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Given an overall aim of improving Scots pine structural wood quality by selective tree breeding, we investigated the potential of non-destructive acoustic sensing tools to accurately predict wood stiffness (modulus of elasticity, MOE) and strength (modulus of rupture, MOR) of sawn boards. Non-destructive measurements of wood density (DEN), acoustic velocity (VEL) and MOE were carried out at different stages of wood processing chain (standing trees, felled logs and sawn boards), whilst destructively measured stiffness and strength served as benchmark traits. All acoustic based MOE and VEL estimates proved to be good proxies ( r A > 0.65) for sawn-board stiffness while MOE TREE and resistograph wood density (DEN HIT and resistograph wood density (DEN RES ) measured on standing trees and MOE LOG measured on felled logs well reflected board strength. Individual-tree narrow-sense heritability ( h i 2 ) for VEL, MOE and MOR were weak (0.05-0.26) but were substantially stronger for wood density (0.34-0.40). Moreover, additive genetic coefficients of variation for MOE and MOR were in the range from 5.4% to 9.1%, offering potential targets for exploitation by selective breeding. Consequently, selective breeding based on MOE FAK measured on felled logs well reflected board strength. Individual-tree narrow-sense heritability ( h i 2 ) for VEL, MOE and MOR were weak (0.05-0.26) but were substantially stronger for wood density (0.34-0.40). Moreover, additive genetic coefficients of variation for MOE and MOR were in the range from 5.4% to 9.1%, offering potential targets for exploitation by selective breeding. Consequently, selective breeding based on MOE TREE or stem straightness (STR) could improve several structural wood traits simultaneously.RES or stem straightness (STR) could improve several structural wood traits simultaneously.

The interactions among saprotrophic fungal species, as well as their interactions with environmental factors, may have a major influence on wood decay and carbon release in ecosystems. We studied the effect that decomposer diversity (species richness and assemblage composition) has on wood decomposition when the climatic variables and substrate quality vary simultaneously. We used two temperatures (16 and 21°C) and two humidity levels (70% and 90%) with two wood qualities (wood from managed and old-growth forests) of Pinus sylvestris. In a 9-month experiment, the effects of fungal diversity were tested using four wood-decaying fungi (Antrodia xantha, Dichomitus squalens, Fomitopsis pinicola and Gloeophyllum protractum) at assemblage levels of one, two and four species. Wood quality and assemblage composition affected the influence of climatic factors on decomposition rates. Fungal assemblage composition was found to be more important than fungal species richness, indicating that species-specific fungal traits are of paramount importance in driving decomposition. We conclude that models containing fungal wood-decay species (and wood-based carbon) need to take into account species-specific and assemblage composition-specific properties to improve predictive capacity in regard to decomposition-related carbon dynamics., (© FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Black ash (Fraxinus nigra Marsh.) is an important species for the W8banaki Nation, which uses its wood for traditional basketry. This study aimed to identify the wood properties required for black ash splints used in basketry. Eleven logs were selected and pounded into 26 longitudinal groups of annual wood layers, which were then transformed into splints. A quality class (high, medium, or low) was assigned by W8banakiak knowledge carriers to each group of rings. We measured wood density, ring width, modulus of elasticity, and modulus of rupture on samples located at the same radial position in wood bolts collected adjacently to the logs used for pounding. To investigate which wood properties were best related to the assigned wood quality class, we applied a generalized linear mixed model. Our model revealed a significant effect of ring width and average ring density on the probability to obtain a given wood quality class. Narrow- to medium-sized rings and relatively dense wood offered the best quality for basketry practice. Based on our results, further research on the effects of growth conditions that favour the production of high-quality black ash wood could be conducted to ultimately propose silvicultural treatments and management strategies. [ABSTRACT FROM AUTHOR]

Variability in Eucalyptus wood density and chemical properties is crucial to understanding important factors for the forest-based industry, such as sampling methods and wood suitability as raw material. This study aimed to evaluate the basic density and chemical composition of the radial positions of young wood from the Eucalyptus urophylla clone grown under different precipitation levels. Trees from E. urophylla clonal plantations were collected in Inhambupe, Jandaíra and Itanagra, Bahia State, Brazil. Trees' basic density and chemical composition (total extractive, lignin, hemicelluloses and α-cellulose) were determined based on the basal log of each tree, at four radial positions (1, 2, 3 and 4). It was found that the basic density and α-cellulose of wood are influenced by the cambial age and the site rainfall. There was greater increase in sections close to the bark (positions 1 and 4) and in more humid environments (sites Itanagra and Jandaríra). This finding highlights the association between wood basic density and chemical composition, mainly in the holocellulose content. [ABSTRACT FROM AUTHOR]

Wood quality has been an ongoing concern for science, having become increasingly important in the current context, in which the demand for wood is increasing and forest fires are more frequent and violent. This study aims to evaluate the quality of wood in trees affected by fires and the negative impact of these phenomena on the speed of wood degradation, as a result of weakening the trees due to the action of stress factors. The study was carried out using modern techniques on beech trees (Fagus sylvatica L.) remaining in an area affected by a litter fire in 2017. Measurements were taken with the Arbotom Rinntech sound tomograph, the IML Resi F-500S resist graph, and the Pressler core sampler to observe the quality of the wood inside the trees. It was found that all the trees were in various stages of decay, the tomograms being able to characterize the severity of decay only in the case of fully decayed wood as a result of the action of xylophages fungi, whose harmful influence is more pronounced when the injuries sustained by the trees are higher. Although the trees attempted to close the fire wounds through their own defense mechanisms, the destructive action of the fungi intensified with time. After the forest fires, for an effective assessment of the wood's internal quality, the resist graph can be used. For valuable trees, one could use the tomograph, but the measurements have to be taken only by qualified operators. [ABSTRACT FROM AUTHOR]

This study aims to compare the yield and quality of Teak wood from a Forest Industry Organization (FIO) plantation and a private teak plantation (PTP) in Thailand to provide guidelines for the sustainable utilization of teak wood. To quantify yields, we employed a randomized design at two locations (FIO and PTP), and determined volumetric proportions, the yields of milled teak and wood properties. We found that the whole lumber yield differed significantly (p≤0.05) between the two locations, although the yield of lumber sheets did not differ (p>0.05). While more teak wood was produced at the FIO plantation than the PTP, the sawing techniques used at the two locations resulted in no significant difference in wood yield. Wood drying had significantly different effects (p≤0.05) between the two locations, but the drying method did not differ (p>0.05). Overall, the lumber yields were greater for timber harvested from an FIO plantation than a PTP. Even though there are differences in sawing techniques adopted, the final lumber yield did not differ significantly between these two sources. The mechanical properties of teak wood improved with kiln drying, FIO plantation exhibits better properties than dried wood from the PTP. [ABSTRACT FROM AUTHOR]

