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Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To explore the radial variation in wood properties of slash pine (Pinus elliottii Engelm.) during its growth process and to achieve the early prediction of these properties, our study was carried out in three slash pine harvest-age plantations in Ganzhou, Jian, and Jingdezhen, Jiangxi province of South China. Wood core samples were collected from 360 sample trees from the three plantations. SilviScan technology was utilized to acquire wood property parameters, such as tangential fiber widths (TFWs), radial fiber widths (RFWs), fiber wall thickness (FWT), fiber coarseness (FC), microfibril angle (MFA), modulus of elasticity (MOE), wood density (WD) and ring width (RD). Subsequent systematic analysis focused on the phenotypic and radial variation patterns of wood properties, aiming to establish a clear boundary between juvenile and mature wood. Based on determining the boundary between juvenile and mature wood, a regression equation was used to establish the relationship between the properties of juvenile wood and the ring ages. This relationship was then extended to the mature wood section to predict the properties of mature wood. Our results indicated significant differences in wood properties across different locations. The coefficients of variation for RD and MOE were higher than other properties, suggesting a significant potential for selective breeding. Distinct radial variation patterns in wood properties from the pith to the bark were observed. The boundary between juvenile and mature wood was reached at the age of 22. The prediction models developed for each wood property showed high accuracy, with determination coefficients exceeding 0.87. Additionally, the relative and standard errors between the measured and predicted values were kept below 10.15%, indicating robust predictability. Mature wood exhibited greater strength compared to juvenile wood. The approach of using juvenile wood properties to predict those of mature wood is validated. This method provides a feasible avenue for the early prediction of wood properties in slash pine. [ABSTRACT FROM AUTHOR]

Qualitative and quantitative anatomical characteristics and radial variations of the major cell components in Paulownia tomentosa wood were examined using optical microscopy and X-ray diffraction to aid in wood identification and as quality indices. The vessel arrangement on the transverse surface was either ring-porous or semi-ring-porous. Most vessels had solitary pores, while some vessels had multiple radial pores. The axial parenchyma was generally confluent and partially of aliform type. Tyloses with high frequency in the vessel lumen and multiseriate rays (2 to 5 cells) were typical. The vessel diameter of earlywood and latewood was approximately 240 and 107 μm, respectively, with a range of 165 to 289 μm in earlywood and 55 to 149 μm in latewood. Ray height and fiber length were approximately 178 and 740 μm, respectively. The vessel diameter in both earlywood and latewood and the fiber length increased gradually with an increasing number of growth rings. Ray height was constant from the pith to the middle section and decreased toward the bark. The anatomical characteristics and radial variation of major components of P. tomentosa can be used as wood identification keys and quality indices.

Abstract Key message This study compares the measured radial variation in wood stiffness, strength, and density of noble fir, Norway spruce, western hemlock, and western red cedar by developing mixed-effects models for each property using age as the explanatory variable. These models could be used to simulate the effect of rotation length and species choice on sawn wood properties. Context Timber production in Great Britain relies primarily on Sitka spruce. The use of multiple species is desirable to mitigate against biotic and abiotic risks posed to a single species. When considering alternative species, quantifying and modeling radial variation in wood properties is important to determine the potential for sawn timber production at a given rotation length. Aims To build empirical models for the radial variation in wood properties that can account for species. Methods Clear-wood samples were produced along radial transects in trees from four conifer species: Abies procera Rehder, Picea abies (L.) Karst, Tsuga heterophylla (Raf.) Sarg., Thuja plicata Donn. ex D.Don. Modulus of Elasticity, Modulus of Rupture, and density were measured on each species according to established standards. Mixed-effects models were built using ring numbers from the pith and species as explanatory variables. Results The same model forms could be used across the four species. Nonlinear models were developed for the Modulus of Elasticity and density. For the Modulus of Rupture, a linear model was most appropriate. The effect of species in the models was significant. Conclusion At similar rotation lengths, noble fir, Norway spruce, and western hemlock can produce timber with comparable properties to Sitka spruce. Overall, western red cedar would have worse properties for structural use.

Key message: This study compares the measured radial variation in wood stiffness, strength, and density of noble fir, Norway spruce, western hemlock, and western red cedar by developing mixed-effects models for each property using age as the explanatory variable. These models could be used to simulate the effect of rotation length and species choice on sawn wood properties. Context: Timber production in Great Britain relies primarily on Sitka spruce. The use of multiple species is desirable to mitigate against biotic and abiotic risks posed to a single species. When considering alternative species, quantifying and modeling radial variation in wood properties is important to determine the potential for sawn timber production at a given rotation length. Aims: To build empirical models for the radial variation in wood properties that can account for species. Methods: Clear-wood samples were produced along radial transects in trees from four conifer species: Abies procera Rehder, Picea abies (L.) Karst, Tsuga heterophylla (Raf.) Sarg., Thuja plicata Donn. ex D.Don. Modulus of Elasticity, Modulus of Rupture, and density were measured on each species according to established standards. Mixed-effects models were built using ring numbers from the pith and species as explanatory variables. Results: The same model forms could be used across the four species. Nonlinear models were developed for the Modulus of Elasticity and density. For the Modulus of Rupture, a linear model was most appropriate. The effect of species in the models was significant. Conclusion: At similar rotation lengths, noble fir, Norway spruce, and western hemlock can produce timber with comparable properties to Sitka spruce. Overall, western red cedar would have worse properties for structural use. [ABSTRACT FROM AUTHOR]

Properties of Sentang wood planted in Kelantan, Malaysia, were studied, focusing on the effect of radial growth rate on variation in the fiber and vessel element dimensions, moisture content, density, shrinkage, bending, and compression strength at the breast height of the tree. The trees were categorized into slow-, average-, and fast-growth categories, based on their breast height diameter and standard deviation. The variations in properties were then examined from the pith to the bark. The fiber length and diameter tend to decrease until a certain distance from the pith, followed by an increase toward the bark. Contrastingly, the vessel element length and diameter tend to increase until a maximum size is reached and then exhibit a relatively constant size toward the bark. The fast-growing trees tended to have longer and larger fibers, while the slow-growing trees tended to have longer and larger vessel elements. In addition, the fast-growing trees tended to have a higher green moisture content and shrinkage, lower density, lower modulus of rupture (MOR), and lower compression strength. The results revealed that growth rate seems to influence the modulus of elasticity (MOE) less than the MOR and compression strength.

