Mass loss and moisture dynamics of Scots pine (Pinus sylvestris L.) exposed outdoors above ground in Sweden

Holzforschung ◽  
2005 ◽  
Vol 59 (2) ◽  
pp. 183-189 ◽  
Author(s):  
Åsa Rydell ◽  
Mikael Bergström ◽  
Torbjörn Elowson

Abstract The durability of 566 Scots pine (Pinus sylvestris) samples was tested during a period of 9 years of exposure to weather in Sweden. The parameters investigated were heartwood/sapwood, origin, surface treatment, end-seal, storage and drying method, annual ring width and density. The weight was measured on 67 occasions during 9 years in order to assess the moisture content of the samples. The mass loss was determined for each sample at the end of the trial. Sapwood had a higher moisture uptake and a higher mass loss compared with heartwood. Even if sapwood was painted with an impermeable paint and then end-sealed, it still had higher average moisture content than heartwood. The results also demonstrated that sapwood was more sensitive to different handling conditions than heartwood. Sapwood was sensitive to air-drying and water storage, which was evident in the higher moisture uptake. In terms of mass loss, some differences were evident but they were not statistically significant due to the large standard deviation of the sapwood samples from water-stored logs. The only positive influence of water storage was on samples end-dipped in oil. One explanation could be that water storage led to increased permeability due to bacterial attack, which in turn enhanced the penetration of the oil. Heartwood had low and stable moisture dynamics during the test period, almost independent of treatment or handling conditions. No correlation with moisture uptake or mass loss was evident among annual ring width, origin or density.

Holzforschung ◽  
2012 ◽  
Vol 66 (2) ◽  
Author(s):  
Thomas K. Bader ◽  
Karin Hofstetter ◽  
Gry Alfredsen ◽  
Susanne Bollmus

Abstract Fungal degradation alters the microstructure of wood and its physical and chemical properties are also changed. While these changes are well investigated as a function of mass loss, mass density loss and changes in equilibrium moisture content are not well elucidated. The physical and chemical alterations are crucial when linking microstructural characteristics with macroscopic mechanical properties. In the present article, a consistent set of physical, chemical and mechanical characteristics is presented, which were measured on the same sample before and after fungal degradation. In the first part of this two-part contribution, elucidating microstructure/stiffness-relationships of degraded wood, changes in physical and chemical data are presented, which were collected from specimens of Scots pine (Pinus sylvestris) sapwood degraded by Gloeophyllum trabeum (brown rot) and Trametes versicolor (white rot) for up to 28 weeks degradation time. A comparison of mass loss with corresponding mass density loss demonstrated that mass loss entails two effects: firstly, a decrease in sample size (more pronounced for G. trabeum), and secondly, a decrease of mass density within the sample (more pronounced for T. versicolor). These two concurrent effects are interrelated with sample size and shape. Hemicelluloses and cellulose are degraded by G. trabeum, while T. versicolor was additionally able to degrade lignin. In particular because of the breakdown of hemicelluloses and paracrystalline parts of cellulose, the equilibrium moisture content of degraded samples is lower than that in the initial state.


2006 ◽  
Vol 55 (1-6) ◽  
pp. 84-92 ◽  
Author(s):  
Anders Fries ◽  
Tore Ericsson

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.


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.


BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 7492-7508
Author(s):  
Ewa Fabisiak ◽  
Beata Fabisiak

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.


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.


2009 ◽  
Vol 24 (5) ◽  
pp. 469-480 ◽  
Author(s):  
Emmi Hilasvuori ◽  
Frank Berninger ◽  
Eloni Sonninen ◽  
Heikki Tuomenvirta ◽  
Högne Jungner

Holzforschung ◽  
2007 ◽  
Vol 61 (5) ◽  
pp. 600-604 ◽  
Author(s):  
Outi Karppanen ◽  
Martti Venäläinen ◽  
Anni M. Harju ◽  
Stefan Willför ◽  
Suvi Pietarinen ◽  
...  

Abstract There is wide variation in the extractive content and decay resistance of Scots pine (Pinus sylvestris L.) heartwood. The heartwood is not visible in standing trees and only poorly visible in timber. Therefore, it is difficult to identify extractive-rich trees, and consequently the most decay-resistant heartwood. On the other hand, knots are clearly visible in standing trees and timber. In the present paper we studied the possibility of measuring the decay resistance of Scots pine heartwood indirectly on the basis of the extractive concentration of knotwood. The material investigated consisted of 40 felled trees with a wide between-tree variation for extractive content and decay resistance of their heartwood. The extractive content of knotwood was found to be four- to five-fold higher than that of heartwood. Statistically significant correlations were found between the mass loss of heartwood and the concentrations of total phenolics and stilbenes in knotwood (r=-0.54, P<0.001 and r=-0.40, P=0.011, respectively), and for the concentration of total phenolics (r=0.42, P=0.008) and stilbenes (r=0.39, P=0.012) between heartwood and knotwood. We suggest further development of this technique in the context of rapid industrial screening of durable pine heartwood.


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.


Sign in / Sign up

Export Citation Format

Share Document