田邊 純

Wood properties (annual ring width, tracheid length, microfibril angle [MFA], basic density, and air-dry density) and mechanical properties (modulus of elasticity [MOE], modulus of rupture [MOR], bending work, and compressive strength) in 34-year-old Chamaecyparis obtusa trees of six half-sib families were measured from pith to bark to clarify radial variations in inheritance of these traits and the relationships between wood properties and mechanical properties. In addition, within-tree and among-family differences in the load-deflection curves were discussed. Radial variations of all wood properties were fitted to linear or nonlinear mixed-effects models with random effects of families. The MFA was correlated with MOE in all radial positions, whereas air-dry density correlated with all mechanical properties in mature wood. Radial variations in broad-sense heritability differed between wood properties. A relatively higher broad-sense heritability was recognized in almost all wood properties for mature wood. Based on the results, it was concluded that mechanical properties in mature wood can be effectively improved using MFA and air-dry density as criteria. In addition, the types of load-deflection curve in mature wood differed from those in juvenile wood, suggesting that not only elastic properties, but also plastic properties in C. obtusa are affected by genetic controls, especially in mature wood.

Amounts of wood chemical components (organic solvent extracts, Klason lignin, and holocellulose) and kraft pulp characteristics (yield and kappa number) were directly determined for 32 trees from eight half-sib Eucalyptus camaldulensis Dehnh. families in second generation of elite trees selected in Thailand. The mean values of all trees were 1.4 % for organic solvent extracts, 21.3 % for Klason lignin, 86.1 % for holocellulose, 44.4 % for kraft pulp yield, and 7.2 for kappa number, respectively. While repeatability values of growth traits and basic density were moderate to high (0.18 to 0.51), those in wood chemical components and kraft pulp characteristics showed quite low values (less than 0.10). No correlation coefficients were found between measured traits, except between stem diameter and tree height. Thus, it is concluded that selection of E. camaldulensis families with superior growth traits is suitable for production of raw material of pulp and paper in respect to quantity and quality of wood.

To clarify sawn-timber quality and those among-family variations of hinoki cypress (Chamaecyparis obtusa), modulus of elasticity (MOE) and modulus of rupture (MOR) were evaluated for 97 pieces of 38 by 89 mm sawn timber produced from half-sib families planted in a progeny test stand at Chiba, Japan. Correlations were evaluated on mechanical properties in standing trees and logs with MOE and MOR in the sawn timber. Elastic properties, such as dynamic Young’s modulus of logs and MOE, were affected by genetic factors compared with air-dry density and MOR. The 5% tolerance limits at a 75% confidence level (f 0.05) of MOE and MOR were 8.03 GPa and 39.4 MPa, respectively. The f 0.05 values of MOR exceeded the characteristic value of the sawn timber in visual grading class SS of Japanese Agricultural Standard for the JS-I. Visual grading of the sawn timber was effective for eliminating timber with lower MOE. Stress-wave velocity and dynamic Young’s modulus of log and timber were significantly correlated with MOE of sawn timber. Correlation coefficients were also significant between MOR of sawn timber and dynamic Young’s modulus or MOE.

type:紀要論文 / Departmental Bulletin Paper

<title>Abstract</title> Pine wilt disease is one of the most serious tree diseases occurring worldwide. Clones of <italic>Pinus densiflora</italic> Siebold et Zucc with pine wood nematode resistance were selected. In addition to resistance, wood quality is also an important criterion in the breeding program of <italic>P. densiflora</italic> because of its use as construction lumber. However, little information is available on the wood qualities of the progenies of resistant clones. The repeatabilities of the wood properties were investigated for 11 open-pollinated families of <italic>P. densiflora</italic> selected for their pine wood nematode resistance. Oven-dry density, latewood tracheid length, the microfibril angle (MFA) of the S2 layer in latewood tracheids, modulus of elasticity (MOE), and modulus of rupture (MOR) were measured in the third or fourth annual ring from the pith. No significant correlations were found between the wood properties and the stem diameter or tree height. However, significant correlations were found between oven-dry density and MOE or MOR, which suggests that oven-dry density is a good indicator for selecting wood with higher bending properties. Among the measured wood properties, oven-dry density had the highest repeatability (<italic>R</italic>=0.47), followed by MOR (<italic>R</italic>=0.33), tracheid length (<italic>R</italic>=0.21), and MFA (<italic>R</italic>=0.14). MOE had the lowest value (<italic>R</italic>=0.01). The 11 families examined were classified into three groups according to their growth characteristics, wood properties, and resistance to pine wilt disease. On the basis of the results, we conclude that genetic improvement of wood properties especially for wood density and MOR is possible for the resistant <italic>P. densiflora</italic>.

