Search Results (190)

Climate extremes threaten the resilience of Eucalyptus plantations, yet hybridization with drought-tolerant species may enhance stress tolerance. This study analyzed xylem anatomical and functional drought responses in commercial Eucalyptus grandis (GG) clones and hybrids: E. grandis × camaldulensis (GC), E. grandis × tereticornis (GT), and E. grandis × urophylla (GU1, GU2). We evaluated vessel traits (water transport), fibers (mechanical support), and wood density (D) in stems and branches. Theoretical stem hydraulic conductivity (k_Stheo), vessel lumen fraction (F), vessel composition (S), and associations with previous hydraulic and growth data were assessed. While general drought responses occurred, GC had the most distinct xylem profile. This may explain it having the highest performance in different irrigation conditions. Red gum hybrids (GC, GT) maintained k_Stheo under drought, with stable F and a narrower vessel size, especially in branches. Conversely, GG and GU2 reduced F and S; and stem k_Stheo declined for a similar F in these clones, indicating vascular reconfiguration aligning the stem with the branch xylem. Almost all clones increased D under drought in any organ, with the highest increase in red gum hybrids. These results reveal diverse anatomical adjustments to drought among clones, partially explaining their growth responses. Full article

Spruce wood is a natural polymeric material, consisting of cellulose, lignin, hemicelluloses and other secondary components, which gives it a unique chemical footprint and architecture. Varnishes are used in musical instruments to protect the wood against humidity variations, wood being a hygroscopic material, but also to protect the wood from dirt. The varnishes used both to protect the wood from resonance and to ensure a special aesthetic appearance are either polymeric varnishes (nitrocellulose, oil-based) or volatile solvents (spirit). In this study, the color changes, the surface morphology and the chemical spectrum produced by three types of varnishes, applied in 5, 10 and 15 layers, on resonance spruce plates were analyzed. The results revealed significant changes in the color parameters: the lightness decreased by approximately 17% after the first layer, by 50% after 5 layers, by 65% after 10 layers and by 70% after 15 layers. The color parameters are most influenced by the anatomical quality of spruce wood (annual ring width and earlywood/latewood ratio) in the case of oil-based varnishes and least influenced in the case of nitrocellulose varnishes. The chemical fingerprint was determined by FTIR spectrum analysis, which revealed that the most pronounced absorptions were the double band 2926–2858 cm⁻¹, corresponding to aliphatic methylene and methyl groups (asymmetric and symmetrical C-H stretch), and the bands at 1724 cm⁻¹ (oil-based varnish), 1722 cm⁻¹ (nitrocellulose varnish) and 1708 cm⁻¹ (spirit varnish), all assigned to non-conjugated carbonyl groups in either carboxylic acids, esters aldehydes or ketones. The novelty of the study lies in the comparative analysis of three types of varnishes used in the musical instrument industry, applied to samples of spruce resonance wood with different macroscopic characteristics in three different layer thicknesses. Full article

Quercus faginea Lam., a winter-deciduous oak native to the Iberian Peninsula, typically grows under a Mediterranean climate. To identify the main drivers influencing radial wood increment, we analyzed the climatic signals in tree-ring width and wood anatomical traits using increment cores. Winter conditions influenced both latewood width and earlywood vessel size in the first row. Latewood was positively correlated with precipitation and temperature, with the long-term positive effect of winter water supply supported by SPEI. In contrast, vessel size showed negative correlations, also reflecting a long-term negative effect of winter precipitation. Consequently, conditions that enhanced latewood width and overall tree-ring growth appear to be associated with the formation of smaller earlywood vessels. Although ample winter precipitation replenishes soil water reserves and supports prolonged wood formation, it may also induce anaerobic soil conditions that promote root fermentation, depleting carbohydrates needed for cell turgor and expansion, and ultimately regulating earlywood vessel size. This physiological decoupling may help explain the lack of a significant correlation between latewood width and earlywood vessel size, underscoring their independent responses to environmental influences. Our findings highlighted the complex interplay between various climatic conditions affecting Q. faginea, with implications for understanding its adaptive capacity in changing climates. Full article

