Fagus crenata Blume is a dominant species in late-successional, cool-temperate forests of Japan. F. crenata has two ecotypes in Japan, one in the Japan Sea region and the other in the Pacific Ocean region. The trees at Nakoso in the Pacific Ocean region suffer higher evaporative demand during the growing season than do those at Appi in the Japan Sea region. This study aimed to determine how leaf morphology and leaf physiology are coordinated to cope with air drought conditions. We investigated intra-crown leaf plasticity for adult trees growing in both regions. The specific hypothesis was that the sun leaves of F. crenata at Nakoso would have a lower osmotic potential and a larger vascular structure within their leaves than those at Appi and, as a result, would have a relatively higher leaf mass per area (LMA) and lower carbon assimilation capacity. Relative to trees at Appi, the sun leaves at Nakoso had a thicker lamina, a larger bundle sheath within the lamina, and a smaller compartment area circumscribed by a bundle sheath extension. Even though LMA in the sun leaves at Nakoso was 1.74 times larger than that at Appi, the area-based photosynthetic rates did not differ between sites. Leaf morphological acclimation to high evaporative conditions at Nakoso included reduced mass-based nitrogen (N) content and the N/C ratio within the lamina as well as reduced mass- and nitrogen-based assimilation rates. Our study indicates that drought tolerance at the leaf level leads to variations in leaf water relations and in leaf morphology. This suggests a trade-off or coordination between leaf water relations and leaf morphology or leaf gas exchange for drought tolerance.

A transcriptome analysis was conducted to identify and characterize the differentially expressed genes (DEGs) in Cryptomeria japonica, a coniferous species endemic to Japan, after short-term treatments with different concentrations of CO₂. The de novo assembly of the obtained RNA reads resulted in 35,211 tentative transcripts. The expression levels of 113 and 30 genes were increased in response to elevated (800 ppm) and lowered (200 ppm) CO₂ concentrations, respectively. The deduced functions of these genes indicated that different molecular pathways were activated in response to the two different CO₂ treatments. The expression levels of the gene transcripts involved in the photosynthesis and photorespiration pathways were not affected by the CO₂ concentration, except for a homolog of a chloroplast RNA polymerase subunit that is involved in the transcription of chloroplast coding genes. Together with the enrichment of genes acting in chloroplasts among detected DEGs, adjusting the transcription of genes related to chloroplast functions may be one of the earliest responses to change CO₂ at the transcriptional level.

To determine the unit work efficiency required to fabricate and install the bamboo strips as cross-drainage ditches, the time required was calculated, and the fabrication and installation cost was determined. Based on the number of working hours spent on the fabrication process, that were obtained via video recording, the efficiency for unit work of the bamboo strips was estimated to be 0.032–0.049 man/unit, and the efficiency for unit work of the cross-drainage ditch including the installation stage was calculated to be 0.067–0.084 man/unit. The cost of the cross-drainage ditches including the installation stage was estimated to be 1,886–2,398 yen/unit, and that of the materials and fuel oil was estimated to be 1,137–1,649 yen/unit.

To construct a simple method for the genotyping MALE STERILITY 1 (MS1), a major causative gene of male sterility in Japanese cedar (Cryptomeria japonica), this study attempted to reduce the labor required for the postPCR procedure using a single-stranded tag hybridization chromatographic printed array strip (STH-PAS), which allows for visual confirmation of PCR products. PCR was performed using tagged DNA- or biotin-modified primers to develop amplification products on stick membranes with complementary tags. After ~15 min the detection line was colored and the MS1 genotype was determined. The diagnostic results were consistent with the electrophoresis results. STH-PAS can significantly reduce the time and labor required for MS1 determination.

Strength tests for components of deer-proof fences were conducted for pole bending, anchor pile pulling-out, and lower-end rope lifting. Although all of 7 pole products were marketed as anti-animal fence poles, the mean pole-bending strength for each product ranged from 66 N to 396 N. Two types of longer anchor piles exhibited the greatest resistances for all horizontal, diagonal, and vertical directions of pull-out tests, and anchor piles showed higher pull-out resistance in the developed clay soil than in the forest soil. The resistances of anchor pile pulling-out for diagonal direction were larger than those for vertical direction, thus we proposed improving deer-proof fences by connecting the lower-end rope and anchor pile tops so that the anchor piles receive a diagonal pulling force, increasing their resistance over receiving a vertical pulling force.

The stand growth of an old-growth forest in Teshikaga, eastern Hokkaido (northern Japan), was monitored over 69 years. There was little change in stand volume throughout the period; growth and stand mortality were almost balanced. However, the number of broad-leaved trees increased and the diameter-at-breast height class distribution changed to an inverted J shape. These results suggest that, in old-growth forest stands, the species composition and stand type change despite long-term stability in terms of the overall stand volume.