Efficiency of the indirect selection and the evaluation of the genotype by environment interaction using Pilodyn for the genetic improvement of wood density in <Emphasis Type="Italic">Cryptomeria japonica</Emphasis>

The efficiency of the indirect selection for wood density using the Pilodyn in Cryptomeria japonica was studied by comparing the Pilodyn penetration (PP) depth and the direct measurement of wood density in three test sites. The influence of the genotype by environment (G × E) interaction of wood density was estimated using the Pilodyn with common 12 C. japonica clones in 10 test sites in Kanto breeding region in Japan. The PP depth was highly correlated with wood density, and the genetic correlation between them was −0.88. The indirect selection using the Pilodyn realized 87% of the genetic gain obtained by the direct selection of wood density. The G × E interaction in PP depth was small. The ratio of the variance component of the G × E interaction to that of genotype was only 0.096 in the PP depth, whereas it was 0.700 in tree height and 1.410 in diameter at breast height. These findings indicate that the Pilodyn is useful for the genetic improvement of wood density in Cryptomeria japonica. The small G × E interaction in wood density estimated using the Pilodyn indicates that the relative clonal performance in wood density is stable among diverse environments in Kanto breeding region in Japan.     

Adhesive performance of woods treated with alternative preservatives

The extended use of woods treated with traditional or alternative preservatives for exterior applications requires an assessment of wood adhesive performance. This study attempts to evaluate the performance of wood adhesives for woods treated with various waterborne preservatives. Two softwood species, i.e. Korean pine (Pinus koraiensis Sieb. et Zucc.) and Japanese Larch (Larix leptolepis [Sieb. et Zucc.] Gordon) were treated with copper–chrome–arsenic (CCA), CB-HDO, or copper azole (CY), and then bonded with four different wood adhesives such as urea–melamine–formaldehyde (UMF) resin, melamine–formaldehyde (MF) resin, phenol–formaldehyde (PF) resin, and resorcinol–formaldehyde (RF) resin. The performance of these adhesives was evaluated by measuring the dry shear strength of adhesive-bonded wood block on compression. Both UMF and MF resins produced a relatively strong adhesive strength for CY-treated pine and larch woods. The PF resin also produced good bond strength when bonded with either larch wood treated with CY or pinewood treated with CB-HDO. The best result was obtained when the CB-HDO-treated woods were bonded with RF resin. For a better bond strength development, a proper combination of adhesive, preservative, and wood species should be selected by taking into consideration of the characteristics of these three parameters as well as their interactions.     

Modulus of elasticity in scarf-jointed wooden beams: a case study with polyvinyl acetate and isocyanate adhesives

In the present study, elastic properties of scarf-jointed oak (Quercus castaneifolia) timbers with the application of two different types of adhesives (polyvinyl acetate and isocyanate) were evaluated using free flexural vibration of free–free beam method in different flexural directions of vibration, i.e., tangential and redial directions. Samples were taken from trees of Hyrcanian forests in Iran with nominal dimensions of 20 × 20 × 360 mm³. Comparing the results of elastic properties of clear oak wood beams with scarf-jointed samples wood showed that scarf joints with the bonding angles of 70° and 75°, covered by polyvinyl acetate adhesive, did not demonstrate any significant effect on modules of elasticity. Scarf-jointed beams with smaller joint angles (60° and 65°) were considerably weaker or totally unreliable in their moduli of elasticity. It is also shown that the magnitude of effect gets worst by using isocyanate rather than polyvinyl acetate adhesive.     

Erratum to: Comparative analysis of a wood-adhesive bondline

The wood–adhesive interface was analyzed using five methods with the objective of quantitatively assessing penetration of adhesive into the porous wood network. Methods included fluorescence microscopy, scanning electron microscopy, backscatter electron imaging, wavelength dispersive spectroscopy, and X-ray microtomography (XMT). Each method provided a visual inspection, and all of the analysis methods were applied to the same field of view. XMT was the primary technique of interest. Rubidium hydroxide was used in place of sodium hydroxide in the formulation of phenol–formaldehyde adhesive. Rubidium was found to increase the X-ray attenuation of the adhesive. However, rubidium migrated beyond the adhesive interphase during specimen preparation, thus reducing its effectiveness for image contrast enhancement. The wood species studied included red oak (Quercus rubra), Douglas-fir (Pseudotsuga menziesii), and hybrid poplar (Populus deltoides × Populus trichocarpa). All techniques used for this study were useful, but each presented some limitations for bondline analysis. Despite the problem with rubidium migration, XMT for this application was promising.     

