Ikumi Nezu

Utsunomiya University

The growth traits (stem diameter at 1.3 m above the ground and tree height), stress-wave velocity of the stems, and log characteristics (taper and dynamic Young’s modulus of logs) were examined for 54 trees from 18 half-sib families planted in a seedling seed orchard of the first-generation Neolamarckia macrophylla (11-year-old) in Wonogiri, Centra...

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)...

Logs of Betula ermaniiCham. were heated at a temperature inside the logs of 80°C for different heating durations of 0, 20, 40, and 60 h using a laboratory oven. After heating treatment, several wood qualities were examined, including residual stresses, moisture content, wood color, and physical and mechanical properties. The effects of the heating...

The aim of this study is to evaluate the possibility of re-establishment of the Paulownia tomentosa (Thunb.) Steud. forestry and wood industry for sustainable wood production in Japan. Bending properties were preliminarily investigated for dimension lumber (2 by 4, 38 by 89 mm in transverse section) and small-clear specimens of this species. The se...

The objectives of the present study are to clarify the effect of macro- and micro-environment on the radial growth patterns and radial variation patterns of basic density in hinoki cypress ( Chamaecyparis obtusa (Sieb. et Zucc.) Endl.). We evaluated the radial variation patterns of cumulative annual ring width (as radial growth pattern) and basic d...

The knowledge of xylem maturation manner is importance to foresters and wood processors as it has major implications for end-product quality. This study aims to evaluate the maturation manner of secondary xylem in Eucalyptus camaldulensis for solid wood production. The samples were 45 twelve-year-old trees from 15 families with different radial gro...

The breeding of a fast-growing tree species, Acacia mangium Willd. has entered the third-generation cycle in Indonesia. To fulfill timber industry needs, wood traits, as well as growth traits, should be improved by conducting appropriate tree breeding programs for this species. In the present study, growth and wood traits were measured for the 10-y...

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 int...

Inonotus obliquus is a pathogenic fungus found in living trees and has been widely used as a traditional medicine for cancer therapy. Although lignocellulose-degrading enzymes are involved in the early stages of host infection, the parasitic life cycle of this fungus has not been fully understood. In this study, we aimed to investigate the activiti...

Tracheid length is lowest at the pith and then it increases rapidly as cambial age increases up until it reaches an asymptote value in what is known as ‘Sanio’s first law’. However, it is still unclear the effect of radial growth rate on latewood tracheid length and the effect of radial variation pattern of latewood tracheid length on the boundary...

The establishment of forest plantations in boreal zones in Mongolia is important for wood production as well as carbon dioxide fixation. The present study aims to elucidate the juvenile wood properties (basic density, modulus of elasticity [MOE], modulus of rupture [MOR], and compressive strength parallel to grain) of plantation-grown Pinus sylvest...

The effects of laminate configuration on mechanical properties were investigated for model glued-laminated timber (GLT) composed of single and mixed fast-growing tree species (Acacia mangium Willd., Maesopsis eminii Engl., and Melia azedarach L.), which were grown in community forests in Indonesia. The simulation of lamina yield was decreased in gr...

The anatomical characteristics (fiber length and fiber area) and mechanical properties (modulus of elasticity, modulus of rupture, compressive strength, tensile Young’s modulus, and tensile strength) of Bambusa vulgaris, Bambusa maculata, and Gigantochloa atter, naturally growing at four different sites in Lombok Island, Indonesia, were examined fo...

The sapwood of Japanese cedar (Cryptomeria japonica D. Don) was decayed by the brown-rot fungus Fomitopsis palustris under bright and dark conditions. Scanning electron microscopy revealed the presence of mycelia inside the wood even after 1 week from the start of fungal exposure. Moreover, holes were observed in the torus after fungal exposure. Ru...

Promoting wood utilization from fast-growing tree species is one solution to address supply and demand issues relating to wood resources while sequestering carbon dioxide in large quantities. Information on the quality of wood from fast-growing tree species and its relationship with changes in stem size is essential for promoting the establishment...

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 radi...

Betula platyphylla Sukaczev, a fast-growing pioneer tree, is an important species for wood resources in boreal regions and steppe areas in Mongolia. We examined the anatomy and maturation of wood in 30 B. platyphylla trees growing in natural populations in three different sites in Mandal, Selenge, Mongolia to clarify the relationship between tree g...

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 propert...

To effectively and sustainably utilize wood resources from boreal forests in Mongolia, anatomical characteristics, tracheid morphology, cell proportion, annual ring width, and latewood percentage were preliminary determined in Pinus sylvestris, Pinus sibirica, Picea obovata, and Larix sibirica trees naturally growing in Mongolia. Based on the obser...

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 %...

Key message Xylem maturation depends on cambial age rather than diameter growth in Shorea macrophylla by the model selections for radial variations in cell length, wood fiber traits, and basic density. AbstractRadial variations in anatomical characteristics and wood properties were investigated in 23-year-old Shorea macrophylla (engkabang) trees pl...

Boundary between core and outer wood should be clarified for tropical fast-growing tree species to utilize its wood resources under sustainable forestry. This study aimed to determine the boundary between core and outer wood based on the mixed-effects models for radial variations of anatomical characteristics and wood properties in three fast-growi...

Longitudinal and geographic variations in the green moisture content and basic density of bamboo culm were evaluated by using linear mixed-effect models for three bamboo species (Bambusa vulgaris Schrad. ex J.C., Bambusa maculata Widjaja, and Gigantochloa atter (Hassk) Kurz ex Munro) naturally grown in four locations in Lombok Island, Indonesia. Th...

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...

