Density Of Pine Wood Research Articles

Оценка качественных признаков древесины в селекционных программах (краткий обзор современной литературы)

The literature review concerning wood quality traits measuring in forest tree breeding programs is given. Methods of wood density measuring by Pilodin and different types of Resistograph are shortly described. Comparison study to measure Scots pine wood density by Pilodin and Resistograph revealed that Resistograph provide more precise wood density data than Pilodin. Method of measuring of wood stiffness an important wood mechanical property using acoustic velocity data is characterized. There is relationship between distortion of lumber and grain angle of wood fibers. Grain angle, i.e. spiral grain, refers to the degree of helical deviation from longitudinal arrangement of wood fibers. It can be measured with a wedge grain angle gauge hammered into a stem of a standing tree. It is shown, that microfibril angle (MFA), referring to the deviation of cellulose microfibrils in the layer of the secondary cell wall from the long axis of cell, is the main determinant of the mechanical properties of wood. There is shortly described the system of instruments with linked software (SilviScan), the main components of this system are optical cell scanner (for measurement of fiber size), X-ray densitometer (density profile and others) and X-ray diffractometer (microstructure traits). A minor negative relationship between growth and wood quality traits is noted, so the index selection is recommended under realization of tree breeding program. Some examples of genomic selection in tree breeding programs for wood quality are given.

Плотность древесины сосны обыкновенной в осушаемом сосняке сфагновом

The task of increasing forest productivity has been and remains one of the current interests of the European North of Russia, especially after the period of primary development of the forest areas. In the European Northeast, excessive humidity is observed at rather low average temperatures, which prevents active surface evaporation. In the twentieth century, the hydrotechnical reclamations were conducted on the large areas of swampy forests that increased the total productivity. The ecologists have an ambivalent attitude concerning forest draining. The supporters, who try to protect the undisturbed forest territories, counteract such activities. At the same time, the cultivation of highly productive forests of the right composition and quality requires measures for natural afforestation, or artificial forests must be created. Besides the total productivity of the stands, wood quality is an important factor in the hydroamelioration. It is mainly determined by density and the ratio between early and late wood. The influence of the landscape peculiarities of the drained forests on the quality of the wood was examined by the devotion of the areas according to the most typical groups of microrelief: flat areas, elevations, transitional areas. In cases of extensive humidity, the death of seedlings and artificial forest plantings was observed (soaking, frost extrusion, etc.). The creation of micro-elevations and the drainage of the excessive moisture guarantee the regeneration and establishment of the highly productive forests. The differences in the density of pine wood before and after the hydrotechnical reclamation were detected according to the landscape. The largest changes in the indicator were determined at the elevations and the flat areas, with the increase and the decrease, respectively. The trees that grow on the flat terrain after the reclamation show a relative excess of early wood over late wood, while at the elevations the presence of the late wood is predominant. For citation: Zagorodski M.A., Tretyakov S.V., Koptev S.V. Density of Scots Pine Wood in Drained Sphagnum Pine Forest. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 2, pp. 160–171. (In Russ.). https://doi.org/10.37482/0536-1036-2023-2-160-171

ФИЗИКО-МЕХАНИЧЕСКИЕ ХАРАКТЕРИСТИКИ МИНЕРАЛИЗОВАННОЙ ДРЕВЕСИНЫ

A comparative analysis of the mineralization of wood with a solution of an organic mineral complex in various modes is carried out: spontaneous (by immersion in a container with a solution) and forced (during autoclave treatment under excessive pressure using an inert gas) modes. This analysis will reveal the optimal parameters of wood mineralization, which, in turn, will help to solve the problem of increasing the durability and reliability of wood materials intended for use in extreme climatic conditions. The composition of the modifying solution is natural polysaccharide arabinogalactan and polymineral quartz-containing sand (10 % arabinogalactan and 10 % polymineral sand). It is found that during 24 hours of processing, the density of pine wood increases by 18 % (with spontaneous flow of the process, this parameter increases by only
 10 %). An increase in the density of samples leads to an increase in their compressive strength by 80 % (during spontaneous processing) and by 91 % (during autoclaving). The Brinell hardness of the prototypes increases more than three times (regardless of the conditions of the process). A detailed description of the individual stages of the process of thermal decomposition of the wood of the prototypes is obtained. It is found that for modified samples (compared with control ones), the degree of thermal destruction is significantly reduced.