Genotypic variation in wood properties and growth traits of <Emphasis Type="Italic">Eucalyptus</Emphasis> hybrid clones in southern China

Growth traits, wood properties and bark percentage were assessed for 19 hybrid eucalypt clones at three sites in southern China sampled at age 51 months. Analysis of variance showed that there were significant differences in growth traits and wood properties between clones and sites, and that the clone × site interactions were also significant except for basic density. Coefficients of variation ranged from 8.4 to 27.9% for growth traits, 2.7–11.1% for wood properties and 14.0–23.3% for bark percentage. Repeatability ranged from 0.73 to 0.96 for growth traits, 0.32–0.93 for wood properties and 0.77–0.88 for bark percentage. Strong genotypic correlations between the same traits in clones at pairs of sites indicated that the traits were rather stable across sites. The genotypic correlations between growth traits and basic density ranged from −0.67 to 0.43, and generally favorable negative genotypic correlations between growth traits and bark percentage were also found. The correlations between growth traits and Pilodyn pin penetration were positive, ranging from 0.28 to 0.65 and therefore unfavorable as lower wood density will be associated with higher values of Pilodyn pin penetration and improved growth rate. The correlations between traits assessed using non-destructive field methods and wood property assessment results indicated that Pilodyn and Fakopp microsecond timer tools can be confidently used to indirectly select for fiber width and basic density.     

Distribution of preservatives in thermally modified Scots pine and Norway spruce sapwood

Studying the impregnation and distribution of oil-based preservative in dried wood is complicated as wood is a nonhomogeneous, hygroscopic and porous material, and especially of anisotropic nature. However, this study is important since it has influence on the durability of wood. To enhance the durability of thermally modified wood, a new method for preservative impregnation is introduced, avoiding the need for external pressure or vacuum. This article presents a study on preservative distribution in thermally treated Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) sapwood using computed tomography scanning, light microscopy, and scanning electron microscopy. Secondary treatment of thermally modified wood was performed on a laboratory scale by impregnation with two types of preservatives, viz. Elit Träskydd (Beckers) and pine tar (tar), to evaluate their distribution in the wood cells. Preservative solutions were impregnated in the wood using a simple and effective method. Samples were preheated to 170 °C in a drying oven and immediately submerged in preservative solutions for simultaneous impregnation and cooling. Tar penetration was found higher than Beckers, and their distribution decreased with increasing sample length. Owing to some anatomical properties, uptake of preservatives was low in spruce. Besides, dry-induced interstitial spaces, which are proven important flow paths for seasoned wood, were not observed in this species.     

The effects of wood species and treatment retention on kinetics of CCA-C fixation reactions

Reaction kinetics of fixation of CCA-C (chromated copper arsenate type C) preservative was studied at 30°C in ground wood of trembling aspen, red pine, and red maple at treatment retentions of 4.0, 6.4, 9.6, and 30 kg/m³, and red maple pre-extracted with hot water at retentions of 6.4 and 30 kg/m³. Reaction orders of cumulative Cr, Cu, and As reactions decreased gradually during the fixation if calculated by Van’t Hoff’s method. With Essen’s method, CCA fixation was best approximated as follows: Cr—3rd order reaction during the first 24 h, and 1st order reaction for the rest of the fixation period; Cu—2nd order reaction; and As—1st order reaction in red pine and aspen, and 2nd order in red maple. Rates of reaction decreased with increased CCA solution concentration for Cr and Cu, and increased for As, except in red maple. Reaction rates for all CCA elements were significantly higher in rapidly fixing red maple than in regularly fixing red pine and aspen, and were higher in unextracted than pre-extracted red maple. Modeling of CCA fixation kinetic for the whole fixation period enabled comparison of fixation reactions among wood species, preservative components, and treatment retentions.     

Hybrid poplar (<Emphasis Type="Italic">Populus</Emphasis> ssp.) selections for arid and semi-arid intermountain regions of the western United States