Properties of Sentang wood planted in Kelantan, Malaysia, were studied, focusing on the effect of radial growth rate on variation in the fiber and vessel element dimensions, moisture content, density, shrinkage, bending, and compression strength at the breast height of the tree. The trees were categorized into slow-, average-, and fast-growth categories, based on their breast height diameter and standard deviation. The variations in properties were then examined from the pith to the bark. The fiber length and diameter tend to decrease until a certain distance from the pith, followed by an increase toward the bark. Contrastingly, the vessel element length and diameter tend to increase until a maximum size is reached and then exhibit a relatively constant size toward the bark. The fast-growing trees tended to have longer and larger fibers, while the slowgrowing trees tended to have longer and larger vessel elements. In addition, the fast-growing trees tended to have a higher green moisture content and shrinkage, lower density, lower modulus of rupture (MOR), and lower compression strength. The results revealed that growth rate seems to influence the modulus of elasticity (MOE) less than the MOR and compression strength. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract To test whether radial variation of wood specific gravity (WSG) is controlled by tree age or tree size in teak (Tectona grandis L.f) plantation trees, opposing different-length pith-to-bark strips which represents the differential lateral growth rate was compared using mixed-effects model which considers the heterogeneity of variances and dependency in the data to gain insight into the stochastic processes that govern the wood formation process. Various models were tested in devising an appropriate radial WSG model. Models that accounted for serial correlation in WSG data performed better than the simple structure that assumes zero correlation between measurements. The autoregressive plus random tree effect structure performed better in describing the radial variation pattern. The variability of the data related to random fluctuations during tree development and the wood formation process is modeled by the autoregressive parameter revealing the intrinsic complexity of wood formation. Since they cannot be attributed to observed factors, models should consider temporal or serial correlations when assessing wood quality. The results revealed that tree age is a decisive factor in controlling the WSG of wood, while tree size is statistically less important. Furthermore, the core wood production period varies with the growth rate. It is shown that the core wood area decreased with slow growth. Findings presented here appear to provide the first demonstration of radial variation in WSG with respect to growth rate and age for planted teak growing in Ghana.

Boundary between core and outer wood should be clarified for tropical fast-growing tree species to utilize its wood resources under sustainable forestry. This study aimed to determine the boundary between core and outer wood based on the mixed-effects models for radial variations of anatomical characteristics and wood properties in three fast-growing tree species grown in community forests in Indonesia – Acacia mangium Willd., Maesopsis eminii Engl., and Melia azedarach L.. On the basis of the results of the radial variation modeling, almost all anatomical characteristics and wood properties were shown to increase or decrease from pith to bark and then become almost stable. The boundary values between core and outer wood based on exponential function with plateau for absolute changing ratios of estimated properties were 6.1, 6.8, and 5.5 cm for A. mangium, M. eminii, and M. azedarach, respectively. In conclusion, boundary between core and outer wood in respect to multiple characteristics and properties in tropical fast-growing tree species can be determined by combination of mixed-effects modeling and exponential function with convergence. [ABSTRACT FROM AUTHOR]

To test whether radial variation of wood specific gravity (WSG) is controlled by tree age or tree size in teak (Tectona grandis L.f) plantation trees, opposing different-length pith-to-bark strips which represents the differential lateral growth rate was compared using mixed-effects model which considers the heterogeneity of variances and dependency in the data to gain insight into the stochastic processes that govern the wood formation process. Various models were tested in devising an appropriate radial WSG model. Models that accounted for serial correlation in WSG data performed better than the simple structure that assumes zero correlation between measurements. The autoregressive plus random tree effect structure performed better in describing the radial variation pattern. The variability of the data related to random fluctuations during tree development and the wood formation process is modeled by the autoregressive parameter revealing the intrinsic complexity of wood formation. Since they cannot be attributed to observed factors, models should consider temporal or serial correlations when assessing wood quality. The results revealed that tree age is a decisive factor in controlling the WSG of wood, while tree size is statistically less important. Furthermore, the core wood production period varies with the growth rate. It is shown that the core wood area decreased with slow growth. Findings presented here appear to provide the first demonstration of radial variation in WSG with respect to growth rate and age for planted teak growing in Ghana. [ABSTRACT FROM AUTHOR]

Radial chromatic aberration (∆E) in xylem is a significant phenotypic characteristic for distinguishing sapwood from heartwood. Investigating its relationship with metabolites is critical to the formation of color differences in wood. In this study, chromatic aberration of the inner heartwood (IH), outer heartwood (OH), transition zone (TZ), inner sapwood (IS), and outer sapwood (OS) were quantified utilizing the CIE color space system, and the secondary metabolite profiles of Toona fargesii wood were identified. The findings showed a radial variation in the wood color of T. fargesii. The chromatic aberration was largest in the OS vs. IH for 22.51 and smallest in OH vs. TZ for 4.92. A total of 646 metabolites from 8 categories were obtained from wood, including flavonoids, phenolic acids, terpenoids, et al. The OS vs. IH had the highest number of differential metabolites with 395, whereas the OH vs. TZ had the fewest differential metabolites with 184. The metabolites were mostly enriched in metabolic pathways and the biosynthesis of flavonoids. The 75 % metabolites in the flavonoid biosynthesis pathway were abundant in HW tissues and gradually decreased from IH to OS. There were 39 shared differential metabolites among six comparison groups, of which flavonoids accounted for 31 %. There were clear radial differences in the flavonoid metabolites, with a generally decreasing trend from IH to OS tissue. The relative content of the flavonoids exhibited negative and positive correlations with L* and a*, respectively. Especially the largest correlation coefficients for 93 % between 2-hydroxynaringenin, aromadendrin and L* showed their importance in chromatic aberration. This study demonstrated the radial variation pattern of chromatic aberration and metabolic profiles. It also identified the key metabolites that affect wood color in T. fargesii , which offered valuable insights into the formation of the chromatic aberration in wood. [Display omitted] • The chromatic aberration of wood in radial direction increased with spatial position of tissues. • A total of 646 metabolites from 8 categories were obtained from various tissues of wood. • The flavonoids enriched in HW tissues and gradually decreased in the radial direction. • Flavonoids content exhibited negative and positive correlations with color index (L* and a*). [ABSTRACT FROM AUTHOR]

Copyright of Forest Research is the property of Forest Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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

Key message: Positive radial trends in WSG were common among light-demanding species, and were mainly explained by radial shift in fiber and parenchyma traits. Trees can modify their wood structure in response to changes in mechanical, hydraulic and storage demands during their life-cycles. Thus, examining radial variations in wood traits is important to expand our knowledge of tree functioning and species ecological strategies. Yet, several aspects of radial changes in wood functional traits are still poorly understood, especially in angiosperm trees from tropical humid forests. Here, we examined radial shifts in wood traits in trunks of tropical forest species and explored their potential ecological implications. We first examined radial variations in wood specific gravity (WSG). Then, we asked what anatomical traits drove radial variations in WSG, and whether WSG, vessel fraction and specific hydraulic conductivity vary independently from each other along the radius gradients. We measured WSG and eight wood anatomical traits, at different radial positions along the trunks, in 19 tree species with contrasting shade-tolerance from a lowland tropical forest in eastern Amazonia. Most species had significant radials shifts in WSG. Positive radial gradients in WSG (i.e., increments from pith to bark) were common among shade-intolerant species and were explained by different combinations of fiber and parenchyma traits, while negative radial shifts in WSG (e.g., decreases towards the bark) were present in shade-tolerants, but were generally weakly related to anatomical traits. We also found that, in general, WSG was unrelated to vessel fraction and specific hydraulic conductivity in any radial position. This study illustrates the contrasting radial variations in wood functional traits that occur in tree species from a humid lowland tropical forest. In particular, our results provide valuable insights into the anatomical traits driving WSG variations during tree development. These insights are important to expand our knowledge on tree ecological strategies by providing evidence on how wood allocation varies as trees grow, which in turn can be useful in studying trait-demography associations, and in estimating tree above-ground biomass. [ABSTRACT FROM AUTHOR]

This work focuses on the genetic variation of Chinese fir clones in the radial direction. Four 20-year-old Chinese fir clones were selected in Kaihua Forest Farm, Zhejiang, China, and the differences and genetic characteristics were studied. Clonal repeatability, genotype coefficient of variable, and phenotypical coefficient of variable were calculated to light on the genetic variation on the radial direction. Results showed significant differences (P < 0.05) between the clones and annual rings of the same clone. The clonal repeatability of the ten wood properties is ranged from 0.5 to 0.8, wherein the fiber length, elastic modulus, and total dry density are higher than 0.7. For all the measured traits, the phenotypic variation of clones is greater than that of the genetic variation. Overall, the measured wood traits, especially the mechanical and physical properties, are strongly controlled by heredity, which means they are potentially helpful for genetic improvement of wood properties and optimal breeding. Furthermore, the clonal repeatability of the measured traits varies between annual rings, and the physical and mechanical properties are relatively stable. The principal component analysis results reveal that the clone of Kai 13 has the highest score. [ABSTRACT FROM AUTHOR]

In this study, we applied thermal dissipation probe technology to examine sap flow in various directions (east, south, west, and north) and at different depths (0-2, 2-4, 4-6 cm) within the stem of natural Picea mongolica trees in the eastern of Otindag Sandy Land to provide a scientific basis for accurately quantifying water consumption of P. mongolica forests through transpiration and to enhance the understanding of water relations. The results showed that the diurnal variation of sap flow in different directions displayed a unimodal curve, with the sap flow sequence being south>east>west>north. The sap flow at different sapwood depths exhibited an obvious unimodal curve, with a significant decrease as sapwood depth increased. Compared with that calculated from the mean sap flux density in four directions (23.57 kg·d -1 ), water consumption calculated using the mean value in south-east, east-west, south-west, north-east, north-south, and north-west was overestimated by 10.2%, 5.5%, 14.5%, and underestimated by 12.3%, 8.2%, 9.8%, respectively. The water consumption calculated using the values from the east, south, and west was overestimated by 6.1%, 14.4%, and 15.4%, respectively, and underestimated by 30.7% in the north. In addition, compared with the water consumption calculated from the mean value in three sapwood depths (48.51 kg·d -1 ), that calculated using sap flux density at sapwood depths of 0-2, 2-4, and 4-6 cm were overestimated by 18.8%, underestimated by 1.7%, and underestimated by 62.9%, respectively. These results indicated that sap flow of P. mongolica had significant azimuthal and radial variations, which considerably influence the estimation of tree water consumption. Installing probes at 0-2 cm simultaneously in both the north and east of the trunk could effectively reduce the estimation error of whole-tree water consumption by 4.2%. This approach enabled the accurate quantification of water consumption of individual P. mongolica trees in sandy areas, thereby improving the precision of transpiration water consumption estimates scaling up from individual level to stand level.

• Key message: This paper investigates the juvenility limit and structure–property relationship in secondary quality beech (Fagus sylvaticaL.) and oak (Quercus petraea(Matt.) Liebl.). The juvenile wood occupies a very small area near the pith. The stabilization of the different parameters varies over time. Adding the microfibril angle (MFA) and the grain angle to the MOE prediction model significantly improves the quality of the model, despite little variation in both parameters. • Context: Using secondary qualities and small logs of hardwoods such as beech and oak for engineered wood products is an increasingly important issue due to the technological challenges of processing smaller logs and denser woods. Secondary quality hardwoods are expected to have less variation in mechanical properties compared to softwoods with high juvenile wood content. • Aims: The first objective of this study was to investigate the radial variation in wood properties of suppressed growth beech and oak trees obtained from thinning operations. The second objective was to develop a model to predict the mechanical properties of these hardwood species based on their structural parameters. • Methods: The microfibril angle, ring wood density, and ring width from the pith to the bark were determined using an X-ray densitometer. The modulus of elasticity and modulus of rupture were evaluated on the small clear specimen using a three-point bending test. The wood density, grain angle, and microfibril angle of this small clear specimen were also measured. • Results: The results show that the juvenile wood in oak has a wider ring and higher microfibril angle, whereas it has wider latewood and higher microfibril angle in beech. For both species, the juvenile wood occupies a very small area, less than 5 cm from the pith. The mechanical properties of oak and beech wood from suppressed growth trees are comparable to properties reported in the literature for dominant trees. The modulus of elasticity of oak was best predicted using wood density, grain angle, and microfibril angle. The modulus of rupture of oak is better predicted with wood density and grain angle, whereas it is best predicted with wood density alone for beech. • Conclusion: Juvenile wood found in the suppressed growth trees of both hardwoods can be used in place of mature wood. It is important to take structural parameters into account when predicting the mechanical properties of hardwood species. [ABSTRACT FROM AUTHOR]

The radial variation and the genetic variation of wood properties between the parents and offspring of Populus deltoides were studied in this work. The chemical composition, density, and anatomical characteristics of Populus deltoides cl. 'Danhong' and its offspring exhibited the phenomenon of transgressive segregation. The chemical compositions of the parents and offspring were decreased in several attributes (benzene alcohol extract, hemicelluloses, lignin) with the increase of the cambial age. Moreover, the fibre length, fibre width, ratio of fibre length to width, and wall thickness to lumen ratio of parents and offspring were increased with cambial age. In addition, the densities of parents and offspring were increased with the increase of cambial age. There were significant differences in wood properties among Populus deltoides and its hybrids. These results indicated that Populus deltoides cl. 'Danhong' could be considered as pulp material and Populus deltoides cl. 'Nanyang' as building material. According to the radial variation rule of each material character, the rotation cutting period can be selected as years 7 or 8. [ABSTRACT FROM AUTHOR]

Pinus elliottii wood from different radial locations within trees was used to prepare two-layer preservative-treated wood joints with alkaline copper quaternary preservative and emulsion polymer isocyanates (EPI) or resorcinol-phenol-formaldehyde (RPF) adhesives. The radial variations in shear strength and wood failure percentage were analyzed. Radial variations in wood density and average penetration depth (AP) of adhesives were investigated to establish relationships between shear strengths and characteristics of bonded joints. The shear strengths of EPIand RPF-bonded joints showed similar increasing trends from pith to bark, and they varied in ranges of 2.92 to 8.13 MPa and 2.03 to 7.12 MPa, respectively. The wood failure percentage of EPI joints (93% to 100%) had no significant differences in all the radial locations, but that of RPF joints (60% to 100%) showed a clear decreasing trend from pith to bark. High positive linear correlations were found between the shear strengths and wood density, and Pearson's correlation coefficients for EPI and RPF were 0.934 (p < 0.01) and 0.931 (p < 0.01), respectively. Wood density is a very important factor influencing radial variations of bonding strengths. The correlation between the AP and shear strength was not significant at the 0.05 level. [ABSTRACT FROM AUTHOR]

The radial variation of rays within the stems of Dahurian larch and Japanese larch growing in Korea was studied to obtain valuable information to identify the two species and determine wood quality. Uniseriate ray height, fusiform ray height, ray number, ray spacing, and epithelial cell number were investigated by optical microscopy. The heights of uniseriate and fusiform rays and epithelial cell numbers in Dahurian larch were lower than those in Japanese larch. Dahurian larch wood had greater ray number and ray spacing than Japanese larch wood. In both species, the heights of uniseriate and fusiform rays and epithelial cell number increased with increasing growth ring number but then stabilized from a certain growth ring number. However, ray number and ray spacing decreased with age but were stable toward the bark. There were significant differences in all ray properties between the two species. Furthermore, in both species, the number and spacing of rays showed a significant negative correlation with uniseriate ray height. The relationships between uniseriate and fusiform ray height, and between ray spacing and ray number were significantly positive. In conclusion, the results from this study provide basic information that can be used to identify these species, and the quality indices from ray properties will improve the effective utilization of the two woody species. [ABSTRACT FROM AUTHOR]

In [9] Anderson's conjecture was proven by comparing values of Bloch functions with the variation of the function. We extend that result on Bloch functions from two to arbitrary dimension and prove that .... In the second part of the paper, we show that the area or volume integral ... for positive harmonic functions u is bounded by the value cu(0) for at least one θ. The integral is also transferred to simply connected domains and interpreted from the point of view of stochastics. Several emerging open problems are presented. [ABSTRACT FROM AUTHOR]

The objective of this study was to characterize the wood anatomical structure of a rubber tree clone, under the influence of two different canopy grafts. The following rubber trees were selected in the system of a doublegrafted PB 311 + FX 2784 and PB 311 + MDF 180. For each tree, discs of wood were cut from the affected branch immediately below the insertion of clone at right angles to the axis, from which the regions corresponding to tension, in opposite and normal wood, were identified. The anatomical analyses were conducted in accordance with the standards established by the International Association of Wood Anatomy Committee. The Kruskal-Wallis nonparametric test was applied for multiple comparisons among the types of woods and radial positions studied, at 5% of significance. Still, multivariate associations were assessed among the anatomical characteristics of both double-grafted rubber trees, by means of a two-step cluster analysis. Quantitative morphological differences were observed in the wood cells of the double-grafted studied clones. The ray height and the vessels diameter were the most important morphologic characteristics for the distinction. The canopy clone exhibited the ability to modulate the quantitative anatomical characters of the panel clone, depending on the plant's needs. [ABSTRACT FROM AUTHOR]

This study aims to understand the effect of the initial planting density on the anatomical variability and basic wood density of Schizolobium parahyba var. amazonicum in a planted forest in Amazonia. The effect of the initial planting density on the radial variation from pith to bark of anatomy and basic density was evaluated. There were two planting densities, planting density-I (624 trees ha-1) and planting density-II (312 trees ha-1). Planting density significantly affected only the ray height, fiber length and wall thickness. Radial position was not significant to the height of the rays and the fiber lumen diameter. The interaction planting density × radial position was only significant for the length of the vessel elements, ray frequency and fiber length. The results indicate that the initial planting density influences the radial behavior of certain anatomical characteristics. To obtain gain in terms of total wood per cultivated area, without harm to the density of the produced wood, planting density-I would be most useful, while planting density-II would be suitable for the production of more homogeneous wood, which tends to form adult wood in advance and with some anatomical characteristics appropriate for the plywood industry.

Radial variations in wood properties, cell morphologies and cell proportions were investigated for nine 4-year-old Neolamarckia cadamba trees planted in a community forest in East Java, Indonesia. The relationships between stem diameter and wood properties, cell morphologies or cell proportions were determined to ascertain the effects of stem diameter on these properties. In the radial variations, almost all of the wood properties, cell morphol- ogies and cell proportion in N. cadamba were changed at around 4 to 6 cm distance from the pith, except for fibre diameter, and the proportion of fibre and axial parenchyma. For trees with larger stem diameter, the vessel diameter was also found to increase. In addition, the ray parenchyma and cell wall proportions in trees with larger stem diameter were lower than those in trees with smaller stem diameter. However, the wood properties obtained from the larger stem diameter trees did not always show lower values. The wood properties in N. cadamba were correlated to fibre wall thickness and vessel diameter. [ABSTRACT FROM AUTHOR]

This study aims to understand the effect of the initial planting density on the anatomical variability and basic wood density of Schizolobium parahyba var. amazonicum in a planted forest in Amazonia. The effect of the initial planting density on the radial variation from pith to bark of anatomy and basic density was evaluated. There were two planting densities, planting density-I (624 trees ha-1) and planting density-II (312 trees ha-1). Planting density significantly affected only the ray height, fiber length and wall thickness. Radial position was not significant to the height of the rays and the fiber lumen diameter. The interaction planting density × radial position was only significant for the length of the vessel elements, ray frequency and fiber length. The results indicate that the initial planting density influences the radial behavior of certain anatomical characteristics. To obtain gain in terms of total wood per cultivated area, without harm to the density of the produced wood, planting density-I would be most useful, while planting density-II would be suitable for the production of more homogeneous wood, which tends to form adult wood in advance and with some anatomical characteristics appropriate for the plywood industry. [ABSTRACT FROM AUTHOR]

The technological properties of wood can be influenced by the characteristics of secondary xylem, such as fiber size, length and thickness, and also the microfibrillary angle in the secondary wall. The objective of the present study was to evaluate the fiber size as a function of the microfibrillary angle of the wood of six Eucalyptus genotypes, in the spinal cord, from three regions of Minas Gerais. Biometric fiber analyzes were performed according to the IAWA committee's anatomy standard. For the microfibrillary angle, the method used was polarized light. The genotypes behaved differently from one another, especially those from E. urophylla, which had the highest biometric values of the fibers. There were significant differences in length and wall thickness of the fibers between the studied genotypes and the radial positions. For the microfibrillary angle, there were no significant differences between the genotypes and the radial positions. However, there was a trend where, as the length and wall thickness of the fibers increase radially, the microfibrillary angle decreases. Genetic factors and the age of the individuals may have influenced of the results. [ABSTRACT FROM AUTHOR]

The fast growth of Tetracentron sinense is a potential valuable timber resource, but whether its anatomy and chemical components are suitable for timber is unknown. We used light microscopy and SEM to examine the anatomical structure and FITR to measure the chemical components of the phloem and xylem of this tree. Radial variations in growth ring width and tracheid dimensions were also evaluated. The sieve tube, phloem parenchyma cell and sclereids clusters were the main cells in phloem, and the tracheid was the fundamental cell in xylem. An unusual tracheid type, fiber-tracheids or vessel-liked elements was visible. Wood rays nonstoried, uniseriate and multiseriate, including heterogeneous II, occasionally I, and usually 3-6 cells wide. The mean growth-ring width was 2.53 ± 0.46 mm, and the percentage of late wood was over 60%. For radial variation, growth-ring width increased at an early growth stage, and reached the largest increment during years 11-15, then decreased. The maximum growth-ring width was 5.313 mm. During late growth (60-85 years), trees also maintained a high radial growth increment. Radial variation in the percentage of late wood was uniform, about 50-70%, throughout the growth years. Growth patterns in the length and width of early and late wood were similar as the trees aged. From the FTIR results, the chemical components differed significantly between xylem and phloem, hemicellulose in particular was higher in the xylem than in the phloem, where it was apparently absent. All of these suggest that the composition of phloem in T. sinense is very similar to that of hardwood, and it has higher growth ratio and uniform wood properties. [ABSTRACT FROM AUTHOR]

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La variación radial y longitudinal de la densidad básica de la madera, a lo largo del fuste, fueron determinadas en árboles de una plantación de Eucalyptus regnans de 16 años, crecida en la Costa de la Provincia de Arauco, Chile. Además, se correlacionó la densidad básica promedio del fuste, con la densidad básica obtenida a distintos niveles de altura. Se muestrearon 9 árboles entre dominantes y codominantes. De cada árbol se obtuvieron rodelas cada 10% de la altura total, hasta una altura del 70%. De las rodelas se extrajeron cubos de 1 cm de arista, de médula a corteza en las direcciones norte y sur, y en ellos se determinó la densidad básica. Se encontraron tres patrones de variación radial para la densidad básica a lo largo del fuste del árbol. En la dirección longitudinal la densidad básica disminuyó desde la base del fuste hasta la altura del 4,5% y luego aumentó linealmente hasta el 70% de la altura total del árbol. Las mejores alturas de muestreo para estimar la densidad promedio del fuste, fueron al 10 y al 20% de la altura total del árbol.The radial and longitudinal variations in wood basic density along the stem were determined in trees from a plantation of Eucalyptus regnans (16 year old) grown at the coast of the Arauco Province, Chile. The weighted stem basic density was estimated and correlated to the basic density at different sampling heights. Nine dominant and/or codominant trees were selected. Discs were obtained each 10% of the total height until a height of 70%. From the discs, small cubic samples of 1 cm edge from the pith to the bark and in the north and south directions were extracted, and in these small samples the basic density was determined. Three radial variation patterns for the basic density along the stem were found. In the longitudinal direction, basic density decreased from the base of the tree to 4.5% of the height, and then increased linearly until 70% of the total tree height. The best sampling heights for estimating the weigthed basic density of the stem were to 10 and 20% of the total tree height.

Objetivou-se caracterizar a densidade básica, retrações lineares e volumétrica e teores de extrativos, lignlina e holocelulose, no sentido medula-casca da madeira de Luehea divaricata, bem como investigar as correlações existentes entre as características mencionadas, a densidade aparente e a estrutura anatômica. Em todas as análises empregaram-se as técnicas usuais para a determinação das propriedades físicas,características anatômicas e constituintes químicos da madeira, sendo os resultados determinados por meio de análise de variância, testes de comparações múltiplas e análises de correlação de Pearson. Os resultados revelaram a tendência de diminuição do teor de extrativos da medula para a casca, já o teor de lignina diminuiu da medula para a posição intermediária e aumentou na casca, consequentemente o teor de holocelulose apresentou valores menores na região próxima à casca. Entre as propriedades físicas, a retração tangencial, índice de anisotropia e densidade básica tenderam a aumentar gradativamente da medula para a casca; a retração volumétrica diminuiu na região intermediária e aumentou na casca, apresentando seu maior valor; já a retração radial também diminuiu na região intermediária com relação à medula, mostrando um aumento na casca, no entanto este valor foi menor do que o registrado na medula. O teor de extrativos apresentou correlações positivas com a frequência dos raios e o diâmetro das fibras e correlações negativas com diâmetro dos vasos e a largura dos raios multisseriados. O teor de holocelulose correlacionou-se positivamente com a largura dos raios multisseriados e unisseriados. Ocorreram correlações positivas entre a espessura da parede das fibras e a densidade básica e densidade aparente. O teor de lignina mostrou correlação positiva com a retração radial. O teor de holocelulose apresentou correlações negativas com a retração volumétrica e retração radial.Objetivou-se caracterizar a densidade básica, retrações lineares e volumétrica e teores de extrativos, lignlina e holocelulose, no sentido medula-casca da madeira de Luehea divaricata, bem como investigar as correlações existentes entre as características mencionadas, a densidade aparente e a estrutura anatômica. Em todas as análises empregaram-seas técnicas usuais para a determinação das propriedades físicas, características anatômicas e constituintes químicos da madeira, sendo os resultados determinados por meio de análise de variância, testes de comparações múltiplas e análises de correlação de Pearson. Os resultados revelaram a tendência de diminuição do teor de extrativos da medula para a casca, já o teor de lignina diminuiu da medula para a posição intermediária e aumentou na casca, consequentemente o teor de holocelulose apresentou valores menores na região próxima à casca. Entre as propriedades físicas, a retração tangencial, índice de anisotropia e densidade básica tenderam a aumentar gradativamente da medula para a casca; a retração volumétrica diminuiu na região intermediária e aumentou na casca, apresentando seu maior valor; já a retração radial também diminuiu na região intermediária com relação à medula, mostrando um aumento na casca, no entanto este valor foi menor do que o registrado na medula. O teor de extrativos apresentou correlações positivas com a frequência dos raios e o diâmetro das fibras e correlações negativas com diâmetro dos vasos e a largura dos raios multisseriados. O teor de holocelulose correlacionou-se positivamente com a largura dos raios multisseriados e unisseriados. Ocorreram correlações positivas entre a espessura da parede das fibras e a densidade básica e densidade aparente. O teor de lignina mostrou correlação positiva com a retração radial. O teor de holocelulose apresentou correlações negativas com a retração volumétrica e retração radial. The radial shrinkage also decreased in the region intermediate with respect to the pith, showing an increase in the bark, but this value was lower than that founded in the pith. The extractives content showed positive correlations with the frequency of rays and the fibers diameter and negatively correlated with vessel diameter and width of multiseriate rays. The holocellulose content presented positive correlations with the width of the multiseriate and uniseriate rays. There were positive correlations between the fiber wall thickness and basic density and specific gravity. The lignin content presented positive correlation with the radial shrinkage. The holocellulose content showed negative correlations with the total and radial shrinkage.

As variações na retratibilidade no lenho das árvores são as principais causas dos defeitos de secagem, como o empenamento e fendilhamento das peças de madeira. Os tipos de madeira presentes em um tronco estão relacionados com as variações dessa importante propriedade física. Este trabalho teve como objetivo estudar a retratibilidade da madeira de sete espécies de eucaliptos. Os parâmetros de retratibilidade, bem como a sua variação na direção radial da medula em direção à periferia do tronco de sete espécies de eucaliptos, foram avaliados de acordo com a Norma brasileira. De modo geral, os resultados indicaram que as espécies de eucaliptos estudados possuíam madeira com elevada retratibilidade. À exceção das madeiras de Eucalyptus tereticornis e E. pilularis, as demais espécies estudadas apresentaram valores menores de retratibilidade na região próxima da medula.The variation of the retratibility in lumber is the main cause of the occurrence of drying defects, especially those characterized by warped and split wood. The different wood types present in the stem are related to the variation of these important physical properties. This work aimed to study the retratibily of seven eucalypt species. The retratibility parameters such as the variation in the pith to bark direction in the peripheral of the trunk were studied according the Brazilian Standard for the seven eucalypts. In general the results showed that the species of eucalypts studied have a high retratibility. Except for Eucalyptus tereticornis and E. pilularis the others species studied showed lower values of retratibility in the pith region.

Variações entre as dimensões e frequênciasdas células da madeira existem entre espéciesdiferentes, entre indivíduos da mesma espécie ouainda dentro da mesma árvore nas direções radial eaxial. Essa variação influencia diretamente nadensidade aparente e consequentemente no uso dasdiferentes madeiras. O presente estudo determinoua variação anatômica radial e sua influência nadensidade aparente no lenho de árvores de Luehea divaricata, a partir de amostras coletadas no DAP,por meio de método destrutivo. Para a avaliaçãoanatômica e da densidade aparente foram empregadastécnicas usuais em anatomia e propriedades físicasda madeira e os dados tratados estatisticamente.Os resultados revelaram que o diâmetro dos vasos,espessura da parede das fibras e a densidadeaparente foram significativamente menores na regiãoda medula, já o lume das fibras foi significativamentemaior nesta região, que também apresentou raiosmais volumosos. Sugere-se que fibras com paredesmais finas e raios com maior volume na região damedula contribuíram de forma determinante paraos menores valores de densidade aparente.Variations between the size and frequencyof the wood cells occur among differentspecies, trees of the same species or even withinthe same tree in the radial and axial directions.These variations affect directly the specific gravityand consequently the use of different woods.This study determined the radial anatomicalvariation and its influence on specific gravity ofthe wood of Luehea divaricata trees, from samplescollected on DBH by using destructive method.For the evaluation of anatomical characteristicsand specific gravity were employed standardtechniques in anatomy and physical propertiesof wood and the data analyzed statistically.The results revealed significantly lower vesseldiameter, fiber wall thickness and specific gravityin pith, fiber lumen was significantly higher inthis region, which also showed very large rays.It is suggested that fibers with thinner walls andrays with greater volume in the pith contributed tothe lowest values of specific gravity.

Vessel grouping in angiosperms may improve hydraulic integration and increase the spread of cavitations through redundancy pathways. Although disputed, it is increasingly attracting research interest as a potentially significant hydraulic trait. However, the variation of vessel grouping in a tree is poorly understood. I measured the number of solitary and grouped vessels in the xylem of Betula platyphylla Roth. from the pith to the bark along the water flow path. The vessel grouping parameters included the mean number of vessels per vessel group (VG), percentage of solitary vessels (SVP), percentage of radial multiple vessels (MVP), and percentage of cluster vessels (CVP). The effects of cambial age (CA) and flow path-length (PL) on the vessel grouping were analyzed using a linear mixed model.VG and CVP increased nonlinearly, SVP decreased nonlinearly with PL. In trunks and branches, VG and CVP decreased nonlinearly, and SVP increased nonlinearly with CA. In roots, the parameters had no change with CA. MVP was almost constant with PL or CA. The results suggest that vessel grouping has a nonrandom variation pattern, which is affected deeply by cambial age and water flow path. [ABSTRACT FROM AUTHOR]

A ultra-estrutura e a composição química da madeira, bem como suas propriedades físicas e mecânicas, variam significativamente entre espécies, entre árvores de uma mesma espécie e, mesmo, entre diferentes partes de uma mesma árvore. Com este trabalho objetivou-se o estudo dos parâmetros de retratibilidade e de densidade básica da madeira Eucalyptus saligna, com idade de 16 anos, proveniente de talhões experimentais da EMBRAPA Florestas, de Colombo, Paraná. As amostras foram retiradas à altura do DAP de quatro posições eqüidistantes a partir da medula em direção à periferia, correspondendo a 0, 33, 66 e 100%, com dimensões nominais de 1,0 x 2,0 x 3,0 cm, sendo a última dimensão no sentido longitudinal. Elas foram mantidas em câmara fechada com ventilação, próximo de soluções salinas supersaturadas, com o objetivo de proporcionar diferentes condições de umidade relativa. Uma vez atingidas as distintas condições de umidade de equilíbrio, as amostras foram secas em estufa a 105 ºC e obtidos os dados de retratibilidade e densidade básica da madeira nas posições mencionadas. Constataram-se valores de contração volumétrica mais baixos na região medular, apresentando um acréscimo para as demais posições. Comportamento semelhante foi observado para os coeficientes das contrações lineares nas direções tangencial e radial. O fator anisotrópico foi consideravelmente mais elevado na região medular, decrescendo substancialmente em direção ao alburno. A densidade básica não mostrou sinais efetivos de estabilidade, apesar de mostrar tendência de aumento em direção à periferia do tronco.The ultra structure and chemical composition of wood, as well as its physical and mechanical properties vary significantly among species, trees of a given species and even among different parts of a given tree. This work aimed to study the parameters of shrinkage and basic density of 16-year-old Eucalyptus saligna wood, originated from Embrapa Forests experimental stands in Colombo, Parana. The samples were collected at DBH from four equidistant positions from the pith to the bark, corresponding to 0,33, 66 and 100%, with nominal dimensions of 1.0 x 2.0 x 3.0 cm, with the latter being longitudinal-wise. They were kept inside a closed chamber under ventilation and near supersaturated saline solutions so as to provide different relative humidity conditions. Once these conditions were reached, the samples were oven-dried at 105 ºC . Shrinkage and basic density data were obtained in the four populations studied. Lower volumetric shrinkage values were found near the pith, increasing in the other positions. Similar behavior was observed for the linear shrinkage coefficients in the tangential and radial directions. The anisotropic factor, i.e., the relationship between tangential and radial shrinkage (T/R), was highest in the pith region, decreasing substantially towards the sapwood. Basic density did not show any signs of effective stability, despite its tendency to increase towards the outer stem.

La variación radial y longitudinal de la densidad básica de la madera, a lo largo del fuste, fueron determinadas en árboles de una plantación de Eucalyptus regnans de 16 años, crecida en la Costa de la Provincia de Arauco, Chile. Además, se correlacionó la densidad básica promedio del fuste, con la densidad básica obtenida a distintos niveles de altura. Se muestrearon 9 árboles entre dominantes y codominantes. De cada árbol se obtuvieron rodelas cada 10% de la altura total, hasta una altura del 70%. De las rodelas se extrajeron cubos de 1 cm de arista, de médula a corteza en las direcciones norte y sur, y en ellos se determinó la densidad básica. Se encontraron tres patrones de variación radial para la densidad básica a lo largo del fuste del árbol. En la dirección longitudinal la densidad básica disminuyó desde la base del fuste hasta la altura del 4,5% y luego aumentó linealmente hasta el 70% de la altura total del árbol. Las mejores alturas de muestreo para estimar la densidad promedio del fuste, fueron al 10 y al 20% de la altura total del árbol. Abstract The radial and longitudinal variations in wood basic density along the stem were determined in trees from a plantation of Eucalyptus regnans (16 year old) grown at the coast of the Arauco Province, Chile. The weighted stem basic density was estimated and correlated to the basic density at different sampling heights. Nine dominant and/or codominant trees were selected. Discs were obtained each 10% of the total height until a height of 70%. From the discs, small cubic samples of 1 cm edge from the pith to the bark and in the north and south directions were extracted, and in these small samples the basic density was determined. Three radial variation patterns for the basic density along the stem were found. In the longitudinal direction, basic density decreased from the base of the tree to 4.5% of the height, and then increased linearly until 70% of the total tree height. The best sampling heights for estimating the weigthed basic density of the stem were to 10 and 20% of the total tree height.

To estimate whole-tree or stand transpiration based on sap flow measurements, sap flux density (Fd) needs to be scaled up over the entire sapwood area. We investigated radial variations in Fd in the dominant oak (Quercus liaotungensis) and a commonly occurring oriental arborvitae (Platycladus orientalis) species using Granier-type thermal dissipation probes in a semi-arid forest in northern China. Our results show that Fd in oak trees reached a maximum just below the cambium and decreased towards the inner sapwood. On the other hand, radial sap flow patterns in oriental arborvitae trees differed among individuals. Fd values at different depths within an individual were highly correlated with each other in both species. We assessed the error of single-depth measurements when upscaling to whole-tree water use using multi-depth measurements as a reference. Omitting radial variations resulted in an overestimation of daily water use by 38% and 78% in oak trees with sapwood depths of approximately 2 and 3 cm, respectively. The outer sapwood annuli (0-1 cm) contributed 74% and 65% to the total water use in the two classes of sapwood depth. These contribution coefficients may be used as correction indices for estimating whole-tree water use. Errors of omitting radial variations in oriental arborvitae trees ranged from 42% to 21%. Using relatively long sensors (e.g. 2 cm) may improve the estimate accuracy in this species. The results would be applicable to the estimation of tree or stand transpiration based on routine depth measurements using one set of sensors. It is suggested that radial variations should be considered for accurately upscaling locally measured sap flow data to whole-tree water use in trees with wide sapwood and that different approaches may be applied to species with different patterns of radial variations. [ABSTRACT FROM AUTHOR]

Accurate estimates of stand transpiration ( E) require the consideration of three types of variation in sap flux density ( J): radial, azimuthal, and tree-to-tree variation. In this study, the J variation of 50-year-old Korean pine ( Pinus koraiensis) trees and its effect on E estimates was evaluated using Granier-type heat dissipation sensors. The value of J decreased exponentially with the radial depth from cambium to pith, and the coefficient of variation (CV) for radial variation was 124.3 %. Regarding the azimuthal variation, the value of J differed significantly among aspects and the average CV was 23.6 %. The average CV for tree-to-tree variation was 34.0 %, and the daily CV increased with increasing vapor pressure deficit ( D). The error in the E estimates caused by ignoring the radial variation was the largest (109.2 %), followed by those caused by ignoring the tree-to-tree and azimuthal variations (24.3 and 12.6 %, respectively). While the contribution of the azimuthal variation to the E estimates was minimal in comparison to the other variations, the azimuthal variation among aspects was significant, and the usage of the north aspect measurement did not generate substantial error in the E estimates (0.6 %). Our results suggest that the variation, particularly the species- and site-specific radial variation, must be considered when accurately calculating E estimates. [ABSTRACT FROM AUTHOR]