scholarly journals Vertical variability of selected macrostructural properties of juvenile wood organization in trunks of Scots pine (Pinus sylvestris L.) trees

2011 ◽  
Vol 76 (1) ◽  
pp. 27-33
Author(s):  
Arkadiusz Tomczak ◽  
Witold Pozdrowski ◽  
Tomasz Jelonek ◽  
Ireneusz Stypuła
Keyword(s):  
Mechanical Properties ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Annual Ring ◽  
Juvenile Wood ◽  
Physical And Mechanical Properties ◽  
Wood Structure ◽  
Annual Rings ◽  
Tree Trunk ◽  
Wood Tissue

The study makes an attempt to analyse the width of annual rings, the width of the latewood zone and the proportion of the latewood within juvenile wood along trunks of Scots pine (<em>Pinus sylvestris</em> L.) trees and to verify the hypothesis about the heterogeneous properties of juvenile wood in a single trunk. It was found that the above-mentioned macrostructural elements of wood structure showed a curvilinear correlation with the height of measurement points along the tree trunk. As the distance from the base of trunk increased, the width of the annual ring and the width of the latewood zone decreased, while the proportion of the latewood increased. These types of changes can affect positively physical and mechanical properties of wood tissue. It can be assumed that there is a mechanism which modifies properties of juvenile wood causing axial diversification of the analysed type of wood tissue. It is probable that axial heterogeneity results in advantageous changes in the mechanics of the tree trunk.

scholarly journals Selected physical and mechanical properties of Scots pine (Pinus sylvestris L.) wood from stands of younger age classes as criteria for rational utilization of timber

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Przemysław Marcin Pikiński ◽  
Jaroslav Szaban ◽  
Gerda Šilingienė ◽  
Robert Korzeniewicz ◽  
Witold Pazdrowski
Keyword(s):  
Mechanical Properties ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Growth Conditions ◽  
Tree Age ◽  
Coniferous Forests ◽  
Forest Site ◽  
Quality Coefficient

The aim of this study was to assess the quality of Scots pine (Pinus sylvestris L.) wood depending on the age of trees, forest site conditions and social class of tree position in the stand. Analyses were based on the determination of specific density and static bending strength, as well as the strength quality coefficient. It was to determine changes in physical and mechanical properties of timber depending on tree age as well as growth conditions reflected in the forest site such as fresh mixed coniferous forests and fresh mixed broadleaved forests. Experimental plots were established in 6 localities with 30, 40 and 60-year-old trees. In each of the stands, a 1-hectare experimental plot was established. Based on the measured DBH and tree height, dimensions of three mean sample trees were calculated, while the classification of social class of tree position in the stand developed by Kraft (1884) was also applied. Analyses were conducted on wood samples with 12% moisture content. Strength tests on wood samples were performed on an Instron 33RH204 universal strength testing machine. A detailed analysis showed properties of pine wood are improved with an increase of tree age in both forest sites. Statistically significant differences were observed for wood density and static bending strength. More advantageous properties were observed for wood of pines from the less fertile forest site, i.e., fresh mixed coniferous forests. Density and static bending strength were markedly determined by tree age and growth conditions. The static bending strength quality coefficient from pines growing in the fresh mixed coniferous forests increased between 30 and 40 years, similarly as it was for the fresh mixed broadleaved forests, while between 40 and 60 years, it deteriorated for the fresh mixed coniferous forests. Wood density from the fresh mixed coniferous forests was by 3% to 7% greater than pines growing in fresh mixed broadleaved forests. In turn, static bending strength of wood from pines growing in fresh mixed coniferous forests was by 4% to 10% greater than trees from the fresh mixed broadleaved forests.  Keywords: Scots pine, wood properties, forest site, Poland

scholarly journals Estimating Genetic Parameters for Wood Density of Scots Pine (Pinus sylvestris L.)

