Latewood Percentage Research Articles

Assessment of growth and stemwood quality of Scots pine on territory influenced by alkaline industrial dust

Long-term influence of alkaline dust (pH 12.3-12.7) pollution emitted over 40 years from a cement plant in Estonia was the reason of alkalisation (pH 6.7-7.9) and high concentrations of K, Ca and Mg in the soil of affected territories. Although dust emission has diminished during the last 10 years, the imbalances in nutrition substrate and their influence on the growth of trees are notable up to now. The study of morphological and physical properties of 70-80-year-old Scots pine (Pinus sylvestris L.) crown, stems and stemwood from three different air pollution zones showed serious deviations in comparison with a relatively healthy forest in an unpolluted area. The specimens from polluted trees, if compared to reference site, showed significantly smaller height growth, radial increment and width of annual rings of sapwood. In heartwood wider annual rings were found in polluted areas. In the period of heartwood formation the dust pollution level emitted from the plant was relatively modest and cement dust, which contains elements necessary for mineral nutrition of trees, may have acted as fertiliser. The moisture content in sapwood and heartwood, especially in the upper layers of stems, was lower in the polluted area than in reference site trees. Regression analysis revealed a strong dependence between latewood percentage and sapwood or heartwood in stems of Scots pine in all sample plots.

Relationships among selected wood properties of 20-year-old Taiwania (Taiwania cryptomerioides) trees

The relationships between bending properties, compressive strength, tracheid length, microfibril angle, and ring characteristics of 20-year-old Taiwania (Taiwania cryptomerioides Hay.) trees were examined. The trees came from different thinning and pruning treatments, but the practices showed no significant effect on the investigated properties. The results showed that based on comparison with the literature, plantation-grown immature Taiwania have noticeably lower average strength properties than mature trees of the same species. Wood density and bending and compressive strengths were not related to either tracheid length or microfibril angle in young Taiwania. There were positive relationships between bending strength and compressive strength. The wood density, ring width, earlywood width, earlywood density, and latewood percentage were the most important predictors of strength by simple linear regressions. The wood density and ring width/earlywood width may be considered as indicators for assessing the bending strength, while wood density and latewood percentage were the best predictors of compressive strength by multiple linear regressions.

Association genetics in Pinus taeda L. I. Wood property traits.

Genetic association is a powerful method for dissecting complex adaptive traits due to (i) fine-scale mapping resulting from historical recombination, (ii) wide coverage of phenotypic and genotypic variation within a single experiment, and (iii) the simultaneous discovery of loci and alleles. In this article, genetic association among single nucleotide polymorphisms (58 SNPs) from 20 wood- and drought-related candidate genes and an array of wood property traits with evolutionary and commercial importance, namely, earlywood and latewood specific gravity, percentage of latewood, earlywood microfibril angle, and wood chemistry (lignin and cellulose content), was tested using mixed linear models (MLMs) that account for relatedness among individuals by using a pairwise kinship matrix. Population structure, a common systematic bias in association studies, was assessed using 22 nuclear microsatellites. Different phenotype:genotype associations were found, some of them confirming previous evidence from collocation of QTL and genes in linkage maps (for example, 4cl and percentage of latewood) and two that involve nonsynonymous polymorphisms (cad SNP M28 with earlywood specific gravity and 4cl SNP M7 with percentage of latewood). The strongest genetic association found in this study was between allelic variation in alpha-tubulin, a gene involved in the formation of cortical microtubules, and earlywood microfibril angle. Intragenic LD decays rapidly in conifers; thus SNPs showing genetic association are likely to be located in close proximity to the causative polymorphisms. This first multigene association genetic study in forest trees has shown the feasibility of candidate gene strategies for dissecting complex adaptive traits, provided that genes belonging to key pathways and appropriate statistical tools are used. This approach is of particular utility in species such as conifers, where genomewide strategies are limited by their large genomes.

Effets de l’intensité des éclaircies sur la densité, les modules d’élasticité et de rupture et de rupture transversale du bois de Pinus brutia Ten.

