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To preliminary evaluate the potential wood utilization of Sukaczev trees naturally regenerated in Mongolia, growth characteristics (stem diameter and tree height), wood properties (annual ring width, basic density, and compressive strength parallel to grain at the green condition) of core samples, and stress-wave velocity in stems were investigated for trees grown naturally in three different sites in Selenge, Mongolia. trees, naturally grown in Nikko, Japan, were also examined to compare wood properties between the two regions. The mean values of stem diameter, tree height, stress-wave velocity of stems, annual ring width, basic density, and compressive strength parallel to grain at green condition in Mongolian were 17.6 cm, 14.1 m, 3.50 km s, 1.27 mm, 0.51 g cm, and 20.4 MPa, respectively. Basic density and compressive strength were decreased first from the pith, and then gradually increased toward the bark. The wood properties of trees grown naturally in Mongolia were similar to those in trees grown in Japan. Growth characteristics, especially stem diameter, were positively correlated with the stress-wave velocity of stems and basic density. Early evaluation of basic density in trees is possible by using wood located 2 cm from the pith. Basic density at the position from the 1st to the 15th annual ring from the pith showed significant between-site differences in Mongolian . Based on the results, it is concluded that the wood of trees grown in Mongolia may be used for industrial products as well as those from similar species in other countries.Betula platyphyllaBetula platyphyllaBetula platyphyllaB. platyphyllaâ1â3B. platyphyllaB. platyphyllaB. platyphyllaB. platyphyllaB. platyphylla

To evaluate the inheritance of natural durability of Acacia mangium Willd., wood-color parameters (Y [lightness], x [red to green], and y [yellow to blue]), mass loss by a white-rot fungus (Trametes versicolor) and brown-rot fungus (Fomitopsis palustris), and three different extracts (methanol extract, total phenol, and total flavanol content) were measured using the inner and outer heartwood of 10-year-old trees from 20 half-sib families in the third-generation A. mangium in Indonesia. The broad-sense heritability (H2) values were moderate to high for the wood-color parameters and mass loss by white- and brown-rot fungi (H2 = 0.210–0.851) and low to moderate for three different extracts (H2 = 0.000–0.576). Significant negative phenotypic correlations were found between the three different extracts and mass loss by T. versicolor and F. palustris. In addition, negative correlations were found between the wood-color parameters and three different extracts. Similar results were found between the total phenol content and y and between the total flavanol content and Y in genetic correlations. Therefore, A. mangium families with lower Y and y in heartwood could produce progenies with higher total phenol and total flavanol content, leading to higher natural decay resistance. [ABSTRACT FROM AUTHOR]

Decay process of wood of Japanese white birch [Betula platyphylla Sukaczev var. japonica (Miq.) H. Hara] tree by Inonotus obliquus (Fr.) Pilát was clarified by using the regression model in wood color and chemical components as a function of height position (1, 2, 3, and 4 m above the ground), wood type (sound wood and decayed wood), and their interactions, and anatomical observations. The 3 m height position, at which a sclerotium of I. obliquus was found, showed the highest decayed area percentage among four height positions. By the results of two-way analysis of variance, wood type affected all color indice. In addition, all factors (height position, wood type, and their interaction) were significant in all wood chemical components except for Klason lignin and hemicellulose. In the wood of the reaction zone, some substances were formed in the lumens of many vessels and a few wood fibers. Based on the results, we proposed the decay process of I. obliquus in naturally grown Japanese white birch, and the proposed process will contribute to a full understanding of the interactions between I. obliquus and Japanese white birch in the future. [ABSTRACT FROM AUTHOR]

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 (f0.05) of MOE and MOR were 8.03 GPa and 39.4 MPa, respectively. The f0.05 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. [ABSTRACT FROM AUTHOR]