This study investigated the mechanical properties of beech (Fagus sylvatica L.) and fir (Abies alba) wood from Bosnia and Herzegovina under outdoor exposure. Samples were exposed for 3-month exposure to assess bending strength, color changes, and surface quality. Results showed outdoor exposure negatively affected mechanical properties, particularly in samples with extended finger joints, causing significant surface cracks in uncoated samples. Beech wood exhibited notable color changes under exposure, with approximately 50% darkening without coating compared to 25% under covered conditions. Coated samples displayed minimal color changes, affirming the efficacy of surface treatment. Fir wood exhibited a roughness of 8.264 μm, while beechwood average roughness increased from 6.767 to 13.916 μm after exposure, with micro-pore development affecting water performance. Microscopic analysis identified prevalent fungal colonies, including Penicillium, Aureobasidium, Sclerophoma, and Chaetomium, underscoring their role in organic matter decomposition. This study highlights the importance of wood exposure and treatment selection for various applications. [ABSTRACT FROM AUTHOR]

Castanopsis hystrix, a precious tree species in Southeast Asia, has the advantages of rapid growth and high-quality wood materials. However, there are problems such as its long breeding cycle and low efficiency, and being time-consuming, which greatly restricts the industrial development of C. hystrix. Performing genome selection (GS) for growth and wood traits for the early selection of superior progeny has great significance for the rapid breeding of new superior varieties of C. hystrix. We used 226 clones in the main distribution and 479 progenies within 23 half-sib families as experimental materials in this study. Genotyping datasets were obtained by high-throughput re-sequencing technology, and GS studies were conducted on the growth (tree height (H), diameter at breast height (DBH)) and wood (wood density (WD), fiber length (FL), and fiber length–width ratio (LWR)) traits. The coefficient of variation (CV) of five phenotypic traits ranged from 10.1% to 22.73%, the average CV of growth traits was 19.93%, and the average CV of wood traits was 9.72%. The Pearson correlation coefficients between the five traits were almost all significantly positive. Based on the Genomic Best Linear Unbiased Prediction (GBLUP) model, the broad-sense heritabilities of growth traits were higher than those of wood quality traits, and the different number of SNPs had little effect on the heritability estimation. GS prediction accuracy first increased and then reached a plateau at around 3K SNPs for all five traits. The broad-sense heritability of these five traits was significantly positively correlated with their GS predictive ability (r = 0.564, p < 0.001). Bayes models had better GS prediction accuracy than the GBLUP model. The 15 excellent progeny individuals were selected, and their genetic gain ranged from 0.319% to 2.671%. These 15 superior offspring individuals were 4388, 4438, 4407, 4468, 4044, 4335, 4410, 4160, 4212, 4461, 4052, 4014, 4332, 4389, and 4007, mainly from three families F5, F6, and F11. Our research lays out the technical and material foundation for the rapid breeding of new superior varieties of C. hystrix in southern China. [ABSTRACT FROM AUTHOR]

Accurate detection of wood surface defects plays a pivotal role in enhancing wood grade sorting precision, maintaining high standards in wood processing quality, and safeguarding forest resources. This paper introduces an efficient and precise approach to detecting wood surface defects, building upon enhancements to the YOLOv8 model, which demonstrates significant performance enhancements in handling multi-scale and small-target defects commonly found in wood. The proposed method incorporates the dilation-wise residual (DWR) module in the trunk and the deformable large kernel attention (DLKA) module in the neck of the YOLOv8 architecture to enhance the network's capability in extracting and fusing multi-scale defective features. To further improve the detection accuracy of small-target defects, the model replaces all the detector heads of YOLOv8 with dynamic heads and adds an additional small-target dynamic detector head in the shallower layers. Additionally, to facilitate faster and more-efficient regression, the original complete intersection over union (CIoU) loss function of YOLOv8 is replaced with the IoU with minimum points distance (MPDIoU) loss function. Experimental results indicate that compared with the YOLOv8n baseline model, the proposed method improves the mean average precision (mAP) by 5.5%, with enhanced detection accuracy across all seven defect types tested. These findings suggest that the proposed model exhibits a superior ability to detect wood surface defects accurately. [ABSTRACT FROM AUTHOR]

Trees in breeding programmes are often selected at 1/4–1/3 of rotation, called 'early selection', which is typically between 8 and 10 years in radiata pine. However, differences between populations and genotypes selected for either basic density or wood stiffness are already apparent at age 2. We report the application of very early screening techniques for wood properties in the New Zealand Radiata Pine Breeding Programme deployment populations. Approximately 3000 trees representing three populations with 92 families and 10 clones were grown in a common garden trial, leaning for 21 months to separate compression and opposite wood. The trees were harvested and analysis carried out separately by wood type. The trial showed the existence of large variability in wood properties at early age, in some cases similar to variability near rotation age, and moderate to high degree of genetic control ( 0.35 ≤ h 2 ≤ 0.71 ). The genetic association between traits was strong, particularly between wood stiffness and longitudinal shrinkage ( - 0.69 ) and between longitudinal and volumetric shrinkage (0.83), suggesting that improving stiffness would also have a strong effect on improving dimensional stability. Basic density was also associated with stiffness and shrinkage, but with lower predictive capacity. These results can be used for roguing deployment populations-which already contain superior growing trees-and quickly upgrade the wood quality of seeds and clones currently available to New Zealand forest growers. We discuss necessary modifications to turn this research work into operation to screen any new material before commercial release. [ABSTRACT FROM AUTHOR]

Cost-effective, non-destructive means of estimating wood properties of eucalypts grown in Guangxi, China, were evaluated using near infrared (NIR) spectroscopy and resistance drilling. For this evaluation, wood samples for NIR analysis and resistance drill measurements were collected from 581 trees, representing eight plantation Eucalyptus taxa across five sites. The near infra-red (NIR) spectra collected from the 581 wood samples were analysed using existing calibrations for kraft pulp yield, cellulose content, hot water extractives and Klason lignin. These spectra and calibrations were effective in predicting over 60% of the variance in total carbohydrates and over 80% of the extractives and lignin values from independent laboratory analysis of a subset of 100 samples. Resistance drilling combined with software developed for processing the drill data proved to be a quick, low cost and effective means of quantifying wood density (as amplitude of the drill torque), stem diameter and bark thickness. [ABSTRACT FROM AUTHOR]

This study explores attitudes toward sustainable-timber resource management and climate-change mitigation by extending the life cycles of wood products and their cascading in Central and Southeastern Europe. A comprehensive survey involving the general public and professional organizations in Bosnia and Herzegovina, Croatia, Serbia, and Slovenia, reveals significant support for wood product reuse in construction, emphasizing ecological aspects and sustainability. Despite doubts about wood product quality, motivation for reuse remains high. Challenges, including limited availability and cost, are acknowledged. Reusing and recycling wood products at the end of their life cycle can extend the life of the wood resource and reduce carbon emissions. Cascading is a promising way to combat climate change and prolong the life cycle of wood products. This study highlights the potential of cascading wood use, underscores the necessity to improve the quantification of wood usage through material intensity analysis of buildings, and emphasizes the requirement for more comprehensive education and explanations to promote sustainable practices. [ABSTRACT FROM AUTHOR]