The sapwood and heartwood of European larch (Larix decidua Mill.) are both used in industrial applications, but they differ in structure and composition, which may lead to surface property differences. This study compared their surface characteristics (on radial and tangential sections) after sanding with aluminium oxide papers of four grit sizes (P60, P120, P180, P240). Surface roughness (Ra, Rz), wettability (contact angle with two reference liquids: water and diiodomethane, 3 and 30 s after droplet deposition), surface free energy, and colour parameters (L*, a*, b*) were analysed. Microscopic measurements were also performed to assess anatomical differences between sapwood and heartwood. The results showed no significant differences in roughness (Ra, Rz) between sapwood and heartwood. Measurement direction and sandpaper grit accounted for about 80% of variability in roughness parameters. Wettability was mainly influenced by wood area, with its effect ranging from 55% to 89% depending on measurement time. The sapwood was characterised by the lower wettability on the tangential section, while the heartwood was characterised by the lower wettability on the radial section. This was examined for the contact angle tests performed 3 s after the water droplet had been applied to the wood surface. Such dependencies were not observed after 30 s. Sapwood exhibited higher surface free energy (SFE) values than heartwood. The greatest colour change ΔE, at level 2.59, was noted for the heartwood on the radial section after sanding with P240 sandpaper. Full article

Fast-growing hardwoods like poplar often lack natural durability in outdoor use and require homogeneous impregnation with protective agents, though achieving homogeneity remains a known challenge. Various anatomical structures influence fluid transport in wood. This study compares characteristics of pits in libriform fibres, between ray–vessel interfaces, and between vessel-to-vessel connections in normal wood and tension wood of a hybrid poplar genotype (Populus × canadensis, ‘Gelrica’), including both impregnated (with an aqueous, dye-containing solution) and non-impregnated regions, to identify anatomical barriers to impregnation. Light and scanning electron microscopy revealed significant differences in pit morphology and frequency in libriform fibres between normal wood and tension wood. In non-impregnated regions, pits were often encrusted. Vessel–ray pits did not differ between normal wood and tension wood but showed distinct differences between impregnated and non-impregnated regions: in the latter, pits were occluded by tylose-forming layers. Intervessel pits differed in border and aperture size between earlywood and latewood in both normal wood and tension wood. Hence, fluid transport is strongly impeded by occluded vessel–ray pits and, to a lesser extent, by encrusted fibre pits. Full article

The aim of the study was to determine the relationship between selected features of wood and the surface properties after sanding operations. Woods presenting different anatomical structures, i.e., ring-porous hardwood (European oak) and diffuse-porous hardwood (Norway maple), were used in the study. The wood surfaces were finished by sanding with aluminum oxide sandpapers of different grits: P60, P120, P180, and P240. It was shown that among the analyzed factors (wood species, anatomical section, measurement direction, and sandpaper grit size) and the interactions between them, the direction of measurement had the greatest influence (47%) on the Ra parameter values for oak wood. The sandpaper grit determined 22% of the Ra parameter variability. The measurement direction and the grit size of the sandpaper were identified as the most influential factors affecting the Rsm parameter values. Comparable patterns were observed in the case of Norway maple wood. Due to its diffuse-porous structure, the roughness of maple wood was less affected by the sandpaper grit compared to that of oak wood. Wood species had the greatest influence, increased from 41% to 71% when examining the contact angle at phase boundary wood-water after 3 s and 30 s. Sandpaper grit showed the greatest impact on the contact angles at the wood–diiodomethane phase boundary. This impact was practically at the same level after testing the contact angles after 3 s (27%) and after 30 s (28%). Wood species determined the color parameters, being responsible for 93% of the L* parameter, 50% of parameter a*, and 78% of parameter b*. The influence of sandpaper grit on the a* and b* parameter values was at a low level, i.e., 4%. SEM micrographs revealed the diverse structural characteristics of the wood following the sanding process. Full article

This study investigates the impact of mild steaming (105 °C and 120 °C for 12 h) on the colour characteristics and chemical stability of beech wood (Fagus sylvatica L.) during natural indoor ageing. Untreated and steamed samples of mature wood and false heartwood were analysed for CIELAB and CIELCh colour parameters (L*, a*, b*, C*, h°) and chemical changes using ATR-FTIR spectroscopy. Steaming resulted in a significant decrease in lightness (L*) and increased a*, b*, and C* values, producing darker and more saturated reddish-brown tones. It also reduced the visual differences between mature wood and false heartwood, enhancing colour uniformity. During the light-induced ageing period, steamed wood—particularly at 105 °C—exhibited improved colour stability, maintaining chroma and hue more effectively than untreated samples. Statistically significant interaction effects between treatment, time, and tissue type revealed that the ageing-related colour changes were jointly influenced by thermal modification and the anatomical characteristics of the wood. In the FTIR spectra, the most pronounced changes were observed in the absorption bands of the aromatic skeleton and carbonyl groups (1504 and 1732 cm⁻¹). These findings confirm that mild steaming alters the original aesthetic properties and colour of beech wood when exposed to an indoor environment. Full article