Formation of density and porosity of pine wood in a tree trunk

Wood is a material with unique properties that contribute to its wide use as a raw material for various types of industries. Different quality requirements are imposed on the raw materialdepending on the material or wood product. However, physical and mechanical properties of wood are not homogenousalong the radius and height of the trunk and depend on the species, location in the trunk and growing conditions. The aim of this research is to study the variability of porosity and density of Scots pine (Pinus sylvestris L.) wood in a tree trunk growing in dry forests of the forest-steppe zone of the Russian Federation. The studies were carried out on wood cuts, sawn at different trunk heights. The change in the density of pine wood along the height of the trunk by 1.43% for each meter has been established. The wood porosity increases from the butt to the top by an average of 5.5%. New information about the variability of wood properties makes it possible to rationally and reasonably approach the choice of raw materials for obtaining materials with specified performance characteristics.

Formation of pine wood density depending on the parameters of annual ring and latitudinal zoning

The article presents the results of studies of changes in wood density depending on annual ring width and its characteristics. Density is a basic indicator for assessing operational and technical properties of wood. At the same time, density is characterized by certain variability within the same species, depending on annual ring characteristics, influenced by environmental factors, age of trees and position in the trunk. The purpose of this study is to establish the formation of density depending on annual ring width and late wood for Scots pine (Pinus sylvestris L.) wood in the central European part of Russia. Density research was made using the specimens with one annual ring by the method of buoyancy. Absolute values of the annual ring of early and late wood were measured in cores. It was found that wood density is only influenced by late wood width in the annual ring, being under strict genetic control. In the southern taiga zone correlation between density and late wood width is varying between 0.49-0.66 and it is less than in the forest-steppe zone. The correlation of density with annual ring width in the southern taiga zone is 0.5. It is less than in the forest-steppe zone (0.57-0.81).

Importance of the Moisture Content of Large-Sized Scots Pine (Pinus sylvestris L.) Roundwood in Its Road Transport

Scots pine (Pinus sylvestris L.) is one of the most important forest tree species in Europe, and its wood is a main raw material in the wood industry of many countries of the region. The high variability of pine wood density in connection with its moisture content is a challenge in transport operations. An important part of the roundwood transport of pine wood by trucks is the transport of large-size roundwood (sawlogs). As part of the research, an analysis was carried out of the influence of absolute wood moisture content, determined in various ways, on selected truck transport parameters of large-size pine wood. The analyses of the supply of wood to a large sawmill in northern Poland took into account different seasons. The results indicate that the average moisture content of the transported pine wood is at a level of approximately 95% (determined by dry weight) and the density at 0.878 Mg m−3 (determined using the stereometric method). Quick measurement with the use of a resistance hygrometer gives significantly lower results both on the side surface and on the cross-cut end of the log. Regardless of the method of measurement, the absolute moisture content of wood in loads depends on the date of delivery (season), which is reflected in the variability of the density and weight of the loads. The indicated strong correlations between the selected, tested characteristics of roundwood transports are important for forestry practice too. It is the possibility of using the methods of quick determination of fresh wood moisture to estimate the density of wood and to predict and determine the mass of the load.

Wood density variation in naturally regenerated stands of Pinus ponderosa in northern Arizona, USA

In the southwestern United States, land managers are implementing large-scale forest restoration projects involving treatments designed to improve forest health, protect ecosystem services, and reduce the risk of catastrophic wildfire in overstocked ponderosa pine (Pinus ponderosa Dougl. ex P. & C. Laws.) forests. A better understanding of wood properties is necessary to improve the currently limited markets for the woody byproducts generated by these treatments. Therefore, our objective was to investigate variations in ponderosa pine wood density across the northern Arizona landscape. We sampled trees from 18 naturally regenerated stands and used X-ray densitometry to quantify the radial and axial variation within and among trees. We modeled within-stem wood density patterns using generalized additive models, and investigated the effects of climatic variation using response function analyses. Additionally, we tested the effects of site-level predictors on whole-tree wood density. We found high variability in radial wood density profiles among trees in our stands compared with that observed in studies of other species grown in plantations — perhaps due to high genetic variation within naturally regenerated stands. Wood density was negatively correlated with precipitation at annual and most quarterly intervals, except for a positive correlation with late-summer monsoon precipitation. The high wood density variation we found among trees highlights the need for further investigation of controls over wood properties in natural nonplantation forests.

