Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Yuya Takashima is active.

Publication


Featured researches published by Yuya Takashima.


Forest Products Journal | 2012

Wood Properties of Young Acacia mangium Trees Planted in Indonesia

Kazuko Makino; Futoshi Ishiguri; Imam Wahyudi; Yuya Takashima; Kazuya Iizuka; and Shinso Yokota; Nobuo Yoshizawa

Abstract This study evaluated the wood properties of 5- and 7-year-old Acacia mangium trees planted in West Java, Indonesia. A plot (20 by 20 m) was selected in each stand. The stem diameter and stress-wave velocity (SWV) were measured for all trees (n = 24 and 18 for 5- and 7-y-old trees, respectively) in the plots. Core samples were taken from all trees in each plot using an increment borer to measure the basic density (BD) and compressive strength parallel to the grain (CS). The mean ± standard deviation stem diameter was 13.1 ± 3.0 and 21.9 ± 3.8 cm in 5- and 7-year-old trees, respectively. There was no significant correlation between stem diameter and SWV. The mean BD and CS for 5-year-old trees were 0.42 ± 0.02 g cm−3 and 30.0 ± 4.4 MPa, respectively, and for 7-year-old trees were 0.45 ± 0.02 g cm−3 and 32.8 ± 3.6 MPa, respectively. There was a positive correlation between BD and CS in 5- and 7-year-old trees (r = 0.790 and 0.583, respectively). The radial variation patterns for BD and CS were simil...


Iawa Journal | 2012

Cell Morphology and wood properties of Shorea Acuminatissima Planted in Indonesia

Futoshi Ishiguri; M. Takeuchi; K. Makino; Imam Wahyudi; Yuya Takashima; Kazuya Iizuka; Shinso Yokota; Nobuo Yoshizawa

In view of the importance of long-rotation plantation forestry in SE Asia to limit soil erosion, the cell morphology and wood properties of 35-yearold plantation trees of yellow meranti, Shorea acuminatissima Sym. were studied. To understand the effects of growth rate on cell morphology and wood properties, 131 trees in a stand were classified according to their stem diameter as fast-, medium-, and slow-growing. Five trees in each category were selected for determining the cell morphology and wood properties. There were significant differences in vessel diameter, vessel frequency, and cell wall thickness of wood fibers in the three categories. The fast-growing trees had a relatively low frequency of wide vessels and thick-walled wood fibers. However, no significant differences in basic density or compressive strength parallel to grain were identified in the three categories. The radial variation in the cell morphology and wood properties showed an almost identical pattern in the three categories, suggesting that xylem maturation depends on the cambial age rather than growth rate.


Australian Forestry | 2012

Variation in anatomical properties and correlations with wood density and compressive strength in Casuarina equisetifolia growing in Bangladesh

Qumruzzaman Chowdhury; Futoshi Ishiguri; Tokiko Hiraiwa; Kahoru Matsumoto; Yuya Takashima; Kazuya Iizuka; Shinso Yokota; Nobuo Yoshizawa

Summary Variation in anatomical properties and relationships with air-dry density and compressive strength were examined in wood of 10-y-old Casuarina equisetifolia. Average vessel diameter increased gradually between sample points 2.5 cm and 7.5 cm from the pith. Vessel frequency decreased between sample points 2.5 cm and 5 cm from the pith and then stabilised. Average fibre diameter decreased gradually from pith to bark, while fibre wall thickness displayed a reverse trend. The proportion of vessels decreased slightly between the 2.5 and 5 cm sample points and then increased again towards the bark. Fibre and cell wall proportions increased from the pith to bark. The proportion of rays was nearly constant along the radius, while the proportion of axial parenchyma decreased somewhat toward the bark. Vessel diameter, fibre wall thickness and the proportions of fibre and cell wall were positively correlated with air-dry density, whereas fibre diameter showed a negative correlation. A significant negative correlation was found between compressive strength and fibre diameter. Strong positive correlations suggest that variation in air-dry density and compressive strength is mainly determined by the proportion of cell wall in transverse sections.


