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Wood density in European larch (Larix decidua Mill.) from selected provenances grown at the Siemianice Forest Experimental Station

Szaban Jarosław, Kowalkowski Wojciech, Łacka Agnieszka, Karaszewski Zbigniew

Drewno : prace naukowe, doniesienia, komunikaty

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2021

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vol. 64, nr 207

27--41

EN

The purpose of this study was to determine variation in the density of wood from different provenances, growing under the same soil and climate conditions. Samples were obtained from an experimental site located at the Siemianice Forest Experimental Station. We analyzed larch wood samples from trees aged 48 years, collected from six different provenances in Poland. Diameter at breast height (DBH) and tree height were used to calculate the parameters for sample trees, from which a 70 cm segment was cut, from breast height upwards (up to 2 m of tree height). Samples with dimensions 20 × 20 × 30 mm were obtained from the material. Sample volume was determined by stereometry. Relative density was determined for 890 samples. The highest wood density was found in trees from Czerniejewo, and the lowest in trees from Rawa Mazowiecka. Analysis of variance, including the mean wood density values of trees, did not demonstrate significant differences between provenances in terms of this characteristic. Mean relative density was higher in larch wood samples from the heartwood zone. The density of samples cut closer to the bark was lower, as the value was affected by the large content of sapwood. A relation was found between the provenances from which the study material was sourced and the relative density of wood.

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Stem quality of Quercus cerris trees from Kosovo for the sawmilling industry

Bajrakatri A., Pimenta R., Pinto T., Miranda I., Knapic S., Nunes L., Pereira H.

Drewno : prace naukowe, doniesienia, komunikaty

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2018

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vol. 61, nr 201

57--69

EN

Quercus cerris is an important species in the forests of Kosovo with a potential high economic value, although there is little information on the stem quality for the saw-milling industry. This study brings data on wood properties, particularly on heartwood, sapwood and bark development within Q. cerris trees grown in two sites in Kosovo, where mature trees were felled, and discs taken at different stem height levels. The average radial growth rate was 1.21 and 1.76 mm yr-1 for both sites. Heartwood decreased from the tree base upwards with a proportion of 53% and 43% until 5 m of height in the two sites. The radial width of sapwood was higher at the stem base (on average 44 mm) and afterwards approximately constant at 32 mm. The taper was low at an average 3.3 mm m-1 between 3.3 and 7.3 m of height. Bark represented on average 16.4% of the total stem cross-section and contained a substantial proportion of rhytidome (51% of the total bark area proportion at stem base and 41% at 9.3 m). Q. cerris in Kosovo showed good potential as a timber species for the supply of stem wood to the saw-milling industry, allowing good yields of heartwood-only sawn wood components. The bark should also be considered for complementary valorization.

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Circumferential variation in heartwood in stands of black locust (Robinia pseudoacacia L.)

Klisz M, Wojda T., Jastrzębowski S., Ukalska J.

Drewno : prace naukowe, doniesienia, komunikaty

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2015

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vol. 58, nr 195

31--44

EN

Within the framework of work on the anatomical structure and durability features of wood, as well as analyses of radial growth, a preliminary analysis was carried out in regard to variation in the heartwood within Black locust trees. The research was carried out in three stands of straight-stemmed trees in western Poland. The variation displayed by the heartwood around its circumference and the eccentricity of the trunks was characterised with reference to: the heartwood radial index (HRI), the cross-sectional shape factor for heartwood (CSsf) and the pith eccentricity index (PEcc). The results confirmed a relationship between the degree of variation around the circumference of the heartwood and the mean age of the stands, while at the same time making clear the high level of differentiation in radial variation at the level of the individual tree. The findings suggest that the fertility of the habitat does not exert much of an influence on the generation of heartwood in Black locust trees. No statistically significant relationship was obtained when the circumferential variation of the heartwood was set against the total height or diameter at breast-height. Only in the case of crown length, and then only at the Wołów site, was there a moderate negative correlation with the coefficients of circumferential variation.

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The activation energy of swelling sap of pine wood (Pinus sylvestris L.) in water

Moliński W., Kuczyński M., Puszynski J., Roszyk E.

Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

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2014

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No. 88

151--156

EN

The activation energy of swelling sap of pine wood (Pinus sylvestris L.) in water. This paper shows the results of the activation energy of swelling sapwood of pine wood in water. The results showed that activation energy value range from 4.8 to 10.7 kJ/mol. It is also noted that its depend on the density.

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Proportion of sapwood and heartwood in stems of European Larch (Larix decidua Mill.) origin from provenances experimental plot

Jakubowski Marcin, Szaban Jarosław, Kowalkowski Wojciech

Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

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2014

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No. 88

87--91

EN

Proportion of sapwood and heartwood in stems of European Larch (Larix decidua Mill.) origin from provenances experimental plot. The aim of this work was to state wether the wood from different provenances of European Larch (Larix decidua Mill.) show differences in proportion of sapwood and heartwood in stems. Research were carried out on 56 trees erepresenting 6 provenances of larch: Bliżyn (10), Czerniejewo (5), Konstancjewo-Tomkowo (3), Krościenko (15), Rawa Mazowiecka-Trębaczew (6), Skarżysko (9). This plot is a part of unique research area established in 1966. Results show important differences between heartwood-sapwood proportion for two provenances: Krościenko - the heighest proportion (largest volume of heartwood) and Bliżyn the lowes proportion (least volume of heartwood). The other provenances show similar proportions.