Community forests in Indonesia are important suppliers of wood resources for the wood industry. In the present study, stress-wave velocity of stems, log characteristics (taper, green density, and dynamic Young's modulus), and wood properties (basic density, compressive strength parallel to grain, modulus of elasticity [MOE], and modulus of rupture [MOE] were investigated for three fast-growing tree species grown in community forests in Indonesia: Acacia mangium Willd., Maesopsis eminii Engl., and Melia azedarach L. Based on the bending properties, the MOE values of laminae (30 x 150 mm in cross-section) and glulam (six layers, 90 x 150 mm in cross-section) were simulated. The mean values of simulated MOE in the laminae were 8.93, 6.82. and 8.63 GPa for A. mangium, M. en:ink and M. azedarach. respectively. When the laminae from a species were randomly laminated, the simulated MOE values of glulam were 8.94, 6.82, and 8.66 GPa for A. mangium, M. eminii, and M. azedarach, respectively. When laminae with a high, medium, and low MOE were laminated at outer, middle, and inner layers of glulam, respectively, the simulated MOE values of glulam increased by about 5 % to 15 % compared to the values of a randomly laminated one. It is concluded that glulam with a high MOE can be produced from fast-growing tree species grown in community forests in Indonesia.

© 2019, The Author(s). β-Thujaplicin (hinokitiol) is an important extractive of Thujopsis dolabrata var. hondae (hinokiasunaro) that confers high durability to its wood. We investigated differences in β-thujaplicin content in wood from plantation- and naturally grown trees of T. dolabrata var. hondae, and also examined growth rate and wood density. A total of 29 trees were collected from two natural forests and a plantation forest in the Shimokita Peninsula, Aomori, Japan. β-Thujaplicin content was determined for each heartwood sample by gas chromatography. The content ranged from 0.29 to 3.67 mg/g (oven-dry weight basis). β-thujaplicin content of plantation-grown trees was significantly higher than for naturally grown trees, though with a large variation. The effect of radial growth rate on β-thujaplicin content was minimal. We conclude that T. dolabrata var. hondae wood from both plantation and natural forest has similar durability. The coefficient of variation of β-thujaplicin content in each stand was higher than for other wood properties. This degree of tree-to-tree variation in the trait suggests that promising production with more durable wood could be achieved by selecting T. dolabrata var. hondae trees containing a high content of β-thujaplicin for plantations.

<p>To clarify the effects of thinning on the growth and wood quality of Eucalyptus camaldulensis trees grown in Thailand, the growth characteristics, anatomical characteristics, and wood properties of T5 clones, which are used on plantations to produce pulpwood, were investigated. Core samples were collected from trees grown on both thinned and unthinned (i.e., control) plots. The effects of thinning on the trees' anatomical characteristics and wood properties were evaluated at bark side (2cm from the bark) of the tree. We identified significant differences between the two plots in terms of stem diameter, wood volume, wall thickness of wood fiber, moisture content, and basic density. However, trends in the radial variation of the measured characteristics were almost the same between the thinned and control plots. These results suggest that prolonged rotation age and subsequent thinning do not negatively affect the quality of solid wood produced by E. camaldulensis.</p>

