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

2021 ◽  
Vol 875 (1) ◽  
pp. 012035
Author(s):  
A V Kiseleva ◽  
S N Snegireva ◽  
A D Platonov

Abstract 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).

2000 ◽  
Vol 11 (1) ◽  
pp. 57-66
Author(s):  
Andrei Gourov

Seven Hylobius species are known from Siberia, while the occurrence of three of them is doubtful. Information available about the supplementary feeding of adult weevils is reviewed. It is likely that H. abietis and H. albosparsus are the only species of economic significance in this territory. In the northern forest-steppe zone, adult weevils usually prefer to feed separately on isolated or border young trees under the canopy of light Scots pine stands, but avoid the undercanopy regeneration in the dense stands. In the southern taiga zone, adults are abundant on cutover areas where they feed in clumps of young regeneration. In fresh clearcuts, up to 100% of juvenile trees may be damaged by the feeding of weevils, whereas the damage intensity declines sharply with the distance to the clearcut. An edge effect in the distribution of adult weevils needs verification and, probably, is time-dependent. Inside the stands, the crowns of mature trees may constitute an additional food niche for adults if the usual sources and preferred environmental conditions are not available.


10.12737/3340 ◽  
2014 ◽  
Vol 4 (1) ◽  
pp. 21-26
Author(s):  
Киселева ◽  
Aleksandra Kiseleva ◽  
Хван ◽  
Yuriy Khvan

There is a relationship between the properties of wood. Percentage of late wood – wood macrostructure characterization is a definite relation to density. This relationship varies slightly depending on the species and environmental factors. Establishment of interrelation of these parameters for wood from different regions and growing conditions, will more accurately judge the quality indicators of wood in specific circumstances. The studies were conducted with a timber of Scots pine growing in the Vologda region. In Ustyuzhansky Forestry two sites differing in conditions of growth are selected - lichen pine forest and blueberry and cranberry pine forest.


2021 ◽  
Vol 875 (1) ◽  
pp. 012005
Author(s):  
T Galdina ◽  
E Khazova

Abstract 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.


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.


2020 ◽  
Vol 50 (4) ◽  
pp. 66-71
Author(s):  
B. M. Ludu ◽  
B. K. Kan-ool

The paper presents the results of the research into the condition, number and concentration of beef cattle of Hereford breed, adapted to the natural and climatic conditions of the East Siberian region. The methodological basis of the study was formed by the methods of systematization, logical and comparative statistical analysis. The research information was based on the official materials of the Ministry of Agriculture and Food of the Republic of Tuva on animal husbandry. Out of the total number of livestock in the region (180 748 heads), Herefords amount to 2869 heads. A comparative analysis of livestock in farms of different forms of ownership and different natural and climatic zones was carried out. The largest population of Herefords (48.94%) is concentrated in the central agricultural and livestock zone with forest-steppe and steppe subzones (by the number of animals Piy-Khem kozhuun ranks first, 19.1%). In the southern zone of dry steppes, there are 27.43% of Herefords (by the number of livestock in the Republic, Tes-Khem kozhuun ranks second, 14.7%). In the western mountain-steppe zone there are 23.63% of Herefords, the largest number is in Barun-Khemchik (7.4%) and in Bai-Taiginsky (7%) kozhuun. Specialized beef cattle have not been brought to the high-mountain Mongun-Taiginsky kozhuun of the western zone or to the eastern high-mountain taiga zone. According to the results of the analysis, taking into account the category of farms, 56.4% of Herefords are kept in peasant farm enterprises, 19.7% – in agricultural production cooperatives, 29.7% – in other agricultural enterprises. All farms practise year-round grazing. Differences in the number of Hereford cattle by districts depend on the capacities of farms and climatic breeding zones. The monitoring which was carried out will allow to determine the prospects for raising purebred cattle of a specialized type, taking into account the terrain and zone of the breeding work in the conditions of year-round grazing in the Republic of Tuva.