Mozambique’s natural forests are increasingly affected by climate change, deforestation, and unsustainable exploitation, threatening both biodiversity and rural livelihoods. This study examines the wood anatomical characteristics of five commercially important tree species—Spirostachys africana Sond., Afzelia quanzensis Welw., Millettia stuhlmannii Taub., Pterocarpus angolensis DC., and Colophospermum mopane (J. Kirk ex Benth.) J. Léonard—to assess their vulnerability to drought, cyclones, and floods. The aim is to enhance current knowledge regarding their wood anatomy and to clarify how these anatomical traits could help to identify species most vulnerable to climate extremes. Wood samples were collected from native forests and analyzed in laboratories in Brazil and Portugal using standardized anatomical methods according to IAWA guidelines. The results show that Afzelia quanzensis, Millettia stuhlmannii, Pterocarpus angolensis, and Colophospermum mopane have solitary vessels with vestured pits and thick-walled fibers, which improve hydraulic conductivity and drought resistance. Colophospermum mopane shows the greatest anatomical adaptation to climatic stressors. By contrast, Spirostachys africana has narrow, grouped vessels and thin walls, indicating higher susceptibility to embolism and limited resilience. Cyclone resistance is associated with higher wood density and parenchyma abundance, which enhance mechanical stability and recovery. Flood resilience, however, appears to depend more on leaf and root adaptations than on wood anatomy alone. These findings highlight the role of wood structure in climate adaptability and underline the urgency of integrating anatomical data into forest management strategies to support the conservation and sustainable use of Mozambique’s forest resources. Full article

This study analyzes near-infrared (NIR) spectral characteristics of the wood of Hevea spruceana (Benth.) Müll. Arg., Hura crepitans L., Ocotea cymbarum Kunth, and Pseudobombax munguba (Mart.) Dugand from an Amazon floodplain forest area located in the Mamirauá Sustainable Development Reserve, aiming at their discrimination using artificial intelligence. The samples were collected as increment cores, from which NIR spectra were randomly collected in the transversal anatomical surface and compared. Principal component analysis (PCA) was applied to explore variation patterns in the data. Additionally, the classifier support vector machine algorithm, partial least squares–discriminant analysis (PLS-DA), and k-nearest neighbors regression were used to evaluate the accuracy in distinguishing the woods based on the NIR data. The results indicate similar spectral behavior among the species, with differences in absorbance intensities. PCA revealed a greater tendency for samples of the same species to cluster together, with Ocotea cymbarum showing the highest tendency for grouping. Among the classifiers, PLS-DA achieved the highest accuracy (98%). We can conclude that NIR spectroscopy combined with artificial intelligence classifiers has the potential to distinct wood species from the Amazon floodplain forest analyzed. Full article

Modern manufacturing technologies include wood processing using laser technologies. The most used laser for wood cutting is the CO₂ laser, which offers many advantages such as processing speed, efficiency, and minimal impact on the material’s structure after cutting. To achieve a high-quality cut, characterized by the cutting kerf parameters, it is necessary to know the appropriate combination of cutting parameters, primarily laser power (P) and the cutting speed (v). Therefore, this article investigates the effect of P, v, and cutting direction on the cutting kerf widths on the upper surface WKU, lower surface (WKL), and their ratio (WKR). The analysis was performed on samples of spruce, beech, and oak wood, while also evaluating the influence of the anatomical cutting direction. The correlation coefficient between the predicted values and the measured values is at least 0.94, with the mean square error not exceeding 4%. Consequently, the employed models demonstrate validity in predicting cutting kerf widths and optimizing the cutting process based on the type of timber, cutting direction, and the specified laser parameters. Full article

The bending test is a good indicator of wood characterization, including compression, tension, and shear stresses. Therefore, many studies have been published on bending tests for wood. Its heterogeneous structure, anisotropic behavior during the physical and mechanical tests, and anatomical and chemical differences due to species and growing area make the characterization difficult. Accordingly, research has focused on mathematical models and simulation programs for predicting material characteristics. More data on using many wood species in such models or programs still need to be collected. This study aimed to eliminate these deficiencies for two softwood species grown in Türkiye. In this context, three- and four-point bending tests were performed on 5656 samples from fir (Abies spp.) and black pine (Pinus nigra) species that were collected from 13 regions. A nonlinear material model was generated from the load-deformation data for both species, and the results were found in agreement regarding the bending features of both softwood species. The results show that nonlinear numerical modeling could predict the bending results with significant rates (min. 94%). Additionally, bending characteristics such as limits of proportionality (LOP), and elastic potential were found and compared between and within the species, regions, and test methods. Load-deformation curves showed that the LOP ranged between 40% and 60% of the maximum load, which was higher than the theoretical approach in the standards. Full article