Genetic improvements in the mechanical properties of wood are important in forestry species used for lumber, such as Picea. The within-tree radial and among-family variations for the modulus of elasticity (MOE), modulus of rupture (MOR), and their related traits [i.e., microfibril angle (MFA) of the S2 layer in latewood tracheid and air-dry density (AD)] were evaluated in nine open-pollinated families of Picea glehnii (F. Schmidt) Mast. The radial variation in MOR was mainly affected by AD, whereas MOE was affected by MFA and AD. Higher F-values obtained by analysis of variance and coefficient of variation were observed for all properties at the 6th–15th annual ring, except for AD at the 6th–10th annual ring. This result suggests that the contribution of genetic effect is larger in these highly variable regions. In addition, positive correlation coefficients were obtained between wood properties at the 6th–15th annual ring and mean values of these properties. Therefore, genetic improvements for MOE, MOR, and their related traits in P. glehnii is likely to be more effective in juvenile wood, specifically at the 6th–15th annual ring from the pith.

Solid wood properties were examined in eight half-sib families of 4-year-old Eucalyptus camaldulensis trees selected for pulpwood production in Thailand. The effects of radial growth rate on solid wood properties were also discussed. The mean values of green moisture content (MC) and basic density (BD) at 1.2 m heights in each family ranged from 86.3 to 106.6% and from 0.49 to 0.57 g cm−3, respectively. Significant among-family differences were found in MC, BD and maximum height of interlocked grain (IG). However, no significant correlations were found between stem diameter and solid wood properties, with the exception of MC and BD at a 5.2 m height, and IG. Based on the results obtained, it is suggested that superior E. camaldulensis trees, with respect to both growth characteristics and solid wood properties, can be selected for pulpwood production.

With emphasis on tree breeding for wood quality in Picea jezoensis, we aimed to evaluate radial and between-family variations in the microfibril angle (MFA) of the S-2 layer in the latewood tracheids in 10 open-pollinated families of 43-year-old P. jezoensis trees. In addition, the relationships between MFA/wood density with the modulus of elasticity (MOE) or modulus of rupture (MOR) were investigated. Significant differences in MFA between families were found from the pith toward the bark. MFA showed higher values around the pith area, although some families showed relatively lower values than others around this area. In addition, due to a larger coefficient of variations of MFA near the pith, the potential for juvenile wood MFA improvement may be greater compared with mature wood. MOE was correlated with MFA in juvenile wood and with wood density in mature wood, whereas MOR was mainly correlated with wood density at radial positions in both woods. Therefore, to improve the MOE and MOR of P. jezoensis wood, both MFA and wood density would be factors to consider in both juvenile and mature woods. On the other hand, there are indications that, only wood density would be an important criterion for improving mature wood properties.

The aim of this study was to evaluate the effects of radial growth on wood properties and anatomical characteristics and to clarify the xylem maturation process in Gmelina arborea. Stem diameter, tree height, and stress-wave velocity were investigated for 54 5-year-old G. arborea trees planted in Indonesia. In addition, radial variations of wood properties (basic density and compressive strength parallel to the grain in green condition) and anatomical characteristics (fiber and vessel morphologies) were investigated for nine trees selected from three different radial growth categories (fast, medium, and slow growing). Stem diameter was positively significantly correlated with stress-wave velocity and compressive strength parallel to the grain in green condition. In addition, compressive strength and anatomical characteristics, except for wood fiber diameter, differed significantly among the radial growth categories. Radial variations of the wood properties and anatomical characteristics gradually increased, and then they showed constant values toward the bark. It is thought that the xylem maturation of G. arborea begins at approximately 5 cm from the pith. In addition, in a fast-growing tree species, such as G. arborea, the trees with faster stem diameter do not always form wood with low strength properties.

Zelkova serrata (Thunb.) Makino ("keyaki'' in Japanese) is an important broad-leaved species for the wood industry in Japan. To analyze the among-family variation of anatomical characteristics in Z. serrata, wood fiber length (WFL), vessel element length in earlywood (VEL), fiber wall thickness (FWT), and vessel diameter in earlywood (VD) were investigated for 20-year-old trees from eight half-sib families. Mean values of WFL, VEL, FWT, and VD ranged from 1.31 to 1.51 mm, 0.19 to 0.22 mm, 1.2 to 2.1 mu m, and 131 to 188 mu m, respectively. Relatively higher F values were obtained by analysis of variance for WFL and VEL, suggesting that these characteristics might be improved though the selection of mother trees under tree breeding programs. In addition, growth characteristics were not significantly correlated with anatomical characteristics, except for FWT.

