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41.
Tatsuhiko Yamada Masako Aratani Satoshi Kubo Hirokuni Ono 《Journal of Wood Science》2007,53(6):487-493
Degradation and decomposition of cellulose were studied in an acid-catalyzed solvolysis treatment of biomass using polyethylene
glycol (PEG) and ethylene carbonate (EC). The solvolysis reaction was followed by a typical reaction system of wood liquefaction
that uses sulfuric acid catalyst at 140° or 150°C at atmospheric pressure. The methods of fractionation and chemical analysis
of the degraded cellulose in the solvolyzed product are discussed. The solvolyzed product was separated into several fractions,
and they were hydrolyzed to release glucose and levulinic acid to determine the quantity of glucosides and levulinates in
the solvolysis product. The data clearly showed that the solvolysis reaction had the same mechanism when using PEG or EC.
Degradation of cellulose leads to the formation of glucosides, which then decompose, resulting in a levulinic acid structure,
and producing a water-insoluble fraction. The conversion rates of both glucosides and levulinates strongly depend on the reaction
conditions of the solvolysis. In particular, EC promotes faster conversion of the reactions. The method discussed here is
a chemical analytical technique for characterization of the products of wood liquefaction. 相似文献
42.
Takashi Masaki Shigeta Mori Takuya Kajimoto Gaku Hitsuma Satoshi Sawata Masuo Mori Katsuhiro Osumi Shobu Sakurai Takeshi Seki 《Journal of Forest Research》2006,11(4):217-225
The individual growth of tree diameter at breast height (dbh) is analyzed in an even-aged plantation of Cryptomeria japonica from stand age of 45 to 94 years, to examine how the growth of individual trees has been affected by the changes in spacing
resulting from thinning operations. At any age, a significant proportion (0.37–0.46) of the variation in dbh growth during
a 5–11-year period was explained by dbh at the beginning of the period, probably due to greater leaf mass of larger trees.
Next, either one-sided or two-sided competition was added to the model, by calculating the basal area (BA) of neighboring
trees around each tree within a given radius or BA for trees having larger dbh than the focal tree within the radius. After
preliminary analyses, a radius of 8 m was selected as the critical range for tree competition. Although both types of competition
explained a significant proportion (0.09–0.43) of growth variation, one-sided competition was not significant at ages greater
than 54 years. Based on the model at 45 years of age, the initial deviation of growth rate for each tree from the predicted
rate was calculated and added to the models as a third variable. This raised the coefficient of determination up to 0.50–0.74.
These findings have practical significance for forest plantation management, particularly for controlling the growth of standing
trees via thinning, to produce high-quality timber in the future. 相似文献
43.
Toru Kohama Nobuya Mizoue Satoshi Ito Akio Inoue Kotaro Sakuta Hiroyuki Okada 《Journal of Forest Research》2006,11(4):235-242
We examined the extent to which direct and indirect measures of light and microsite conditions could explain variation in
tree height and diameter at the base of 6-year-old Cryptomeria japonica trees planted in a group selection opening of about 0.32 ha on a steep slope at Shiiba, Miyazaki Prefecture, southern Japan.
We first used the gap light index (GLI) and soil thickness (ST) as directly measured indices. For an indirect measure of light, we used a between-cohort competition index (BCI) estimated from the position and total height of residual trees. For indirect measures of microsite, we examined topographic
indices (slope, plan and profile curvature, average slope gradient, and relative elevation) derived from digital elevation
models (DEMs) with different resolutions ranging from 2 to 10 m. The multiple linear regression using GLI and ST explained about 45% of variation in tree size, while simple regression using only GLI explained about 35%. The contribution of ST was about half of GLI. The multiple regressions using BCI and the topographic indices did not explain any more variation than using BCI alone (R
2 of about 0.26). We conclude that microsite conditions with shallower soil and steeper slope have negative effects on tree
growth in group selection openings, although the relative importance is smaller than light conditions. More comprehensive
studies considering several openings with more heterogeneous topography including different species are needed to generalize
our growth prediction using the indirect measures, which are useful for practical forest management. 相似文献
44.
Keisuke Kikuchi Rie Yamashita Satoshi Sakuragawa Keigo Hasumi Yasuhiro Mukai Hiroya Kobayakawa Shojiro Wakabayashi Yukie Saito 《Journal of Wood Science》2018,64(5):642-649
Bamboo-derived activated carbon prepared by superheated steam (BAC) exhibited performance for utilization as an electric double layer capacitor (EDLC) electrode. Pore structure and EDLC performances were investigated by comparison with phenol resin-derived activated carbon (MSP-20), which is commercially available and often used for the purpose. The nitrogen adsorption isotherm showed that BAC had a large BET-specific surface area of 1268 g/m2 with a developed pore structure, especially of the mesopore, in comparison with MSP-20. It is considered that inherent ash in bamboo promoted activation, in addition to physical activation by superheated steam. Capacitance per electrode volume (CV) was 52 F/cm3 with BAC. Because the density of BAC is high (0.78 g/cm3) compared with that of MSP-20 (0.58 g/cm3), sufficient CV for usage was obtained, although the capacitance per electrode mass (CM) at 5 mA/cm2 itself of BAC (67 F/g) was lower than that of MSP-20 (126 F/g). With IR drop, the resistance value of BAC (9.7 Ω) was lower than that of MSP-20 (10.5 Ω). Especially, the diffusion resistance of BAC disclosed to be smaller than that of MSP-20. These results indicated that BAC produced by steam activation is a promising material with a pore structure suitable for ion transfer in EDLC. 相似文献
45.