The purpose of this study was to determine the effects of plantation thinning on various wood properties of Pinus brutia Ten. Tree samples were obtained from heavily and moderately thinned and unthinned 33–35 year-old plantations. Wood properties were examined in various wood zones including 16 annual rings after the first treatment. The results of this study showed that there was a significant relationship between thinning intensity and radial increment (1.30 m) for an individual tree. Thinning treatments increased annual ring width especially a few years after thinning. Heavy thinning treatments were especially effective in impacting mean ring width values at breast height. However, the percentage of late wood did not differ much between the samples. Based on the results of correlation analysis between ring width and late wood percentage there was no significant correlation identified. Mean wood density was not affected by the treatments. Also, no significant correlation was found between thinning and examined strength properties (MOR, MOE and compression strength parallel to grain). However, a relationship was found between wood density and all strength properties except for MOE. The current results suggest that thinning can produce improvements in ring width without any negative impacts on investigated wood properties. It is recommended that subsequent studies should be designed to understand genetic effects and maximize treatment effects.

Effects of early thinning regime and tree status on the radial growth and wood density of Scots pine

In this work, we studied the effects of early thinning on the radial growth and wood density over a 12-year post-thinning period in Scots pine (Pinus sylvestris L.) trees grown on a site with a rather poor nutrient supply. Ring width, early and late wood width and early wood percentage, mean intra-ring wood density and early- and late wood density were analyzed in 98 sample trees using X-ray microdensitometry. For the analyses, ten different thinning plots with post-thinning stand density varying from 575 to 3400 stems ha were grouped into four classes representing heavy thinning, moderate thinning, light thinning and no thinning. We found that the radial growth in the thinned treatments increased significantly compared to that of the unthinned treatment. Despite this, the mean intra-ring wood density did not decrease significantly as a result of heavy thinning, although it was 2% less, on average (with a range of 1–4% in large and small trees), compared to that of the unthinned treatment. In the lightly thinned treatment, the mean intra-ring wood density even increased by 5%, on average (with a range 4–7% in small and large trees), but in the moderately thinned treatment, the level of change was not as clear. The thinning response of trees representing different status in a stand differed significantly and was also affected by the post-thinning stand density. Altogether, observed simultaneous increases in early and late wood widths and late wood density, but a decrease in early wood density indicate that as a result of heavy thinning, especially, un-uniformity of wood density will increase. On the other hand, although heavy thinning increased tree growth by 9–20%, on average, compared to moderate thinning, which corresponds quite well with business-as-usual management, mean wood density decreased only 0–4% depending on tree status in a stand (from large to small trees). Thus, the decrease observed in wood density was less than expected as a result of heavy thinning at an early stage of stand development, which has recently been recommended as one possible management option in Scots pine in Finland.–1

Comparison of the bordered pits of two species of spruce (Pinaceae) in a green and kiln-dried condition and their effects on fluid flow in the stem wood in relation to wood preservation

Summary The relationship between bordered pit aspiration, pit sizes and permeability measured as preservative uptake and expressed as porosity was examined in two species of spruce, Sitka spruce ( Picea sitchensis (Bong.) Carr.) grown in the UK and Eastern spruce ( Picea orientalis (L.) Link.) grown in Turkey, before (in the freshly felled green condition) and after kiln drying. A 2.5 per cent chromated copper arsenate preservative solution was allowed to fl ow in either the longitudinal or tangential direction of the stem wood and the uptake was assessed. Bordered pit anatomy was examined by light and scanning electron microscopy and image analysis was used to characterize the samples. The permeability of the wood declined following drying but less so in the Sitka spruce. From an analysis of measurements made on the wood features it appeared that basic density, latewood percentage and degree of pit aspiration were the most important features explaining these results. The structure of the bordered pits varied between the two species and the relative size of the aperture in comparison with the pit chambers was greater in the Eastern spruce. The effects of these and other variables including differences in conventional drying systems and natural tree responses to environmental conditions on pit behaviour affecting permeability are discussed.