2006 ◽  
Vol 55 (1-6) ◽  
pp. 84-92 ◽  
Author(s):  
Anders Fries ◽  
Tore Ericsson
Keyword(s):  
Pinus Sylvestris ◽  
Wood Density ◽  
Scots Pine ◽  
Annual Ring ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Ring Width ◽  
Stem Diameter ◽  
Mature Wood ◽  
Annual Rings

Abstract Wood density was analysed and annual ring width was measured on increment cores from 1400 trees in a 30-year-old full-sib progeny test of Scots pine (Pinus sylvestris L.) in north Sweden. Genetic parameters for wood density were analysed separately for ten outer annual rings, and for simple averages of the five most recent years. The evaluation included genetic correlations with height and stem diameter. Heritabilities of density estimated separately for each annual ring was 0.14-0.26 without any age trend, and jointly for the ten or five latest rings 0.30-0.33; for height growth it was 0.30-0.42 and for stem diameter 0.11-0.13. Additive genetic correlations with height and stem diameter were negative with the simplest statistical model (ȓA = -0.425 and 0.511, respectively) but vanished or diminished when ring width was added as covariate. Density breeding values calculated for the parent trees for each of ten annual rings separately varied considerably between parent trees and between years, tending to increase with increasing age, with a substantial increase between the ages 14 to 16 years from the pith. This age fits well with literature data on the change from juvenile to mature wood. The genetic correlation for wood density between rings from different years was high: ȓA = 0.8 ten years apart, increasing to 1.0 for neighbouring rings. The high genetic correlations for wood density between the innermost and outermost annual rings indicate possible strong covariation between juvenile and/or transition wood and mature wood. The annual variation in wood density in relation to genetic regulation, phenology, environmental conditions, and development from juvenile to mature age is discussed.

Variation of tracheid length within annual rings of Scots pine and Norway spruce

Holzforschung ◽  
2008 ◽  
Vol 62 (1) ◽  
pp. 123-128 ◽  
Author(s):  
Harri Mäkinen ◽  
Tuula Jyske ◽  
Pekka Saranpää
Keyword(s):  
Picea Abies ◽  
Pinus Sylvestris ◽  
Norway Spruce ◽  
Scots Pine ◽  
Juvenile Wood ◽  
Mature Wood ◽  
High Fertility ◽  
Annual Rings ◽  
Tracheid Length

Abstract Variation of tracheid length was studied within individual annual rings of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) from the pith to the bark. The material consisted of six Scots pine and six Norway spruce trees growing on sites of both low and high fertility. Microtome sections of 0.25 mm thick were cut from annual rings 7, 20 and 50 counted from the pith outwards, i.e., juvenile, transition and mature wood, respectively. After maceration, tracheid lengths were separately measured in each sample. In juvenile wood of Scots pine, tracheids were on average 17% longer in the latewood than in earlywood. However, in juvenile wood, the first formed earlywood tracheids were slightly longer than those in the middle of the earlywood zone. In the transition and mature wood of Scots pine, the increase in tracheid length was more gradual from earlywood to latewood, and no significant differences were found between earlywood and latewood. In Norway spruce, tracheids were 2–4% longer in the latewood than in earlywood. In general, tracheid length is highly variable within annual rings and the variation can differ from ring-to-ring even within the same tree.

scholarly journals Wood structure of Scots pine (Pinus sylvestris L.) growing on flotation tailings

2019 ◽  
Vol 61 (2) ◽  
pp. 112-122
Author(s):  
Marta Górska ◽  
Edward Roszyk
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Industrial Area ◽  
Radial Increment ◽  
Wood Structure ◽  
Annual Rings ◽  
Flotation Tailings ◽  
Spring Frost ◽  
Xylem Tissue ◽  
Control Samples

Abstract The aim of this study was to examine Scots pine (Pinus sylvestris L.) xylem changes caused by heavy metal pollution. Annual rings width, number of tracheids in radial rows and the length of tracheids in the wood from trees growing on post-flotation tailings have been measured. Dimensions of tracheids have been examined separately for early- and latewood of each radial increment. The most demonstrable changes are observed in the tracheids length, which appears to be shorter in the xylem from the industrial area than in the control samples. In the wood from the polluted site, the variability of length of tracheids is increased. Microscopic observations revealed numerous deformations in the xylem tissue and deviations from the standard cell arrangement. Circumferential deformations occurring in the wood structure may indicate the increasing spring frost vulnerability of these trees.