The rapid growth rates of hybrid poplar (Populus spp.) enable rotations of 3–6 years for biofuels or 10–15 years to obtain merchantable timber, but many clones are susceptible to nutrient deficiencies when grown in alkaline soils. A 1995 Oregon study demonstrated that clone OP-367 (P. deltoides × P. nigra) was the only clone tested that performed well on alkaline soils. Tests in Colorado and New Mexico confirmed the adaptation of this clone. A multi-clonal trial was established in 2003 at Farmington, New Mexico and Ontario, Oregon in order to screen a larger number of clones for adaptability to alkaline soils. Trees were planted at 1.5 × 1.5 m spacing and irrigated by surface drip irrigation. Diameter at breast height (DBH) and tree height were recorded annually (2003–2006); wood volumes (WVol) and total aboveground biomass (TAB) were calculated from these measurements. Of the 25 clones tested, 19 were common to both sites. Mean height was greater at the Ontario site through the first 3 years (2003–2005). By the end of four seasons, the tallest Farmington entry was OP-367 at 9.4 m with 177 Mg ha⁻¹ TAB while the tallest Ontario entry was Malheur-3 at 8.9 m with 195 Mg ha⁻¹ TAB and several other clones had statistically similar production. Given the growth and productivity range at these two sites, it is difficult to make generalizations across wide areas, but it appears feasible to identify clones suited to alkaline soils in arid and semi-arid regions.     

Chloride content and biomass partitioning in Eucalyptus hybrids grown on saline sites

Eucalyptus camaldulensis × globulus and E. camaldulensis × grandis hybrids have been developed to combine the salt–waterlogging tolerance and high-quality wood fibre of their respective parents. The aim is to develop trees that will grow in relatively dry and/or saline environments and provide commercial wood products. Previous studies indicate that the hybrids exhibit faster growth than either of their pure species parents, and that there are significant differences in growth rates between them. We undertook a comparative study of the partitioning of above-ground biomass (AGB) to examine biomass and chloride (Cl) allocation of trees growing on two saline-irrigated sites in south-eastern Australia. Eucalyptus camaldulensis × globulus had a higher proportion of AGB in leaves (20–29% cf. 15–16%), and lower proportion in live branches (3–10% cf. 6–14%) than E. camaldulensis × grandis. The concentration of Cl was highest in the stembark (4.2–9.6 g kg⁻¹) and lowest in the stemwood (0.6–2.0 g kg⁻¹), suggesting that trees can export Cl through bark shedding. Total Cl content was strongly related to volume under bark (R² = 0.99), and differences in partitioning of Cl into tree components differed between the hybrids in the same way as AGB. Preferential partitioning of Cl to live branches rather than foliage in E. camaldulensis × grandis suggests that this hybrid may be compartmentalising Cl to reduce the risk of Cl toxicity in the leaves.     

Characterization of urea–formaldehyde resin penetration into medium density fiberboard fibers

The amount of UF resin penetration into fibers, used for the production of medium density fiberboard (MDF), is unknown. To evaluate the relationship between resin viscosity and resin penetration depth, an experimental procedure involving confocal laser scanning microscopy (CLSM) and a Toluidine Blue O staining system was performed. The results indicate that CLSM in combination with a Toluidine Blue O staining system is a good way to characterize UF resin penetration into wood fibers. The main penetration direction is toward the fiber lumen. For wet fibers, whose moisture content is about 88%, the effect of resin viscosity with a range of 80 cps – 340 cps on penetration is very similar, with all adhesives reaching or almost reaching the fiber lumen after 60 min at room temperature. For MDF industrial samples, the highest depth of penetration of the adhesive was attained in the second dryer stage. After the second dryer stage, the resin penetration into the fiber did not increase.     

Tree and stand growth for clonal <Emphasis Type="Italic">E. urophylla</Emphasis> × <Emphasis Type="Italic">grandis</Emphasis> across a range of initial stockings in southern China

A large initial stocking × fertilizer factorial field trial established in 1993 with a Eucalyptus urophylla × grandis hybrid clone in southern Guangxi province, China, included 6 initial stocking treatments ranging from 667 to 2,222 trees ha⁻¹ and 6 fertilizer treatments. Growth data was collected at various intervals up to age 192 months and also data on outer-wood pilodyn penetration (as an indicator of wood density) and acoustic velocity through the outer-wood (as an indicator of modulus of elasticity) at the last assessment. This report examines the results for the main effect of initial stocking treatments and stocking × fertilizer interactions across ages. There were significant differences between initial stockings for both average individual tree volume and standing volume ha⁻¹ at all ages up to 144 months, but just average individual tree volume at 192 months. At ages up to 75 months total standing volume decreased as initial stocking decreased—maximum volume being obtained at 2,222 trees ha⁻¹. From 88 to 110 months the highest standing volume was obtained at 1,667 trees ha⁻¹ and then at ages 144 and 192 months, 833 trees ha⁻¹ provided the highest standing volume. Average individual tree volume at all ages generally increased as initial stocking decreased—the largest trees were obtained at 667 trees ha⁻¹. As age increased the proportional differences between tree volumes at higher and lower stockings increased—at age 27 months average individual tree volume at 667 trees ha⁻¹ was 72% greater than that at 2,222 trees ha⁻¹ and differences increased steadily with age up to 190% at 192 months. There were no significant differences between initial stockings for the properties of the outer-wood assessed by pilodyn penetration and acoustic velocity. Also, no significant interactions were found between initial stocking and fertilizer treatments for any traits at any ages implying that effects of initial stocking and fertilizer are additive for the traits assessed.     

