Search Results (15)

Evaluating sawlog quality is vital for both forest managers and wood processors. While external traits, such as tree form, branch architecture and visible growth features can be evaluated through visual inspection, many key wood quality indicators remain hidden, such as knot type and distribution, or the heartwood-to-sapwood ratio. This highlights the need for technologies capable of “seeing through” logs. Today, X-ray scanners in sawmills enable comprehensive, continuous, non-destructive assessment of internal stem structure at large scale. This study leveraged a newly compiled database of approximately 726,000 scanned logs to characterize variability in knot distribution and sapwood proportion across three major European softwood species and estimate the moisture content. The analysis highlights inter-and intra-species differences. Sapwood proportion decreased with sawlog diameter in spruce and silver fir but remained high in pine. Pine also presented significantly larger and more variable knots. Between March and August, we observed a seasonal trend in sapwood moisture content, affecting fresh density, while heartwood moisture content remained stable. These findings provide valuable information to support decision-making processes, linking tree characteristics to wood qualities and guiding forest management. Full article

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. Full article

Heartwood formation is an important ontogenetic stage in Scots pine (Pinus sylvestris L.). The amount of heartwood determines the proportion of functionally active sapwood in the total trunk biomass as well as the quality of wood. The key criterion for heartwood formation is the death of xylem ray parenchyma cells. Previously, models that described the patterns of heartwood formation, depending on the cambial age, were derived from Scots pine trees of different ages. The cambial age is the number of annual xylem layers at the core sampling site at a certain trunk height. We studied the features of the occurrence of programmed cell death (PCD) processes during the xylem differentiation and heartwood formation of 80-year-old Scots pine trees, depending on the cambial age, under the lingonberry pine forest conditions in the transition area of the northern taiga subzone and tundra. We have shown that the distance from the cambial zone to the heartwood boundary does not change significantly with stem height. As the cambial age increases, the lifespan of the formed xylem ray parenchyma cells increases and the activity of PCD genes decreases during the formation of both (1) xylem (in the outer layers of sapwood) and (2) heartwood (in the inner layers of sapwood and transition zone). We hypothesized that the decisive factor in the PCD initiation during heartwood formation is the distance of the xylem ray parenchyma cells from the cambial zone. The younger cambium forms wider annual increments, and therefore the xylem ray parenchyma cells in these parts of the trunk reach the distance from the cambial zone earlier, which is necessary for PCD initiation. Full article

Stem profile modeling is crucial in the forestry sector, particularly for commercially valuable species like teak (Tectona grandis Linn F.), whose value depends on its stem dimensions, heartwood proportion, and age. We proposed a nonlinear mixed-effect model to describe the evolution of the stem and heartwood profiles of clonal teak trees with ages between 4 and 12 years in the Brazilian Amazon. Tapering models were used to estimate the bark, bark-free, and heartwood diameters. Dummy variables were included in each tapering model to estimate each type of diameter and enable compatibility. We used mixed models with age as a random effect in order to improve the accuracy. The Demaerschalk model provided the most accurate and compatible estimates for all three types of stem diameter. Also, age as a random effect significantly improved the model’s accuracy by 7.2%. We observed a progressive increase in the heartwood proportion (14% to 34%) with advancing age, while the proportions of bark (23% to 20%) and sapwood (63% to 45%) showed inverse behavior. The growth rate of the heartwood differed from that of the bark volume, emphasizing the importance of considering the age of heartwood maximization when determining the cutting cycle of the species. Full article

Cunninghamia lanceolata is one of the most important tree species in China due to its significance both in economy and ecology. The aims of the present study were to construct a high-density genetic map and identify a quantitative trait locus (QTL) for C. lanceolata. In this study, an F1 population comprising 81 individuals was developed. Using specific length amplified fragment sequencing (SLAF-seq) technology, a total of 254,899 loci were found to be polymorphic. After linkage analysis, 2574 markers were used to construct genetic linkage maps. Specifically, 1632 markers were allocated to 11 linkage groups (LGs) for the female map, 1038 for the male map, and 2574 for the integrated map. The integrated map consisted of 4596 single-nucleotide polymorphisms (SNPs) loci, resulting in an average of 1.79 SNP loci per SLAF marker. The marker coverage was 1665.76 cM for the female map, 1436.39 cM for the male map, and 1748.40 cM for the integrated map. The average interval between two adjacent mapped markers was 1.03 cM, 1.40 cM, and 0.68 cM for the female map, male map, and integrated map, respectively. Using the integrated map, we performed interval mapping (logarithm of odds, LOD > 2.0) to detect traits of interest. We identified a total of 2, 1, 2, 5, 1, 2, 1, and 3 QTLs for diameter at breast height, heartwood diameter, heartwood proportion, heartwood a*, heartwood b*, heartwood L*, sapwood a*, and sapwood L*, respectively. The number of markers associated with each QTL ranged from 1 to 14, and each marker explained phenotypic variances ranging from 12.70% to 23.60%. Furthermore, a common QTL was identified for diameter at breast height and heartwood color a*, while another common QTL was observed for heartwood color L* and heartwood color a*. These findings suggest possible pleiotropic effects of the same genes on these traits. In conclusion, we successfully constructed high-density genetic maps for C. lanceolata using the SLAF-seq method with an F1 population. Notably, these linkage maps represent the most comprehensive and densest ones available to date for C. lanceolata and will facilitate future chromosome assignments for C. lanceolata whole-genome sequencing. These identified QTLs will serve as a valuable resource for conducting fine-scale QTL mapping and implementing marker-assisted selection in C. lanceolata, particularly for growth and wood-color traits. Full article

The article presents the differences in some physical and chemical properties of wood with false heartwood, mature wood, and sapwood of Fagus sylvatica L.: density of wood in the dry state, color in the color space CIE L*a*b* on the tangential surface and the planed surface at w = 10 ± 0.5%, as well as moisture and acidity of wet wood. As part of chemical analyses, the relative proportion of cellulose, hemicelluloses, lignin, and extractive substances in individual zones of beechwood in trunks with false heartwood was determined. From the carried out analyses, it follows that the biggest difference between the wood of false heartwood, mature wood, and sapwood is the color of the wood. The red-brown color of the wood with false heartwood in the color space CIE L*a*b* is described by the following coordinate values: L* = 64.9 ± 4.9; a* = 12.9 ± 1.4; b* = 19.6 ± 1.7. The most significant differences between the values of the color space are on the lightness coordinate, where the light ochre-white of mature wood shows a decrease of ∆L* = −14.0 compared with the color of false heartwood, and the white—pale grey color of sapwood shows a decrease of ∆L* = −17.5. The density of dry beechwood with false heartwood is higher by ∆ρ₀ = 4.7% than the density of mature wood, and the density of sapwood is ∆ρ₀ = 12.3% lower than the density of wood with false heartwood. The exact opposite applies to the acidity of wet beechwood. The results of wet wood acidity measurements also point to certain differences. While the acidity of the wet wood of false heartwood is pH = 5.32 ± 0.13, the acidity of the sapwood is 5.1% lower. The higher acidity of beech heartwood is attributed to the presence of organic acids in polyphenols during heartwood formation. From the comparison of the representation of cellulose, hemicellulose, lignin, and extractive substances, it follows that the relative content of lignin and hemicelluloses is higher in false heartwood than in mature wood and sapwood. On the contrary, the content of holocellulose and cellulose is highest in sapwood. The presented divisions in the physical and chemical properties of beechwood with false heartwood do not limit the use of beechwood in industrial applications, except for a change in color; the definition of color boundaries in the color space CIE L*a*b* creates space for sorting beechwood according to color and can be used to increase the color variety of compositions of construction-carpentry products. Full article

Eastern spruce budworm (Choristoneura fumiferana Clem.) is considered the most important disturbing insect in coniferous stands in eastern North America. During an outbreak, spruce budworm can cause severe defoliation in balsam fir (Abies balsamea (L.) Mill.), which can affect wood properties such as moisture content and mechanical properties. This project aimed to assess the influence of the duration of spruce budworm defoliation on the wood quality of mature balsam fir trees. To do this, we studied sapwood proportion, decay, moisture content, mechanical properties and tracheid dimensions in stands that had suffered three, four or five years of defoliation. We also compared living and dead balsam firs and evaluated the change in wood properties with time. Our results showed that dead balsam firs suffered from a loss of wood quality rapidly after their death, particularly in terms of moisture content and decay in the sapwood. Sapwood proportion was similar between living and dead trees, but the sapwood of dead trees contained more decay and had a lower moisture content than living trees. Mechanical properties and tracheid dimensions were 10% and 4% lower in dead trees than in living trees. We did not observe any major differences in wood properties between the three durations of defoliation, suggesting that wood degradation occurs before that. The study did not make it possible to determine the optimal duration of defoliation to harvest the stands. Full article