Variation of different tree-ring parameters in samples from each terminal shoot of a Norway spruce tree

Variability of wood parameters in a tree is sometimes a rather nebulous concept since variability is evident within single cells, from early to latewood, from pith to bark and from stem base to the top of a tree. So far, stem analyses have been done using a restricted number of parameters, mostly ring-width, and using a restricted number of samples in the longitudinal direction. This study analyses a number of parameters from a single tree. An 81-year-old spruce tree was felled and internodial discs were taken from each annual terminal shoot. All tree rings in each disc were measured and a whole-stem analysis was completed for the following parameters: ring-width, mean ring density, maximum density, percentage of latewood, type of transition from early to latewood, intra-annual density fluctuation, number of resin ducts per tree-ring and position of resin ducts within the tree-rings. All parameters showed calendar-year patterns, visible as lines parallel to the bark. The most clear calendar-year pattern was seen for the type of transition from early to latewood and for intra-annual density fluctuations. The strongest inter-series correlation between calendar rings was seen for ring-width. None of the parameters showed significant inter-series correlations for cambial rings. These results may help us to understand how cores or discs taken at breast height represent the entire tree.

Global climate analysis of growth rings in woods, and its implications for deep-time paleoclimate studies

Quantitative analysis of growth rings in pre-Quaternary fossil woods is commonly used as a paleoclimatic indicator. In this paper, a global analysis of the relationship between climate and growth ring parameters in modern trees is presented that, in part, invalidates the use of fossil woods in this way. Data reprocessed from the International Tree-Ring Data Bank are used to analyze three parameters, mean ring width, mean sensitivity, and percentage latewood, from 727 sites across a global climatic range. Results allow the complex relationship between climate and growth ring parameters to be quantified at the global scale for the first time. They reveal the enormous variability in tree response to climate-forcing, which is influenced by disparate factors such as taxonomy, ontogeny, ecology, and environment. Quantitative analysis of fossil growth ring data in light of the modern results indicates that even the largest and most detailed fossil studies conducted to date are probably inadequate in distinguishing a paleoclimate signal from the background noise of variability. The validity of using quantitative growth ring parameters as indicators of Pre-Quaternary climates is therefore questionable. Only in well-constrained studies where paleoclimatic, ontogenetic, and taxonomic sources of variability can be controlled, and data sets are very large, may fossil growth ring analysis provide useful paleoecological data. The findings of this paper do not invalidate in any way the use of growth rings in fossil woods as qualitative paleoclimatic indicators.

Profile of bordered pit aspiration in Cryptomeria japonica using confocal laser scanning microscopy: pit aspiration and heartwood color

Nine trees of Cryptomeria japonica from six elite tree clones with a broad range of heartwood colors were selected. The profiles of pit aspiration percentage (ASP) of earlywood and latewood from pith to bark for green and air-dry conditions were determined to study the relationship between heartwood color and pit aspiration. Confocal laser scanning microscopy (CLSM) observations showed that the ASP of earlywood was low in sapwood and high in heartwood in the green condition. Pit aspiration increased in intermediate wood when compared with sapwood. On the other hand, latewood pits did not aspirate during heartwood formation. Comparing the air-dry condition with the green condition, sapwood pits aspirated during drying in both earlywood and latewood; however, there was no significant difference in pit aspiration of heartwood. There was no significant difference between samples with red and black heartwoods for ASP. The difference in ASP between individual trees was larger than that by heartwood color. The general advantage of CLSM over light microscopy is that serial optical sections along the Z axis can be obtained for any moisture condition, without the need for thin sectioning or embedding.