Raman spectroscopic study on the behavior of boric acid in wood

 Raman spectra of Japanese cedar (Cryptomeria japonica D. Don) treated by vacuum impregnation with aqueous boric acid solutions (8.1 × 10⁻² to 7.29 × 10⁻¹ mol dm⁻³) were recorded using a near-infrared laser as an excitation source. Raman spectroscopic measurements were carried out on treated wood blocks of two sizes: 20(T) × 20(R) × 5(L) mm (A-type) and 15(T) × 15(R) × 50(L) mm (B-type). Our attention was focused on a prominent band (ν ₁) assigned to a symmetrical stretching vibration of the BO₃ group because no Raman band due to boron species was observed except bands of B(OH)₃. We observed a change in ν ₁ band intensity with increasing boric acid concentration in the aqueous solution used to treat the A-type wood blocks and investigated the correlation between the intensity and the peak-top wavenumber. Raman line maps in the longitudinal direction of the treated B-type wood blocks revealed that B(OH)₃ is concentrated near the cut ends. These results suggested that two groups of B(OH)₃ exist in wood in terms of the chemical species in the nearest neighbor sphere. Received: March 11, 2002 / Accepted: June 26, 2002     

How dense is my blue gum? prediction of whole-tree basic density of <Emphasis Type="Italic">Eucalyptus globulus</Emphasis>

Accurate prediction of whole-tree wood basic density (BD) from indirect density measures is important for estimating Eucalytpus globulus breeding values and genetic gain. We measured 100 E. globulus trees at 6.5 years of age on each of a high productivity site (Albany) and a low productivity site (Esperance), sampling 16 full-sib families and seven open-pollinated ‘check’ seedlots. On each tree we assessed pilodyn penetration at 1.3 m and BD of: (a) the outer 10 mm which was penetrated by the pilodyn pin of a bark-bark core, (b) a whole bark-bark core at 1.3 m, (c) a cross-sectional disk at 1.3 m and (d) the whole tree, represented by cross-sectional disks at five heights. Site effects and genetic values for families and checks were determined by mixed model analysis. A trend of increasing BD from pith to bark was more pronounced at Albany, where wood formed before age 3.5 years was 12 kg/m³ less dense than at Esperance (P = 0.01) and wood formed from 3.5 to 6.5 years was 27 kg/m³ denser than at Esperance (P < 0.001). Mean whole-tree BD was 19 kg/m³ greater at Albany (P < 0.001). Pilodyn penetration was well-correlated with BD of the 10 mm sample of penetrated wood and this relationship was not greatly affected by site variation. Genetic values for pilodyn penetration formed precise relationships with BD of breast-height discs and whole-tree BD although they were site-specific. Pilodyn penetration was a better predictor for genetic values of whole-tree BD than were bark-bark cores.     

Growth and wood basic density of acacia hybrid clones at three locations in Vietnam

Field trials testing a total of 27 clones of the interspecific hybrid Acacia mangium × A. auriculiformis and seedling controls of the parental species were established at Ba Vi and Yen Thanh in the north of Vietnam and Long Thanh in the south. At both Ba Vi and Yen Thanh there were significant (P < 0.001) differences in height and diameter at breast height (DBH) among 22 tested clones at 4 years. At Long Thanh, twelve hybrid clones did not differ significantly in DBH at age 3 years, but did (P < 0.001) at age 5 years. At the two northern sites the acacia hybrid clones had significantly greater DBH than control seedlots of the parental species. At Long Thanh, DBH of the hybrid clones and A. mangium was similar, with a genetically improved seedlot of A. mangium displaying the best DBH. Mean wood basic density at breast height of the acacia hybrid clones was 539 kg m⁻³ at Yen Thanh at age 8 years, and 473 kg m⁻³ at Long Thanh at age 5 years; density for A. mangium at Long Thanh was only slightly lower than the hybrid clones at 461 kg m⁻³. Linear regressions of Pilodyn penetration (PP) at breast height on wood basic density explained 60% of the variance in density of treatments (clones and control seedlots) at Yen Thanh and 36% at Long Thanh. There were significant differences between hybrid clones in PP at all three trial sites. Clonal DBH performance was not strongly correlated across the three trial sites; Pearson correlations of clone mean DBH between pairs of sites ranged from −0.47 to 0.20. Clonal rankings for PP were more stable, with Pearson correlations between pairs of sites ranging from r = 0.71 to 0.78.     

