Annual Ring Width Research Articles

Anatomical and Morphological Features of Scots Pine Heartwood Formation in Two Forest Types in the Middle Taiga Subzone

Currently, there is no consensus on how growing conditions affect the heartwood formation in Scots pine. Comparing the results obtained by different authors is difficult due to methodology differences and poor descriptions of the objects used. We selected two sample plots in (1) a blueberry pine forest on nutrient-rich and moist soil and (2) a lichen pine forest on nutrient-poor and dry soil and performed their detailed characterization. The sample plots were located 22 km apart in the middle taiga subzone (Karelia Republic, northwest Russia). In each sample plot, we selected five dominant trees (model trees), from which we took cores at different trunk heights (0.3, 1.5, 4.5, 7.5 and 10.5 m). The cores were treated with 2,6-dichlorophenolindophenol to identify the heartwood zone. Additionally, samples were taken to study the structural features of the transition zone between sapwood and heartwood. In both forest types, the number of heartwood rings depended on the cambium age, and the patterns of parenchyma cell death did not differ in the transition zone. These facts point to a predominantly internal regulation of the heartwood formation in Scots pine. The heartwood radius and its proportion on the cross-sections were significantly higher in the blueberry pine forest than in the lichen pine forest, despite the relative values of the annual ring width. Further research is needed to develop successful Scots pine heartwood width models under a wide range of conditions.

How Bark Beetle Attack Changes the Tensile and Compressive Strength of Spruce Wood (Picea abies (L.) H. Karst.)

Since 2014, forestry in the Czech Republic has been significantly affected by a bark beetle outbreak. The volume of infested trees has exceeded processing capacity and dead standing spruce (Picea abies) remain in the forest stands, even for several years. What should be done with this bark beetle wood? Is it necessary to harvest it in order to preserve the basic mechanical and physical properties? Is it possible to store it under standard conditions, or what happens to it when it is “stored” upright in the forest? These are issues that interested forest owners when wood prices were falling to a minimum (i.e., in 2018–2019) but also today, when the prices of quality wood in Central European conditions are rising sharply. To answer these questions, we found out how some of the mechanical properties of wood change in dead, bark beetle-infested trees. Five groups of spruce wood were harvested. Each of these groups was left upright in the forest for a specified period of time after bark beetle infestation, and one group was classified as a reference group (uninfested trees). Subsequently, we discovered what changes occurred in tensile and compressive strength depending on the time left in the stand and the distance from the center of the trunk. When selecting samples, we eliminated differences between individual trees using a CT scanning technique, which allowed us to separate samples, especially with different widths of annual rings and other variations that were not caused by bark beetle. The results showed the effect of log age and radial position in the trunk on tensile and compressive strength. The values for tensile strength in 3-year infested trees decreased compared to uninfested trees by 14% (from 93.815 MPa to 80.709 MPa); the values for compressive strength then decreased between the same samples by up to 25.6% (from 46.144 MPa to 34.318 MPa). A significant decrease in values for compressive strength was observed in the edges of the trunks, with 44.332 MPa measured in uninfested trees and only 29.750 MPa in 3-year infested trees (a decrease of 32.9%). The results suggest that the use of central timber from bark beetle-infested trees without the presence of moulds and fungi should not be problematic for construction purposes.

Water use efficiency of poplars grown for biomass production in the Midwestern United States

AbstractWater availability and other site conditions influence poplar biomass productivity and affect clonal performance due to genotype × environment interactions. It is important to select genotypes with high water use efficiency (WUE) that maximizes yield with available amounts of water at sites, while avoiding drought stress and growth impacts to the trees. During drought, stomatal closure induces increased accumulation of δ13C carbon isotope in tree tissues, which is strongly correlated with WUE of trees and usually expressed through carbon isotope discrimination (Δ). Our primary objectives were to evaluate differences in WUE among poplar genotypes grown in the Midwestern United States, and to identify genotypes with high WUE for future deployment on water‐limited sites in the region. Sites included 10‐year‐old biomass plantations in Escanaba, Michigan; Waseca, Minnesota; and Ames, Iowa established from 2000 to 2001 with seven poplar genotypes’ three genomic groups. Following harvest, height, diameter, and biomass were determined. Wood samples were collected from individual growth rings to assess annual ring width and WUE through δ13C and Δ. Aboveground dry biomass varied among sites (p = .0007), clones (p < .0001), and their interactions (p = .0134), ranging from 3.1 to 14.0 Mg ha−1 year−1. Δ varied among sites (Δ = 18.9–19.7‰; p < .0001) and clones (Δ = 18.6–19.9‰; p < .0001), indicating effects of site conditions on WUE of tested genotypes. Clones varied in their water‐conserving strategies. Some clones were characterized as water consumers with high growth and high WUE (“C916000”; “C916400”), while other genotypes were water conservers using lower amounts of water with moderate biomass production (“NC13624”; “NC13649”; “NM2” to a certain extent). Although δ13C carbon isotope accumulation correlates with WUE, Δ should only be used for selection when it is integrated with other parameters such as productivity, soils information, and climate data.