The extracellular lignocellulolytic enzymes secreted by Porodaedalea pini were investigated for their ability to degrade the wood of Picea jezoensis over various time periods. In addition, changes in wood chemical component contents were also investigated. Enzyme production and wood degradation by P. pini significantly increased starting at 60 days of incubation. The total lignin, holocellulose, and a cellulose contents, as well as pH, decreased during the degradation process, while hot water, 1% NaOH, and ethanol-toluene extract contents significantly increased. These results indicate that P. pini simultaneously degraded the lignin and polysaccharides of P. jezoensis wood. Additionally, P. pini continuously produced xylanase, fi-glucosidase, and endoglucanase with higher activities than those of exoglucanase and cellobiose dehydrogenase. Manganese(II)-dependent peroxidase showed the highest ligninolytic activity, followed by lignin peroxidase and laccase. These results indicate that P. pini produces a variety of lignocellulolytic enzymes, and that the produced enzymes contribute to the degradation of P. jezoensis wood components. (C) 2016 Elsevier Ltd. All rights reserved.

Five 40-year-old Pinus taeda trees growing in Tochigi, Japan, were used to evaluate juvenile wood (JW) and mature wood (MW) properties and the bending properties of lumber. The boundary between JW and MW existed from the 14th to the 19th ring from pith in the sample trees. There were obvious differences in wood properties between the JW and MW: the MW had higher values in the latewood percentage and basic density and lower values in the microfibril angle. The microfibril angle and the air-dry density were closely related to the bending properties of the SW lumber and the MW lumber, respectively.

Picea glehnii is one of the most important plantation species in Hokkaido, Japan. Basic density (BD) and microfibril angle (MFA) of the S2 layer in latewood tracheid in 16 full-sib families and their six parental clones planted in Hokkaido were examined to clarify among-family and clonal variations of wood properties and their inheritance from parents to offspring. Mean values of BD and MFA in full-sib families and parental clones were 0.36 and 0.35 g cm(-3) and 16.1 degrees and 10.7 degrees, respectively. Estimated repeatabilities of BD and MFA in juvenile wood (jW) were higher than those in mature wood. In addition, larger genetic coefficient of variation was detected for jW, indicating that improvement of jW properties is important to Hokkaido's tree breeding program. Parent-offspring correlation coefficients were positive and significant in all properties. These results suggest that the influence of parental clones on wood properties is inheritable to offspring. Moreover, there were no significant differences between reciprocal crosses of wood properties, suggesting that plus-tree clones with good wood properties can be used as either female or male parents for producing offspring. There is a possibility of improving wood properties in P. glehnii by crossing clones with desirable properties.

Growth characteristics and wood properties were investigated for 26-year-old Eucalyptus alba trees grown in Ambon, Indonesia. The mean stem diameter and tree height were 27.9 cm and 19.5 m, respectively. In addition, the mean stress-wave velocity (SWV) of trees and basic density (BD) of outer wood (2 cm from the bark) were 3.23 km s&lt sup&gt -1&lt /sup&gt 0.67 g cm&lt sup&gt -3&lt /sup&gt , respectively. The mean BD of outer wood was almost the same in fast-growing and medium-growing trees. No significant correlations were found between stem diameter and SWV of trees and BD of outer wood. Based on the results, trees with faster-growing characteristics of E. alba do not always have the lower wood properties. Radial profiles in relation to relative distance from pith to bark were almost the same among three growth categories, suggesting that xylem maturation in E. alba might depend on cambial age.