Membrane emulsification technology has garnered increasing interest in emulsion preparation due to controllable droplet size, narrower droplet size distribution, low energy consumption, simple process design and excellent reproducibility. Nevertheless, the pore structure and surface engineering in membrane materials design play a crucial role in achieving high-quality emulsions with high throughput simultaneously. In this work, an oriented interpenetrating capillary network composed of highly aligned and interconnected wood cell lumens has been utilized to fabricate an emulsion membrane. A novel honeycomb porous ZnO layer obtained by a seed prefabrication–hydrothermal growth method was designed to reconstruct wood channel surfaces for enhanced microfluid mixing. The results show that through the unique capillary mesh microstructure of wood, the emulsion droplets were smaller in size, had narrower pore-size distribution, and were easy to obtain under high throughput conditions. Meanwhile, a well-designed ZnO layer could further improve the emulsion quality of a wood membrane, while the emulsifying throughput is still maintained at a higher level. This demonstrates that the convection process of the microfluid in these wood capillary channels was intensified markedly. This study not only develops advanced membrane materials in emulsion preparation, but also introduces a brand-new field for functional applications of wood. [ABSTRACT FROM AUTHOR]

Tectona grandis L. f. (teak) is highly valued in the international market, but its volume and properties vary depending on its genetic material and planting site. Evaluating these factors is crucial for promoting new plantations. Therefore, this study aimed to assess the impact of genetic material (clones TG1 and TG3 and seminal material) and planting site (Nova Maringá and Água Boa, Mato Grosso, Brazil) on morphological parameters (heartwood, sapwood, bark, pith proportions, and pith eccentricity), physical properties (shrinkage and air-dry density), and mechanical properties (static bending strength—fm, compressive strength—fc0, Janka hardness—fH90, and shear strength—fv0). For this purpose, we sampled five trees aged 13 years per genetic material from commercial plantations. In Nova Maringá, trees exhibited, on average, 56.07% heartwood, while in Água Boa, this value was less than 50%. Seminal material showed the lowest percentage of heartwood (49.2%). The pith percentage was significantly greater in Água Boa than in Nova Maringá, regardless of the genetic material. We observed the highest standard deviation (5.61) in pith eccentricity for the seminal material. Both the planting site and genetic material influenced the air-dry density (~12% moisture content), which ranged from 0.535 to 0.618 g·cm−3. Trees grown in Nova Maringá produced wood with higher dimensional stability than those from Água Boa, exhibiting a 14% lower radial shrinkage and a 6% lower volumetric variation. In Nova Maringá, the wood from the seminal material exhibited greater resistance. On the other hand, in Água Boa, that material showed lower resistance (fv0, fm, and fc0), or there was no significant difference (fH90) compared to the clonal materials. When comparing the clonal materials (TG1 and TG3) at each planting site, they demonstrated similar mechanical properties. The variability in physical and mechanical properties among different genetic materials and planting locations highlights the need to select appropriate teak genetic materials for each region. We concluded that more productive teak clones can be selected without compromising the physical and mechanical properties of the wood. [ABSTRACT FROM AUTHOR]

Understanding how thinning strategies impact wood quality and quantity for different purposes is of interest, given that plantation management is often based on parameters that require validation under varying growth conditions. Planted forests for solid purposes in the northern region of Urugay, western Argentina and South of Brazil are usually managed in initial stockings ranging from 800 to 1200 trees·ha−1 depending on the use of clones or seeds. Subsequent thinnings are applied (at plantation ages varying from 3 to 11 years) up to final stockings of around 200 trees·ha−1. This study evaluated contrasting thinning regimes applied early in the crop cycle, with an initial tree density of 840 trees·ha−1. Two thinning treatments were applied at 1.5 and 7.3 years, reducing tree densities to 700–400 and 400–100 trees·ha−1, respectively. Growth analyses were conducted from 1.5 to 20.8 years, considering total height, diameter at breast height, individual volume, total and commercial volume per hectare, mean annual increase, and current annual increase. At the final harvest, contrasting tree densities of 100, 250, and 400 trees·ha−1 were sampled to assess wood density and mechanical properties (bending and compression on small-scale clear samples). Individual growth and wood properties were related to a Stand Density Index to understand the effect of competition on these values. The results identified thinning regimes that resulted in the most significant individual and per-hectare growth (both in thinning and clear felling) and the optimal harvest time under specific growth conditions. We assessed the proportions of commercial logs for sawmill and pulp uses, providing valuable inputs for subsequent economic analyses of thinning regimes aiming for the most convenient combination of wood products. Wood's physical and mechanical properties were relatively little affected by contrasting levels of competition between trees; therefore, the choice of silvicultural system will depend on production and economic criteria. [ABSTRACT FROM AUTHOR]

Chemical modification is an efficient strategy for improving wood quality; however, for some fast-grown wood species unwanted shrinkage occur upon treatment with alkaline solution. This study was devised to reveal the shrinkage behavior of poplar and radiata pine woods treated with 5, 10, 15 and 20 % alkaline sodium silicate (SS) solutions. Wood treated with sodium hydroxide (SH) solution adjusting to the same pH as the specific SS solution was used as a reference sample. The weight loss, chemical components analysis, and confocal microscopy revealed that treatments with SS caused considerable reductions in hemicellulose and acid-insoluble lignin (AIL) of poplar wood up to 51 % and 21 %, respectively. In contrast, such reductions of the SS-treated radiata pine wood were only 13 % and 2 %, respectively. Consequently, shrinkage of poplar wood in the tangential- and radial-directions reached up to 22 % and 11 % respectively. However, such shrinkage for radiata pine was less than 2 % in either direction. The crystallinity index of poplar and radiata pine woods after treatment increased up to 35.3 % and 4.8 %, respectively, attributable to removal of the amorphous fraction. The scanning electron microscopy displayed that treatments had minor effect on the cell structure of radiata pine, but brought about significant collapse of poplar cells. The above results show that radiata pine is more chemically stable to alkaline treatment than poplar. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the wood chemical and energetic characteristics of Eucalyptus spp. clones planted in three sites in the Midwest of Brazil. Thus, five clones from Eucalyptus spp. were planted in different sites aiming to determine the qualitative characteristics of the wood resulting from the variation in the tree growth environment and the genetic material. The same clones were planted in the three sites to determine the genotype × environment interaction. The trees were then sampled at 5 years after planting for their physical–chemical and energetic characterization. The results showed that the wood characteristics vary in different proportions according to the clone, just as the growth environment of the trees alters the behavior of the clones for the same characteristics. The edaphic variables affected the wood characteristics, inferring that the water content in the soil has more effect on the wood properties than the water content in the air, mainly on wood basic density. The results of this study indicate that using the appropriate genotype related to the environment conditions determines the wood characteristics, since the wood properties are strongly influenced by the edaphoclimatic variables. [ABSTRACT FROM AUTHOR]