Improving spatial synchronization between X-ray and near-infrared spectra information to predict wood density profiles

Wood density is one of the most important physical properties of the wood, used in improvement programs for wood quality of major timber species. Traditional core sampling of standing trees has been widely used to assess wood density profiles at high spatial resolution by X-ray microdensitometry methods, but alternative methods to predict wood properties quality are also needed. Near-infrared (NIR) spectroscopy, a non-destructive technique, is being increasingly used for wood property assessment and has already been demonstrated to be able to predict wood density. However, the estimation of wood density profiles by NIR has not yet been extensively studied, and improved models using spectra information (NIR) and X-ray data need to be developed. To this end, partial least square regression (PLS-R) models for predicting wood density were developed at a 1.4 mm spatial resolution on Pinus pinaster wood cores, with an improved spatial synchronization along the tangential and radial directions of the strip, between X-ray data and NIR spectra. The validation of the best model showed a high coefficient of determination (0.95), low error (0.026) and no outlier. Compression wood samples were not detected as outliers and were correctly predicted by the model. However, pith spectra were detected as outliers and its predicted values were overestimated by 33% due to unusual spectra suggesting a diverse chemical composition. The results suggest that NIR-PLS models obtained can be used for screening maritime pine wood density profiles along the radii at 1.4 mm spatial resolution.

Плотность древесины сосны в осушаемых сосняках кустарничково-сфагновых

Плотность древесины сосны в осушаемых сосняках кустарничково-сфагновых

Determination of the Strength Parameters of Pinewood Based on the Non-Destructive Sclerometric Test with a Wood Hammer

Abstract To assess the technical condition of a structure and design it using existing elements, it is necessary to know its parameters. For existing facilities, it is often not possible to get a sample of material and examine it directly in the laboratory. For this reason, in situ nondestructive testing is very important. The main goal of the paper is to present the issues related to determining the strength parameters of a particular wood based on the non-destructive sclerometric test performed with a wood sclerometric hammer. The study also presents the results of the impact of pinewood density on its compressive strength.

Climate has a larger effect than stand basal area on wood density in Pinus ponderosa var. scopulorum in the southwestern USA

Stand basal area of ponderosa pine ( Pinus ponderosa var. scopulorum Engelm.) in the US Southwest has little effect on the density of the wood produced, but climatic fluctuations have a strong effect. Wood density increases during drought, particularly if the drought occurs in late winter/early spring. Future droughts, as are predicted to increase in the US Southwest, may lead to production of smaller radial increments of higher density wood in ponderosa pine. Forest restoration treatments in the US Southwest are generating large quantities of small-diameter logs. Due to negative perceptions about ponderosa pine wood quality, this material is often seen as a “waste disposal” problem rather than a high-value resource. Our objective was to understand more about variation in southwestern US ponderosa pine wood density, an important indicator of wood quality. Specifically, we investigated the effect of stand basal area on wood density, and the effect of annual and quarterly climatic variation on wood density. We collected samples from 54 trees grown at six different basal area levels from a replicated stand density experiment. Pith-to-bark strips were used in an X-ray densitometer to obtain annual density and growth measurements from 1919 to the present. Stand density had a strong effect on growth rate, but little effect on wood density. However, climatic variation did influence wood density, which increased in drought years before quickly returning to pre-drought levels. Stand basal area is not a good indicator of wood density for foresters planning to utilize material from timber harvests in the southwestern USA. Future droughts, as are predicted to increase in the region, will likely reduce wood volume production but may increase wood density in ponderosa pine.

Wood density of pine and spruce stands according to trees diameter distribution after thinning

In this paper, we present the results of studies on the relationship between the stand composition, the distribution row by the diameter classes of the stand and the wood density. Objects of study were coniferous forest stands with different participation of pine and spruce passed by thinning. Wood cores sampling was carried out on this stands and basic density of wood according to trees diameter classes determinate by maximum moisture method. The influence of the distribution curve of the trunks by the diameter classes on the wood density of pine and spruce is presented. Different trees quantitative representation of these species reflects on wood density and varies with the share of main species participation in the stand.

The effect of tree distribution by diameter classes on the density of pine and spruce trees in mixed coniferous forest stands without forestry impact

In this paper, we consider the influence of tree distribution rows by the diameter classes on the wood density of pine and spruce in coniferous stands not covered by felling. Dependences of the wood density in pure and mixed coniferous stands were studied with changes in the composition of the stand and the quantitative representation of pine and spruce trees by diameter classes. On the basis of the obtained quantitative material, the relationship between the density of wood and trunks thicknesses was modeled according to the diameter classes of pine and spruce trees. The developed regression equations make it possible to predict the density changes of pine and spruce wood in stands with different shares of their participation.