The aquarium trade includes a niche but significant market for ornamental wood, yet its sustainability remains largely unexamined. This study combines traditional wood anatomical methods with conservation assessments to investigate the sustainability of this overlooked sector. We investigated the botanical identity of aquarium wood products to assess mislabelling, conservation concerns, and potential environmental risks. Using macroscopic and microscopic wood anatomy techniques, we analysed wood samples from the aquarium trade to determine taxonomic identity. We also examined the origin, conservation status, and possible ecological implications of the identified taxa. We identified woods from diverse families, including Myrtaceae, Ericaceae, Fabaceae, and Ebenaceae, with some species listed as threatened. Widespread mislabelling obscures conservation status, enabling unsustainable trade. Moreover, several samples were identified as roots, raising concerns about soil disruption and habitat degradation. By linking wood anatomy and ecosystem impacts, we show that the aquarium wood trade lacks transparency, posing risks to biodiversity conservation and ecosystem stability. Our findings underscore the pressing need for effective regulatory oversight, accurate labelling, and sustainable sourcing to mitigate environmental impacts and promote responsible trade practices. Full article

European mistletoe is a hemi-parasitic plant increasingly infesting forests in Central Europe, causing premature tree death, and is anticipated to expand its range due to global warming. This study aimed to describe the unique anatomical features of mistletoe and examine the morpho-anatomical response of pine trees to infestation. Anatomical analyses were conducted on mistletoe internodes and the branch wood of affected pines. The findings revealed that mistletoe infestation triggers callose deposition in the cell walls of pine tracheids, a defense mechanism that restricts water flow to the mistletoe. Unique structural features of mistletoe were also identified, including structural dimorphism with the inner system forming only vessels and parenchyma cells, in contrast to the outer system, composed of protective, ground, and conductive tissues, and which displays an uneven distribution of chlorophyll and starch grains along the plant axis. Additionally, starch and chlorophyll were present in the parenchyma cells of the haustorium. Starch presence there may potentially enable internal photosynthesis, and the compounds formed after starch hydrolysis may facilitate water uptake from the host’s xylem sap. These results provide new insights into the anatomical adaptations of mistletoe and the defensive responses of pine trees, contributing to a deeper understanding of host–parasite interactions in forest ecosystems. Full article

The black locust tree is a plantation-grown species that occupies a large area in Hungary. Due to variations in the growth environment of trees across different locations, the anatomical features of wood may differ. This study investigated the variability in fiber properties (fiber length, width, wall thickness, vessel length, and width) and growth rate of Robinia pseudoacacia L. from five counties and in three specific growing conditions. The parameters were investigated based on a sample of discs taken from the trees at breast height. The statistical analysis revealed significant differences in wood fiber and vessel dimensions, as well as ring width, between counties and growth conditions. Nearly all examined parameters showed the lowest values in Bács-Kiskun County, whereas the highest values were observed in Szabolcs-Szatmár-Bereg and Vas. Regarding the growth conditions, wood in poor growth conditions (mixed trees) and good growth conditions produced superior wood fiber properties and ring widths. Full article

Costa Rica is located along the narrow isthmus that connected South America to North America beginning in the mid-Cenozoic. The exchange of vertebrates between the two continents has received considerable study, but paleobotanical aspects are less known. The Pacific coast “ring of fire” volcanoes produced abundant hyaloclastic material that provided a source of silica for wood petrifaction, and the tropical forests contained diverse taxa. This combination resulted in the preservation of petrified wood at many sites in Costa Rica. Fossil wood ranges in age from Lower Miocene to Middle Pleistocene, but Miocene specimens are the most common. Our research involved the study of 54 specimens, with the goal of determining their mineral compositions and interpreting the fossilization processes. Data came from thin-section optical microscopy, SEM images, and X-ray diffraction. Two specimens were found to be mineralized with calcite, but most of the woods contained crystalline quartz and/or opal-CT. The preservation of anatomical detail is highly variable. Some specimens show evidence of decay or structural deformation that preceded mineralization, but other woods have well-preserved cell structures. This preliminary study demonstrates the abundance and botanical diversity of fossil wood in Costa Rica, hopefully opening a door into future studies that will consider the taxonomy and evolutionary aspects of the country’s fossil forests. Full article