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Summary: A Bursaphelenchus species belonging to the hofmanni group (corneolus subgroup) was isolated from a small piece of larval faeces of the longhorn beetle Aeolesthes chrysothrix chrysothrix in its pupal chamber. The chamber was constructed in a dead wood section of Quercus glauca obtained from a live tree. The material was obtained during a management procedure of a garden tree to remove the dead part from live tree. The species is typologically characterised by its three-lined lateral field, the position of its secretory-excretory pore overlapping with the metacorpus anterior half, a very small spicule with distinctive broad and rounded condyles, a flattened trapezoid-shaped rostrum and small flattened cucullus, the presence of seven (P1, P2 and P3 papilliform and P5 gland) male genital papillae, a female vulva with a side flap and female tail forming an elongate conoid with a strongly ventrally curved posterior half and narrowly rounded or digitate tip. The species is typologically close to B. corneolus , sharing a small cucullus and female tail shape, but can be distinguished from the other species by the position of the secretory-excretory pore and the spicule rostrum shape. Phylogenetically, the new species forms a well-supported clade with B. corneolus , but can be distinguished by its clearly separable phylogenetic status inferred from SSU and D2-D3 LSU sequences and the difference in the ITS sequence. The new species is described as B. glaucae n. sp. Although the nematode was isolated from the larval faeces of A. c. chrysothrix , it has not been directly isolated from the insect body to date, thus, the carrier insect of the nematode has not been determined. [ABSTRACT FROM AUTHOR]

We investigated factors affecting the community composition of lignicolous myxomycetes in dead wood with white and brown rot through summer and autumn surveys in a subalpine forest in Central Japan. In both seasons, wood had decayed to a softer state under brown rot than under white rot. The pH of wood with white rot was nearly neutral, while wood with brown rot was weakly acidic. Wood pH was lower in summer than in autumn. Forty-two myxomycetes taxa in 19 genera were identified in 302 fruiting-body colonies; white rot yielded 31 taxa and brown rot 24 taxa. Species diversity was higher on wood with white rot than on wood with brown rot. The effect of wood hardness on species composition depended on season. Several species exhibited a preference for one of the rot types. The substrate conditions associated with brown rot limit myxomycetes species diversity. [ABSTRACT FROM AUTHOR]

This study aims to reveal the diversity of thermal-softening temperatures and identify the factors that determine this temperature. To achieve this, the thermal-softening properties of the radial direction of wood were measured under water-saturated conditions for 15 softwood and 72 hardwood specimens. Wood samples were obtained from the xylarium of the Forestry and Forest Products Research Institute, Japan. A dynamic viscoelastic measurement was performed on samples with uniform heating and cooling history because the difference in cooling rate can alter in the mechanical properties of wood. The storage and loss elastic moduli increased linearly as wood density increased, regardless of the wood species. However, the thermal-softening temperature (defined in this study as the peak temperature of loss tangent) was unrelated to the density, anatomical features, species, latitude, and annual rainfall in the habitat. When the relationship between thermal-softening temperature and lignin structure was investigated, a negative correlation was observed between the thermal-softening temperature and the syringyl ratio (syringyl/(syringyl+guaiacyl)) of lignin aromatics. This indicates that the thermal-softening temperature is higher for wood species with denser lignin structures, supporting the prior research showed correlation between thermal-softening temperature and methoxyl group content of wood. [ABSTRACT FROM AUTHOR]