Optical density of Scots pine wood and climatic conditions in Toruń, Poland

Abstract The aim of the studies was to evaluate the usefulness of the microscopic features of wood in characterising the climatic conditions of a period for which only proxy data are available. Samples were taken from historical wood from Koronowo collegiate church and from a living Scots pine tree growing in the Toruń-Wrzosy site. All measurements were performed using ImageJ software. The dendroclimatological analysis was carried out in the program DendroClim2002. The results show a correlation between the microscopic features of wood and climatic conditions. For the period 1951–2000 the maximum optical density of pine wood depends on average May air temperature and June precipitation, with correlation coefficients of −0.32 and −0.29, respectively. A similar correlation was found for mean maximum and minimum temperatures in May; -0.35 and -0.37, respectively. Additional correlations between selected meteorological elements and the maximum optical density of the wood were found using 30-year moving averages and moving intervals.

TRUNK WOOD DENSITY OF SCOTS PINE IN THE SOUTHERN DNIEPER POLISSYA

Today the dominant role of forests in biosphere stability is a generally accepted factor, therefore special attention is paid to forest ecosystems processes monitoring. Against the background of forestry researches greening assessment of forests bioproductivity will solve ecological, silvicultural, and energetic problems. Investigations of trunk wood density of Scots pine were carried according to P.I. Lakida's procedure. In the course of investigations 50 test trees were cut and measured, taxation indicators of the plantations in which they grew were determined, 350 wood samples were analyzed. Test trees age is from 7 to 82 years. Natural wood density was determined as the ratio of sample mass to its volume in green state, the basic one – as the ratio of sample mass in absolutely dry condition to its volume in green state. In the course of statistical analysis it was determined that the basic wood and trunk bark density with tree age, diameter and height has direct correlation, and natural one – inverse correlation. Based on the above obtained data the search and calculation of regression equations were carried out. The adequacy of obtained models to the initial data was estimated by the statistics of their residuals and by the coefficients of obtained equations determination. The results of these studies are consistent with O. I. Poluboyarinov and V. A. Usol'tsev conclusions in that tree age is the most informative factor, determining trunk wood density. Obtained data were compared with P. I. Lakida's data for the Polissya and Forest-Steppe of Ukraine, with V.V. Uspensky's data for the western forest-steppe (Voronizh region) and with V. P. Pasternak, V. V. Nazarenko, U. V. Karpets' data for the forest-steppe of Kharkiv region. The more territorially closer the regions are the less is the difference in the wood density. Identified peculiarities of investigated indexes of Scots Pine wood density are to be taken into account when determining the dynamics of phytomass, carbon deposits volumes and development of activities aimed at strengthening of climate-regulating functions of forests in the Southern Dnieper Polissya.

A Dosimetric Study on Slab-pinewood-slab Phantom for Developing the Heterogeneous Chest Phantom Mimicking Actual Human Chest.

The aim is to study the density, isodose depths, and doses at different points in slab-pinewood-slab (SPS) phantom, solid phantom SP34 (made up of polystyrene), and chest level of actual patient for developing heterogeneous chest phantom mimicking thoracic region of human body. A 6 MV photon beam of field size of 10 cm × 10 cm was directed perpendicular to the surface of computed tomography (CT) images of chest level of patient, SPS phantom, and SP34 phantom. Dose was calculated using anisotropic analytical algorithm. Hounsfield units were used to calculate the density of each medium. Isodose depths in all the three sets of CT images were measured. Variations between planned doses on treatment planning system (TPS) and measured on linear accelerator (LA) were calculated for three points, namely, near slab–pinewood interfaces (6 and 18 cm depths) and 10 cm depth in SPS phantom and at the same depths in SP34 phantom. Density of pinewood, SP34 slabs, chest wall, lung, and soft tissue behind lung was measured as 0.329 ± 0.08, 0.999 ± 0.02, 0.898 ± 0.02, 0.291 ± 0.12, and 1.002 ± 0.03 g/cc, respectively. Depths of 100% and 90% isodose curves in all the three sets of CT images were found to be similar. Depths of 80%, 70%, 60%, 50%, and 40% isodose lines in SPS phantom images were found to be equivalent to that in chest images, while it was least in SP34 phantom images. Variations in doses calculated at 6, 10, and 18 cm depths on TPS and measured on LA were found to be 0.36%, 1.65%, and 2.23%, respectively, in case of SPS phantom, while 0.24%, 0.90%, and 0.93%, respectively, in case of SP34 slab phantom. SPS phantom seemed equivalent to the chest level of human body. Dosimetric results of this study indicate that patient-specific quality assurance can be done using chest phantom mimicking thoracic region of human body, which has been fabricated using polystyrene and pinewood.