46.
Satoshi Yamashita Tsutomu Hattori Shin Abe Hideaki Goto Hiroki Sato 《Journal of Forest Research》2014,19(1):143-153
Improvement cutting, which decreases tree density by cutting and thinning while leaving logging residues, has been practiced on Okinawa Island since the 1970s and changes not only the vegetation composition but also the amount and composition of woody debris on the forest floor. To quantitatively compare the effect of improvement cutting with the effects of woody debris and vegetation on the community structure of aphyllophoraceous fungi, we conducted a field survey of vegetation composition, the amount and composition of woody debris, and the aphyllophoraceous fungi flora on Okinawa Island in December 2006. We established 3 plots in forest stands without logging and 13 plots in a forest that had undergone improvement cutting from 1 to 22 years before our field survey. The number and volume of woody debris tended to be highest soon after improvement cutting. We recorded 1,172 fungal samples belonging to 81 species in four orders. Fungal species richness was correlated with the composition of the woody debris. Fungal species composition in forest plots 1 year after improvement cutting differed from most of the other logged forests. Variation partitioning revealed that the effects of improvement cutting explained 14.1 % of the total variation in fungal species composition, and that differences in woody debris and vegetation not related to improvement cutting explained 40.4 %. Changes in the composition of woody debris caused by improvement cutting explained at most 2.7 % of the variation. This suggests that improvement cutting does not have a strong effect on fungal community structure, but woody debris does. 相似文献
47.
Thinning alters crown dynamics and biomass increment within aboveground tissues in young stands of Chamaecyparis obtusa 总被引:1,自引:0,他引:1
Qingmin Han Daisuke Kabeya Satoshi Saito Masatake G. Araki Tatsuro Kawasaki Chiharu Migita Yukihiro Chiba 《Journal of Forest Research》2014,19(1):184-193
The stand density of a forest affects the vertical distribution of foliage. Understanding the dynamics of this response is important for the study of crown structure and function, carbon-budget estimation, and forest management. We investigated the effect of tree density on the vertical distribution of foliage, branch, and stem growth, and ratio of biomass increment in aboveground tissues; by monitoring all first-order branches of five trees each from thinned and unthinned control stands of 10-year-old Chamaecyparis obtusa for four consecutive years. In the control stand, the foliage crown shifted upward with height growth but the foliage quantity of the whole crown did not increase. In addition, the vertical distribution of leaf mass shifted from lower-crown skewed to upper-crown skewed. In the thinned stand in contrast, the foliage quantity of individual crowns increased two-fold within 4 years, while the vertical distribution of leaf mass remained lower-crown skewed. The two stands had similar production rates, numbers of first-order branches per unit of tree height, and total lengths of first-order branches. However, the mortality rate of first-order branches and self-pruning within a first-order branch were significantly higher in the control stand than in the thinned stand, which resulted in a higher ratio of biomass increment in branch. Thinning induced a higher ratio of biomass increment in foliage and lower in branch. The increased foliage quantity and variation in ratio of biomass increment after thinning stimulated stem growth of residual trees. These results provide information that will be useful when considering thinning regimes and stand management. 相似文献
48.
Zhengjun Xia Hiroko Sato Satoshi Watanabe Shiji Kawasaki Kyuya Harada 《Euphytica》2005,141(1-2):129-137
We have constructed a soybean (Glycine max (L.) Merrill) bacterial artificial chromosome (BAC) library from green leaf protoplasts of the cultivar, Misuzudaizu. The library contains 53,760 clones with an average insert size of 116 kb. About 2.9% chloroplast DNA origin was revealed by PCR and colony hybridization. Apart from 2.8% clones having no insert, this library represents 5.2 genome equivalents. With this genome coverage, the probability of having any DNA sequence represented in the library is higher than 99.5%. Three-dimensional pools of the BAC library in combination with the use of a high efficiency genome scanning (HEGS) electrophoresis facilitate rapid and efficient PCR-based screening. An average of five positive clones were identified after screening the BAC library with SSR and STS markers. BAC-end walking was performed for three SSR associated BACs. This library will provide a good resource for positional cloning of agronomically and biologically important QTL genes that Misuzudaizu possesses. 相似文献
49.
Kenji Asano Etsuo Shimosaka Yoko Yamashita Takashi Narabu Satoshi Aiba Itaru Sakata Kotaro Akai Satoshi Okamoto Seiji Tamiya 《Breeding Science》2021,71(3):354
Occurrence of pale potato cyst nematode, Globodera pallida (Stone) Behrens, was first recorded in Japan in 2015. Among several control measures, cultivation of resistant potato (Solanum tuberosum L.) varieties is the most effective in cost and environmental impact. As no G. pallida-resistant varieties have yet been developed in Japan, great emphasis is being placed on screening of germplasm possessing the resistance and development of the resistant varieties. In this study, we first improved previously reported DNA markers linked to the G. pallida resistance loci (GpaIVsadg and Gpa5) and then used these to screen more than 1,000 germplasms to select several candidate germplasms with resistance. We performed inoculation testing on the selected candidates and identified several resistant germplasms to the Japanese G. pallida population. Furthermore, we developed a simultaneous detection method combining three DNA markers linked to G. pallida and Globodera rostochiensis (Wollenweber) Behrens resistance loci. We validated the ability of C237-I marker to select resistant allele of GpaIVsadg and predict the presence of resistance in a Japanese breeding population. Resistant germplasms identified in this study could potentially be used to develop G. pallida-resistant varieties. The marker evaluation methods developed in this study will contribute to the efficient development of resistant varieties. 相似文献
50.