Changes in tree species composition have important effects on the overall rate of litter decomposition at a community level because litter decomposability varies among species and between leaf and wood litter. To understand how changes in tree species composition affect litter dynamics and carbon sequestration at the ecosystem level, it is important to clarify interspecific variations in leaf and wood litter decomposability, and the traits driving the variation. Using field data, field experiments, and laboratory experiments, we explored rates of leaf and wood litter decomposition and their relationships to traits of ten deciduous hardwood species in a temperate forest in Japan. Rates of leaf and wood litter decomposition at the community level were also estimated by considering species‐specific litter inputs and decomposition rates. Rates of leaf and wood litter decomposition were not correlated under either field or controlled laboratory conditions. This is probably because the traits that affect decomposition rate differ between leaf and wood litter. Interspecific variation in litter decomposability of leaves and wood was generally consistent between field conditions and laboratory experiments using a single fungus, suggesting that the decomposing fungi set the species‐specific decomposition rates. Moreover, the leaf and wood traits that affected decomposition by their specific fungi were different. The aboveground input of wood litter was less than half that of leaf litter, but its half‐life was > 3 times longer, suggesting that wood and leaves make similar contributions to litter accumulation. Focusing on either leaf or wood litter alone may produce misleading estimates of how species composition changes affect litter dynamics at the community level. Our results provide insight into predicting the response of carbon dynamics to future climate change. [ABSTRACT FROM AUTHOR]

Summary: The study aims to provide the morphological and molecular characterisation of two newly discovered Cryptaphelenchus species, namely: C. curvatum n. sp. and C. tumidus n. sp. Morphologically both species are minute nematodes, possess medium-sized stylets with basal knobs laterally directed, and short post-uterine sacs (PUS). Cryptaphelenchus curvatum n. sp. was detected from the local Pinus branch samples and is characterised by having an equal proportion of adult males and females, medium-sized body lengths of females 353 (320-388) μ m and males 277 (256-293) μ m, lateral fields with four lateral lines, 8-10 μ m long stylet, PUS about one vulva body width long and conical posterior body end with a blunt pointed tip. Cryptaphelenchus tumidus n. sp. was detected in a packaging wood sample from Japan and is characterised by having rare male, short body lengths of females 236 (217-270) μ m and males 180 μ m, obscure lateral fields, stylet 6.8 (6.0-7.5) μ m, PUS about half vulva body width long and a slim conical posterior body end with a finely rounded tip. The phylogenetic trees were also constructed based on rRNA gene sequences (D2-D3 segments of the 28S, ITS and 18S) and discussed in detail. Since Cryptaphelenchus species offer multitrophic relationships among their insect vectors and associated microbiota, species recognition and molecular studies of recovered populations will facilitate researchers to determine whether these species might play any ecological roles in insect bionomics or the residing host tree. [ABSTRACT FROM AUTHOR]

The benthic macrofauna of Arctic and subarctic seas is mainly represented by widespread species and is generally devoid of endemics. The exceptions are reduced habitats, such as cold seeps, hydrothermal areas, and wood falls, which include endemics of at least the species level. A detailed study and analysis of such endemics allows us to understand the mechanisms of colonization and to assess the age of the fauna of high-latitude marine regions. Here, the new species Provanna annae sp. nov. is described from the geothermal zone of the Piip volcano in the Bering Sea (subarctic Pacific) based on the morphological and molecular phylogenetic data. The new species appears to be the northernmost and one of the most shallow-water species among the known representatives of the family and is suggested to be endemic to the region. The new species is related to a group of Provanna species from reducing habitats off Japan. Composition of the gut content indicates that the new species bottom sediments. Bacteria are found on the gills of the mollusc and are probably symbionts that also provide nutrition. This type of mixotrophic feeding is rare in gastropods and may be a unique feature among Caenogastropoda. [ABSTRACT FROM AUTHOR]

The current distributions of organisms have been shaped by both current and past geographical barriers. However, it remains unclear how past geographical factors—currently cryptic on the sea floor—affected the current distributions of terrestrial animals. Here, we examined the effects of currently cryptic ancient rivers on current genetic differentiation of the large Japanese wood mouse, Apodemus speciosus, which inhabits islands in the Seto Inland Sea, Japan. Genome-wide polymorphisms were identified by GRAS-Di (Genotyping by Random Amplicon Sequencing, Direct) analysis of 92 A. speciosus individuals. Maximum-likelihood analysis was performed with 94,142 single nucleotide polymorphisms (SNPs) identified by GRAS-Di analyses. Ancient rivers were visualized by Geographic Information System (GIS) channel analysis. Maximum-likelihood analysis showed strong support for the monophyly of each population in the islands in the Seto Inland Sea; it also showed close relationships between Innoshima-Ikuchijima, Ohmishima-Hakatajima-Oshima, Ohmishima-Hakatajima, Ohsakikamijima-Ohsakishimojima, Kamikamagarijima-Shimokamagarijima, and Kurahashijima-Etajima islands. The principal component analyses of the SNPs also supported these relationships. Furthermore, individuals from islands located on the east and west sides of the main stream of the ancient river were clustered on each side with strong support. These phylogenetic relationships were completely congruent with the paleogeographic relationships inferred from ancient rivers. In conclusion, the findings demonstrated that the current distribution of genetically distinct island lineages was shaped by ancient rivers that are currently submerged beneath the Seto Inland Sea, Japan. [ABSTRACT FROM AUTHOR]