Measuring Relative Fibre Length in Scots Pine by Non-Destructive Wood Sampling

Holzforschung ◽  
2003 ◽  
Vol 57 (4) ◽  
pp. 400-406 ◽  
Author(s):  
A. Fries ◽  
T. Ericsson ◽  
T. Mörling
Keyword(s):  
Scots Pine ◽  
Annual Ring ◽  
Genetic Parameters ◽  
Juvenile Wood ◽  
Fibre Length ◽  
Small Diameter ◽  
Tree Height ◽  
Annual Rings ◽  
Slight Tendency ◽  
Non Destructive

Summary Wood fibre length of Scots pine (Pinus sylvestris L.) was measured in wood sticks and 5-mm increment cores. The aim was to evaluate whether fibre length estimates from such small-diameter cores could be used to calculate genetic parameters, in spite of the increased amount of cut fibres produced at boring. The correlation between mean fibre lengths obtained from cores and sticks, with substantially fewer cut fibres, was high (r = 0.87, n = 53) and of the same magnitude as the correlation between samples from varied positions in the same tree (r = 0.87, n = 46). As regards evaluation of genetic tests and ranking for selection purposes, values from non-destructively sampled 5-mm cores from 0.5 m tree height appear to serve well. Fibre length development along annual ring classes started to differentiate between trees at annual rings 13–15, and after ring 16 there was a slight tendency towards stabilisation which may be interpreted as a reasonably advanced transition from juvenile wood to mature wood.

scholarly journals Influence of Scots Pine (Pinus sylvestris L.) Veneers Quality on Selected Properties of Layered Composite for Flooring Materials

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1017
Author(s):  
Izabela Burawska-Kupniewska ◽  
Paweł Mycka ◽  
Piotr Beer
Keyword(s):  
Mechanical Properties ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
Deformation Modulus ◽  
Physical And Mechanical Properties ◽  
Production Costs ◽  
Base Layer ◽  
Class A

The article concerns the quality issues in wood industry, and especially the advisability of removing defects from veneers. The research purpose of the study was to analyse the influence of the layered structure of plywood base layer made of low-quality wood on selected mechanical properties of floor composites. The utilitarian purpose is to analyse the possibility of producing floors from low-quality materials reducing waste. Four quality classes of Scots pine veneers (Pinus sylvestris L.) were taken into account: A, B, C, D, from the highest class-A without defects to the lowest class-D characterized by a lot of knots (including broken and falling out ones) and cracks. The base layer of the floors was made of these wood quality classes. The value of the modulus of elasticity in elastic deformation, modulus of elasticity in the dynamic and fatigue tests, stiffness and static bending strength were investigated. The test results showed that, as expected, the samples made of class A had the highest values of the measured parameters (static bending strength, static and dynamic modulus of elasticity, and stiffness). However, the values of the tested parameters for the remaining classes B, C, and D did not significantly differ. It was concluded from the research that the change of the plywood base layer conditions regarding the quality of veneers does not significantly affect the physical and mechanical properties of composites. Hence, it is possible to use wood of lower quality classes for production without verification of which class they belong to, which will significantly reduce the production costs.

Effect of thermomechanical densification of pine wood (Pinus sylvestris L.) on cutting forces and roughness during milling

2021 ◽  
Vol 113 ◽  
pp. 36-42
Author(s):  
Barbara Białowąs ◽  
Karol Szymanowski
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Statistical Analysis ◽  
Pinus Sylvestris ◽  
Cutting Forces ◽  
Physical And Mechanical Properties ◽  
Milling Process ◽  
Pine Wood ◽  
Roughness Index ◽  
Modified Wood

Effect of thermomechanical densification of pine wood (Pinus sylvestris L.) on cutting forces and roughness during milling. The paper presents the results of research concerning the assessment of machinability of pine wood thermomechanically compacted. The assessment was made on the basis of the cutting forces and surface roughness after the milling process. Selected properties of native and modified wood were examined. Based on the research, it was found that compacted wood is characterized by higher cutting forces during milling. The surface quality after milling was examined and the roughness index Ra values were determined. The research shows that the modified wood is characterized by a lower Ra value both along and across the grain. Statistical analysis showed that the modification had a statistically significant effect on the values of cutting forces and the physical and mechanical properties of the tested wood.

Sign in / Sign up

Export Citation Format

Share Document