Iawa Journal | 2014

ANATOMY AND CHEMICAL COMPOSITION OF LIRIODENDRON TULIPIFERA STEMS INCLINED AT DIFFERENT ANGLES

Tokiko Hiraiwa; Haruna Aiso; Futoshi Ishiguri; Yuya Takashima; Kazuya Iizuka; Shinso Yokota

The anatomical and chemical characteristics of reaction wood (RW) were investigated in Liriodendron tulipifera Linn. Stems of seedlings were artificially inclined at angles of 30 (RW-30), 50 (RW-50) and 70° (RW-70) from the vertical, and compared with normal wood (NW) from a vertical seedling stem. The smallest values for the wood fibre length and vessel number were observed in RW-50. The pit aperture angle was less than 10° in RW-30 and RW-50, in which reduced lignin content was observed in the S2 layer of the wood fibres. An increase in the glucose content and a decrease in the lignin and xylose content was observed in RW-50. The stem inclination angle affected the degree of RW development with regard to anatomical and chemical characteristics: the severest RW was observed in RW-50, followed by RW-30. RW-70 was similar in anatomical and chemical characteristics to NW, apparently because the inclination was too strong to enable recovery of its original position. In this case a vertical sprouting stem was formed to replace the inclined stem.


Iawa Journal | 2014

Reaction Wood Anatomy in a Vessel-Less Angiosperm Sarcandra Glabra

Haruna Aiso; Futoshi Ishiguri; Shinso Yokota; Yuya Takashima; Kazuya Iizuka

Anatomy and lignin distribution in artificially inclined stems of Sarcandra glabra were investigated to clarify the characteristics of reaction wood (RW) in a vessel-less angiosperm species. Of the five coppiced stems studied from a single tree, two stems were fixed straight and classified as normal wood (NW) and the remaining three stems were inclined at 50 degrees from the vertical to induce the formation of the RW. Compared with NW, the lower side of the inclined samples had a relatively high compressive surface-released strain and an increase in the microfibril angle of the S2 layer of tracheids. However, no significant change was observed in the length or cell wall thickness of the tracheids. The results of Wiesner and Maule colour reactions indicated that the amount of guaiacyl lignin in the cell walls of tracheids was increased in RW. It appears that RW in Sarcandra is formed on the lower side of inclined stems, and its anatomical characteristics and chemical composition are similar to those of the compression wood (CW) found in gymnosperm species (the so-called“CW-like RW” type).


Journal of Wood Science | 2013

Variation in tree growth characteristics, stress-wave velocity, and Pilodyn penetration of 24-year-old teak (Tectona grandis) trees originating in 21 seed provenances planted in Indonesia

Fanny Hidayati; Futoshi Ishiguri; Kazuya Iizuka; Kazuko Makino; Yuya Takashima; Sri Danarto; Widaryanti Wahyu Winarni; Denny Irawati; Mohammad Na’iem; Shinso Yokota

Growth characteristics [stem diameter (D), tree height (H), and bole volume (V)], stress-wave velocity (SWV), and Pilodyn penetration (P) were measured for 21 seed provenances of 24-year-old teak trees planted in Indonesia to characterize variation in tree growth characteristics, SWV, and P among seed provenances. Broad-sense heritability and correlations between the measured characteristics were also determined. Significant differences for all measured characteristics were observed among provenances, indicating that these characteristics are genetically controlled. Broad-sense heritabilities of growth characteristics, SWV, and P are moderate values. These results indicate potential for improving growth characteristics and wood properties of teak trees with the help of breeding programs. Highly significant positive correlations were observed among the growth characteristics, suggesting that they are closely related. In contrast, no significant correlations were observed between the growth characteristics and SWV, indicating that they are independent. We conclude that mechanical properties are also important criteria for selecting plus trees in tree breeding programs. Principal component analysis revealed that seed provenances from Indonesia (Bangilan, Deling, and Randublatung) and India (Malabar and Central Province) have high scores of growth characteristics and SWV.


Forest Science and Technology | 2012

Radial variation of bending property in plantation grown Acacia auriculiformis in Bangladesh

Md. Qumruzzaman Chowdhury; Futoshi Ishiguri; Tokiko Hiraiwa; Yuya Takashima; Kazuya Iizuka; Shinso Yokota; Nobuo Yoshizawa

Acacia auriculiformis is one of the major fast-growing plantation species in Bangladesh. Understanding the radial variation of bending property has importance in tree improvement and wood utilization. In this study, the radial variation of modulus of elasticity (MOE) and modulus of rupture (MOR) in static bending were examined in 11-year-old plantation-grown Acacia auriculiformis from Bangladesh. MOE and MOR increased up to about 6 and 8 cm radial distance from the pith, respectively, and then both properties were nearly stable toward the bark. MOE did not show significant correlation with air-dried density. Conversely, MOR showed significant correlation with air-dried density. Significant variation among the trees indicates that the air-dried density and MOR could be used in plus tree selection for wood quality improvement of this species through tree breeding.