The IML PD series Resi is a device used to assess the drilling resistance of wood. The IML PD series Resi instrument is being widely adopted for commercial wood quality assessment due to its speed, cost-effectiveness, and precision when combined with web-based trace processing. Collecting Resi data with fixed feed speed and RPM settings is challenging due to inherent basic density variations within and between tree species. Altering these settings affects the drilling resistance amplitude of the Resi data, impacting basic density predictions. This study introduces the concept of chip thickness to combine feed speed and RPM into a single parameter to minimise the effects of different sampling conditions on the basic density predictions. Regression models, with chip thickness as the regressor variable, account for 97% to 99% of variance in mean Resi outerwood amplitude across six species. The demonstrated adaptability of chip thickness for adjusting feed speed and RPM settings, along with species-specific functions correlating it with Resi amplitude, holds promise for standardizing amplitude values across diverse feed speeds and RPM settings. Optimal sampling conditions needed to predict basic density lie within the 30%–40% amplitude range. To drill a ~30 cm diameter tree, the recommended fastest settings were 200 cm/min and 3500 RPM for Southern Pine (Pinus elliottii var. elliottii (Engelm) × Pinus caribaea var. hondurensis (Sénéclauze)) and Radiata Pine (Pinus radiata (D. Don.)), 200 cm/min and 2500 RPM for Hoop Pine (Araucaria cunninghamii (Mudie)), 50 cm/min and 5000 RPM for Spotted Gum (Corymbia citriodora subsp. variegata (F. Muell.)), 200 cm/min and 4500 RPM for White Cypress (Callitris glaucophylla (Thompson & Johnson)), and 150 cm/min and 3500 RPM for Shining Gum (Eucalyptus nitens (H. Deane & Maiden) Maiden) based on the billets sampled. [ABSTRACT FROM AUTHOR]

This study explores the perspectives and practices of architects regarding the reuse of wood in construction across five South–Central European countries: Slovenia, Serbia, North Macedonia, Bosnia and Herzegovina (BiH), and Montenegro. Based on a survey of architectural professionals, this research explores their attitudes, challenges, and motivations for using reclaimed wood, with a focus on circular construction principles. Key findings reveal unanimous agreement among respondents that both their profession and government entities inadequately support or promote wood reuse within the context of circular construction. While architects value reclaimed wood, there are country-specific variations. Environmental benefits, unique aesthetics, historical value, and sustainability are cited as primary motivators for reclaimed wood use. Additionally, respondents emphasize the ecological aspect as the most important consideration in wood product reuse, followed by economic and technological factors. Common concerns revolve around the long-term quality and maintenance of wood products. This research provides insights into the challenges and opportunities surrounding reclaimed wood use in South–Central Europe, highlighting the need for support mechanisms and increased awareness to advance circular construction practices in the region. These findings can have implications for architects and investors by identifying market opportunities, promoting eco-friendly practices, and providing valuable insights for future building designs with a focus on reclaimed wood elements within circular construction. [ABSTRACT FROM AUTHOR]

European forests are facing ongoing climate change, and certain tree species are being critically impacted. The Norway spruce (Picea abies (L.) Karst.) is one of the most sensitive species to climate fluctuations, a fact manifesting itself through massive dieback resulting in a lack of high-quality timber and timber market destabilization. Therefore, the possibility of wood substitution with non-native spruce species, namely, black spruce (Picea mariana (Mill.) Britt., Sterns, et Poggenburg), Serbian spruce (Picea omorika (Pančić) Purk.), and blue spruce (Picea pungens Engelm.), under the specific conditions of forest reclamations with great potential for future afforestation was tested. Wood density, modulus of rupture, and modulus of elasticity were used to evaluate wood quality in comparison with native Norway spruce. The results confirmed that only the Serbian spruce reached the quality of Norway spruce and even exceeded it in terms of wood density (P. omorika 525 kg·m−3 vs. P. abies 517 kg·m−3) and exhibited comparable parameters with regard to other properties. The density of the other species was significantly lower for blue spruce (476 kg·m−3) and black spruce (468 kg·m−3). A similar trend was found for other wood parameters, which confirmed that Norway spruce quality was nearly comparable with that of Serbian spruce. On the other hand, black spruce and blue spruce did not match the quality of Norway spruce. The within-stem variability of the properties tested was low for all the spruce species examined. In conclusion, the Serbian spruce showed great potential for future usage in forest management and is one of the possible methods of Norway spruce replacement in times of unprecedented forest disturbances under the effects of global climate change. [ABSTRACT FROM AUTHOR]

Selecting individuals in breeding programs for pulp production, the physical and chemical wood traits must be considered in the genotype selection. In this study, trees from hybrid progeny tests of Corymbia torelliana x Corymbia citriodora (CTOxCCT) and progenies of Eucalyptus dunnii (EDU) were investigated. Sawdust of genetically selected standing trees was collected, classified and prepared for near infrared (NIR) spectra readings. The chemical properties of the selected trees were determined through kraft pulping. Predictive models for each property were developed based on the reference data and NIR spectra. Two approaches for models were developed. The first approach, models were fitted with 25 samples of CTOxCCT, and in the second approach, models were fitted using 61 samples (25 of CTOxCCT and 36 of EDU). The estimated R²cv values were 0.60 and 0.73 for basic chip density, 0.37 and 0.65 for extractive contents, 0.56 and 0.53 for total lignin contents, 0.63 and 0.66 for S/G ratio, and 0.52 and 0.77 for screened pulp yield for the first and second approaches, respectively. All developed models have potential for ranking trees in breeding programs. NIR spectroscopy can potentially be applied as a high-throughput field phenotyping tool where thousands of varieties need to be evaluated. [ABSTRACT FROM AUTHOR]

Quantitative anatomical characteristics and their radial variation in compression (COW), lateral (LAW), and opposite (OPW) woods of Agathis loranthifolia and Pinus merkusii stem woods growing in Indonesia were observed and compared to understand wood quality. The length, diameter, wall thickness, and lumen diameter of tracheids and ray height and numbers were observed using optical microscopy. In both species, COW had the shortest tracheid length, smallest tracheid and lumen diameter, thickest cell wall, and highest ray numbers among the parts, while LAW and OPW showed comparable or variable values in quantitative characteristics. In A. loranthifolia, COW had the highest ray height, whereas, in P. merkusii, it had the lowest uniseriate and fusiform ray heights. No significant difference was observed in ray numbers and heights between LAW and OPW. In both species, the tracheid length and lumen-to-diameter ratio in COW, LAW, and OPW tended to increase from near the pith to near the bark while the wall-to-diameter ratio decreased. The ray heights of all parts increased with increasing distance from the pith, whereas the ray number decreased. [ABSTRACT FROM AUTHOR]

The article presents the impact of drying process and selected parameters on the color changes on the surface of pine wood (Pinus sylvestris L.). Three predetermined process conditions (modes), mild, normal, and intensive, were investigated. The experiments were conducted using a semi-industrial scale dryer designed at the Gdańsk University of Technology with a loading capacity of 0.55 m3. The drying process was applied to pine wood grown in the northern part of Pomeranian region in Poland. The specimens were selected taking into consideration the radial angle of the growth rings. During each drying mode, 25 pieces of wood with dimensions (thickness, width, length) of 0.03 m, 0.2 m, and 1.5 m, respectively, were dried. The total color change (E) after drying process and color saturation (h*) before and after drying processes of the wood surface was determined using the normalized CIELAB methods. The obtained results indicated that the color change of the pine wood surface increased simultaneously with the intensification of the drying process. However, the normalized wood quality after drying under intensive drying process conditions remained within the standard limits. The application of intensive drying process conditions remarkably changes the surface color of the obtained material, while remarkably reducing the drying process duration. [ABSTRACT FROM AUTHOR]

