Haruna Aiso

Physical and Mechanical Properties of Woods from Three Native Fast-Growing Species in a Secondary Forest in South Kalimantan, Indonesia

Abstract 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 bali...

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

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.

Reaction Wood Anatomy in a Vessel-Less Angiosperm Sarcandra Glabra

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).

ANATOMY AND LIGNIN DISTRIBUTION OF “COMPRESSION-WOOD-LIKE REACTION WOOD” IN GARDENIA JASMINOIDES

Anatomical characteristics and lignin distribution of ‘compression-wood-like reaction wood’ in Gardenia jasminoides Ellis were investigated. Two coppiced stems of a tree were artificially inclined to form reaction wood (RW). One stem of the same tree was fixed straight as a control, and referred to as normal wood (NW). Excessive positive values of surface-released strain were measured on the underside of RW stems. Anatomical characteristics of xylem formed on the underside of RW and in NW stems were also observed. The xylem formed on the underside exhibited a lack of S3 layer in the secondary fibre walls, an increase of pit aperture angle in the S2 layer, and an increase in lignin content. Some of the anatomical characteristics observed in the underside xylem resembled compression wood in gymnosperms. These results suggest that the increase of microfibril angle in the secondary wall and an increase in lignin content in angiosperms might be common phenomena resembling compression wood of gymnosperms.

The Effects of Radial Growth Rate on Wood Properties and Anatomical Characteristics and an Evaluation of the Xylem Maturation Process in a Tropical Fast-Growing Tree Species, Gmelina arborea

Abstract 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...

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

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

Radial variation of wood properties in Neolamarckia cadamba trees from an East Java community forest

Radial variations in wood properties, cell morphologies and cell proportions were investigated for nine 4-year-old Neolamarckia cadamba trees planted in a community forest in East Java, Indonesia. The relationships between stem diameter and wood properties, cell morphologies or cell proportions were determined to ascertain the effects of stem diameter on these properties. In the radial variations, almost all of the wood properties, cell morphol- ogies and cell proportion in N. cadamba were changed at around 4 to 6 cm distance from the pith, except for fibre diameter, and the proportion of fibre and axial parenchyma. For trees with larger stem diameter, the vessel diameter was also found to increase. In addition, the ray parenchyma and cell wall proportions in trees with larger stem diameter were lower than those in trees with smaller stem diameter. However, the wood properties obtained from the larger stem diameter trees did not always show lower values. The wood properties in N. cadamba were correlated to fibre wall thickness and vessel diameter.

Wood properties of 7-year-old balsa (Ochroma pyramidale) planted in East Java

ABSTRACT The effect of radial growth rate on wood properties was evaluated for 7-year-old balsa trees grown in plantation forest in East Java, Indonesia. The standing trees in the experiment site in the plantation were categorised into three groups (slow-, medium-, and fast-growth) according to their stem diameter. Mean values of stem diameter, tree height, and stress-wave velocity (SWV) were 311 mm, 25.4 m, and 2.96 km/s, respectively. No significant correlations were found between growth characteristics and SWV of stems. The mean values of basic density, compressive strength parallel to grain, modulus of elasticity, and modulus of rupture were 0.14 g/cm3, 10.4 MPa, 4.53 GPa, and 22.9 MPa, respectively. The wood properties were almost constant up to 80-mm from the pith, and then they sharply increased toward the bark. Therefore, separation of the wood at around 80 mm from the pith is likely to be useful for wood industries.

TENSION WOOD-LIKE REACTION WOOD IN VESSEL-LESS TETRACENTRON SINENSE

The objective of this study is to clarify the anatomical characteristics and lignin distribution of reaction wood in a vessel-less angiosperm species, Tetracentron sinense Oliv. Sample disks (1 cm in thickness) were collected from three different positions of a Tetracentron sinense tree. Cell morphologies, the microfibril angle (MFA) in the S2 layer, lignin distribution, and lignin content were measured. There was neither a gelatinous (G-)layer nor an S3 layer on the upper side of inclined samples. However, the secondary wall of the normal tracheids was only weakly stained by Maule and phloroglucinol-HCl. MFA in the S2 layer and lignin content decreased on the upper side of inclined samples. This qualifies the reaction wood of Tetracentron as “tension wood-like”. The so-called “unusual tracheids”, typical for the wood of Tetracentron, showed weaker changes in their anatomical and chemical characteristics in reaction wood than normal tracheids, indicating their special function in water transport. It is hypothesized that vessel-less angiosperms rich in syringyl units in their lignin, produce tension wood-like reaction wood on the upper side of inclined stems or branches, with lower MFA and lignin content in their normal tracheid walls, irrespective of whether a typical G-layer is formed or not.

Anatomical characteristics and wood properties of Melaleuca leucadendron naturally growing in secondary forest in Indonesia

Summary Dynamic Young’s modulus of elasticity (DMOE) of logs, anatomical characteristics and wood properties were determined for naturally regenerated Melaleuca leucadendron trees grown in secondary forest in an area of peat swamp, South Kalimantan, Indonesia. The mean value of DMOE of logs was 7.99 GPa. Mean basic density (BD) and compressive strength (CS) ranged from 0.43 to 0.60 g cm−3 and 34.5 to 52.4 MPa, respectively. Vessel diameter and wood fibre length increased along the first 2 cm of the radius from the pith and then showed almost constant values between that point and the bark, suggesting that xylem maturation starts at about 2 cm from the pith. The wall thickness of wood fibres gradually increased from pith to bark, and the radial profile of this property was very similar to that of BD. There were significant differences in BD, CS and cell wall thickness of wood fibres among 10 selected logs, suggesting that BD and mechanical properties can be genetically improved by selecting mother trees.