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

The representative heights in the trunk to indicate whole-tree values and the within-tree variations of derived wood properties, namely flexibility coefficient, wall coverage ratio, vessel diameter radial/tangential (R/T) ratio, fiber diameter R/T ratio, and fiber coarseness, were examined in Eucalyptus camaldulensis and E. globulus trees. In both species, within-tree variations were generally observed as high in the upper and outer parts of the trunk for wall coverage ratio and in the lower parts for flexibility coefficient and vessel diameter R/T ratio. In E. camaldulensis, within-tree variations were observed as high in the upper and outer parts of the trunk for fiber coarseness, and in the lower and inner parts for fiber diameter R/T ratio. In E. globulus, within-tree variations were observed as high in the outer parts for fiber coarseness, but fiber diameter R/T ratio had no clear trend. The representative height assessing the derived wood properties was 2.8 m in E. camaldulensis and 1.8 m in E. globulus, regardless of differences in tree height (growth rate). No representative height was found for wall coverage ratio

Origin and hydrodynamics of xylem sap in tree stems, and relationship to root uptake of soil water

Although 10 years have passed since Japan's Fukushima nuclear accident, the future radiation risk from ¹³⁷Cs contamination of wood via root uptake is a serious concern. We estimated the depth at which the roots of evergreen coniferous sugi (Cryptomeria japonica) and broadleaf deciduous konara (Quercus serrata) trees actively take up soil water by using positive δD values from the artificial D₂O tracer and seasonal changes in the δ¹⁸O values of soil water as a natural environmental tracer. We compared the tracer concentration changes in xylem sap with those in the soil water and ascertained that both tree species primarily took up water from a depth of 20 cm, though with mixing of water from other depths. Using sap hydrodynamics in tree stems, we found that water circulation was significantly slower in heartwood than in sapwood. Heartwood water was not supplied by direct root uptake of soil water. The measured diffusion coefficients for D₂O, K⁺, Cs⁺, and I⁻ in xylem stems were greater in sapwood than in heartwood, and their magnitude was inversely correlated with their molecular weights. The distribution of D₂O and ¹³⁷Cs concentrations along the radial stem could be explained by simulations using the simple advective diffusion model

Geographic variations of wood properties of Larix sibirica naturally grown in Mongolia

Geographic variations in growth, stress-wave velocity of stem, dynamic Youngâs modulus of stems and logs, annual ring width, latewood percentage and basic density were investigated for (Münchh.) Ledeb. naturally grown in Mongolia. A total of 250 trees with 20 to 30 cm in stem diameter at a height of 1.3 m above ground level were selected from each natural stand in five different provenances in Mongolia. In addition, five trees in each stand were cut for measuring dynamic Youngâs modulus of stems and logs, annual ring width, latewood percentage and basic density. Mean values of stress-wave velocity of stems in each stand ranged from 2.92 to 3.41 km s, and the mean value of five stands was 3.23 km s. Mean values of dynamic Youngâs modulus of logs in each stand ranged from 5.17 to 9.72 GPa. A significant correlation (â=â0.798, â<â0.01) was found between stress-wave velocity of stems and dynamic Youngâs modulus of logs. Among the five stands, the highest and the lowest values of average annual ring number were 193 and 44, respectively. Mean values of basic density in five trees within each stand were examined and ranged from 0.52 to 0.56 g cm. Significant differences among five stands were found in tree height, stress-wave velocity of stem, dynamic Youngâs modulus of stems and logs, annual ring width and latewood percentage, suggesting that trees naturally grown in Mongolia have geographic variations in mechanical properties of wood.Larix sibiricaâ1â1rpâ3L. sibiric

Secondary xylem maturation evaluated by modeling radial variations in anatomical characteristics and wood properties of Shorea macrophylla (De Vr.) Ashton planted in Sarawak, Malaysia

Radial variations in anatomical characteristics and wood properties were investigated in 23-year-old Shorea macrophylla (engkabang) trees planted in Sarawak, Malaysia. The efects of radial growth rates on anatomical characteristics and wood properties and the manner of xylem maturation were determined based on selected mixed-efects models. The best models of radial variation were ftted by linear functions for wood fber length, wood fber wall thickness, basic density, and compressive strength. Logarithmic functions were applied for vessel element length and vessel frequency, and quadratic functions were applied for vessel diameter and wood fber diameter. Vessel diameter and wood fber length were afected by radial growth rates although these efects on the other properties were minimal. In the fxed part of the models, the results showed small mean absolute error values of radial variation in relation to the distance from the pith according to vessel frequency and vessel diameter. In contrast, in relation to the estimated cambial age, smaller mean absolute error values were obtained for cell length, wood fber traits, and basic density, suggesting that all properties varied from pith to bark in relation to the cambial age, except for vessel traits. Thus, in S. macrophylla, xylem maturation in cell length, wood fber traits, and basic density were due to cambial age rather than diameter growth, but xylem maturation in vessel traits depended on diameter growth

