Ophiostomatoid fungi associated with bark beetles onAbies veitchii in wave-regenerated forests     

Nobuaki Ohtaka  Hayato Masuya  Shigeru Kaneko  Yuichi Yamaoka  Masashi Ohsawa 《Journal of Forest Research》2002,7(3):145-151

Relationships between tree mortality and bark beetle infestation onAbies veitchii at the wave-regenerated forest in Mt. Asahi, Okuchichibu area were investigated. Most of the firs with green needles and newly developed current year’s shoots in the dieback zone were heavily infested by bark beetles before the death of the trees. After heavy infestation of beetles, about half of the infested firs died within the year, and the other half died in the next year. When the species composition of bark beetles and associated ophiostomatoid fungi were investigated in Mt. Asahi and also at a typical wave-regenerated forest in Mt. Shimagare, Yatsugatake area,Cryphalus montanus andC. piceae were dominant beetle species for Mt. Asahi and Mt. Shimagare, respectively.Ophiostoma subalpinum andO. europhioides were dominant fungal species at both wave-generated forests. BecauseO. subalpinum was detected more frequently from deeper areas of sapwood thanO. europhioides, it was suggested that the fungal species may accelerate the death of stressed firs in wave-regenerated forests. Contribution No. 169, Laboratory of Plant Parasitic Mycology, Institute of Agriculture and Forestry, University of Tsukuba.  相似文献   

Nickel-catalyzed carbonization of wood for coproduction of functional carbon and fluid fuels I: production of crystallized mesoporous carbon     

Tsutomu Suzuki  Kyoko Suzuki  Yukio Takahashi  Mitsuhiro Okimoto  Tetsuo Yamada  Noriyasu Okazaki  Yuichi Shimizu  Masashi Fujiwara 《Journal of Wood Science》2007,53(1):54-60

Japanese larch wood loaded with nickel (1%–4%) alone or with nickel and calcium (0.25%–1.5%) was carbonized at 800°–900°C for 0–120min with a heating rate of 5°–20°C min⁻¹ in a helium flow of 5.8−46.4 ml STP cm⁻² min⁻¹ to examine the influence of these variables on the crystallization of carbon (the formation of T component) and the development of mesoporosity. From the obtained results, reaction conditions suitable for effective production of carbon with the dual functions of adequate electroconductivity and adsorption capacity in liquid phase were established, thereby explaining the factors that govern the process. It was also confirmed that mesopore having a diameter of about 4 nm was selectively produced at the cost of specific (BET) surface area in parallel with the formation of T component. This result provided good insight into how the simultaneous dual function could be realized.  相似文献   

Differences in spectral trajectory with stand volume development between Japanese larch and Japanese oak in Hokkaido,Japan     

Tsuyoshi Kajisa  Takuhiko Murakami  Nobuya Mizoue  Shigejiro Yoshida 《Journal of Forest Research》2007,12(6):435-441

Our objective was to investigate the differences in the spectral trajectory of the LANDSAT Thematic Mapper with stand volume development between Japanese larch (Larix kaempferi) and Japanese oak (Quercus mongolica var. crispula) in the experimental forest of Kyushu University, Hokkaido, Japan. We used nonlinear regression and a categorical variable to investigate the relationship between spectral reflectance factor and stand volume for each forest type. This research showed that the reflectance factor of Japanese larch and Japanese oak reached saturation and that both forest types had different spectral trajectories with stand development. In addition, we found that middle of development stage (stand volume was between 100 and 200 m³/ha) of each forest type had similarity in reflectance factor.  相似文献   

Effects of chronic acid fog exposure with soil acidification or nitrogen loading on nutrient status in Abies firma seedlings     

Koji Yoshida  Shoko Inaba  Chisato Takenaka  Takafumi Tezuka 《Journal of Forest Research》2005,10(2):157-161

To clarify the nutrient status in momi fir (Abies firma Sieb. et Zucc.) seedlings under complex stress conditions of acid fog with soil acidification or nitrogen loading, we exposed seedling shoots to simulated acid fog (pH 3) and simultaneously loaded the soil with acid or excess nitrogen for 17 months. Proton and nitrogen loading reduced K concentration in soil, but these treatments had little effect on the nutrient status of fine roots in momi fir seedlings. Acid fog exposure resulted in reduced concentrations of Mg, Al, and Fe in current-year needles and Mg, Al, Cu, Fe, and Zn in 1-year-old needles. The complex effects of acid fog exposure with proton or nitrogen loading on nutrient status were relatively slight. However, elements such as Al and Cu notably reflect the effects of proton loading. These results show that the nutrient status of trace elements, rather than major elements, in needles of momi fir seedlings is sensitive to exposure to acid fog or proton loading.  相似文献   

Structure of xylan from culms of bamboo grass (Sasa senanensis Rehd.)     