Moisture movement and thickness swelling in oriented strandboard. Part 2: Analysis using a nuclear magnetic resonance imaging body scanner

The previous paper in this series demonstrates the use of a nuclear magnetic resonance (NMR) micro-imaging system to observe the movement of liquid water through small specimens (11 × 16 mm² cross-section) of oriented strandboard (OSB) and solid wood. In the present paper, a NMR body scanner is utilized to obtain images of moisture penetration into ASTM D 1037–99 standard sized (152 × 152 mm²) thickness swelling specimens at different intervals during water soaking. As with the micro-imaging study, silicone was applied to the surfaces and edges of some of the specimens in order to observe the directional characteristics of moisture movement through OSB. Specimens with commercially applied edge sealant were also included in the study in order to observe the effectiveness of the sealant of reducing moisture penetration and thickness swelling. The presence of voids and areas of low density were shown to contribute significantly to moisture penetration into the specimens.     

Adhesive penetration in beech wood: experiments

A study with synchrotron radiation X-ray tomographic microscopy (SRXTM) of PUR, PVAc, and UF adhesive bond lines in beech wood, bonded under various growth ring angles, is presented. The bond line morphologies and the adhesive penetration into the wood structure were evaluated after determining the hardening characteristics of the adhesives. Distinct bond line imperfections were found for the different adhesive systems. To describe the adhesive distribution inside the bond line, the saturation of the pore space instead of the commonly used maximum penetration depth seems to be adequate.     

应用EDAX能谱仪SQ技术测定CCA防腐剂在木材中的渗透曲线

了解防腐剂在木材中的渗透情况传统的显色剂指示方法虽然能够直接观察到防腐剂的渗透深度,但无法了解防腐剂在木材各组织中的分布,更不能了解防腐剂在各层深度中的含量。 EDAX9100能谱仪可对试样进行定点、线扫描以及面扫描分析,对元素成分分析可以定性、定量。进行全定量分析时试样的几何条件要求比较严格,分析面必须光滑。木材试     

双钩异翅长蠹生物学特性及用防腐剂TWP防治试验

双钩异翅长蠹是橡胶树锯材及其制品的严重害虫。在海南岛1年完成二至三代,约有16种阔叶材被害。用新的水溶性木材防腐剂TWP进行防治试验的结果:①TWP在木材中保持量1.0kg/m~3,初龄幼虫死亡率100％;②新鲜橡胶树锯材用2％TWP真空加压或振荡加压法处理,药剂保持量不少于3.7kg/m~3,可获得长久的保护效力;③TWP不含氯化酚化合物,对人畜和环境十分安全。     

Pilodyn在桉树活立木材性质评估中的应用

测定了建立在广西22个4年生桉树无性系的Pilodyn值、木材基本密度、边材木材密度、心材木材密度和弹性模量。结果表明：Pilodyn值为9．44—15．41mm、木材密度为0．3514-0．4913g&#183;cm^-3、弹性模量在3．94GPa到7．53GPa之间;Pilodyn值在不同处理、不同方向及不同参试无性系间均存在极显著差异。Pilodyn值与各材性指标间的相关系数在-0．433到-0．755之间,呈显著到极显著负相关。研究表明,Pilodyn方法可以预测桉树活立木的木材密度和弹性模量。     

Digital X-ray analysis of density distribution characteristics of wood-based panels

Twelve commercial nominal 4 × 8 ft.² (1,200 × 2,400 mm²) wood-based panels, Medium Density Fiberboard, Particleboard, Oriented Strand Board and Plywood, were scanned for horizontal density distribution using a high resolution and accuracy digital X-ray system. Density distribution at a size of grid cell varying from 0.5 × 0.5 to 12 × 12 in.² (12.7 × 12.7 to 304.8 × 304.8 mm²) was analyzed based on the X-ray scanned images of the panels. Detailed density distribution characteristics of the four types of wood-based panels are presented in this research. Comparisons of density variation are carried out between different panel types and between different spatial resolutions (i.e. sizes of grid cells). Results of analysis and comparison in density distribution are presented in different forms with industrial as well as academic implications.