scholarly journals Influence of pine (Pinus sylvestris L.) growth rings width on the strength properties of structural sawn timber

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 5402-5416
Author(s):  
Piotr Mankowski ◽  
Izabela Burawska-Kupniewska ◽  
Slawomir Krzosek ◽  
Marek Grzeskiewicz

Annual growth ring width was considered relative to the mechanical properties of timber from the Silesian Forestry Region in Poland. The timber was acquired from raw wood aged approximately 120 years old, with log quality A, B, and C. The study was conducted on 210 pieces of timber; 70 of them were from each part of the log: butt, middle, and top. The tested parameters, modulus of elasticity (MOE) and modulus of rupture (MOR), were measured on fully dimensional timber (40 × 138 × 3500 mm3) that had been dried and planed in industrial conditions. The density of wood (stereometric method) and annual rings width were calculated after MOR and MOE determination on samples including the entire cross-section cut near the failure zone. The tests revealed that the correlation between the width of growth rings and MOE or MOR depended on the log area: it was the highest for timber from butt logs and the lowest for timber from top logs. Moreover, the correlation between growth ring width and MOE or MOR depended also on the quality class of the logs from which the samples were obtained: it was the highest for timber from class A, and the lowest for class C.

1986 ◽  
Vol 16 (5) ◽  
pp. 1041-1049 ◽  
Author(s):  
K. C. Yang ◽  
C. A. Benson ◽  
J. K. Wong

The distribution and vertical variation of juvenile wood was studied in an 81-year-old dominant tree and an 83-year-old suppressed tree of Larixlaricina (Du Roi) K. Koch. Two criteria, growth ring width and tracheid length, were used to demarcate the boundary of juvenile wood. The width of juvenile wood, expressed in centimetres and the number of growth rings, decreased noticeably from the base to the top of the tree. The volume of juvenile wood decreased in a similar pattern. These decreasing trends had a strong negative correlation with the year of formation of cambial initials at a given tree level. The length of these cambial initials decreased with increasing age of formation of the cambial initials. In the juvenile wood zone, there was a positive linear regression between the growth ring number (age) and the tracheid length. The slopes of these regression lines at various tree levels increased as the age of the year of formation of the cambial initials increased. At a given tree level, the length of tracheids increased from the pith to a more uniform length near the bark. However, the number of years needed to attain a more uniform tracheid length decreased from the base to the top of the tree. These relationships suggest that the formation of juvenile wood is related to the year of formation of the cambial initials. Consequently, the juvenile wood is conical in shape, tapering towards the tree top.


BioResources ◽  
2010 ◽  
Vol 6 (1) ◽  
pp. 386-399 ◽  
Author(s):  
Mehran Roonia ◽  
Mohammad-Ali Hossein ◽  
Seyed-Ehsan Alavi-Tabar ◽  
Ajang Tajdini ◽  
Ahmad Jahan-Latibari ◽  
...  

In this study, variation in acoustic properties of Arizona cypress wood was monitored from pith to bark as affected by tapering of the growth ring width. Specific modulus of elasticity, acoustic coefficient, damping, and acoustic conversion efficiency were calculated. It was shown that the outer parts of the stem, close to the bark containing narrower growth rings, exhibited lower damping due to internal friction and higher sound radiation. Our finding theoretically justified the luthier craftsmen’s traditional preference toward timbers with narrow growth rings to make sounding boards in musical instruments.


2008 ◽  
Vol 13 (1) ◽  
pp. 57-66
Author(s):  
Jerzy Boryczka ◽  
Maria Stopa-Boryczka ◽  
Szymon Bijak

Abstract The paper discusses periodic climate changes in Europe determined on the basis of dendrochronological data dating back one thousand years. In tree-ring width sequences of trees growing in Poland there are approximately 8-, 11-, 100- and 180- year periods. The tree-ring widths of oaks growing in Poland for the last centuries are characterised, without any significant amplitude, by 8- and 11-year periods (Tab. 1). In turn, chronologies of pine, spruce, larch, oak and fir growing in Europe are characterised by 100- and 180-year periods (Tab. 2). Cycles of dendrochronological variables approximate cycles of air temperature and North Atlantic Oscillation NAO as well as those of solar activity. The forecast of annual growth (ring width) for 2001-2100 was calculated by interference of the tree-ring width cycles determined by the sinusoidal regression method. Because of much longer empirical sequences of specific periods, the credibility of forecasts for tree-ring widths is greater than that for air temperature.


2013 ◽  
Vol 74 (3) ◽  
pp. 189-195
Author(s):  
Ivan Sopushynskyy ◽  
Alfred Teischinger

Abstract. The paper presents analysis of biometric features of ash with wavy-grained wood, which has decorative appeal. The research results shows that fresh broadleaves ash forest stands growing in the Vinnytsya and Sokyryany Regions of Ukraine have high potential for growing curly ash. The differences between straight-grained and wavygrained wood density and macrostructure were analysed and estimated. Statistical evaluation of the aesthetic macrostructure of wood characteristics indicated that the length of wave varied from 3,25 to 10,83 mm and its amplitude varied from 0,37 to 1,74 mm. The average width and mean height of anomalies in wood formation were equal to 15,89 mm and 5,00 mm, and their mean occurrence was 30 times m-2. Average annual growth ring width of wavy-grained ash wood was clearly greater (by 25%) than that of straight-grained wood. The density of wavy-grained wood was 82 kg·m-3 higher than straight-grained wood after oven-drying and 70 kg·m-3 higher prior to oven-drying


Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Guillermo Riesco Muñoz

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.