Conifers growing at the alpine timberline are exposed to combinatorial stresses that induce embolism in xylem during winter. We collected branches of Abies mariesii Mast. at the timberline on Mt Norikura of central Japan to evaluate the seasonal changes in the loss of xylem hydraulic conductivity (percent loss of hydraulic conductivity; PLC). Concurrently, we evaluated the distribution of embolized tracheids in native samples via cryo-scanning electron microscopic (cryo-SEM) observation in comparison with the drought-induced embolism samples used for the vulnerability curve. The twigs collected in late winter showed 100 PLC at a water potential of ~−3 MPa, and air-filled tracheids were observed sporadically in the cryo-SEM images. The cryo-SEM images also showed that nearly all pits of the samples from the timberline were aspirated in the xylem with 100 PLC. Conversely, in drought-induced samples used for vulnerability analysis, lower frequency of aspirated pits was observed at similar water potentials and all tracheids in the earlywood of xylem with 100 PLC were filled with air. We hypothesized that pit aspiration is the primary cause of the pronounced winter xylem conductivity loss at the timberline when water potential is near, but still above, the drought-induced vulnerability threshold. Pit aspiration before water loss may be an adaptation to severe winter conditions at timberlines to prevent widespread xylem embolism. The possible causes of pit aspiration are discussed in relation to complex stresses under harsh winter conditions at timberlines. [ABSTRACT FROM AUTHOR]

Since 2011, we have collected fungi that form synnema-like structures (SSs) bearing many acanthophyses at the apex on water-splashed wood in streams in various regions of Japan. A provisional phylogenetic analysis of strains isolated from SSs based on their nrDNA sequences implied affinity with Physisporinus (Polyporales, Basidiomycota). However, it has not been reported that this genus forms SSs in freshwater habitats. We found a fungus forming not only SSs on the water-boundary part of wood but also resupinate basidiocarps with poroid hymenophores on nonsubmerged parts, and the morphological characteristics of the basidiocarps matched those of Physisporinus. Therefore, we investigated the relationship between SS-forming fungi and their sexual states by taxonomic approaches. Phylogenetic analyses based on nrDNA internal transcribed spacer (ITS) and large subunit (LSU) sequences indicated that SS-forming fungi diverged into five clades in Physisporinus. Each clade was discriminated by the color of SSs, morphology of acanthophyses, and cultural characteristics. Of the five clades, Clade 1, which consisted only of sequences of strains isolated from SSs and basidiocarps produced on rhizomorphs, was closely related to P. eminens and P. undatus, but the morphology of basidiocarps and the manner of basidiocarp development differed. Clade 5 was closely related to P. castanopsidis, P. crocatus, P. pouzarii, P. sanguinolentus, P. subcrocatus, P. tibeticus, and P. vitreus, but the basidiocarp morphology differed. Therefore, Clades 1 and 5 were described as two new species. Regarding Clades 2, 3, and 4, further taxonomic studies with additional specimens are required. SS and acanthophysis formation in wet habitats in streams and in culture could be recognized as new taxonomic and ecological characters of Physisporinus. [ABSTRACT FROM AUTHOR]