Limited research exists on wood properties in E. nitens × E. globulus hybrid genotypes grown in water-limited conditions generated by the climate change influence in Mediterranean areas. The EUCAHYDRO project aimed to assess environmental stress impacts on eucalyptus genotypes, including responses to reduced water availability, and to evaluate wood density and resistance using the non-destructive drill resistance technique. This study focused on 10-year-old E. nitens × E. globulus hybrids and Eucalyptus badjensis Beuzev. & Welch, revealing that low irrigation led to a 13% (p < 0.05) decrease in diameter and a 6.5% (p > 0.05) increase in wood density for the hybrids. On the contrary, E. badjensis demonstrated a noteworthy 22% increase in wood density (p < 0.05), while showing a corresponding 0.6% growth increase (p > 0.05), as measured by the diameter at breast height. Drill resistance measurement results indicated that E. nitens × E. globulus' amplitude ranged from 20.1% to 26.6%, while E. badjensis' ranged from 20.8% to 27.2%. The study revealed a high correlation between resistance amplitude and wood density, with coefficients of 0.97 observed for E. nitens × E. globulus and 0.84 for E. badjensis (p < 0.05). These findings fall within the range reported in similar studies involving Eucalyptus spp. The primary focus of the research was to assess the growth potential and wood quality of novel Eucalyptus spp. under conditions of water limitation. The study also explored the utility of drill resistance as a predictive measure for evaluating wood density as an indicator of wood quality. [ABSTRACT FROM AUTHOR]

The evaluation of surface quality after milling still represents a challenge due to the stratified structure of wood. In this paper, the surface quality of beech wood obtained by profile milling was analyzed differentiating between tool marks, fuzzy grain, and accidental surface gaps overlapped onto the deep anatomical cavities. The samples were milled at two rotation speeds, 3308 rpm (n1) and 6594 rpm (n2), and two feed speeds of 6.53 m/min (vf1) and 23.74 m/min (vf2). After the samples were cut, approximately 600 m of beech wood were further processed before measuring the surface quality again. The surface waviness measured by Wa increased more than double when the feed speed increased from vf1 to vf2. Rk increased with the feed speed (with the feed per tooth, fz, for a constant n, respectively) for n2 by a significant 57%. An increase in the rotation speed from n1 to n2 has reduced Rk, but the effect was not significant. The processing quality, Rk, measured at different depths did not differ statistically, in spite of the local differences in the cutting speed. The moment of measuring the surface roughness, such as immediately after sharpening or after a working period, influenced the surface quality. After the tool processed 600 m of beech material, the surface quality improved by 30%. The statistical analysis showed that the most important factor affecting the surface quality was the feed speed (implicitly fz, for constant n and number of cutters). [ABSTRACT FROM AUTHOR]

Understanding the durability of emerging plantation hardwood resources is important for optimising their production and use. This study compared timber density, extractives content and decay resistance in 12–13-year-old plantation and native forest regrowth Gympie messmate (Eucalyptus cloeziana) trees. Density increased from pith to bark for both plantation and native forest trees. Inner heartwood density of the plantation timber was significantly lower than that of the native forest regrowth timber. While the total extractives content of the outer heartwood was comparable in the plantation and native forest regrowth trees, the inner heartwood of the latter contained significantly greater extractives levels. Laboratory decay tests showed that all heartwood zones of plantation and native forest regrowth Gympie messmate were resistant to decay by the white rot Pycnoporus coccineus. The inner heartwood of the plantation timber was, however, susceptible to decay by the brown rot Fomitopsis ostreiformis. The results illustrate the potential variations in wood quality parameters to be considered when moving from native forest to plantation resources that are harvested at a younger age and managed for more rapid wood production. [ABSTRACT FROM AUTHOR]

The acoustic vibration performance of wood affects the quality of many musical instruments, and the variability of wood causes obvious differences between individual timber samples. To mitigate the variations among the individual timber samples intended for musical instruments, in this study, we combined finite element simulation with experimental testing to investigate the effect of the periodic annular groove structure on the comprehensive acoustic vibration characteristics of wood. The results revealed that there are discernible correlations between the structural parameters of the periodic annular groove and the key acoustic parameters of wood, including the resonant frequency, equivalent dynamic modulus of elasticity, equivalent specific dynamic modulus of elasticity, equivalent acoustic radiation quality constant, and equivalent acoustic impedance. These relationships can be used to fine-tune the overall acoustic vibration performance of wood and harmonize the acoustic vibration characteristics among different timber specimens. The effects of the periodic annular groove structure on the five acoustic vibration parameters obtained through finite element simulations exhibited minimal differences to the corresponding results from experimental tests. Furthermore, there was a remarkably strong correlation between the outcomes of the finite element simulations and the experimental test results, with the coefficient of determination exceeding 0.99. [ABSTRACT FROM AUTHOR]

The present work aimed to evaluate the wood of fourteen genetic materials (nine species, between native and exotic, and five clones of Eucalyptus) cultivated under two post-planting irrigation regimes in the Brazilian semiarid region. For each genotype, six trees (11 years old) were selected and subjected to two initial irrigation regimes (up to 12 months and up to 36 months) after planting. Discs of different stem heights were taken: 0% (base), breast height (DBH), 20%, 40%, 60%, 80%, and 100%. Samples were extracted along the radial axis of each disk at three regions (the pith-adjacent region, intermediate region, and bark-adjacent region). Samples were subsequently saturated in water to determine their density via the water displacement method. The irrigation systems caused changes in the pattern of radial and longitudinal variation in the clones regarding the proportion of woody material in the stem. Among the native species, Angico stood out with a high density and little juvenile wood, and Pau d'arco, with a low density and a high rate of juvenile wood. Among the exotic species, Nim presented a high density and a low rate of juvenile wood, and Chichá presented a high rate of juvenile wood and a low density. In the Eucalyptus hybrids, VE38 stood out with a high density. Overall, there was an influence from irrigation management, observed with greater intensity in exotic species for Mahogany and Acacia and for the VE41 and AEC1528 clones of Eucalyptus. The values of basic densities in the trees varied from 0.35 to 0.85 g·cm−3. There was good adaptation of native and exotic species and clones to the planting area in the Semiarid region. [ABSTRACT FROM AUTHOR]

The quality control of thermally modified wood and identifying heat treatment intensity using nondestructive testing methods are critical tasks. This study used near-infrared (NIR) spectroscopy and machine learning modeling to classify thermally modified wood. NIR spectra were collected from the surfaces of untreated and thermally treated (at 170 °C, 212 °C, and 230 °C) western hemlock samples. An explainable machine learning approach was practiced using a TreeNet gradient boosting machine. No dimensionality reduction was performed to better explain the feature ranking results obtained from the model and provide insight into the critical wavelengths contributing to the performance of classification models. NIR spectra in the ranges of 1100–2500 nm, 1400–2500 nm, and 1700–2500 nm were fed into the TreeNet model, which resulted in classification accuracy values (test data) of 94.35%, 89.29%, and 84.52%, respectively. Feature ranking analysis revealed that when using the range of 1100–2500 nm, the changes in wood color resulted in the highest variation in NIR reflectance amongst treatments. As a result, associated features were given higher importance by TreeNet. Limiting the wavelength range increased the significance of features related to water or wood chemistry; however, these predictive models were not as accurate as the one benefiting from the impact of wood color change on the NIR spectra. The developed framework could be applied to different applications in which NIR spectra are used for wood characterization and quality control to provide improved insights into selected NIR wavelengths when developing a machine learning model. [ABSTRACT FROM AUTHOR]