Log characteristics and basic density were evaluated in four common Mongolian softwoods, Pinus sylvestris L., Pinus sibirica Du Tour, Picea obovata Ledeb., and Larix sibirica Ledeb. by developing the linear or nonlinear mixed-effects models for longitudinal and radial variations of measured characteristics. Total of 19 trees from four species were...

To utilize wood resources in Mongolia, amounts of wood chemical components (hot-water extracts, 1% NaOH extracts, ethanol-toluene extracts, holocellulose, -, -, and -cellulose, Klason lignin, and ash) were determined in four common Mongolian softwoods, Pinus sylvestris, Pinus sibirica, Picea obovata, and Larix sibirica. In addition, decay resist...

Wood properties, such as annual ring width, wood fiber length, vessel element length, basic density, air-dry density, dynamic Young’s modulus, modulus of elasticity (MOE), modulus of rupture (MOR), absorbed energy in impact bending, compressive strength parallel to grain, and shearing strength, were investigated for wood from 10 naturally regenerat...

Pine wilt disease is one of the most serious tree diseases occurring worldwide. Clones of Pinus densiflora 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 P. densiflora because of its use as construction lumber. However, little inform...

Pinus sylvestris L., Pinus sibirica Du Tour, Picea obovata Ledeb., and Larix sibirica Ledeb. are important forest tree species in Mongolia. The radial variations of wood anatomical characteristics, physical and mechanical properties were evaluated by linear or nonlinear mixed-effects models for effective wood utilization of those of conifers. Many...

Inonotus obliquus is pathogenic fungus on living trees and has been widely used as a traditional medicine for cancer therapy. Although it has been reported that lignocellulose-degrading enzymes are involved in the early stage of host infection, the parasitic life cycle of this fungus has not been fully clarified. In the present study, we investigat...

Sustainable pulpwood production from fast-growing tree plantations is needed for pulp and paper industries. To increase the pulpwood production efficiency, the anatomical characteristics and derived-wood properties of 75 trees from 15 half-sib families of Eucalyptus camaldulensis Dehnh. planted in Thailand were investigated, and then the family was...

Wood properties were investigated for nine naturally regenerated trees of Betula platyphylla Sukaczev var. japonica (Miq.) H. Hara in Nikko, Japan to effectively utilise the wood resources. The following properties were determined: stress-wave velocity of stems in radial direction, cell length, basic density, shrinkage, dynamic Young’s modulus, mod...

The modulus of elasticity (MOE) and modulus of rupture (MOR) were evaluated for 190 pieces of dimension lumber (2 by 4 lumber, 38 by 89 mm in cross-section) produced from Larix sibirica trees grown in Mongolia. The 5% tolerance limits of the MOE and MOR were 5.70 GPa and 15.1 MPa, respectively. The value of the 5% tolerance limit of the MOR exceede...

The quality of dimension lumber (2 by 4 lumber) was preliminarily investigated in four common Mongolian softwoods: Pinus sylvestris L., Pinus sibirica Du Tour, Picea obovata Ledeb., and Larix sibirica Ledeb. to produce high quality dimension lumber for structural use. In total 61, 39, 67, and 37 pieces of lumber were prepared for Pinus sylvestris,...

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...

We examined the physical and mechanical properties of wood in Siberian larch (Larix sibirica) trees that grow naturally in five Mongolian provenances (Khentii, Arkhangai, Zavkhan, Khuvsgul, and Selenge) and the geographic variations between them. Five trees with stem diameters of 20 to 30 cm at 1.3 m above ground were collected from each provenance...

Wood properties, including Young’s modulus, differ among clones in Larix kaempferi; however, available information is still limited on among-clonal variations of lumber qualities in L. kaempferi. The objectives of this study were to clarify the clonal variations in lumber quality and to identify the effects of juvenile wood on lumber quality in L....

To promote solid wood production, the diameter at breast height, height, stress-wave velocity, surface-released strain, basic density and compressive strength parallel to the grain were measured for 10 half-sib families of 12-year-old Eucalyptus camaldulensis Dehnh. trees growing in Thailand. Based on the results, growth rates, correlations among m...

This study aims to investigate whether it is possible to predict the modulus of elasticity (MOE) and modulus of rupture (MOR) of lumber produced from different heights using the stress-wave velocity of standing trees or the dynamic Young’s modulus of logs in Siberian larch (Larix sibirica). A total of 190 pieces of lumber (38 by 89 mm in cross sect...

The aim of this study is to obtain the basic wood properties of planted Borneo ironwood (Eusideroxylon zwageri) from a plantation established about 80 years ago. Stem diameter at 1.3m above the ground, tree height, and stress-wave velocity (SWV) of stem were measured on 36 planted E. zwageri trees. Later, core samples were collected from four trees...

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...

Annual ring width, warp, dynamic Young’s modulus, and static bending properties were evaluated for 2 × 4 lumber produced from Larix sibirica trees naturally grown in five different provenances of Mongolia. The lumber was also visually graded according to Japanese Agriculture Standard for structural lumber for wood frame construction. Mean values of...

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 unthin...

Inonotus obliquus is a medicinal fungus in the family Hymenochaetaceae and commonly known as chaga. The sclerotium of this fungus has been used as a traditional medicine for long time. In this study, we present the mitochondrial genome sequence of I. obliquus. The mitochondrial DNA (mtDNA) is 119,110 base pairs in length and contained genes for 58...

In order to promote plantation establishment of Larix gmelinii var. olgensis (syn. L. olgensis A. Henry), a ‘near threatened’ species, the wood and lumber properties were preliminary investigated for five trees from two clones of 57-year-old trees planted in Japan. The mean value of dynamic Young’s modulus of logs was 10.16 GPa. The mean values of...