IAWA Journal ◽  
1991 ◽  
Vol 12 (3) ◽  
pp. 257-262 ◽  
Author(s):  
Lidia Helińska-Raczkowska ◽  
Ewa Fabisiak

Radial variability of the axial element length in oak-wood is most prominent in the juvenile wood which inc1udes approximately 30 annual rings. The length of fibres, tracheids and vessel elements increases from the pith outwards according to a second degree curve. This dependence is most apparent for wood fibres, whereas it is the least distinct for vesseI elements. In the mature zone, anatomical elements are, on average, 10 to 20% Ion ger than in juvenile wood. With deteriorating conditions of tree growth, the length of the anatomical elements tends to increase. There is a negative correlation between length of the measured elements and growth ring width; this is most c1early so for fibres. A similar relationship exists between the length of anatomical elements and wood density.


Author(s):  
Vladimír Gryc ◽  
Jiří Holan

The work was focused on problematics of annual-rings width according to position within the tree stem. Annual-ring widths, ratio of late wood and early wood by spruce with compression wood were investigated. Statistically significant differencies of individual zones in tree were occured. Zone of compression wood showed bigger width of annual-rings, common occurence of late wood and higher percentual ratio of late wood. Obtained results agree with common results in literature. Variability of annual-ring width according to position within the tree stem was confirmed. Width of annual-ring was changed mainly according to radius of stem. In height position within the stem no more significant variability of annual-ring width was observed.


2015 ◽  
Vol 67 (4) ◽  
pp. 1399-1404 ◽  
Author(s):  
Dusan Jokanovic ◽  
Dragica Vilotic ◽  
Suzana Mitrovic ◽  
Danijela Miljkovic ◽  
Milan Rebic ◽  
...  

This paper shows correlations between vessel characteristics and differences in growth-ring width in heartwood and sapwood. Analyzed samples were from an iron-wood tree (Gymnocladus canadensis Lam.) that grew in the Muzljanski Rit area, of the Srpska Crnja municipality in Serbia. According to previous research, it was deduced that Gymnocladus canadensis Lam. belongs to ring-porous species with big vessel lumen in the earlywood zone and thicker cell walls in the latewood. Vessels were more numerous in the latewood zone, and the same was true for heartwood and sapwood. For both layers, sapwood possessed a few more vessels than heartwood, and a statistically significant difference was confirmed by t-test during the early phase. The greatest negative value of correlation coefficient was between the number of vessels and growth-ring width during the early phase for sapwood. The number of vessels decreased in the wider growth rings. The correlation between growth-ring width and the area of vessels had a statistically significant positive value of correlative coefficient, which means that wider growth rings had larger vessel areas in the early phase for sapwood.


2002 ◽  
Vol 32 (3) ◽  
pp. 498-508 ◽  
Author(s):  
Seija Anttonen ◽  
Riikka Piispanen ◽  
Jari Ovaska ◽  
Pia Mutikainen ◽  
Pekka Saranpää ◽  
...  

Three-year old Betula pendula Roth clones were grown at two nutrient levels in a field experiment to investigate the responses and recovery in growth and wood properties to a range of defoliation levels (0–100%). No general threshold value of defoliation level for negative effects in growth was found, since the sensitivity of saplings to defoliation varied according to plant traits studied. However, responses were related to defoliation intensity. Saplings compensated for 25% defoliation in terms of height growth and number of current branches and were able to tolerate 50% defoliation without effects on diameter growth 1 year after the defoliation. Nutrient availability was significant only in determining how total biomass responded to defoliation. Fertilized saplings were able to tolerate 25% defoliation without reduction in total biomass, but nonfertilized saplings were not. The interaction between defoliation and fertilization disappeared in the second growing season after the defoliation. Saplings were not able to compensate for 75% defoliation in terms of total biomass or for 100% defoliation in terms of growth and branching even in 2 years' recovery time. In stemwood, complete defoliation reduced growth ring width and vessel diameter simultaneously and also induced a narrow zone of secondary xylem with defects. Our results suggest that defoliation level and recovery time played a crucial role in compensatory growth of birch saplings, while nutrient availability had a minor role.


IAWA Journal ◽  
2019 ◽  
Vol 40 (2) ◽  
pp. 276-287 ◽  
Author(s):  
Marcos González-Cásares ◽  
Marín Pompa-García ◽  
Alejandro Venegas-González

ABSTRACTOngoing climate change is expected to alter forests by affecting forest productivity, with implications for the ecological functions of these systems. Despite its great dendrochronological potential, little research has been conducted into the use of wood density as a proxy for determining sensitivity to climate variability in Mexico. The response of Abies durangensis Martínez, in terms of wood density and growth ring width, to monthly climatic values (mean temperature, accumulated precipitation and the drought index SPEI) was analyzed through correlation analysis. Abies durangensis presents a high response, in terms of radial growth, to climatic conditions. Tree-ring widths are more sensitive to hydroclimatic variables, whereas wood density values are more sensitive to temperature. In particular, mean (MeanD) and minimum (MND) wood density values are more sensitive to climate than maximum (MXD). We found very marked spatial variations that indicate that A. durangensis responds differently to drought conditions depending on the indices of density.


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