Todomatsu (Abies sachalinensis) is a commercial plantation species on Hokkaido Island, Japan. In the present study, to improve the decay resistance of todomatsu wood, seven families of 22-year-old todomatsu trees were investigated for family diversities in decay resistance of heartwoods against Fomitopsis palustris and Trametes versicolor and n-hexane-extractive contents in heartwoods. In addition, antifungal activity tests of n-hexane extracts were conducted for F. palustris and T. versicolor. Mean percentages of wood mass loss by F. palustris and T. versicolor were 18.2 and 10.5 %, respectively. Significant differences in mass loss and n-hexane-extractive contents were not found among seven families tested here. The mean value of n-hexane-extractive contents was 6.4 mg/g. By gas chromatography/mass spectrometry analysis, a main component of n-hexane extracts was suggested to be juvabione. Results of the antifungal activity test show that mycelial growth of F. palustris and T. versicolor was strongly inhibited over the concentration of 225 and 150 A mu g per disc, respectively. These concentrations corresponded to about 10.0 and 6.6 mg/g in wood. Thus, it is concluded that the todomatsu trees containing more than 10.0 mg/g of n-hexane extracts should be selected among the families for high decay resistance.

This study aimed to evaluate radial and among-family variations of wood properties in Picea jezoensis. A total of 174 trees were randomly selected from 10 open-pollinated families in a progeny trial for measuring stem diameter, dynamic Young's modulus of log (DMOElog), annual ring width (ARW), air-dry density (AD), modulus of elasticity (MOE), and modulus of rupture (MOR). Mean values of DMOElog, AD, MOE, and MOR were 9.60 GPa, 0.41 g/cm(3), 9.44 GPa, and 76.6 MPa, respectively. Significant differences among families were observed in all properties. F values obtained by analyzing variance in wood properties were higher than those generally observed in growth traits. In addition, F values in wood properties remained relatively higher from the 1st to 25th annual ring from the pith, although F value in ARW rapidly decreased with each increase in annual ring number. These results indicate that genetic factors largely contributed to the variance in wood properties compared with the growth traits.

The objectives of this study are to clarify the wood properties of Sanbu-sugi cultivar of sugi (&lt;i&gt;Cryptomeria japonica&lt;/i&gt; D. Don) planted in Chiba prefecture, Japan. Stress-wave velocity (SWV) of stem, dynamic Young&#039;s modulus (DMOE) of logs, wood properties (basic density, latewood tracheid length, microfibril angle of S&lt;sub&gt;2&lt;/sub&gt; layer in latewood tracheid, and static bending properties), and bending properties of 2 by 4&#039;s were investigated for Sanbu-sugi cultivar with different 5 stand ages (11, 19, 30, 48, and 70-years-old). From obtained results, changes of wood properties due to changes of stand age were also discussed. Based on the radial variation of wood properties, juvenile wood of Sanbu-sugi existed from pith to 15th or 20th annual ring from pith. SWV of stem and DMOE of logs increased with increase of stand age up to 30 years, and then it slightly decreased. Thus, SWV of stem and DMOE of logs became stable from about 30-years-old due to increase of mature wood volume. Mean values of modulus of elasticity and modulus of rupture in 2 by 4&#039;s were 8.54 GPa and 56.2 MPa, respectively. Modulus of elasticity of 2 by 4&#039;s in mature wood was almost the same for that obtained from trees with different stand age.

Growth characteristics and basic wood properties of three native fast-growing species, terap (Artocarpus elasticus Reinw. ex Blume), medang (Neolitsea latifolia (Blume) S. Moore), and balik angin (Alphitonia excelsa (Fenzel) Reissek ex Benth), were investigated. All three species are grown in a secondary forest in South Kalimantan, Indonesia. No significant correlations between growth characteristics (stem diameter and tree height) and stress-wave velocity of the stems were found. The mean basic density (BD) for whole trees of terap, medang, and balik angin were 0.34, 0.55, and 0.39 g cm(-3), respectively. The BD in medang wood was similar in both radial and longitudinal directions. On the other hand, the BD gradually increased from pith to bark, decreased from 1 to 3 m above the ground, and then gradually increased to the top of the tree in terap and balik angin. Significant positive correlations between radial and tangential shrinkages and BD were found. Compressive strength parallel to grain and air-dry density also showed high positive correlations for all species. Analysis of variance showed significant differences in wood properties among the five sample trees in each species.

