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Variability of selected macrostructure features, density and compression strength along the grain of “Tabórz” Scots pine wood (Pinus sylvestris L.)

Wąsik Radosław, Michalec Krzysztof, Barszcz Anna, Mudryk Krzysztof

Drewno : prace naukowe, doniesienia, komunikaty

2020

vol. 63, nr 205

171--182

The aim of the study was to determine the variability of annual ring width, share of latewood, density and compression strength along the grain of “Tabórz” Scots pine wood (Pinus sylvestris L.). The wood samples for examination were obtained from three trunks of 260-year-old Scots pines felled in the Sosny Taborskie Nature Reserve. In total, 106 samples were obtained, with cross-sectional dimensions of 20 × 20 mm and a length of 30 mm along the grain. The mean values for all tested wood samples were as follows: annual ring width 1.28 mm, share of latewood 28.9%, wood density 0.487 g·cm-3, and compression strength 47.3 MPa. The least variability within trees was found for wood density and compressive strength along the grain. Very high positive correlation was found between wood density and compressive strength, and high positive correlations were found between share of latewood and wood density and between share of latewood and compressive strength. To the authors’ knowledge, the results presented here are the first empirical data published concerning the features of wood macrostructure, density and compression strength along the grain of the Tabórz Scots pine, the trunks of which are considered a valuable timber in Europe.

The effect of stand origin on the wood structure of Norway spruce

Michalec Krzysztof, Wąsik Radosław, Barszcz Anna, Sowa Janusz M.

Drewno : prace naukowe, doniesienia, komunikaty

2020

vol. 63, nr 206

137--146

A study was carried out to compare the annual ring width, latewood share and density of spruce wood from the north eastern a nd south w estern ranges of Norway spruce. Twelve trial plots were located in the north eastern range, while within the south w estern range eight trial plots were established in the Sudeten Mountains and twelve trial plots in the Carpathian Mountains. On ev ery trial plot fifteen spruce trees were chosen, from which increment cores were sampled using a Pressler borer. Next, the increment cores had their surfaces smoothed and measurements were made of the width of annual rings, latewood zones and the share of latewood. Then the cores were divided into 2 cm sections, for which the relative wood density was determined. The analyses indicate that annual rings were wider in trees growing within the north eastern range than in those from the south western range an d the Kruskal Wallis test showed the differences to be statistically significant. T he latewood share followed an opposite pattern: t he wood from the Mazury region had a higher proportion of latewood than the wood from the mountainous areas and the statist ical test again indicated that the differences were significant. The analys i s of wood density showed slight differences between the density of wood from the north eastern and south western ranges, but in this case the Kruskal Wallis test showed the differe nces to be statistically insignificant.