Japanese larch (Larix kaempferi) is an important plantation species in Japan as well as in Europe. The inheritance of wood color (L*, a* and b*), mass loss by a white-rot fungus (Trametes versicolor) and a brown-rot fungus (Fomitopsis palustris), and polyphenol content (as the taxifolin equivalent) in heartwood were examined for 75 trees in 15 full-sib families of L. kaempferi. The mean values of all trees were 74.5 in L*, 8.4 in a*, 23.0 in b*, 18.3 and 26.0% in mass loss by T. versicolor and F. palustris, and 0.045 µmol/mg in polyphenol content. The narrow-sense heritability (h2) showed higher values in heartwood color (h2 = 0.70–0.87), but mass loss and polyphenol content showed relatively lower values (h2 = 0.00–0.33). Significant negative correlations were found between polyphenol content and mass loss by white-rot and brown-rot fungi. In addition, the polyphenol content of heartwood was significantly correlated with the color of heartwood. Similar results were obtained in genetic correlations. Thus, it is concluded that parents with lower L* and higher a* and b* in heartwood could produce progenies with higher polyphenol content in heartwood, thereby leading to higher decay resistance. [ABSTRACT FROM AUTHOR]

Summary: We isolated two tylenchid species belonging to the Sychnotylenchinae, Sychnotylenchus hibisci n. sp. and Neoditylenchus xiphydriae n. sp., from the bark beetle Ernoporus corpulentus and wood wasp Xiphydria ogasawarai , respectively. Sychnotylenchus hibisci n. sp. is characterised by its moderately stout body in both male and female, gubernaculum to spicule length ratio of one-third or less, crustaformeria structure composed of four columns with six large, rounded cells, and a broad female tail with a rounded terminus. The new species is closely related to S. ulmi , with which it shares body shape and gubernaculum to spicule length ratio, but is distinguished by the female tail shape and several morphometric values. Neoditylenchus xiphydriae n. sp. is characterised by its oval to leaf-shaped male bursa, male tail tip reaching the distal end of, and protruding beyond the bursa, a long post-vulval uterine sac (PUS), and a conical female tail with a narrowly rounded terminus. The species is typologically similar to N. pinophilus but is distinguished by its male spicule shape, gubernaculum to spicule length ratio, and longer PUS. Phylogenetically, the Sychnotylenchinae belongs under the Anguinidae (superfamily Sphaerularioidea) and is closely related to several Ditylenchus , Neotylenchus , Neomisticius , and Ficotylus species. [ABSTRACT FROM AUTHOR]

The EFSA Panel on Plant Health performed a pest categorisation of Sirex nitobei (Hymenoptera: Siricidae), the nitobe horntail, for the territory of the EU. S. nitobei is not listed in Annex II of Commission Implementing Regulation (EU) 2019/2072 but was identified as a potential regulated pest in a commodity risk assessment of Pinus thunbergii artificially dwarfed plants from Japan. This species is present in Japan (except Hokkaidō), the Republic of Korea and 13 Chinese provinces. S. nitobei attacks several Pinus species and has been reported less frequently on Abies firma and Larix spp., including L. leptolepis. The females oviposit into the sapwood. Eggs are deposited together with a phytotoxic mucus and a symbiotic fungus, Amylostereum areolatum or A. chailletii. The combined action of the venom and the fungus results in the death of the host trees. The fungus degrades the lignocellulosic components of the wood, and the larvae feed on the liquid fraction of the digested residues left by the fungus. All immature stages live in the hosts sapwood. The lifecycle of the pest lasts 1 year. S. nitobei can travel with conifer wood, wood packaging material or plants for planting, but these pathways from third countries are closed by prohibition. However, a derogation exists for artificially dwarfed Japanese black pine (Pinus thunbergii) from Japan, which therefore provides a potential pathway. Climatic conditions in several EU member states and host plant availability in those areas are conducive for establishment. The introduction of S. nitobei is potentially damaging for pines. Phytosanitary measures are available to reduce the likelihood of entry and further spread, and there is a potential for biological control. S. nitobei satisfies all the criteria that are within the remit of EFSA to assess for it to be regarded as a potential Union quarantine pest. [ABSTRACT FROM AUTHOR]