Journal of forest and environmental science | 2015

Variations in Growth Characteristics and Stress-wave Velocities of Zelkova serrata Trees from Eight Half-sib Families Planted in Three Different Initial Spacings

Agung Prasetyo; Ryota Endo; Yuya Takashima; Haruna Aiso; Fanny Hidayati; Jun Tanabe; Futoshi Ishiguri; Kazuya Iizuka; Shinso Yokota

Abstract Zelkova serrata is an important hardwood species for the timber industry in Japan. Tree breeding programs for this species have mainly focused on growth characteristics such as stem diameter (D), tree height (TH), stem form, and branching. In order to fulfill timber industry needs, wood quality improvement should be included in the tree breeding program of this species. In the present study, growth characteristics, such as D and TH, and the stress-wave velocity (SWV), which is highly correlated with Young’s modulus of wood, were measured for 20-year-old Z. serrata from eight half-sib families planted in a progeny test site with three different initial spacings. Significant differences in all the measured characteristics were found among the eight half-sib families. The variance components of the half-sib families for D, TH, and SWV were 27.2%, 47.3%, and 33.5%, respectively. These results indicate that all the measured characteristics of this species could be improved by tree breeding programs. In addition, only low correlation coefficients were obtained between the growth characteristics and SWV, indicating that extensive selection on SWV in tree breeding programs may not always lead to a reduction in yield volume.Key Words: Zelkova serrata, wood quality, stress-wave velocity, spacing effect, growth characterists


Journal of Wood Science | 2013

Ozone treatment of spent medium from Auricularia polytricha cultivation for enzymatic saccharification and subsequent ethanol production

Denny Irawati; Yuya Takashima; Chisato Ueda; J.P.Gentur Sutapa; Sri Nugroho Marsoem; Futoshi Ishiguri; Kazuya Iizuka; Nobuo Yoshizawa; Shinso Yokota

We examined the enzymatic saccharification and ethanol fermentation of the spent media (SMs) from Auricularia polytricha cultivation using wood meals of Falcataria moluccana, Shorea sp., and Tectona grandis. Although the hydrolysis weight decrease and reducing sugar yield were higher in SM of F. moluccana, the ethanol yield was higher in SM of Shorea sp. Ozone treatment of SM further increased the hydrolysis weight decrease, reducing sugar, and ethanol yields in Shorea sp. These results indicate that SM of A. polytricha is a suitable biomass material to produce fermentable sugars for ethanol production, and that ozone treatment is a suitable method for increasing the ethanol yield.


Journal of Wood Science | 2011

Stress wave velocity, basic density, and compressive strength in 34-year-old Pinus merkusii planted in Indonesia

Futoshi Ishiguri; Kazuko Makino; Imam Wahyudi; Yuya Takashima; Kazuya Iizuka; Shinso Yokota; Nobuo Yoshizawa

The relationship between the growth speed and wood properties of Pinus merkusii was investigated using 34-year-old trees planted in Indonesia in an attempt to promote the establishment of plantation of this species. The trees in the test plot were categorized as fast, middle, or slow growing according to the mean stem diameter and standard deviation in the plot. Five trees were selected from each category to investigate the effects of the growth rate on the wood properties [basic density (BD) and compressive strength parallel to the grain in a 5-mm-diameter core sample (CS)]. No significant correlation was recognized between the stem diameter and the stress wave velocity of trees. Clearly lower values of BD and CS were found in slow-growing trees than in fast- and middle-growing trees. The BD of xylem near the pith was reduced by extraction with organic solvent. BD after extraction and CS gradually increased from pith to bark. The results obtained in this study clarified that an early selection of trees with high BD is possible by using the BD after extraction at 4 cm from the pith.

Collaboration


Dive into the Yuya Takashima's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Nobuo Yoshizawa

United States Department of Agriculture

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Imam Wahyudi

Bogor Agricultural University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge