Tracheid Length Research Articles

Comparisons of tracheid lengths in Pinus densiflora Siebold & Zucc.: earlywood versus latewood and province versus province

Abstract The tracheid length (TL) in conifer species is a primary factor to determine quality of paper and wood products. However, TL in Pinus densiflora Siebold & Zucc., a dominant conifer species in Korea, has not been monitored systematically across the country yet. To this end, the TL of early- and latewoods of Korean red pine from 16 provinces of the Republic of Korea was measured and compared to verify the differences (1) between the monitoring years (2014–2018), (2) between early- and latewoods of the trees from the same provinces, and (3) between the early- and latewoods from different provinces. Analysis of 31,500 tracheids revealed that the variation of TL of early- and latewood from two and six out of 16 sites, respectively, were not statistically meaningful and the TL of latewood displayed a lower annual variation than that of the earlywood during the monitoring years. The TL of the latewood was longer than that of the earlywood; however, four out of 16 sites showed shorter TL for the latewood. So, it was verified that the relationship between the TL of the early- and latewood can change. Moreover, the TL was longer for the trees located in the southeast regions.

Forest Adaptation to Climate Change: Altitudinal Response and Wood Variation in Natural-Growth Cunninghamia lanceolata in the Context of Climate Change

This research delves into the impact of climate change on the wood traits of Cunninghamia lanceolata across various altitudinal gradients, aiming to understand the influence of altitude and climatic factors like temperature and precipitation on key wood characteristics. Employing a comprehensive approach, samples were collected from different altitudes for detailed phenotypic analysis. Methods included Pearson correlation, principal component analysis, cluster analysis, and random forest analysis. Results revealed significant variations in wood traits such as heartwood ratio, tracheid length, and width across altitudes. Notably, wood traits in lower- and middle-elevation populations exhibited higher variability compared to higher elevations, indicating greater environmental diversity and genetic adaptability at these altitudes. Climatic factors, particularly temperature and precipitation, were found to increasingly influence wood trait variation with altitude. The research concludes that the adaptation of Cunninghamia lanceolata to climate change is significantly influenced by both altitudinal and climatic factors, highlighting their importance in forest genetic breeding and conservation strategies amidst global climate change.

The phenotypic and genetic effects of drought-induced stress on wood specific conductivity and anatomical properties in white spruce seedlings, and relationships with growth and wood density.

Drought frequency and intensity are projected to increase with climate change, thus amplifying stress on forest trees. Resilience to drought implicates physiological traits such as xylem conductivity and wood anatomical traits, which are related to growth and wood density. Integrating drought-stress response traits at the juvenile stage into breeding criteria could help promote the survival of planted seedlings under current and future climate and thus, improve plantation success. We assessed in greenhouse the influence of drought-induced stress on 600 two-year-old white spruce (Picea glauca) seedlings from 25 clonal lines after two consecutive growing seasons. Three levels of drought-induced stress were applied: control, moderate and severe. Seedlings were also planted at a 45° angle to clearly separate compression from normal wood. We looked at the phenotypic and genetic effects of drought stress on xylem specific hydraulic conductivity, lumen diameter, tracheid diameter and length, and the number of pits per tracheid in the normal wood. We detected no significant effects of drought stress except for tracheid length, which decreased with increasing drought stress. We found low to high estimates of trait heritability, which generally decreased with increasing drought stress. Genetic correlations were higher than phenotypic correlations for all treatments. Specific conductivity was genetically highly correlated positively with lumen diameter and tracheid length under all treatments. Tracheid length and diameter were always negatively correlated genetically, indicating a trade-off in resource allocation. Moderate to high genetic correlations sometimes in opposite direction were observed between physico-anatomical and productivity traits, also indicating trade-offs. A large variation was observed among clones for all physico-anatomical traits, but clonal ranks were generally stable between control and drought-induced treatments. Our results indicate the possibility of early screening of genetic material for desirable wood anatomical attributes under normal growing conditions, thus allowing to improve the drought resilience of young trees.

A comparative study on quantitative anatomical characteristics of compression, lateral, and opposite woods in Agathis loranthifolia and Pinus merkusii

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

Anatomical characteristics of the leaning stem in Pinus merkusii seedling

Abstract. Safitri NM, Prastiwi FW, Salsabila S, Feriawan Y, Brilianto A, Nugroho WD. 2023. Anatomical characteristics of the leaning stem in Pinus merkusii seedling. Biodiversitas 24: 3796-3802. Pinus merkusii Jungh. & de Vriese is one of the tropical conifer species. The species formed reaction wood called compression wood (CW) when the stem grows in an abnormal position. CW in stem wood is frequently found to cause several problems for utilization in the use of its products. However, there are few studies on the anatomical characteristics of reaction wood in tropical conifer. This study aimed to observe the differences in anatomical characteristics between compression (CW) and opposite (OW) woods in leaning the stem of P. merkusii seedlings and their anatomical differences compared to normal wood (NW). Approx. 1-year-old P. merkusii seedlings from a nursery in Trenggalek, East Java, Indonesia, that were naturally bent or tilted were used in the study. Anatomical characteristics of wood, namely the dimension of tracheids, rays, resin canals, and the proportion of cells were observed in the study. The results showed that CW of P. merkusii seedlings formed a rounded tracheid shape and intercellular space. The differences between CW and OW in P. merkusii seedlings were significant in terms of height of ray cells, tracheid proportion, and resin canal proportion. However, tracheid length, tracheid diameter, tracheid wall thickness, resin canal diameter and frequency, rays frequency, and ray proportion were not significantly different compared to OW and NW.

The Variations in Tracheid Length of Pseudotsuga menziesii (Mirb.) Franco Wood in Relation to Cambium Age, Site, and Growth

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

Radial growth rate does not affect radial variation of latewood tracheid length in aged trees of Thujopsis dolabrata var. hondae

Summary Tracheid length is lowest at the pith and then it increases rapidly as cambial age increases up until it reaches an asymptote value in what is known as ‘Sanio’s first law’. However, it is still unclear the effect of radial growth rate on latewood tracheid length and the effect of radial variation pattern of latewood tracheid length on the boundary position between juvenile and mature wood in aged trees. Radial variation modeling was applied to annual ring width and latewood tracheid length in aged trees (79–238 years old) of Thujopsis dolabrata var. hondae grown in natural forests and a plantation in Shimokita Peninsula, Aomori, Japan. In addition, the effect of differences in radial variation patterns of latewood tracheid length on the boundary age between juvenile and mature wood was evaluated. Cambial age showing the maximum values of current annual increment and mean annual increment was 42–121 and 65–189 years for natural forests and 30–33 and 46–52 years for the plantation, respectively. A mixed-effects model based on a logarithmic function with an explanatory variable of only cambial age, and random intercepts of stand and individual tree, was selected as the one best explaining the radial variation of latewood tracheid length. The estimated boundary cambial age was approximately 20 years in all trees regardless of radial growth rate. We concluded that (1) the regularity of radial variation in tracheid known as ‘Sanio’s first law’ can be adapted to at least about 250 annual rings from the pith in T. dolabrata trees, (2) the boundary cambial age is similar to that in younger trees, and (3) the effect of radial growth rate on latewood tracheid length is minimal in T. dolabrata.

Influence of Four Spacings between Trees and Four Samplings Heights on Selected Wood Quality Attributes of White Spruce (Picea glauca (Moench) Voss)

Four Picea glauca (Moench) Voss trees grown at each of four square spacing intensities between trees: 1.2 m, 1.8 m, 4.3 m, and 6.1 m in a plantation established in 1967 in the Petawawa Research Forest, Ontario, Canada (lat. 45.59° N, long. 77.25° W, elev. 168 m) and sampled at four different heights (1.3 m, 4.3 m, 7.3 m, 10.3 m) were used to study the impact of spacing between trees and sampling height on nine wood quality attributes (ring width, ring density, tracheid length, tracheid diameter, latewood proportion, intra-ring density variation, ring area, earlywood width, and latewood width). In the juvenile wood, ring width was wider and ring density higher than in the mature wood. Tracheid length was longer and tracheid diameter wider in the mature wood compared to the juvenile wood. The variation of ring density between the two wood zones was limited, and latewood proportion did not show any difference with wood zone. Sampling height induced variation in more wood quality attributes than did spacing. Except for growth rate, spacing between trees did not significantly impact wood quality attributes. Most of these variations were registered between widely different spacings.

Dendro-anatomical Study for Identification of Pine at Korea

This study identified Korean red pine (Pinus densiflora) and exotic pines (Pinus resinosa, Pinus sylvestris) with a similar anatomical structure using a dendro-anatomical method that applied dendrochronology, tracheid length, and uniseriate ray cell size. Korean red pine samples were collected from 13 national parks, while exotic pine samples were secured from two wood importers. Tracheid length was measured by distinguishing earlywood from latewood, and uniseriate ray height and cell number were determined. As the exotic pine tree-ring chronology was consistent with the foreign standard tree-ring chronology and displayed high statistical significance, the country and region where the pine samples had been felled and the exact felling date were confirmed. According to the results, which compared tracheid length and uniseriate ray size, no difference was observed between the Korean red and Russian pines. However, the tracheid length of the Russian pines turned out to be slightly longer than the length of the Korean red pine. Additional research securing a larger number of exotic pines (P.resinosa, P.sylvestris) is required to yield more accurate results in the future.

Radial variations of broad-sense heritability in wood properties and classification of load\u2013deflection curves in static bending for six half-sib families of Chamaecyparis obtusa

Wood properties (annual ring width, tracheid length, microfibril angle [MFA], basic density, and air-dry density) and mechanical properties (modulus of elasticity [MOE], modulus of rupture [MOR], bending work, and compressive strength) in 34-year-old Chamaecyparis obtusa trees of six half-sib families were measured from pith to bark to clarify radial variations in inheritance of these traits and the relationships between wood properties and mechanical properties. In addition, within-tree and among-family differences in the load–deflection curves were discussed. Radial variations of all wood properties were fitted to linear or nonlinear mixed-effects models with random effects of families. The MFA was correlated with MOE in all radial positions, whereas air-dry density correlated with all mechanical properties in mature wood. Radial variations in broad-sense heritability differed between wood properties. A relatively higher broad-sense heritability was recognized in almost all wood properties for mature wood. Based on the results, it was concluded that mechanical properties in mature wood can be effectively improved using MFA and air-dry density as criteria. In addition, the types of load–deflection curve in mature wood differed from those in juvenile wood, suggesting that not only elastic properties, but also plastic properties in C. obtusa are affected by genetic controls, especially in mature wood.

A comparative study of the tracheid and crystalline properties of Dahurian larch (Larix gmelinii) and Japanese larch (Larix kaempferi) wood

The tracheid and crystalline properties of earlywood and latewood within the stems of Korean-grown Dahurian and Japanese larches were studied to obtain valuable information for identifying these two species and determining their wood quality. The tracheid length and width were examined via optical microscopy, and the relative crystallinity and crystallite widths were examined using the X-ray diffraction method. The tracheid length and width were greater in the Dahurian larch compared to the Japanese larch. In both wood species, the tracheid length and width increased as the growth ring number increased but stabilized at a certain growth ring number. The relative crystallinity was higher in the Japanese larch wood compared to the Dahurian larch wood, while the crystallite width in both species was similar. Neither the relative crystallinity nor the crystallite width displayed a constant trend from pith to bark. The differences in the tracheid properties and the relative crystallinity of both species could be used to identify them and evaluate their wood quality for their effective utilization.

Изменчивость длины трахеид сосны обыкновенной в зависимости от лесотипологических условий

The article provides a comparative analysis of the lengths of early and late tracheids of dominant coeval Scots pine trees. It has been established that tracheids of juvenile wood are characterized by significant differences in length and the difference between them reached 400%, while in the zone of mature wood, the length of both early and late tracheids stabilizes, demonstrating small fluctuations (in within 10%). That makes it possible to use the obtained results to assess forest typological variations. It was shown that the longest tracheids were found in sorrel pine forests, and the shortest – in sphagnum; ericetal pine forests showed intermediate results. The idea of significant differences between the lengths of tracheids in the zone of mature wood of model trees of 3 trial plots is substantiated.

Insight Into the Multiple Branches Traits of a Mutant in Larix olgensis by Morphological, Cytological, and Transcriptional Analyses.