Modelling the effects of genetic improvement on radiata pine wood density

Density is a key wood quality trait, which is moderately to highly heritable, and has been the focus of selective breeding efforts in radiata pine (Pinus radiata D.Don) in New Zealand. Forest managers require information on realised gain in wood density in order to help them make decisions about which tree stocks to plant, how to manage stands and when to harvest in order to achieve certain wood quality outcomes. The aim of this study was to quantify realised genetic gain in radiata pine wood density and to incorporate it into existing modelling systems for predicting growth and wood quality. A national model of radiata pine wood density, which predicts wood density at breast height as a function of ring number from the pith and a “local parameter”, was modified to account for the effects of genetic improvement. The value of this local parameter was estimated for 679 radiata pine families with differing levels of genetic improvement (as quantified by their GF Plus rating for wood density) that were growing in 18 trials established by the Radiata Pine Breeding Company. The value of Wood Density Index (defined as the breast height outerwood density at age 20 years) was calculated from the estimate of the local parameter. Simulations were performed to show the impact of genetic improvement on whole-log average density and the variation in density within a log. There was a strong positive relationship between GF Plus rating for wood density and Wood Density Index (R 2 = 0.73), with a one-unit increase in GF Plus corresponding to a 2.16 kg m−3 increase in wood density. An increase in GF Plus density rating from 18 to 27 would result in an increase in breast height outerwood density at age 20 years of 18.5 kg m−3. Over the same range of genetic improvement, average whole-log density is predicted to increase by 14–16 kg m−3. Validation of the model using independent data from older trees showed that it was able to correctly predict the effect of genetic improvement. It also indicated that the assumption that the expression of genetic gain is constant across sites with different wood density potentials is valid, although data from additional trials located across a wider range of sites is required to confirm this. The effect of genetic improvement on wood density has been quantified and included in growth and yield modelling systems. This enables forest managers to estimate wood density in radiata pine plantations for any site and management regime established using tree stocks with a specific wood density rating.

Влияние структуры древостоя на плотность древесины сосны и ели в черничном типе леса

Mixed stands of spruce and pine of myrtillus y forest types occupy large areas of the forest
 fund of the Leningrad region. For the theory and practice of forestry it is important to know the impact
 of plantations on the density of wood in bunk mixed spruce-pine stands. In mixed stands of
 pine and spruce disks and cores of wood species were selected from the model tree to determine the
 basic density by the method of maximum water capacity. The study of basic wood density of pine
 and spruce in the coniferous bunk stands revealed that its rates are higher for both species in the
 mixed forest stand than in pure coniferous plantations in the region of the study. With the predominance
 of pines in the stand composition, its wood density is higher than in stands dominated by
 spruce. Density of pinewood increases from smaller to larger classes of stand diameters. Variability
 of wood density by diameter of trunk is higher in spruce than in pine in mixed stands. In stands, after
 cutting dilutes the density of pinewood is lower than in the plantation, which is not passed with
 felling. In the bunk spruce-pine the stand, to the age of maturity, larger mass of stem wood of coniferous
 species is formed than in the pure one-tier stands of pine or spruce. Developed regression
 equations depending on the density of the wood at a height of 1.3 m to the average density of trunk
 allow for a more accurate assessment of this parameter in mixed stands than previously published
 equations for pure stands of myrtillus forest types for the study area.

Effect of genotype-by-spacing interaction on radiata pine wood density

SummaryEffects of spacing, family and spacing-by-family interaction on corewood and outerwood density, and annual latewood percentage from cambial age 2 to 21 years in radiata pine (Pinus radiata D.Don) were studied using 55 families planted at three spacings (1 × 1, 1 × 2 and 2 × 3 m). Significant family effects were observed for corewood and outerwood density, and latewood percentage, but spacing effects were significant only for outerwood density and latewood percentage. There was significant spacing-by-family interaction on corewood density (rB = 0.62). Closer spacing increased latewood percentage in both corewood and outerwood and reduced corewood proportion but it did not increase wood density in corewood significantly. It was also observed that closer spacing had no effect on outerwood length, but increased wood density in outerwood significantly. Closer spacing increased heritability for wood density (1.11 ± 0.27 vs 0.46 ± 0.15) and increased juvenile–mature genetic correlations for wood density while increasing the negative genetic correlations between diameter at breast height (DBH) and corewood density. There were positive genetic correlations between latewood percentage and density in both corewood and outerwood. The significant genotype-by-spacing interaction for corewood density may be used to increase wood density of corewood through breeding.

Изменение плотности древесины сосны, поврежденной пожаром при длительном хранении в различных условиях

The results of changes in the density of pine wood after harvesting, drying and long-term storage, and with a long stay at the root and undamaged wood are shown. The results of research on the effects of different types of fire on pine wood allowed establishing patterns of change in the average density of pine wood in trunk height in different conditions. It is found that long-term storage at room conditions, the density of pine wood damaged with strong grassroots and weak crown fire is not changed and the corresponding to values at the time of felling.