Modeling of radial variations of wood properties in naturally regenerated trees of Betula platyphylla grown in Selenge, Mongolia

Wood properties, such as annual ring width, wood fiber length, vessel element length, basic density, air-dry density, dynamic Young’s modulus, modulus of elasticity (MOE), modulus of rupture (MOR), absorbed energy in impact bending, compressive strength parallel to grain, and shearing strength, were investigated for wood from 10 naturally regenerated trees of Betula platyphylla Sukaczev in Mandal, Selenge, Mongolia. Mixed-effects models were used to evaluate the radial variations in the wood properties. The mean values of wood properties obtained in the present study were in almost the same range, with a few exceptions, as those reported by other researchers for other Betula species. The radial variations of wood properties in B. platyphylla were well-fitted to a nonlinear mixed-effects model (logarithmic formula); all examined wood properties increased from the pith and then became constant toward the bark side. The wood properties significantly differed between the core and outer wood. Basic density, air-dry density, and dynamic Young’s modulus were significantly correlated with MOE, MOR, and compressive strength. It is concluded that when the wood of B. platyphylla is utilized as raw materials for solid wood products, the differences between the core wood and outer wood should be considered. In addition, the selection of wood with higher strength properties can be achieved using the wood density and dynamic Young’s modulus as indicators.

Impact of Anthropogenic Activities on Woodland in Northern Syria (4th–2nd Mill. BC): Evidence from Charcoal Assemblages and Oak Measurements

ABSTRACT In this paper charcoals from the Syrian sites Tell Mozan and Tell Jerablus are investigated to understand the impact of 4th to 2nd millennium BC settlement on the vegetation. Charcoals from these sites have been identified and oak fragments have been measured for their maximal diameter and annual ring widths. Our results show that while oak had reached its maximal expansion in the Mid-Holocene, and vegetation in the Euphrates Valley was lusher than today, strong anthropogenic impact on the vegetation was occurring, probably already prior to the Late Chalcolithic period. Due to potentially enormous herds of sheep and goat, and possibly large-scale agriculture with perhaps some understory cropping, oak was growing very slowly, to the degree that it must often have had a shrub-like appearance. People did not apply systematic oak woodland management practices, such as coppicing or pollarding. They used dung as an additional fuel, probably to cover for shortages in wood resources. The land appears to have been used both intensively and extensively to a degree that was not sustainable in the long term. This, combined with aridity impact on the oak, probably led to a decrease in oak proportion at Mozan in the Middle Bronze Age.

Direct and Indirect Effects of Environmental Limitations on White Spruce Xylem Anatomy at Treeline.

Treeline ecosystems are of great scientific interest to study the effects of limiting environmental conditions on tree growth. However, tree growth is multidimensional, with complex interactions between height and radial growth. In this study, we aimed to disentangle effects of height and climate on xylem anatomy of white spruce [Picea glauca (Moench) Voss] at three treeline sites in Alaska; i.e., one warm and drought-limited, and two cold, temperature-limited. To analyze general growth differences between trees from different sites, we used data on annual ring width, diameter at breast height (DBH), and tree height. A representative subset of the samples was used to investigate xylem anatomical traits. We then used linear mixed-effects models to estimate the effects of height and climatic variables on our study traits. Our study showed that xylem anatomical traits in white spruce can be directly and indirectly controlled by environmental conditions: hydraulic-related traits seem to be mainly influenced by tree height, especially in the earlywood. Thus, they are indirectly driven by environmental conditions, through the environment’s effects on tree height. Traits related to mechanical support show a direct response to environmental conditions, mainly temperature, especially in the latewood. These results highlight the importance of assessing tree growth in a multidimensional way by considering both direct and indirect effects of environmental forcing to better understand the complexity of tree growth responses to the environment.

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.