Wood density is a crucial factor in determining the quality of wood in boreal ecosystems within the Northern Hemisphere. Climate variables play a significant role in shaping wood density, posing challenges for forest managers and stakeholders in the wood industry to adapt amidst climate change. However, our current understanding of these effects remains incomplete. This systematic literature review explores the multifaceted influences on wood density in the boreal zone, encompassing both climate-related and non-climatic factors. The findings demonstrate that warmer temperatures can cause both increases and decreases in wood density, primarily due to their impact on tracheid lignification and cell wall thickening. Nonetheless, the outcome depends on various factors, including species type, age, soil conditions, presence of pests and diseases, fire, windstorms, and silviculture practices. The quantification of complex relationships between these factors and wood density has been insufficient in existing literature. Understanding the impacts of both climate and non-climate factors on wood density is essential for fostering a sustainable wood industry, while effectively mitigating adverse effects and maximizing benefits. Forest managers can leverage this knowledge to optimize wood production strategies, ensuring long-term ecological resilience amidst the increasingly variable climate challenges. [ABSTRACT FROM AUTHOR]

To improve the processing quality of wood products, the effects of different wood microstructure on the cutting quality of cherry wood were studied in the experimental process of gas-assisted laser processing. Based on the absorption ability of wood relative to laser wavelength, the composite processing of CO2 laser and inert gas was carried out. Kerf width and surface roughness were used as evaluation indexes, with analysis by factor experiments. The results showed that under the same parameter conditions, due to the difference in internal structure of wood, the cavity structure in the tracheid was more conducive to the diffusion and absorption of laser energy during perpendicular cutting. In addition, the kerf width and surface roughness of parallel cutting were smaller than that of perpendicular cutting. The microscopic morphology and surface carbon content of the kerf surface showed that during perpendicular cutting, due to the plugging effect of small holes, heat accumulation was not conducive to the flow of flue gas and carbide; thus carbon particles remained in the tracheid, and the carbon content of kerf surface was higher. [ABSTRACT FROM AUTHOR]

The band saw blade, used on the wood log cutting, is exposed in service manufacturing to applications which can cause mechanical damages and affect the quality of the tool and the wood produced. To related applications, the shear stress is essential to the correct wood machining. the proposal of this paper was the numerically analyze the influence of the parallel shear force, applied vertically at the saw blade tooth, in response to the normal longitudinal tensions (sy) in service. A numeric model was constructed, by using of the commercial software based on the Finite Elements Method (FEM). In a first analysis, only a tensile stress was applied to the model on the upper edge of the blade, the deformation results obtained were used in the secondary analysis, with the simultaneous application of vertical point loads on the saw teeth. [ABSTRACT FROM AUTHOR]

Forestry measurement is aimed at volumetric production of wood; however, for the pulp processing industry, the main interest is productivity in wood biomass and, to know this variable, it is necessary to determine the basic wood density (BWD) beforehand. Artificial neural networks (ANN) have been used in the forestry sector quite successfully to describe the dynamics of forest characteristics, such as estimating wood volume. In this context, the objective of this study was to assess the accuracy of the basic wood density estimates by means of ANN's with Continuous Forest Inventory (CFI) and edaphoclimatic input variables. The database consisted of 3,797 data, from permanent plots of the CFI conducted in Eucalyptus sp stands and edaphoclimatic data from the planting sites. The five best ANNs were selected and the analysis of the estimates was carried out through the correlation between the estimated and BWD, the relative root mean square error (RMSE%) and graphical information. It was observed that both the CFI, edaphoclimatic information and the combination of both are potential and present similar results for the basic wood density estimate, and the errors associated with the estimates are between 3.9% to 3.5%. The ANNs based only on the CFI information presented higher RMSE. The use of ANN's is feasible for estimating BWD and allows for excellent accuracy statistics. [ABSTRACT FROM AUTHOR]

Deadwood is an important yet understudied carbon pool in tropical ecosystems. Wood microclimate, as defined by wood moisture content and temperature, drives decomposer (microbial, termite) activities and deadwood degradation to CO2. Microclimate is strongly influenced by local climate, and thus, climate data could be used to predict CO2 fluxes from decaying wood. Given the increasing availability of gridded climate data, this link would allow the rapid estimation of deadwood-related CO2 fluxes from tropical ecosystems worldwide. In this study, we adapted a mechanistic fuel moisture model that uses weather variables (e.g. air temperature, precipitation, solar radiation) to characterize wood microclimate along a rainfall gradient in Queensland, Australia. We then developed a Bayesian statistical relationship between microclimate and CO2 flux from pine (Pinus radiata) blocks deployed at sites and combined this relationship with our microclimate simulations to predict CO2 fluxes from deadwood at 1-hour temporal resolution. We compared our pine-based simulations to moisture-CO2 relationships from stems of native tree species deployed at the wettest and driest sites. Finally, we integrated fluxes over time to estimate the amount of carbon entering the atmosphere and compared these estimates to measured mass loss in pines and native stems. Our statistical model showed a positive relationship between CO2 fluxes and wood microclimate variables. Comparing cumulative CO2 with wood mass loss, we observed that carbon from deadwood decomposition is mainly released as CO2 regardless of the precipitation regime. At the dry savanna, only about 19 % of the wood mass loss was released to CO2 within 48 months, compared to 86 % at the wet rainforest, suggesting longer residence times of deadwood compared to wetter sites. However, the amount of carbon released in-situ as CO2 is lower when wood blocks are attacked by termites, especially at drier sites. These results highlight the important but understudied role of termites in the breakdown of deadwood in dry climates. Additionally, mass loss-flux relationships of decaying native stems deviated from that of pine blocks. Our results indicate that wood microclimate variables are important in predicting CO2 fluxes from deadwood degradation, but are not sufficient, as other factors such as wood traits (wood quality, chemical composition, and stoichiometry) and biotic processes should be considered in future modeling efforts. [ABSTRACT FROM AUTHOR]

Planting spacing plays an important role in tree growth and wood formation. Thus, the aim of this study was to determinate how planting spacing and genetic material affect the radial variation of basic density and chemical composition of wood. The sampling of this study was based on 4 clones of Eucalyptus urophylla × Eucalyptus grandis at 5 years of age planted in four spacings (3 × 1, 3 × 2, 3 × 3 and 3 × 4 m). To determine the basic density (BD), extractive (EXT) and lignin (LT) content, wood discs were removed at breast height, which were sectioned in three radial positions (pith, intermediate and sapwood). The results showed that genetic material, planting spacing and radial position affected the values of BD, EXT and LT content. The BD and EXT content tended to increase with increased planting spacing, while the LT content tended to decrease. In relation to the radial variation, the basic density showed an increase in the pith-bark direction, while the EXT content showed a decrease in this direction. For LT, no significant difference was observed in the pith-bark direction. In general, the largest planting spacings promoted the highest rates of variation of the properties studied. [ABSTRACT FROM AUTHOR]