EFFECTS OF RADIAL GROWTH RATE ON WOOD AND LUMBER ROPERTIES OF 67-YEAR-OLD JAPANESE LARCH (LARIX KAEMPFERI) TREES PLANTED IN TOCHIGI, JAPAN

The wood and lumber properties were examined for 67-yr-old Japanese larch (Larix kaempferi) trees with different radial growth rates planted in Tochigi Prefecture, Japan. The trees were categorized into slow-, medium-, and fast-growing groups based on the stem diameter. No significant difference in stresswave velocity of stems, which is closely related with Young’s modulus of wood, was found among three radial growth categories (stem diameter classes). The boundary between juvenile wood (JW) and mature wood (MW) determined by latewood tracheid length (TL) existed about the 20th annual ring from the pith in all sample trees. Significant differences between JW and MW were found in most of examined wood and lumber properties. It was found that trees with fast growth do not always cause lower grade lumberproperties.  

Selection of Eucalyptus camaldulensis Families for Sustainable Pulpwood Production by Means of Anatomical Characteristics

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 classified by suitability of wood as raw material for pulp and paper products using principal component analysis and clustering. The mean values of vessel diameter, vessel frequency, fibre diameter, fibre lumen diameter, and fibre wall thickness at 2 cm from the cambium were 128 &micro;m, 16 no./mm2, 11.1 &micro;m, 7.1 &micro;m, and 1.88 &micro;m, respectively. In addition, the Runkel ratio, Luce&rsquo;s shape factor, flexibility coefficient, slenderness ratio, solids factor, and wall coverage ratio (i.e., derived-wood properties) were 0.53, 0.42, 0.64, 85.3, 68 &times; 103 &micro;m3, and 0.34, respectively. Significant differences in fibre diameter, fibre lumen diameter, and Runkel ratio were found among families. Although significant differences among families were not found for other anatomical characteristics and derived-wood properties, the p-values obtained by an analysis of variance test ranged from 0.050 to 0.088. Based on the results of a principal component analysis and cluster analysis, 15 families were classified into four clusters with different expected pulp and paper characteristics. The suitability of wood from E. camaldulensis half-sib families for pulp and paper can be evaluated by principal component analysis using anatomical characteristics and physical properties as variables. Based on the results, desirable pulp and paper quality may be obtained through the selection of families from this species

Within-tree radial and among-family variations in wood density, microfibril angle, and mechanical properties in Picea glehnii

Genetic improvements in the mechanical properties of wood are important in forestry species used for lumber, such as . The within-tree radial and among-family variations for the modulus of elasticity (MOE), modulus of rupture (MOR), and their related traits [i.e., microfibril angle (MFA) of the S layer in latewood tracheid and air-dry density (AD)] were evaluated in nine open-pollinated families of (F. Schmidt) Mast. The radial variation in MOR was mainly affected by AD, whereas MOE was affected by MFA and AD. Higher -values obtained by analysis of variance and coefficient of variation were observed for all properties at the 6thâ15th annual ring, except for AD at the 6thâ10th annual ring. This result suggests that the contribution of genetic effect is larger in these highly variable regions. In addition, positive correlation coefficients were obtained between wood properties at the 6thâ15th annual ring and mean values of these properties. Therefore, genetic improvements for MOE, MOR, and their related traits in is likely to be more effective in juvenile wood, specifically at the 6thâ15th annual ring from the pith.Picea2Picea glehniiFP. glehni

Longitudinal and geographic variations in the green moisture content and basic density of bamboo culm in three species naturally grown in Lombok Island, Indonesia

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. The mean green moisture contents and basic densities were 74.2 and 0.69 g cm-3 for B. vulgaris, 78.5 and 0.65 g cm-3 for B. maculata, and 80.3 and 0.65 g cm-3 for G. atter, respectively. No significant differences in green moisture content and basic density were found among the species. A significant negative correlation between basic density and green moisture content was found in all three species. Based on the results of model selections for longitudinal variations, the green moisture content decreased with an increase in the culm height in all three species, and basic density tended to increase from the base to the top of the culm. Relatively large geographical variation was found in the green moisture content and basic density of G. atter, although the main reasons for variation of these properties were individual culm in three species. © 2022 Japan Society of Tropical Ecology. All Rights Reserved