Macroscopic structure of Pinus sylvestris L. wood during introduction to the Central forest-steppe

The macroscopic structure of Pinus sylvestris L. wood growing in the geographical cultures of the Central forest-steppe (Bryansk, Voronezh, and Volgograd climatypes), natural forests of the broad-leaved forest zone of the Bryansk region, the zone of the southern forest-steppe of the Voronezh region and the dry steppe of the Volgograd region was studied. The dependence of the annual ring width on the degree of humidification was found. When Pinus sylvestris L. moving in arid conditions of the dry steppe, changes in the annual ring width were noted, this is an adaptive feature of plants to environmental conditions. The early wood is more susceptible to changes in width depending on the growing conditions than late wood. In geographical cultures of Pinus sylvestris L. created in the Central Forest-steppe of the Voronezh Region climatypes from the Bryansk region have a decrease in the annual ring width and climatypes from the Volgograd region have an increase in the annual ring width, which is related to a change in the degree of humidification. Macrostructural features of wood can be an indicator of the climate in certain natural conditions.

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).

Вплив змін клімату на насадження сосни звичайної: стан, проблеми, виклики

It is proved that since the beginning of the XIX century. the degradation of pine stands is enormous on all continents. In Ukraine, according to the Ministry of Environmental Protection and Natural Resources of Ukraine, the average annual temperature since the beginning of the 20th century has increased by more than 2 °C, including 1.2 °C over the past 30 years. In recent years, the number of days with maximum summer temperatures above 35 °C and 40 °C has almost doubled in extreme weather. In most of the territory of Ukraine, there is already a tendency towards an increase in drought, increased fire hazard, recurrence of years during which plantations will experience water stress, damage by pests, as well as degradation of forest ecosystems as a whole as a result of an increase in forest areas. number and duration of hot periods. It was found that dendrochronological methods are used to study the relationship between climate change and pine radial increment. The main methods for studying radial increment are taking cores at a height of 1.3 meters from two opposite radii in order to prevent the influence of random factors on radial increment. The annual ring width is determined using dendrochronological instruments with automatic data recording. The data on the values of annual rings are processed according to the programs of the International Tree Ring Data Bank (ITRDB). To synchronize the series with the establishment of the calendar year for the formation of each annual increment, the specialized COFECHA program is used. It has been established that the growth of scots pine is limited by the humidification of the climate and the presence of sufficient moisture in the soil, however, in the presence of extreme temperatures, the negative tendency towards drying out of plantations persists.

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.

Correlation between Anatomical Grading and Acoustic–Elastic Properties of Resonant Spruce Wood Used for Musical Instruments

This paper deals with the acoustic and elastic properties of resonant wood, classified into four classes, according to the classification of wood quality by the manufacturers of musical instruments. Traditionally, the quality grades of resonant wood are determined on the basis of the visual inspections of the macroscopic characteristics of the wood (annual ring width, regularity, proportion of early and late wood, absence of defects, etc.). Therefore, in this research, we studied whether there are correlations between the acoustic and elastic properties and the anatomical characteristics of wood used for the construction of violins. The results regarding the identification of the anatomical properties of resonant spruce, the wood color, and the acoustic/elastic properties, determined by ultrasonic measurements, were statistically analyzed to highlight the connection between the determined properties. From the statistical analysis, it can be seen that the only variables with the power to separate the quality classes are (in descending order of importance) the speed of sound propagation in the radial direction, Poisson’s ratio in the longitudinal–radial direction, and the speed of propagation of sounds in the longitudinal direction.

Prediction of shear strength parallel to grain in clear wood of oak (Quercus robur L.) on the basis of shear plane orientation, density and anatomical traits

Abstract Oak wood is popular for use in construction and as flooring. Evaluating the mechanical strength of oak timber is difficult and time consuming. Therefore, models for predicting mechanical properties, based on easy-to-obtain variables, may be useful. The purpose of the study was to build models for predicting shear strength parallel-to-grain in oak clear wood. With this goal, the shearing resistance was tested on 198 defect-free specimens (target dimensions 50 × 50 mm in tested section) obtained from a sample of 40 oak trees felled in north-western Spain. The mean shear strength of the sampled oak wood provenance was 15 N mm−2, which was almost equal to the highest mean value reported in previous studies. Analysis of the relationships between the variables tested enabled development of a model relating shear strength parallel to grain at 12% moisture content, with air-dry wood density and angle between tangential and shear plane as predictor variables ( R adj 2 ${R}_{\text{adj}}^{2}$ = 0.61, p < 0.01, bias = −0.80%, RMSE = 13.66%, for wood with wavy grain; R adj 2 ${R}_{\text{adj}}^{2}$ = 0.36, p < 0.01, bias = −1.46%, RMSE = 17.22%, for wood without wavy grain). The independence of shear strength relative to the presence/absence of sapwood or the annual growth ring width was also demonstrated.