Differences in wood density and growth of fertilized and nonfertilized loblolly pine associated with a mutant gene, cad-n1

A rare mutant allele (cad-n1) of the cad gene in loblolly pine (Pinus taeda L.) causes a deficiency in the production of cinnamyl alcohol dehydrogenase (CAD). Effects associated with this allele were examined by comparing wood density and growth traits of cad-n1 heterozygous trees with those of wild-type trees in a 10-year-old open-pollinated family trial growing under two levels of fertilization in Scotland County, North Carolina. In all, 200 trees were sampled, with 100 trees for each fertilizer treatment. Wood density measurements were collected from wood cores at breast height using X-ray densitometry. We found that the substitution of a cad-n1 for a wild-type allele (Cad) was associated with a significant effect on wood density. The cad-n1 heterozygotes had a significantly higher wood density (+2.6%) compared with wild-type trees. The higher density was apparently due to the higher percentage of latewood in the heterozygotes. The fertilization effect was highly significant for both growth and wood density traits. This study indicates that the cad-n1 allele could be a valuable gene to the pulp and paper industry for the purpose of enhancing pulp yields by increasing wood density.

Effect of elevated [CO2] on stem wood properties of mature Norway spruce grown at different soil nutrient availability

AbstractThe objective of the present study was to investigate the interactive effects of elevated [CO2] and soil nutrient availability on secondary xylem structure and chemical composition of 41‐year‐old Norway spruce (Picea abies (L.) Karst.) trees. The nonfertilized and irrigated‐fertilized trees were, for 3 years, continuously exposed to elevated [CO2] in whole‐tree chambers. Elevated [CO2] decreased concentrations of soluble sugars, acid‐soluble lignin and nitrogen in stem wood, but the effects were not consistent between sampling height and/or fertilization. The effect of 2*ambient [CO2] on wood structure depended on the exposure year and/or fertilization. Radial lumen diameter decreased and annual ring width increased in the second year of exposure (1999) in elevated [CO2]. In the latter, the CO2 effect was significant only in the nonfertilized trees. Stem wood chemistry and structure were significantly affected by fertilization. Fertilization increased the concentrations of nitrogen and gravimetric lignin, annual ring width, and radial lumen diameter. Fertilization decreased C/N ratio, mean ring density, earlywood density, latewood density, cell wall thickness, cell wall index, and latewood percentage. We conclude that elevated [CO2] had only minor effects on wood properties while fertilization had more marked effects and thus may affect ecosystem processes and suitability of wood for different end‐use purposes.

Pastures fertilization effect on the delimitation and caracteristics of Pinus radiata D. Don juvenil wood

This study presents the effects of prairie fertilization on the juvenile wood delimitation, on wood basic density, late wood percentage and on ring wide for Pinus radiata in Chile. Wood samples were taken at diameter at breast height (DBH). Two silvopastoril trails were evaluated, one corresponding to a fertilized prairie and the other to a non-fertilized prairie. In addition, tree height dominance was considered on each prairie (dominants, intermediate, and suppressed). Results showed at f irst, that production of juvenile wood in Pinus radiata growing on silvopastoril cultivation ceases between the 7th and the 11th year of age. At second, it was found that prairie fertilization had no significant effects on juvenile wood formation. At third, prairie fertilization tended to produce wood of low basic density and low percentages of late wood, but greater ring width. Finally, the end of the juvenile period occurred when the current annual increment in tree height and DBH reached the maximum.

Modeling Ovendry Softwood Resistivity Based on the Resistor Network Theory

Summary This study develops a method to theoretically calculate ovendry softwood resistance and resistivity based on block transformation theory. The resistance of a single cell was calculated as the sum of a combination of serial and parallel connections of the two end cell walls, four side cell walls and cell cavity. One cell was considered as a resistor, and the wood as a network of single cell resistors. Resistance was calculated for a group of four resistors. After several iterations, the total resistance of wood was obtained. To test the model, experiments were conducted on Masson pine specimens. The resistances of fifty specimens were measured and their resistivities calculated. A comparison of the theoretical calculations and the measured results revealed a difference between the measured average resistivity of specimens and the model calculations of less than 8%. The resistivity of softwood was found to relate to the size of wood cells, amount of ray cells and the percentage of latewood.