Currently, there is no consensus on how growing conditions affect the heartwood formation in Scots pine. Comparing the results obtained by different authors is difficult due to methodology differences and poor descriptions of the objects used. We selected two sample plots in (1) a blueberry pine forest on nutrient-rich and moist soil and (2) a lichen pine forest on nutrient-poor and dry soil and performed their detailed characterization. The sample plots were located 22 km apart in the middle taiga subzone (Karelia Republic, northwest Russia). In each sample plot, we selected five dominant trees (model trees), from which we took cores at different trunk heights (0.3, 1.5, 4.5, 7.5 and 10.5 m). The cores were treated with 2,6-dichlorophenolindophenol to identify the heartwood zone. Additionally, samples were taken to study the structural features of the transition zone between sapwood and heartwood. In both forest types, the number of heartwood rings depended on the cambium age, and the patterns of parenchyma cell death did not differ in the transition zone. These facts point to a predominantly internal regulation of the heartwood formation in Scots pine. The heartwood radius and its proportion on the cross-sections were significantly higher in the blueberry pine forest than in the lichen pine forest, despite the relative values of the annual ring width. Further research is needed to develop successful Scots pine heartwood width models under a wide range of conditions. Full article

The article presents a study of wood excavated from archaeological site in Poland (2100–1650 BC). The large amount of collected samples created a unique opportunity for research because the subfossil wood was in very good preservation state. This made it possible to carry out dendrotypological analysis. This is the first such study conducted for Early Bronze Age timber originating from Poland. The main goal of the study was to determine whether the presence of strong and abrupt reductions and releases of growth, observed within tree-ring sequences, is due to natural stand dynamics, results from the influence of extreme environmental factors or whether they should be linked to specific silvicultural practices already known in ancient times. Another purpose of the study was to determine the type of forest management techniques applied to the trees growing in Bruszczewo site. The research was conducted using the dendrochronological method. In addition to the measurements of growth-ring width, the development of earlywood and latewood zones, the proportion of sapwood and the presence of specific features of tree trunks were analysed. A detailed study allowed identifying the samples originating from coppiced and shredded trees. A characteristic feature of the trees subjected to these silvicultural practices is the presence of strong and abrupt reductions and releases of growth. Moreover, coppiced trees were specified by the large proportion of sapwood in the cross-section of the stem, reduced number of sapwood rings, small and numerous earlywood vessels, diminished earlywood vessels area. In turn, shredded trees distinguished themselves by a strong reduction in the earlywood width in the years following the shredding event. The research of archaeological wood from the ancient settlement proves that during the Early Bronze Age various forest management techniques were used in this site. These treatments were aimed at improving the quality and quantity of the raw material harvested from forest areas. Full article

Soil influences the growth of trees and the characteristics of the wood; but could this influence change during the ontogeny of trees? To answer this question, we analyzed the wood anatomy of 9-year-old trees and 2-year-old saplings of Enterolobium contortisiliquum, known as “tamboril”, growing in eutrophic and oligotrophic soil in the Brazilian Cerrado, and assessed the effect of age on plant–soil relationship. Sapwood samples were collected from the main stem, anatomical sections were prepared in the lab, and 12 anatomical wood traits were measured. Individuals in eutrophic soil had greater stem diameter and height than those in oligotrophic soil. Trees in eutrophic soil had vessel-associated parenchyma cells with abundant storage compounds. Fibers walls were 47% thicker and intervessel pits diameter were 14% larger in trees of eutrophic soil. A greater proportion of solitary vessels (74%) was observed in trees rather than in saplings (50%). The secondary xylem of trees was mainly formed by fibers (63%) whereas in saplings it was mainly formed by storage tissue (64%). Our study provides evidence that the influence of soil conditions on tree growth reflects variations in wood anatomical features. No significant response to soil type was observed in saplings, thus demonstrating that the relationship between soil type and wood growth is mediated by tree age. These findings help to develop reliable reforestation strategies in tropical ecosystems characterized by different levels of soil fertility. Full article

Tectona grandis is a valuable timber species with heartwood that is used worldwide. Most of the previous studies on its heartwood and sapwood have focused on dominant or mean trees, while trees with different social status might show different vertical and horizontal distributions of heartwood and sapwood. Studies on their heartwood and sapwood properties could be conducive to increasing heartwood yield at stand level. In 31-year-old plantations of T. grandis in southwest Guangxi, China, the trees were divided into three groups including dominant, mean and suppressed trees. Stem analysis was conducted for sampled trees in each of these groups to explore the differences in the horizontal and vertical distribution of their heartwood and sapwood. The results indicated that the heartwood radius, heartwood and sapwood areas of T. grandis showed significant differences in horizontal and vertical directions among trees of different social status. Heartwood began to form when xylem radius was 2–3 cm, and the heartwood radius ratio tended to be stable when the xylem radius reached about 8 cm. Heartwood radius and area, sapwood area and section heartwood volume all decreased with increasing tree height. The ratios of heartwood radius and area were relatively stable for sections under 50% of tree height. The sapwood width did not vary largely in horizontal and vertical directions among the three social status tree groups, which mainly fluctuated in the range of 1–4 cm. The heartwood volume proportions for dominant, mean and suppressed trees were 60%, 55% and 51%, respectively. There was a significant exponential relationship between heartwood volume and diameter at breast height (DBH) regardless of social status. The model HV = 0.000011 × DBH^2.9787 (R² = 0.8601) could accurately estimate heartwood volume for all T. grandis with different social statuses at this age. These findings could provide evidence for stand management and high-quality and large-sized timber production of T. grandis. Full article