Author(s):  
Kaspars Šķēle ◽  
Dace Cīrule ◽  
Anda Alksne ◽  
Jurijs Hrols

The paper considers the variation o f annual ring parameters and physical properties of wood of the pine species prevailing in Latvia’s forests, depending on the forest type (bog-land, vacciniosa) and the growth region in Latvia (Vidzeme, Latgale). Wood samples were taken from the stem butt-end, the middle and 3 A o f the height, in its sapwood or core part. An average annual ring width, latewood and earlywood width in the year ring, the percentage of latewood in the annual ring, wood density in oven-dry state (0), tangential swelling (tg) and radial swelling (rad) o f wood, as well as volume swelling (v) and swelling anisotropy coefficient (k) o f wood were determined for the samples. A comparison of these data shows that, in the majority of cases, the indices for the wood of pines grown in vacciniose have higher values, which suggests the advantage of pine wood over the bog-land pine wood. In its turn, no unambiguous distinctions between the parameter values for pine wood o f Latgale and Vidzeme origin were found, although the pine wood of Vidzeme origin had a somewhat higher indices. It may be concluded that the greatest impact on the leading pine wood properties is caused by the forest types regarded herewith, and not the belonging o f the pine wood site to its different growth regions in Latvia.


1992 ◽  
Vol 70 (7) ◽  
pp. 1429-1432 ◽  
Author(s):  
Yousry A. El-Kassaby ◽  
Hugh J. Barclay

The balance between allocating energy resources to reproduction or growth has considerable theoretical interest. Conflicting ecological requirements and evolutionary pressures often necessitate a trade-off in energy allocation. We obtained measurements on seed-cone production and annual ring width of 365 Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees from 29 open-pollinated families for 8 years. Phenotypic, genetic, and environmental correlations were computed for seed-cone production and ring width for each year. Five of the eight environmental correlations were negative (range −0.077 to −0.305), reflecting the reality of the trade-off in physiological terms. Six of the eight genetic correlations were negative (range −0.199 to −0.776), indicating that a trade-off exists at the genetic level between energy allocation to reproduction and to somatic growth. These findings agree with the current theory of life-history evolution. Key words: Pseudotsuga menziesii, cone production, annual ring width, genetic correlation.


2014 ◽  
pp. 175-188
Author(s):  
Branko Stajic

This paper defines pointer years and years with distinctive tree rings in the growth of beech in 3 sites (ecological units-EU) of the area of Djerdap, in order to observe the reactions of trees to the effects of various factors of growth. The pointer years were determined by the Schweingruber (1983) methodology. The years with distintive tree rings were defined as the years of beech growth with very pronounced distinctive growth rings (annual ring width at least ? 2 standard deviations higher or lower than the arithmetic mean) and pronounced typical growth rings (annual ring width at least ? 1.5 standard deviation higher or lower than the arithmetic mean). The common pointer years for the growth of beech in the site conditions of all three ecological units are 1977 and 1988 (negative pointer years). A particular pointer year is 1988, when in more than 90% of trees under the analyzed environmental conditions the marked reduction of tree rings width of the trees (EUB) or very pronounced reduction in the width of tree rings (EUA and ESV) were observed.


2020 ◽  
Vol 78 (6) ◽  
pp. 1061-1074 ◽  
Author(s):  
Tadios Habite ◽  
Anders Olsson ◽  
Jan Oscarsson

Abstract Knowledge of annual ring width and location of pith in relation to board cross-sections, and how these properties vary in the longitudinal direction of boards, is relevant for many purposes, such as assessment of shape mechanical properties and stability of sawn timber. Hence, the present research aims at developing a novel method and an algorithm, based on data obtained from optical surface scanning, by which the pith location along the length of sawn timber boards can be determined accurately and automatically. The first step of the method is to identify clear wood sections, free of defects along boards. Then time-frequency analysis, using the continuous wavelet transform, is applied to detect the surface annual ring width distribution of the four sides of the selected sections. Finally, the pith location is estimated by comparing annual ring width distributions on the different surfaces, and assuming that annual rings are concentric circles with the pith in the centre. The proposed algorithm was applied to a total sample of 104 Norway spruce boards. Results indicate that optical scanners and the suggested automatic method allow for accurate detection of annual ring width and location of pith along boards. For a sample of boards with the pith located within the cross-section, a mean error of 2.6 mm and 3.2  mm in the depth and thickness direction, respectively, was obtained. For a sample of boards of which 60% with pith located outside the cross-section, a mean discrepancy between automatically and manually determined pith locations of 3.9 mm and 5.8 mm in depth and thickness direction, respectively, was obtained.


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