Fuel quality is an important measure to assess as conventional fuel resources have been depleted at an alarming rate over recent years. For centuries, wood-based biofuels have been used extensively as the primary fuel source for boilers or heating plant operations. In a heating plant scenario, operating temperature, moisture content, gas usage, emission controls, etc., play a significant role in fuel quality assessment. Additionally, the advent of solar energy and its popularity in drying applications has provided ample opportunities to explore wood solar drying. Hence, improving the wood-based biofuel quality by implementing solar drying strategies has caught research attention in recent decades. However, there is a lack of well-documented review on the classifications of wood solar drying systems and the various modeling and simulation approaches that evolved in recent years for their performance optimization. This work reviews extant wood fuel quality problems and regional and technical challenges worldwide. Further insights into the possible solutions (through modeling or simulation) to enhance wood-based fuel quality by adopting solar drying technologies are discussed briefly. Notably, a case study of real-time data assessment of wood chips as biofuel in a boiler plant in Miskolc, Hungary, is presented. The outcomes of this review would serve as a benchmark and aid industries and researchers in further exploring wood solar drying potential. [ABSTRACT FROM AUTHOR]

Acoustics is a field with significant application in wood science and technology for the classification and grading, through non-destructive tests, of a large variety of products from standing trees to building structural elements and musical instruments. In this review article the following aspects are treated: (1) The theoretical background related to acoustical characterization of wood as an orthotropic material. We refer to the wave propagation in anisotropic media, to the wood anatomic structure and propagation phenomena, to the velocity of ultrasonic waves and the elastic constants of an orthotropic solid. The acoustic methods for the determination of the elastic constants of wood range from the low frequency domain to the ultrasonic domain using direct contact techniques or ultrasonic spectroscopy. (2) The acoustic and ultrasonic methods for quality assessment of trees, logs, lumber and structural timber products. Scattering-based techniques and ultrasonic tomography are used for quality assessment of standing trees and green logs. The methods are based on scanning stress waves using dry-point-contact ultrasound or air-coupled ultrasound and are discussed for quality assessment of structural composite timber products and for delamination detection in wood-based composite boards. (3) The high-power ultrasound as a field with important potential for industrial applications such as wood drying and other applications. (4) The methods for the characterization of acoustical properties of the wood species used for musical instrument manufacturing, wood anisotropy, the quality of wood for musical instruments and the factors of influence related to the environmental conditions, the natural aging of wood and the effects of long-term loading by static or dynamic regimes on wood properties. Today, the acoustics of wood is a branch of wood science with huge applications in industry. [ABSTRACT FROM AUTHOR]

Drying is an indispensable process for the industrial use of wood because it results in greater stability, durability, quality, and value of the final product. However, pre-established programs for tropical species have been poorly evaluated. The objective of this study was to formulate and evaluate drying programs for tropical species. The woods of Astronium lecointei (muiracatiara), Dinizia excelsa (faveira-ferro) and Hymenolobium heterocarpum (angelim-pedra) were used. The anatomical characteristics and physical properties of these species were evaluated. The drying programs for each wood were elaborated based on the drying potential to estimate the initial and final temperatures. The programs were executed in a laboratory oven with forced air circulation and afterward, the drying rates and defects were evaluated. The highest values of basic density were observed for faveira-ferro (0.92 g cm-³) followed by muiracatiara (0.70 g cm-³), and angelim-pedra (0.59 g cm-³). As for the volumetric shrinkage, the values were increased in the following order: angelim-pedra (9.87%), faveira-ferro (12.70%), and muiracatiara (14.23%). The anisotropy coefficient of the three wood evaluated was less than 1.5. The density and vessel diameter influenced the drying rate of the woods. The application of the drying programs in this work resulted in a high rate of top and surface cracking, which can compromise the use of wood for more demanding purposes. The woods were classified as first-class because the warping did not exceed the allowed limits. [ABSTRACT FROM AUTHOR]

The study assessed CNC routing quality on maple and oak samples, using 90º V-Grooving router bits at various milling angles as function of grain orientation: 0°, 15°, 30°, 45°, 60°, 75°, 90°, and feed speeds of 3 and 6 m/min at spindle speed of 15,000 rpm. The routing quality was evaluated by roughness parameters for the V flank surfaces and by visual examination for the flanks’ edges. The change in the feed speed had no significant effect for the flanks surface quality of both species, but roughness values were considerable higher for maple samples at 90º and u=3 m/min (Rk = 23.7 µm compared to along the grain, Rk=9.83 µm for u=6 m/min) due to possible processing vibrations. The milling angle as function of grain orientation was significant in the case of oak, as the processing roughness increased with the cutting angle from 0° (Rk=11 to 13 µm) to 60°(Rk =28 to 30 µm). Fuzziness around the earlywood pores of oak was higher for the 6 m/min feed speed. A substantial increase in waviness coinciding with the annual growth areas was measured for crosscut oak samples (Wa = 34.0 µm, compared with Wa =7 .39 µm along the grain). The surface waviness of maple was not sensitive to the variation in the cutting angle or feed speed (Wa was around 3 to 4 µm). For the flank edges, the best visual option was found for cutting along the wood grain and the worst was for 60º, which caused biggest ruptures and especially for the 3 m/min feed speed, for both species. [ABSTRACT FROM AUTHOR]

This research aimed to determine the yield of sawn wood and the distribution of pine classes depending on the species, size, and quality of the log. 101 pine logs classified with NMX-C-359-1988 were analyzed, collecting data on species, class, diameter, taper, and length. The products obtained were counted and classified with NMX-C-224-ONNCCE-2001 in order to determine the volumetric yield per log. Homogeneity of variance, ANOVA, Shapiro-Wilk, and Pearson's correlation tests were performed at a significance = 0.05. It was found that, the larger the diameter of the log and the smaller the taper, the yield per class of sawn wood increases. Log quality exhibits a highly significant effect on sawn wood quality. The aforementioned variables are good predictors to estimate the volumetric yield and proportion of sawn pine wood classes. [ABSTRACT FROM AUTHOR]

Robinia pseudoacacia, native to the United States of America and naturalized on various continents, is the third most cultivated fast-growing broadleaf in the world. In Argentina, cultivation for productive purposes is minimal, its local market is small, and there are few studies on its behaviour in commercial forestations. Due to the possibility of constituting a viable productive alternative, the adaptation of the species and the lack of data on its productive behaviour in the region, the aim of this contribution is to integrate different forestry-productive aspects of R. pseudoacacia. Dendrology, growth, yields, uses, pests and fungal diseases, seed production and propagation methods of the species were reviewed. Due to its plasticity and adaptation in the region, R. pseudoacacia constitutes a silvicultural alternative with a potential production of quality and multipleuses wood. Although, under proper management, the production of quality wood is promising, studies are needed on productive behaviour, management, yields, products, the real impact of pests and diseases, and market niches in the region. There are sources of local genetic material that would allow starting a breeding program from naturalized populations in the region. [ABSTRACT FROM AUTHOR]