Larix olgensis is a tall deciduous tree species that has many applications in the wood fiber industry. Bud mutations are somatic mutations in plants and are considered an ideal material to identify and describe the molecular mechanism of plant mutation. However, the molecular regulatory mechanisms of bud mutations in L. olgensis remain unknown. In this study, dwarfed (or stunted), short-leaved, and multi-branched mutants of L. olgensis were found and utilized to identify crucial genes and regulatory networks controlling the multiple branch structure of L. olgensis. The physiological data showed that the branch number, bud number, fresh and dry weight, tracheid length, tracheid length-width ratio, inner tracheid diameter, and epidermal cell area of mutant plants were higher than that of wild-type plants. Hormone concentration measurements found that auxin, gibberellin, and abscisic acid in the mutant leaves were higher than that in wild-type plants. Moreover, the transcriptome sequencing of all samples using the Illumina Hiseq sequencing platform. Transcriptome analysis identified, respectively, 632, 157, and 199 differentially expressed genes (DEGs) in buds, leaves, and stems between mutant plants and wild type. DEGs were found to be involved in cell division and differentiation, shoot apical meristem activity, plant hormone biosynthesis, and sugar metabolism. Furthermore, bZIP, WRKY, and AP2/ERF family transcription factors play a role in bud formation. This study provides new insights into the molecular mechanisms of L. olgensis bud and branch formation and establishes a fundamental understanding of the breeding of new varieties in L. olgensis.

Influence of juvenile and mature wood on anatomical and chemical properties of early and late wood from Chinese fir plantation

The proportion of juvenile wood affects the utilization of wood seriously, and the transition year of juvenile wood (JW) and mature wood (MW) plays a decisive role in the rotation and the modification of wood. To find out the demarcation of JW and MW, the tracheid length (TL) and microfibril angle (MFA) of early wood (EW) and late wood (LW) from four Chinese fir clones were measured by optical microscopy and X-ray diffraction. Then the data were analyzed by the k-means clustering method. The correlation and the differences among wood properties between JW and MW were compared. Results indicated that the LW showed better properties than that of EW, but the anatomical differences between EW and LW did not influence the demarcation of JW and MW. The cluster analysis of TL and MFA showed that the transition year was in the 16th year and the transition zone of EW and LW was different among clones. The MW has longer and wider tracheid, thicker cell walls, and smaller MFA. In terms of chemistry, MW had a higher content of holocellulose, α-cellulose, less content of extract, but no significant difference in lignin content compared with JW. The stabilization of chemical components was earlier than that of the anatomic properties. Correlation analysis showed that there were strong correlations between the chemical composition and anatomical characteristics in JW and MW. In general, compared with chemical components, anatomical indicators were more suitable for JW and MW demarcation. The differences and correlations between JW and MW properties provide a theoretical basis for wood rotation and planting.

Flow resistance characteristics of the stem and root from conifer (Sabina chinensis) xylem tracheid

Xylem tracheids are the channels for water transport in conifer. Tracheid flow resistance is composed of tracheid lumen resistance and pit resistance. The single tracheid structure parameters in the stem and root of Sabina chinensis were obtained by dissociation and slicing, combined with numerical simulation to analyze the tracheid flow resistance characteristics. The results showed that the tracheid lumen resistance was determined by the tracheid width and tracheid length. The pit resistance was determined by the number of pits and single pit resistance. The single pit resistance was composed of four elements: the secondary cell wall, the border, the margo and the torus. The margo contributed a relatively large fraction of flow resistance, while the torus, the border and the secondary cell wall formed a small fraction. The size and position of the pores in the margo had a significant effect on the fluid velocity. The number of pits were proportional to tracheid length. The power curve, S-curve and inverse curve were fitted the scatter plot of total pit resistance, total resistance, total resistivity, which was found that there were the negative correlation between them. The three scatter plot values were larger in the stem than in the root, indicating that the tracheid structure in the root was more conducive to water transport than the stem. The ratio of tracheid lumen resistance to pit resistance mainly was less than 0.6 in the stem and less than 1 in the root, indicating that the pit resistance was dominant in the total resistance of the stem and root.

Tracheid dimensions of Norway spruce in uneven-aged stands

Tracheid length and width patterns from pith to bark at a height of 0.6 m in uneven-aged Norway spruce (Picea abies (L.) Karst.) trees were studied. Identification of the main factors and a comparison with even-aged stands were also carried out. Ninety-six trees were sampled from experimental stands in southern Finland. The material encompassed the variation in tracheid properties from early years to silvicultural maturity, i.e., from corewood to outerwood up to a cambial age of 111 years. Data from 39 Norway spruce trees from even-aged stands were utilized for comparison. Models fitted to the data indicated that annual ring widths did not influence mean tracheid dimensions but that the latewood proportion had a significant influence on tracheid dimensions. Tracheids in uneven-aged stands were slightly wider and longer at the base of the stem in trees with a similar diameter, cambial age, and annual ring number.