Application of the drilling resistance method for annual ring characteristics: evaluation of Taiwania (Taiwania cryptomerioides) trees grown with different thinning and pruning treatments

The effects of various thinning and pruning methods on the density profile and annual ring characteristics of Taiwania (Taiwania cryptomerioides Hay.) using the drilling resistance technique were investigated. The results showed that thinning caused wider annual rings than medium thinning or no thinning, and pruning caused narrower annual rings than no pruning. Moreover, the thinning treatment affected annual rings more effectively than the pruning treatment. The average ring density after the thinning treatments showed a trend as follows: no thinning > medium > heavy. This indicates that thinning reduces the average ring density. The average ring density after the pruning treatments showed a trend as follows: medium > no pruning > heavy. However, the differences between thinning and no thinning were not statistically significant. The percentage of latewood in Taiwania after these three thinning and pruning treatments are shown. The results with silvicultural treatments have the order: medium > not treated > heavy, but there are no statistically significant differences among thinning, pruning, and thinning where pruning interactions were observed. Moreover, there were highly significant negative relations between the average ring width and the various ring densities for Taiwania, but the determination coefficients were small. In addition, there was a highly positively significant relation between the latewood percentage and latewood width.

Relationship between growth rates and xylem hydraulic characteristics in young, mature and old‐growth ponderosa pine trees

ABSTRACTThe first objective of the present study was to quantify the effects of tree age and stem position on specific conductivity (ks), vulnerability to embolism and water storage capacity (capacitance) in trunks of young, mature and old‐growth ponderosa pine. The second objective was to determine relationships between hydraulic characteristics and radial and height growth rates to increase the understanding of possible tradeoffs. Within sapwood at all heights and in all ages of trees, outer sapwood had 25–60% higher ks than inner sapwood. The water potential at which embolism started (air entry point) was 1.3 MPa lower in inner sapwood than outer sapwood within the mature trees, but there was no difference in the other trees. There was no significant difference in capacitances between the tops of the old growth trees, the mature trees and the young trees. Taking all data together, the capacitances increased sharply with an increase in ks and an increase in vulnerability to embolism. The hydraulic characteristics of the three age classes were correlated with the height growth rate but not with the diameter growth rate. Within these age classes, high ks was associated with the slowest yearly increase in sapwood area and with a low percentage of latewood, whereas high vulnerability to embolism and high capacitance were more closely associated with high height growth rates.

INFLUENCE OF CLIMATE CHANGES ON TREE-RING CHARACTERISTICS OF SCOTS PINE PROVENANCES IN SOUTHERN SIBERIA (FOREST-STEPPE)

Scots pine provenances from all over Russia planted in 1964 at the forest- steppe zone were analyzed. Eight tree-ring characteristics from 12 different provenances were measured densitometrically. The time span of tree-ring observation covers the period from 1969 to 1997. The sensitivity coefficient of latewood width, latewood and maximum densities and latewood percentage decreases in relation to the increasing latitude of the provenances. The growth of all studied provenances is dictated by the local weather and climate. The correlation coefficients of indices between the local provenance and the other provenances are not lower than 0.46–0.97, and the synchronicity coefficients are minimally 0.84. The Euclidean distances vary from 0.11 to 0.13 between the local provenance and the other provenances. All statistical parameters show that the interannual variability reflects the prevailing influence of the local weather conditions. Variability of weather conditions determines up to 87% of the growth variability in the forest-steppe of southern Siberia.

Genetic variation in wood properties of interior spruce. I. Growth, latewood percentage, and wood density

Quantitative genetic variation in growth, latewood percentage, and wood density was investigated for British Columbia's interior spruce (the common name for white spruce, Picea glauca (Moench) Voss; Engelmann spruce, Picea engelmanni Parry ex Engelm.; and their hybrids). The study included 160 half-sib families from the East Kootenay and Prince George regions. At the time of sampling, progeny tests for those two regions were 20 and 22 years old, respectively. Univariate and multivariate restricted maximum likelihood (REML) estimates of genetic parameters were obtained. Estimates of genetic variances and heritabilities differed greatly across planting sites for the examined traits, especially after transplantation between the regions. Significant negative genetic correlation between overall growth and wood density was found for the East Kootenay progenies, while negative but nonsignificant genetic correlation between these traits was found for the Prince George progenies. Generally, there was no significant decrease in heritability for ring width and latewood percentage in successive growth rings. A general age trend for genetic correlation between those traits was not apparent, except that the correlation remained negative during the observed period. Our results show that it is not possible to select certain families as superior based on 1-year results because of the family by growing season interactions. Nevertheless, genetic age–age correlations for cumulative increments were high, having a decreasing trend with increasing difference in age.