Shigeki Yoshida  Atsushi Kuno  Naoto Saito  Masakazu Aoyama  Isao Kusakabe 《Journal of Wood Science》1998,44(6):457-462

Xylan prepared from culms of kumaizasa (Sasa senanensis Rehd.), a representative species of bamboo grass, was hydrolyzed with-xylanase ofStreptomyces olivaceoviridis E-86. Four arabinoxylo-oligosaccharides and two glucuronoxylo-oligosaccharides were isolated from the enzymatic hydrolysate of the xylan by chromatography on a charcoal column, a Dowex 1-x8 column, a Toyo-pearl HW-40S column, and a LiChrospher 100 NH₂ column and on preparative paper chromatography. The results of the structural analyses of the saccharides showed that the isolated oligosaccharides had the structures of 3²--l-arabinofuranosyl-xylobiose, 3²--l-arabinofuranosyl-xylotriose, 3²--[-d-xylopyranosyl-(1 2)-l-arabinofuranosyl]-xylobiose, 3³--[-d-xylopyranosyl-(1 2)-l-arabinofuranosyl]-xylotriose, 2³--4-O-methyl-d-glucuronosyl-xylotriose, and 2³--d-glucuronosyl-xylotriose. From the structural analysis of the oligosaccharides derived from the xylan, kumaizasa xylan was concluded to be a kind of arabinoglucuronoxylan having not only stubs of singlel-arabinose and singled-glucuronic acid but also stubs of disaccharide units such as-d-xylopyranosyl-(1 2)-l-arabinofuranose.  相似文献   

Continuum contraction of tension wood fiber induced by repetitive hygrothermal treatment     

Sujan  KC  Yamamoto  Hiroyuki  Matsuo  Miyuki  Yoshida  Masato  Naito  Kazuhiro  Shirai  Tatsuya 《Wood Science and Technology》2015,49(6):1157-1169

Wood Science and Technology - Tension wood, when kiln-dried, is likely to deform hugely, which is probably caused by a gelatinous layer of the gelatinous fiber. To elucidate the mechanism behind...  相似文献   

Predictive modes of action of pesticides in uterine adenocarcinoma development in rats     

Midori Yoshida  Kaoru Inoue  Miwa Takahashi 《Journal of toxicologic pathology》2015,28(4):207-216

Endometrial adenocarcinoma in the uterine corpus is a malignant cancer that occurs in menopausal women and aged rodents. Because of the similarities in pathogenesis and morphology of endometrial adenocarcinoma in rodents and humans, prediction of the modes of action (MOA) in uterine carcinogenesis is important for extrapolation of rodent data to humans. Three MOAs have been accepted as major pathways for uterine carcinogenesis in rodents: 1) estrogenic activity, 2) increased serum 17beta-estradiiol (E2) to progesterone (P4) ratio and 3) modulation of estrogen metabolism to produce 4-hydroxyestradiol via P450 induction. Inhibition of estrogen excretion and increased aromatase in situ in the tumor are also a potential pathway. Here, chemicals showing uterine carcinogenicity were chosen from approximately 300 pesticides evaluated in Japan within the past decade, and their mechanisms were predicted using parameters from mechanistic and toxicity studies. Seven pesticides increased uterine tumor formation in rats, and the pathways of 4 pesticides could be predicted based on various mechanistic studies. The MOAs of cyenopyrafen and benthiavalicarb-isopropyl were predicted to be modulation of estrogen metabolism, while those of pyriminobac-methyl and spirodiclofen were predicted to be increased E2 to P4 ratio. The driven pathways of metazosulfuron and isopyrazam could not be predicted using several mechanistic studies. No mechanistic studies have been reported for sedaxane, which has a chemical structure and toxicological profile similar to isopyrazam. Our results indicated that appropriate mechanistic studies are useful for mechanism prediction in risk assessment. From this analysis, a flowchart showing a decision tree for predictive MOAs in uterine carcinogenesis was proposed.  相似文献   

Estimating aboveground carbon using airborne LiDAR in Cambodian tropical seasonal forests for REDD+ implementation     

Tetsuji Ota  Tsuyoshi Kajisa  Nobuya Mizoue  Shigejiro Yoshida  Gen Takao  Yasumasa Hirata  Naoyuki Furuya  Takio Sano  Raul Ponce-Hernandez  Oumer S. Ahmed  Heng Sokh  Vuthy Ma  Eriko Ito  Jumpei Toriyama  Yukako Monda  Hideki Saito  Yoshiyuki Kiyono  Sophal Chann  Nang Ket 《Journal of Forest Research》2015,20(6):484-492

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Comparing 30-year diameter censuses and tree-ring chronologies in natural old-growth Cryptomeria japonica forest on Yakushima Island,Japan     

Shizu Itaka  Shigejiro Yoshida  Nobuya Mizoue  Tetsuji Ota  Atsushi Takashima  Tsuyoshi Kajisa 《Journal of Forest Research》2015,20(2):255-262

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Reducing radioactive cesium transfer from sawdust media to Pleurotus ostreatus fruiting bodies     

Masakazu Hiraide  Masahide Sunagawa  Hitoshi Neda  Nur Humaira’ Lau bt. Abdullah  Satoshi Yoshida 《Journal of Wood Science》2015,61(4):420-430

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