for achieving proximal outcomes and the "ideal state of forests" are less clear. Additionally, we analyzed the top 10% of the 158 plans for national and private forests, which are subordinate to the Basic Plan for Forests and Forestry. A high number of the targets for logging, thinning, and reforestation over the past five years in these plans remained unmet. We reviewed the evaluations of these performances and found that, in many cases, the reasons for non-achievement were unclear. The causes are thought to be unrealistic target-setting without considering changing circumstances, and a lack of personnel and expertise in the municipalities. Finally, we presented measures to address these issues.

Pseudomonas tolaasii causes blown blotch and rotting in Pleurotus ostreatus. Previously, the Ps. tolaasii mutant MUR31 was generated by a single transposon (mini-Tn5km1) insertion into the regulatory gene rtpA+ of the wildtype PT814. MUR31 exhibits pleiotropic deficiency in pathogenicity-related traits, such as tolaasin production, the main cause of brown blotch. Transformation of MUR31 by recombinant rtpA+ DNA resulted in the wild-type trait restoration. However, in this study, we report that MUR31 carrying the rtpA+ DNA exhibits the same over-elongated cells on Pl. ostreatus as MUR31 carrying the vector plasmid. To the best of our knowledge, this is the first report of over-elongated cells of a Ps. tolaasii mutant defective in tolaasin production and associated with mushrooms that do not revert to wild-type morphology by the wild-type allele of the mutated gene. Whether epigenetics or other changes in the genome structure is responsible for the phenomenon needs to be clarified.

The pollen of Cryptomeria japonica (sugi), an economically important conifer species, was treated with various organic solvents—acetone, ethanol, chloroform, and hexane—to evaluate their effectiveness in pollen handling and preservation. When pollen was soaked in acetone or ethanol for 24 h at 4°C, its germination rate was significantly lower than that of the control (p < 0.01). In contrast, treatment with hexane did not significantly affect pollen germination (p > 0.05). Further storage of sugi pollen in hexane at 4°C decreased germination rate from 67.0% to 37.8% within one week, maintaining 36.2% viability after one month. Furthermore, hexane enabled the collection of viable pollen from male flowers harvested in December and February, before flowering. These findings suggest that the use of hexane offers a novel approach for the collection and temporary preservation of coniferous sugi pollen.

Focusing on microtopography units, we examined the physicochemical properties of soils within a small watershed (Kahoku Experimental Watershed No. 2) in the northern part of Kumamoto Prefecture. This watershed is part of the Forestry and Forest Products Research Institute Flux Observation Network. Regarding general physical properties, our results revealed that bulk density was high, while total porosity was low, particularly in the B horizons. Saturated hydraulic conductivity was greater at the mid-slope than at the ridge. Effective porosity, which contributes to the soil’s water storage capacity, was generally low, with small porosity being especially low. In terms of chemical properties, our findings indicated that the soil had low pH and exchangeable cation concentrations, classifying it as acidic and oligotrophic. Additionally, both carbon and nitrogen concentrations were considerably lower than the national average, suggesting that the soil was more weathered than in other areas of Kyushu.

We assembled a database of plant bite marks (bite marks on stem and leaf, and bark stripping) assessed with the “DNA kit for distinguishing sika deer and Japanese serow”, which were collected in North Tohoku District (Akita, Aomori and Iwate) for 8 years. Of the 3,572 stem and leaf samples collected throughout the year, 17.1 % were positive for deer and 18.0 % for serow. Of the 67 bark stripping samples collected from January to June, 61.2% were from deer, whereas serow was rarely detected. Deer can be detected with a high probability in winter by targeting the bite marks of dwarf bamboo and bark stripping of deciduous trees. Conversely, herbaceous plants, such as Elatostema involucratum and Achyranthes bidentate, were considered unsuitable for sampling because they were not detected with the DNA kit.