Genetic variations of wood properties and growth characters of Korean pines from different provenances

Totally 26 provenance stands of 17-year-old Korean pine were selected for investigating wood properties and growth characters in Mao’ershan Experimental Forest Farm of Northeast Forestry University in 1999. The anatomical property indexes, including tracheid length, tracheid diameter and wall-indiameter ratio, and the physical property indexes, such as growth ring width, late wood percentage and growth ring density, were measured for wood properties. Growth character indexes, including tree height and diameter at breast height, were also measured. The analytical results showed that there exited obviously difference in wood property indexes between different provenances, which is suggested that wood properties are controlled by their genetic differences. The growth character indexes of Korean pines presented significant difference and they might also be controlled by their genetic differences. Most parameters of wood properties mainly varied in the direction of longitude, but the parameters of growth characters varied in the direction of latitude.

Genetic parameters and gains for growth and wood properties in Florida source loblolly pine in the southeastern United States

One hundred and thirteen open-pollinated families from Florida source loblolly pine (Pinus taeda L.) were tested in four states in the southeastern United States. Heritabilities and genetic correlations were estimated for volume, specific gravity, and latewood percentage at three different growth stages: juvenile (ages 0–10 years), mature (11–17 years), and total (0–17 years). Heritabilities of growth traits (0.09–0.11) were consistently lower than for wood property traits (0.16–0.33). Growth traits for Florida loblolly exhibited high genotype × environment interaction (rB = 0.44), whereas wood properties did not (rB = 0.90). The higher heritabilities and genetic stability across environments make wood properties amenable to genetic manipulation through breeding programs. In contrast, the high genotype × environment interaction of growth traits for Florida loblolly pine requires more research to understand the possible implication of these effects on breeding programs. Trait–trait and age–age genetic correlations were determined for growth and wood properties. Strong positive age–age correlations were present for latewood percentage, volume, and specific gravity. Weak negative trait–trait genetic correlations existed between specific gravity and volume across ages (–0.13 to –0.43). No genetic correlation existed between latewood percentage and volume, while a moderate favorable genetic correlation existed between latewood percentage and specific gravity (0.47 to 0.59). Genetic gains in volume and specific gravity were compared for various types of selection. In one type, forward selection of the top 20 individuals (of 3484) based on 17-year volume, resulted in a 20.5% genetic gain in volume; however, a concomitant loss of –6.4% also occurred in specific gravity. If a selection index was used to hold specific gravity constant, a gain in total volume of 14% was obtained.

Genetic and environmental signals in tree rings from different provenances of Pinus sylvestris L. planted in the southern taiga, central Siberia

Seeds of Scots pine provenances originating from all over Russia were planted in the Boguchany provenance trial at a central Siberian location (southern taiga) in 1974. Eight tree-ring density and width parameters for 16 different provenances were measured with densitometric techniques. The tree-ring data were recorded from 1982 to 1996. Correlation analysis calculated by raw series showed that tree-ring width decreases and percentage of latewood increases with an increase in the latitude of the seed source. High variability was found for raw tree-ring characteristics from tree to tree within each provenance for an observed period (individual variability). The age trend of each tree is well described by the chosen fitting curve, and is similar for the mean series of each provenance. As a consequence of these findings, the indexed chronology for each provenance mainly shows climatic signals. The SD of the indexed chronology (chronological variability) is low for each provenance, showing low sensitivity to climatic influences. A cluster analysis of provenances represented by tree-ring characteristics differentiated the provenances into three groups. However, the statistical distance between the groups was minor. So we can confirm that Scots pine provenances are highly adaptable to local ecological conditions and regional climatic influences.