Thickness Analysis of Beech Stems Using Annual Rings

This article deals with the evaluation of a thickness analysis on the vuts of beech wood using annual rings. The study was performed at the state enterprise Lesy SR, a branch plant in Smolenice on the territory of Forrest District MajdĂĄn. In order to perform a thickness analysis of the beech logs, it was necessary to know the number of annual rings on the butt end and the number of annual rings on the small end. Based on these two quantities, it was necessary to derive the number of annual rings in the middle of the trunk. All these characteristics were related to the length of the stem and the thickness of the stem. The data set contained 1000 logs. For a period of 3 years - i.e. from 2017 to 2019 in total for all types of intentional felling, starting with tending intentional felling up to 50 years, tendingt intentional felling over 50 years and ending with prescribed final felling, incidential felling was not included in the investigation. The aim of this publication was to determine the thickness characteristics of beech stem logs, which are characterized in the territory of branch Smolenice by a full-wood stem and to create input quantities for a model log of a beech stem. The results include the average width of annual rings depending on the length of the stem, the average number of annual rings per 1 meter of length, the average reduction in the number of annual rings depending on the length recalculated per 1 meter of length, the average height increment. The results showed interesting findings, the largest average width of annual rings was recorded in improvement intentional felling over 50 years, despite advanced age. Another interesting finding was the average height gain of 0.5 m. The average number of annual rings served to confirm the accuracy of the calculation of the stem thickness depending on the width of the annual ring. The average reduction in the number of annual rings showed the convergence of the stem in cm depending on the length of the cut.

Multi-stage parallel model in determining the quality of structural timber by the penetration method

Multi-stage parallel model in determining the quality of structural timber by the penetration method. Various devices are used in situ to diagnose the quality of structural timber. A semi-destructive method is used for the approximate determination of wood density. The Pilodyn 6J uses a depth of cut that correlates with wood density. The experiments were performed on spruce wood (Picea excelsa, Karst. L.). Boards 40 × 200 × 2500 mm3, were tested, n = 5 pcs. The density of wood was determined by the gravimetric method according to EN 408 (2013). The penetration depth (hp), number and width of annual rings (RoG) were determined on the boards. Based on the density of the wood, the quality of the structural timber was specified by strength classes according to EN 338 (2016). The dependences between the measured characteristics were expressed in a model with a multi-stage parallel scale (penetration depth ~ number of annual rings  rate of growth  strength class and density wood). It is possible to predict visual strength class of board and indicative density of wood (EN 338) by the proposed model in situ. Methods of model are easy to use, reliable and economically undemanding.

The European Beech Annual Tree Ring Widths Time Series, Solar–Climatic Relationships and Solar Dynamo Regime Changes

In this study, the results from the analysis of annual ring widths (‘Dm’) time series of two “very sensitive” to the climate and solar–climate relationships of long lived European beech (Fagus sylvatica) samples (on age of 209 ± 1 and 245 ± 5 years correspondingly) are discussed. Both series are characterized by very good expressed and relating to the solar magnetic Hale cycle 20–22-year oscillations. A good coincidence between the changes of ‘Dm’ and the growth or fading of the solar magnetic cycle is found. The transition effects at the beginning and ending of the grand Dalton (1793–1833) and Gleissberg minima (1898–1933) are very clearly visible in the annual tree ring width data for the one of beech samples. Some of these effects are also detected in the second sample. The problem for the possible “lost” sunspot cycle at the end of 18th century is also discussed. A prediction for a possible “phase catastrophe” during the future Zurich sunspot cycles 26 and 27 between 2035–2040 AD as well as for general precipitation upward and temperature fall tendencies in Central Bulgaria, more essential after 2030 AD, are brought forth.

SOME WOOD PROPERTIES OF MELIAa AZEDARACH L. TREES GROWN IN DUHOK PROVINCE

Melia azedarach L. was introduced into Kurdistan region and planted as an ornamental tree at the nurseries, parks and streets. This study investigated the quality of wood of 9 year old M. azedarach trees grown in Duhok province. Samples of wood from five trees were taken at breast height diameter; and their wood quality was studied in terms of morphological, physical and anatomical properties. Results revealed that the values of morphological properties were: the Heartwood percentage (69.01%), Sapwood percentage (12.93%), Bark percentage (8.06%) and Annual Ring Width (7.74mm). While, the values of the physical properties were: specific gravity (0.42), basic density of wood (0.36g/cm3), annual ring growth width (7.74cm), moisture content (44.46%), maximum moisture content (208.36%), volumetric shrinkage (13.18%), volumetric swelling (16.25%), fiber saturation point (36.34%), cell wall (28.05%) and porosity (71.94%). The values of anatomical properties were: fiber length (0.792 mm), fiber diameter at the mid- point of the fiber (17.75 μm), fiber double cell wall thickness (9.67 μm), fiber lumen width (8.07μm), runkel ratio (1.55), flexibility ratio (47.17), slenderness ratio (47.58), vessel length (241.57μm), vessel diameter at the mid- point of the vessel (169.09μm), and vessel lumen diameter (158.26μm). All properties showed a significant variation from pith to bark and between the trees. The results equip a basis for determining management planning opportune to production wood of M. azedarach plantation trees in Kurdistan region. Also M. azedarach is characterized by low strength resistance and perhaps low pulping production too, therefore according to its low wood quality for some properties, is not recommended for structural purposes. While anatomical properties, showed medium values of fiber dimensions which could be used for production of special type of paper

