Jyunichi Ohshima

Investigation of relationships between cell and pulp properties in Eucalyptus by examination of within-tree property variations

Abstract Relationships between cell and pulp properties were investigated by examining the within-tree property variations in Eucalyptus camaldulensis and Eucalyptus globulus. Properties investigated included proportions of ray and axial parenchyma, thickness of cell walls and cell wall percentages. The characteristics of the ray and axial parenchyma (their proportions and wall thickness) were found to have a significant influence on all measured pulp properties, including paper strength properties. Multiple regression of pulp properties in relation to cell properties revealed that nearly all measured pulp properties were explained by cell properties at the 1% significance level. It was concluded, therefore, that all cell types are important for predicting pulp properties, and it is strongly recommended that tree breeding programs for Eucalyptus include the measurement of all cell types.

Examination of within-tree variations and the heights representing whole-tree values of derived wood properties for quasi-non-destructive breeding of Eucalyptus camaldulensis and Eucalyptus globulus as quality pulpwood

Within-tree variations of derived wood properties of Runkel ratio, Luce’s shape factor, slenderness ratio, and solids factor were examined for Eucalyptus camaldulensis and Eucalyptus globulus trees and the tendency difference in the within-tree variations between individuals and between species, in both radial and axial directions by statistical data analysis. These properties are important for quality breeding of pulpwood. In both species, within-tree variations were generally observed as higher values in the upper and outer parts compared with other parts of the trunk for Runkel ratio and Luce’s shape factor. In E. camaldulensis, within-tree variations were observed as higher values in the upper and outer parts compared with other parts of the trunk for slenderness ratio and solids factor. In E. globulus, within-tree variations were observed as higher values in the outer parts compared with other parts for slenderness ratio and solids factor. However, significant difference of tendency was observed in radial variation between individuals of E. globulus for Runkel ratio and in both radial and axial variations between species for solids factor. Furthermore, within-tree variations of derived wood properties were analyzed to determine a sampling height in the trunk which can be used to represent whole-tree values. Representative heights of derived wood properties from two trees were found to be 2.8 m in E. camaldulensis (except for Runkel ratio and Luce’s shape factor) and 1.8 m in E. globules (except for Runkel ratio), regardless of differences in tree height (growth rate) and in tendency of within-tree variation of derived wood properties.

Rapid Determination of Cell Morphology in Eucalyptus Wood by Fourier Transform Raman Spectroscopy

Analysis of cell morphology in native wood is a lengthy, multistep procedure, although it has a marked effect on product quality and the use of wood. The feasibility of using FT-Raman spectroscopy for rapid determination of cell length and cell wall ratio as cell morphology in native wood was examined with the use of wood meals of two Eucalyptus species, including samples of various ages and colors. The second-derivative transformation of Raman spectroscopic data and the partial least-squares regression revealed highly significant correlations between conventionally measured and Raman predicted values for cell length and cell wall ratio with correlation coefficient r > 0.9 and 0.8, respectively, in the calibration (for known samples, n = 55) and in the prediction (for unknown samples, n = 25).

Quantitative FT-Raman spectroscopy to measure wood cell dimensions

Vibrational spectroscopy is utilized to determine compounds. However, it has never been applied to quantify architecture of multicell biological specimens. By using Fourier transform Raman spectroscopy coupled with multivariate data analysis and wood meal samples of Eucalyptus camaldulensis and E. globulus trees, cell width and cell wall thickness of vessels and fibers, which mainly constitute hardwood xylem, were successfully quantified with correlation coefficients >0.8, both in the calibration and in the prediction against microscopically measured values for all traits. The important frequencies were found to contain wood chemical and physical information.

Wood, Chemical, and Pulp Properties of Woods from Less-Utilized Fast-Growing Tree Species Found in Naturally Regenerated Secondary Forest in South Kalimantan, Indonesia

This study aimed to identify fast-growing tree species suitable for pulpwood obtained from a secondary forest in South Kalimantan, Indonesia. Chemical and pulp properties were determined for terap (Artocarpus elasticus Reinw. ex Blume), medang (Neolitsea latifolia (Blume) S. Moore), and balik angin (Alphitonia excelsa (Fenzel) Reissek ex Benth). The mean values of ethanol-toluene extract and total lignin contents in terap, medang, and balik angin were 1.5 and 29.7, 2.1 and 25.0, and 3.0 and 24.6%, respectively. A significant negative correlation (r = −0.573) was obtained between lignin content and pulp yield, suggesting that low lignin content in these woods leads to high kraft pulp yields. On the basis of these results, it can be considered that medang and balik angin woods are promising raw materials for bleached pulp, whereas terap wood is suitable for unbleached pulp.

Representative Heights for Assessing Whole-Tree Values and the Within-Tree Variations of Derived Wood Properties in Eucalyptus Camaldulensis and E. Globulus

The quality breeding for high pulp yield and strength in the pulp production has attracted interest especially for Eucalyptus. The increment core method without cutting a tree is effective and efficient in the practical quality breeding program [1], but this is an indirect selection method that requires the prediction of whole-tree properties using clear implications between wood and pulp properties. Derived wood properties, such as Runkel ratio, solid factor, vessel R/T ratio and fiber coarseness, have been recognized an important traits for pulp and paper properties in Eucalyptus [2]. We examined the within-tree variations of derived wood properties in E. camaldulensis and E. globulus trees with the aim of determining the representative height in the trunk to indicate whole-tree values.

Within-tree variation of vessel morphology and frequency, and representative heights for estimating whole-tree values in Eucalyptus camaldulensis and E. globulus

Often vessels have a major effect on causing the paper properties of Eucalyptus [1, 2, 3]. They are picked from the paper during printing, causing a non-uniform paper surface, which affects the distribution of ink [1]. Vessel morphology and frequency are important selection indices in the quality breeding program for pulp production. However, the most appropriate core-sampling position has not as yet been reported for vessel morphology and frequency on a whole-tree basis. We examined and the representative height in the trunk to indicate whole-tree values of vessel morphology (length, radial, tangential and average diameters, and wall thickness) and frequency through the within-tree variation in Eucalyptus camaldulensis and E. globulus trees [4].

Among-family variations of solid wood properties in 4-year-old Eucalyptus camaldulensis trees selected for pulpwood production in Thailand

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.

Properties of Juvenile and Mature Wood and Their Effects on the Bending Properties of Lumber in Pinus taeda Growing in Tochigi, Japan

Abstract 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 JW lumber and the MW lumber, respectively.

Wood properties of Larix sibirica naturally grown in Tosontsengel, Mongolia

ABSTRACT The wood properties were examined for Larix sibirica naturally grown in Tosontsengel, Mongolia. The dynamic Youngs modulus of the logs ranged from 6.31 to 9.65 GPa. The mean values of wood properties were as follows: water-extracted basic density = 0.44 g cm−3, air-dry density = 0.59 g cm−3, shrinkage at 1% moisture content change in the radial and tangential directions = 0.18% and 0.32%, modulus of elasticity = 11.24 GPa, modulus of rupture = 102.4 MPa, compressive strength parallel to the grain = 53.1 MPa, and mass loss by Fomitopsis palustris and Trametes versicolor = 10.4% and 18.6%. Mass loss in the heartwood was higher than that in the sapwood, indicating that the larger mass loss values in the heartwood of L. sibirica might be related to the larger amount of arabinogalactan.