Summary: Three undescribed Ruehmaphelenchus species were isolated from dead wood of Quercus crispula collected in three different localities in Japan. One of these three species was successfully cultured using Botrytis cinerea as its food fungus and is described and figured as R. fujiensis n. sp. The new species is characterised by the following features: male tail, conical with or without a projection; female tail, conical with variously shaped terminal mucron or projection; and male spicule possessing a relatively long and triangular condylus. The new species is close to, or almost a cryptic species of R. digitulus , i.e. , the typological characters and morphometric values of these two species are mostly overlapping. In a molecular phylogenetic relationship inferred from near-full-length small subunit (18S) and D2-D3 expansion segments of the large subunit (28S) of ribosomal RNA, the new species is close to R. asiaticus , R. digitulus , R. formosanus , and Ruehmaphelenchus sp. NKZ202; however, it was clearly separated from these species. [ABSTRACT FROM AUTHOR]

Wood has a long-standing history as an industrial material and fuel. Generic life cycle assessment data is therefore needed to assess the quantitative environmental impact of wood. The aim of this study was to estimate cradle-to-gate greenhouse gas emissions for round wood production of four common Japanese tree species. This study focused on Japanese cedar ( Cryptomeria japonica ), hinoki cypress ( Chamaecyparis obtusa ), Japanese larch ( Larix kaempferi ) and Sakhalin fir ( Abies sachalinensis ) because these four tree species constitute more than 80% of total round wood production in Japan. This study encompassed all major forestry activities, such as planting, thinning and final felling. In addition to these activities, indirect processes, such as construction of forest roads, were also included. The functional unit used for this study was 1 m 3 over bark of green wood (ob). All 47 prefectures were modeled in order to investigate the site characteristics across Japan. Activity data such as yield per area, required seedling numbers, and thinning method were collected for each tree species and for each prefecture. By combining actual surveyed data and simulation data, information collection challenges on variations in sites and time were overcome. The results of this study suggested that greenhouse gas emissions relating to round wood production of Japanese cedar, hinoki cypress, Japanese larch, and Sakhalin fir were 21.7, 25.9, 24.9 and 25.5 kg-CO 2 e/m 3 ob, respectively. The weighted average value for all of Japan was estimated to be 23.0 kg-CO 2 e/m 3 ob. The amount of temporal carbon storage for these tree species was calculated as 585–762 kg-CO 2 e/m 3 ob. The results also revealed large variation between different prefectures across Japan. Regarding hinoki cypress, for example, the largest greenhouse gas emissions and land use values as an inventory indicator among evaluated prefectures were approximately 1.5 times and 2.7 times larger than the smallest emissions and land use values, respectively. A prefecture with a higher share of heavy forestry machinery tended to indicate relatively higher greenhouse gas emissions. A comprehensive analysis of the target geographical area is therefore required to produce values representative of the region of interest. Among the processes assessed, the final felling process contributed to the largest portion of greenhouse gas emissions in all tree species. An improvement of the energy efficiency of this process is therefore needed. Improving labor productivity would reduce greenhouse gas emissions resulting from commuting workers. [ABSTRACT FROM AUTHOR]

CO2 emissions reduction from coal-fired power plants is an urgent issue in Japan, as well as around the world. The purpose of this study is to estimate the CO2 emissions and economy of using carbonized wood pellets produced overseas and co-fired at coal-fired power plants in Japan. We examined carbonized wood pellets produced in Canada and Vietnam, since those countries are major exporters of wood pellets for Japan. The results obtained are as follows: (1) The CO2 emissions and calculated cost per calorific value of carbonized wood pellets (CP25), which have a fixed carbon content of 25 wt.%, are lower than those of wood pellets at the port of import in Japan. When the fixed carbon of carbonized biomass is controlled at 25 wt.% or more via a carbonizer, sufficient pyrolysis gas (the heat source used for drying and carbonization without auxiliary fuel) can be obtained. (2) Carbonized wood pellets manufactured in Vietnam are more economical than those manufactured in Canada, since the resource of wood is less expensive and the transportation distance is shorter from Vietnam compared to Canada. (3) When carbonized wood pellets at CP25 are co-fired in coal-fired power plants, they do not affect the cost of the electricity generated, even if the carbonized pellets are blended at a high ratio. [ABSTRACT FROM AUTHOR]