Radial variation of wood anatomical and chemical properties in eight poplar clones

Wood properties are crucial for the development and application of poplar clones. Here, the effects of clone and age on anatomical and chemical properties were analyzed in eight poplar clones (50, Zhonglin46, 108, 36, N179, Danhong, Sangju, and Nanyang) from Henan province, China. The results show that the effects of clone and age are both significant for these wood properties. The eight clones were grouped into three clusters according to their annual ring width, fiber quality, and chemical properties. For some properties, including annual ring width, fiber length, and microfibril angle, all clones displayed the same radial variation trends; however, for other properties, such as holocellulose content, the radial variation trends were different depending on the clones. The culmination of the mean annual increment corresponded to the turning ages of wood properties such as annual ring width in the eight clones, and holocellulose content in the partial clones except for fiber length, microfibril angle, and vessel length. The recommended rotation age of these poplar clones is 8–9 years based on the fiber quality and chemical components. These results indicate strong genetic and age control of the wood properties and highlight the rich source of variation for poplar clone selection.

Variations in Wood Density, Annual Ring Width and Vessel Properties of Quercus brantii Affected by Crown Dieback

Tree decline due to climate change results in physiological weaknesses, attacks by harmful pests and pathogens and threats to forest ecosystem stability. In the work described here, the effects of drought on wood density, tree ring width and variations in vessel morphology are investigated in Persian oak (Quercus brantii) in the forest of the Zagros Mountains, Ilam Province, western Iran. Discs are cut from trunks of declined and healthy trees and woodblocks are cut radially from the sapwood near the bark, at a mid-point between the vascular cambium and the pith (middle) and from wood near the pith. Observations are made on transverse sections from the blocks using microscopy. In trees with decline symptoms, wood density is greater than in healthy trees. Furthermore, declining trees have the narrowest ring width, reduced vessel diameter and area and the highest numbers of vessels and tylose in pith towards the bark. It is concluded that changes in anatomical features are associated with the weakening of trees and are components of declining tree health.

Assessing bias in diameter at breast height estimated from tree rings and its effects on basal area increment and biomass

Above-ground forest productivity can be reliably estimated from tree-ring width measurements. In doing so, annual growth is linked to the tree’s basal area increment (BAI), which is the change in cross-sectional area associated with each annual ring. When BAI is estimated from ring-width series, a value for the diameter of the tree is required. This diameter is ideally measured in the field, but can also be estimated as the sum of the annual ring widths. Tree biomass can also be estimated directly from the diameter estimates derived from tree-rings. Summing the ring widths, however, typically underestimates the tree’s true diameter. To evaluate this potential bias in diameter, we compared field-measured diameter and diameter estimated from the sum of the ring widths using tree-ring chronologies for seven common species in the eastern United States. We then evaluated the impacts of using the biased diameter estimates on derived BAI and biomass values. To simulate field-sampling error (i.e., failure to reach the pith when obtaining a core sample), we re-calculated BAI and biomass after removing a portion of the innermost rings from each tree. Comparisons of these various methods quantify the substantial and consistent underestimations in forest productivity estimates. To reduce the bias in diameter when using ring widths, we developed a regression model to adjust the diameter using core samples. This model is predicated on having some field-measured diameter values available at a site to calibrate and validate the model, but it can then be used to produce estimates at similar sites with similar species where no field-measured diameter values are available. Values of BAI and biomass derived from model-estimated diameter were more accurate at representing absolute growth than values produced by using the sum of the ring widths. Assessing the interannual variations in tree-growth is dependent on having metrics that accurately reflect the area and mass of wood produced. Our results suggest that published estimates of BAI and biomass using the sum of the ring widths to estimate diameter have substantially underestimated these productivity metrics. Our new procedure allows for more reliable estimates of productivity metrics that use diameter-at-breast height derived from tree rings.