Tree improvement programs for teak (Tectona grandis) have mainly focused on breeding of trees with superior growth characteristics. However, improvement in wood quality should be included in breeding programs for high yield and high quality timber. In the present study, growth characteristics [stem diameter (D), tree height (H), and bole volume (V)], stress-wave velocity (SWV), and Pilodyn penetration (Py) were measured for 15 clones of 12-year-old teak trees planted at two different sites in Indonesia to clarify the variations in tree growth characteristics, SWV, and Py among clones, their repeatability, interaction between genotype and environment, and correlations between measured characteristics. Significant differences of all measured characteristics were found among 15 clones at both sites. Their repeatability showed relatively moderate to high values in both sites. These results indicate that these characteristics are closely related to genetic factors. Significant interaction between genotype and environment was found in all measured characteristics. In addition, SWV and Py showed lower interaction between genotype and environment than growth characteristics. No significant correlation was found between growth characteristics and SWV. These results suggest that wood properties and growth characteristics of teak trees can be improved by application of an appropriate tree breeding program.

Eucalyptus camaldulensis Dehnh. is extensively planted in Thailand to produce wood chips used as raw material for pulp and paper. To promote the utilization of the wood from plantation-grown E. camaldulensis for solid lumber, stress-wave velocity of trees and dynamic Young's modulus of logs were investigated for 4-year-old trees of eight half-sib families selected for pulpwood production on the basis of the growth characteristics in the previous tree breeding program. For the eight families, the mean stem diameter at 1.3 m above ground level and mean tree height were 7.6 cm and 11.9 m, respectively. The mean stress-wave velocity of eight families was 3.45 km/s. Dynamic Young's modulus of logs ranged from 7.88 to 17.64 GPa, and the mean value for the eight families was 11.72 GPa. Stress-wave velocity of trees was significantly correlated with dynamic Young's modulus of logs, suggesting that dynamic Young's modulus of wood can be evaluated nondestructively by stress-wave velocity of trees. Significant differences in stress-wave velocity and dynamic Young's modulus of logs were obtained among families. Thus, to promote the utilization of E. camaldulensis wood for solid lumber production, selection of trees with high Young's modulus should be applied to trees already selected for the growth characteristics in the previous tree breeding program. © 2013 The Japan Wood Research Society.

Solid wood properties of two Eucalyptus camaldulensis clones (clone A and clone B), derived from different pulp and paper companies and planted in Thailand for pulpwood production, were investigated to evaluate the possibility for lumber production. Clone A had significantly higher Young's modulus, greater density, and straighter grain compared with clone B. These results suggest that some clones may have more favorable properties for lumber production than others. Thus, wood properties should be included in clonal trials and early testing of this species.

The Strength properties, such as bending, shearing, and partial compression, were examined for full-size specimens (120 by 240 by 4000mm) of 10-ply laminae of the same thickness (24mm) of sugi (&lt;i&gt;Cryptomeria japonica&lt;/i&gt;) and hinoki (&lt;i&gt;Chamaecyparis obtusa&lt;/i&gt;) and 6-ply and 5-ply of hinoki laminae of the same thickness at the outer layer and different thicknesses of sugi elements (36 and 72mm). For each piece of laminated lumber, two laminae of hinoki were used on both sides of the outer layer. All strength properties in all types of laminated lumber showed higher values than those of solid sugi lumber. In addition, the coefficients of variation in the modulus of elasticity and modulus of rupture were lower in the laminated lumber than in the solid sugi lumber. On the other hand, no significant differences in strength properties, except for the modulus of shearing, were found among the three types of laminated lumber, suggesting that there was no decrease in strength properties in laminated lumbers made of thick elements instead of laminae. These results indicated that the strength properties of laminated lumbers composed of laminae and elements of different thickness without finger joints were almost the same as those of laminated lumbers composed of laminae of the same thickness.