The transpiration of Nothofagus glauca (Phil.) Krasser and advanced Pinus radiata D. Don. regeneration was measured in a fragment of native N. glauca forest. Over the eight months of this study, P. radiata contributed approximately 60% of the total stand transpiration. This was out of proportion with the approximately 34% of the stand sapwood area contributed by P. radiata. This was due to the significantly greater sap flux density of the P. radiata compared to the N. glauca between May and October. Though the results are from a small study conducted as part of a larger experiment, it is argued that they suggest that invasion by P. radiata may substantially increase the risk from climate change to reserves of N. glauca forest in the Maule region of central Chile. In some reserves of N. glauca forest, Forestal Arauco S.A. manually removed P. radiata that regenerated after the wildfire of January 2017. This was a costly operation and there is a need for indices to assess competition. The ratio of sapwood area to leaf area is suggested as a potential index for assessing competition to identify stands at risk. Full article

This paper analyzes sapwood variability and allometry within individuals of Populus tremuloides, Pinus contorta, Pinus banksiana, Picea mariana, and Picea glauca. Outside bark diameter at breast height (DBH) and sapwood depth (sd) in four cardinal directions were measured in individuals in stands in Alberta and Saskatchewan, Canada. The microscopical analysis of wood anatomy was used to measure sd, and the error associated with the measures was observed. Sapwood allometry analyses examined the influence of DBH on sd and on sapwood area (SA). All species were observed to have varying sapwood depths around the trunk with statistical analyses showing that Pinus banksiana has a well defined preference to grow thicker in the North-East side. The largest sd values were observed for the Populus tremuloides set. Unlike Populus tremuloides and Picea glauca, for the species Pinus contorta, Pinus banksiana, and Picea mariana, incremental growth in DBH does not directly drive sapwood growth in any direction. For these three species, SA increases only because of increases in DBH as sd remains nearly constant. These results show that sapwood depth and sapwood area seem to behave differently in each studied species and are not always proportional to the tree size as is normally assumed. Full article

The aim of this work is to develop a tool to predict some pulp properties e.g., pulp yield, Kappa number, ISO brightness (ISO 2470:2008), fiber length and fiber width, using the sapwood and heartwood proportion in the raw-material. For this purpose, Acacia melanoxylon trees were collected from four sites in Portugal. Percentage of sapwood and heartwood, area and the stem eccentricity (in N-S and E-W directions) were measured on transversal stem sections of A. melanoxylon R. Br. The relative position of the samples with respect to the total tree height was also considered as an input variable. Different configurations were tested until the maximum correlation coefficient was achieved. A classical mathematical technique (multiple linear regression) and machine learning methods (classification and regression trees, multi-layer perceptron and support vector machines) were tested. Classification and regression trees (CART) was the most accurate model for the prediction of pulp ISO brightness (R = 0.85). The other parameters could be predicted with fair results (R = 0.64–0.75) by CART. Hence, the proportion of heartwood and sapwood is a relevant parameter for pulping and pulp properties, and should be taken as a quality trait when assessing a pulpwood resource. Full article

The semi-arid region of China’s Loess Plateau is characterized by fragile ecosystems and a shortage of water resources. The major natural forest type in this region is the secondary forest with the flora dominated by the Liaodong oak (Quercus liaotungensis Koidz.). To understand its transpiration water use in relation to environmental factors, we applied Granier-type thermal dissipation probes to monitor stem sap flows of 21 sample trees, representing different classes of diameter at breast height in a permanent plot. The stem- and stand-scale transpiration values during the 2008–2010 growing seasons were estimated using measurements of sap flux densities and corresponding sapwood areas. The dominant factors affecting stand-scale transpiration varied with time scales. Daily stand transpiration correlated with daily solar radiation and daytime average vapor pressure deficit. Seasonal and interannual changes in stand transpiration were closely related to leaf area index (LAI) values. No obvious relationship was observed between monthly stand transpiration and soil moisture or precipitation during the period, probably as a result of both the hysteretic effect of precipitation on transpiration, and changes in LAI throughout the growing season. Stand transpiration during the three growing seasons ranged from 75 to 106 mm, representing low to normal values for the semi-arid forest. The proportion of transpiration by oak trees in the stand was stable ranging from 60% to 66% and corresponded to their basal area proportion of approximately 59%. The results suggest that the natural forest consisting mainly of oak trees is in a formal stage of forest development that maintains a normal magnitude of annual water consumption. Full article