Relationship of tracheid length, annual ring width, and wood density in Scots pine (Pinus sylvestris L.) trees from different social classes of tree position in the stand

This study investigated the relationship between the length of the tracheids, the width of annual rings, and the wood density of Scots pine (Pinus sylvestris L.) obtained from the dominant, intermediate, and suppressed classes of a 60-year-old stand. Measurement of tracheid length was performed on the material macerated from the following annual rings: 3, 6, 9, 12, 15, and thence every 5 annual rings. Basic density was determined on samples that included five annual rings from the core to bark. Tree position in the stand had a significant impact on the examined properties of wood. In a given biosocial class, tracheid length decreased as the width of annual rings increased. As the biosocial position of a tree in the stand improved, the length of the tracheids increased, and wood density decreased. In wood of the same density range, the increment in tracheid length was the greatest in wood of dominant trees and the lowest in wood of suppressed trees.

Ray Traits of Juvenile Wood and Mature Wood: Pinus massonia and Cunninghamia lanceolata

Ray traits affect secondary xylem development and wood properties. Pinus massonia and Cunninghamia lanceolata, commercially important timber species, were chosen to study the differences in wood ray traits of juvenile versus mature wood. Seven ray traits, i.e., percentage of rays, ray spacing, ray number, uniseriate ray height, fusiform ray height, ray parenchyma cell length and ray tracheid length, as well as eight wood axial tissue traits, were investigated quantitatively. Intraspecific variations in ray traits and axial tissue traits between juvenile wood and mature wood were displayed in violin plots. The results showed that anatomical differences between juvenile wood and mature wood were significant for both ray traits and axial tissue traits. Juvenile wood generally possessed the larger percentage of rays, higher ray spacing and ray number, smaller ray height and shorter ray cells than mature wood. A positive correlation was present between the ray parenchyma cell length and ray tracheid length. Negative correlations of the ray number and ray spacing with uniseriate ray height were found. Additionally, the axial tracheid cell wall thickness all had Pearson’s correlations with ray spacing, ray number and ray parenchyma cell length.

Anatomical, physical, and mechanical parameters of clone plantation tree, Cunninghamia lanceolata

Anatomical characteristics of the plantation tree, Cunninghamia lanceolata were studied. Clonal variability and intra-tree variation, as well as its possibilities of application to the wood industry were analyzed for four clones. Tracheid length from the first to 17th annual ring within clones increased rapidly at first, and then plateaued. The maximum value appeared at the 14th annual ring of clone IV (3795 μm), and the minimum value appeared at the 1st annual ring of clone I (849 μm). Tracheid width and tracheid double wall thickness increased first and then tended to be flat or slightly decreased; tracheid length to width ratio showed an overall increasing trend; the variation of tracheid double wall thickness was not significant. Between clones, the variation coefficient of tracheid width, double wall thickness, and wall to cavity ratio were large. The tissue proportion within clones from large to small was the following: tracheid proportion > wood ray proportion > parenchyma proportion, and there was no significant difference between clones. The basic density within clones showed a gradual increase but a certain fluctuation; the difference between clones was not significant. The maximum crystallinity appeared in clone II (sapwood 55.1%, heartwood 51.2%), and the difference between clones was not significant.

Morphological and wood anatomical traits of Rhododendron lepidotum Wall ex G. Don along the elevation gradients in Nepal Himalayas

ABSTRACT Though variability in morphological features along the environmental gradients has been extensively studied, less information is available on possible adaptations and trends of anatomical features. We examined the variation in morphological and stem anatomical features of a widely distributed (2,200–5,300 m a.s.l.) Rhododendron lepidotum across elevation gradients in Langtang and Sagarmatha National Parks of Nepal Himalayas. Plant samples in each site were collected from three elevation bands (ca. 3,000, 4,000, and 5,000 m a.s.l.). In both study sites, all morphological features measured had their highest value at the lowest elevation and vice versa. Vessel density of basal stem increased but diameter and area of xylem vessels, and length of vessel element and fiber tracheids decreased as elevation increased. Similarly, height and the number of cells in uniseriate rays and height, width, area, and density of multiseriate rays also decreased toward the highest elevation. However, anatomical features of the ultimate branch did not show any distinct pattern with elevation. Morphological features showed more plasticity than anatomical features along the elevation gradients. Decreased plant height, individual leaf area, specific leaf area, and the existing trade-off relationship between vessel diameter and density could have supported a wide distribution of R. lepidotum in Nepal Himalayas.