The aim of this study was to develop scoring tables based on log quality, sawn wood quality and physical and mechanical properties for the selection of Eucalyptus clones for the production of solid wood. Five clones were selected, being three hybrids of Eucalyptus grandis x Eucalyptus urophylla, a clone of Eucalyptus urophylla and a clone of Eucalyptus grandis, 10 years of age. For the classification of the best clone, two scoring tables were created, one considering the result of the statistical analysis and the other the absolute values. With the tables it was possible to classify the clones according to the analyzed parameters (quality of the logs, quality of the sawn wood, sawn wood yield, physical properties and mechanical properties) separately and to observe more clearly some factors that directly influence the results. The clone of Eucalyptus grandis (clone 4) presented the best results, being classified as of superior quality in relation to the others for the production of solid wood. Thus, the scoring tables using statistical analysis or absolute values proved to be useful and applicable tools for the qualitative classification of clones. [ABSTRACT FROM AUTHOR]

Understanding the maturation stress and wood properties of poplar tension wood is critical for improving lumber yields and utilization ratio. In this study, the released longitudinal maturation strains (RLMS), anatomical features, physical and mechanical properties, and nano-mechanical properties of the cell wall were analyzed at different peripheral positions and heights in nine artificially inclined, 12-year-old poplar (Populus × euramericana cv. 'Zhonglin46') trees. The correlations between the RLMS and the wood properties were determined. The results showed that there were mixed effects of inclination on wood quality and properties. The upper sides of inclined stems had higher RLMS, proportion of G-layer, bending modulus of elasticity, and indentation modulus of the cell wall but a lower microfibril angle than the lower sides. At heights between 0.7 m and 2.2 m, only the double-wall thickness increased with height; the RLMS and other wood properties such as fiber length and basic density fluctuated or changed little with height. The RLMS were good indicators of wood properties in the tension wood area and at heights between 0.7 m and 1.5 m. The results of this study present opportunities to better understand the interactions and effects of these two phenomena, which both occur quite frequently in poplar stands and can influence the wood quality of valuable assortments. [ABSTRACT FROM AUTHOR]

Wood processing is one of the most widely used in agriculture and industry. Low precision and high time delay of machine learning in wood defect detection are currently the main factors restricting the production efficiency and product quality of the wood processing industry. An SPP-improved deep learning method was proposed to detect wood defects based on the basic framework of the YOLO V3 network to improve accuracy and real-time performance. The extended dataset was firstly established by image data enhancement and preprocessing based on the limited samples of the wood defect dataset. Anchor box scale re-clustering of the wood defect dataset was carried out according to the defect features. The spatial pyramid pooling (SPP) network was applied to improve the feature pyramid (FP) network in YOLO V3. The validity and real-time performance of the proposed algorithm were verified by a randomly selected test set. The results show that the overall detection accuracy rate on the wood defect test dataset reaches 93.23% while the detection time for each image is within 13 ms. [ABSTRACT FROM AUTHOR]

The surface checks or internal cracks from drying could significantly affect the processing and utilization of the wood. Therefore, it is of great significance to investigate the formation mechanism of cracks and reduce its occurrence. In this work, the development of cracking was quantified and its relationship with moisture content (MC) gradient and anisotropic shrinkage was analyzed. Results showed that the slight shrinkage occurred at the MC of 40%, and the shrinkage ratio at the end of drying was about 7.38% in the tangential (T) direction and 4.35% in the radial (R) direction. The shrinkage ratio of T/R in the MC range of 30%–15% was about 1.8, which was higher than that (1.65) in the MC range of 15%–5%. Cracks initiation was observed at average MC of 45%. The area and number of cracks reached a maximum at 15% MC. During the late stage of drying, the drying stress of the surface layer was reversed from tensile to compressive, which leads to the narrowing or closure of the cracks. Moreover, the fracture morphology of wood cells was observed at the microscopic level, indicating that the failure firstly occurred in the intercellular layer between the ray tissue and the tracheid in the latewood. The ray cells presented intact, and the lamellar structure between ray tissues and between the ray cells and the tracheids were the weak points of wood during drying. The results would contribute to keeping in minimum drying defects and improving the drying quality of wood. [ABSTRACT FROM AUTHOR]

Jabon (Anthocephalus cadamba) is a promising fast-growing wood species to overcome the decreasing wood supply from natural forests. However, fast-growing wood has inferior properties compared to wood from natural forests, so improving the wood quality through oil heat treatment is needed. This research aimed to determine the effects of treatment temperature during oil heat treatment on the physical and mechanical properties of jabon wood. Each wood specimen was oil heat-treated at 170℃, 190℃, and 210℃ for 4 hours. Color change of wood after treatment was evaluated using the CIE-Lab color system. The weight changes, volume shrinkage, density, moisture content, compressive strength, and hardness before and after heat treatment were also observed. The results revealed that the lightness (L*) of wood remarkably decreased after oil heat treatment, showing a darker color with increasing treatment temperature so that it resembled the color of exotic wood with high economic value. Oil heat treatment resulted in a weight gain and a volume reduction of jabon wood, followed by an increase in density. The wood moisture content decreased as the temperature increased, indicating that wood is more hydrophobic after oil heat treatment, thereby enhancing its dimensional stability. Moreover, the oil heat treatment also increased the compressive and hardness of wood samples. In conclusion, it was found that the characteristics of jabon wood could be enhanced with oil heat treatment. [ABSTRACT FROM AUTHOR]

This study investigated the variations in tracheid length of Pseudotsuga menziesii (Mirb.) Franco from three sites in Croatia in relation to cambium age, within- and between-site differences, and growth rate. Tracheids are the main structural element in P. menziesii wood, varying in length following different patterns that should be precisely determined. After the maceration procedure, earlywood tracheid length (EWTL), latewood tracheid length (LWTL), annual growth ring tracheid length (RTL), earlywood ring width (EWW), latewood ring width (LWW), and annual ring width (ARW) were measured in selected annual growth rings. The significant effect of annual growth rings and zone interaction for EWTL and LWTL, as well as of annual growth rings, trees, and sites for RTL, was determined. The results conclude on the differences between the trends in EWTL and LWTL from pith toward the bark. In addition, the correlation analysis between the tracheid length and different growth patterns was investigated, and very weak or no association between the variables was detected. This research contributes to better understanding the degree of wood uniformity of P. menziesii from the technological perspective, as well as the variability factor in the optimization of forest management with favoring overall wood quality. [ABSTRACT FROM AUTHOR]

High quality processing key to improving product quality and enterprise benefits. In this work, an adaptive network–based fuzzy inference system (ANFIS) was combined with milling experiments to understand the effects of tool geometry and milling parameters on the surface quality of wood fibre–reinforced magnesium oxide composite (WRMC). Specifically, changes in surface roughness (Ra) and damage of WRMC at different milling conditions were assessed using ANFIS and micro-analysis methods. Development of ANFIS models were confirmed to be reliable for predicting surface roughness. Changes in surface roughness at different milling conditions were determined, and the lowest surface roughness was obtained at the highest rake angle, highest cutting speed, and smallest milling depth. Furthermore, pitting-type damage irregularly distributed on the machined surface is attributed to the pulling out and debonding of wood fibres. Overall, high cutting speed, shallow cutting depth, and high rake angle is recommended for fine machining of WRMC where a smooth surface is desired. This study showcases how neuro-fuzzy models can be combined with conventional micro-analysis to optimize milling parameters for WRMC to minimize surface damage, and paves the way for future studies to optimize cutting tool life and energy consumption. [ABSTRACT FROM AUTHOR]