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Radial variation of macrostructural parameters and density of wood in dominant trees of coniferous species

Czajka M., Fabisiak E.

Drewno : prace naukowe, doniesienia, komunikaty

2016

vol. 59, nr 197

179--187

This paper presents the results of measurements of wood macrostructure parameters and wood density in dominant trees of Scots pine, Norway spruce, and European larch, originating from an even-aged stand, therefore growing on identical sites and in identical climatic conditions. The influence of the cambial age of annual rings and the cross-section area on the measured features was determined in this study. The measurements of macrostructural parameters were taken using an image analyser. Basic density was determined on samples containing three annual rings. In the analysed species the widths of annual rings demonstrated significant differences in the first 50 years of tree growth. The smallest widths of annual rings throughout the whole period of tree growth were observed in the case of spruce wood. The latewood share, analysed within 25-year increment zones, demonstrated statistically significant differentiation between tested species in all selected zones of the cross-section. For each of the tested species the lowest shares were observed for juvenile wood. The lowest density values were observed, therefore, in this zone. In the mature wood of larch and pine an approximate 20% increase in the density was observed and furthermore, all the way to the circumference, density showed slight fluctuations. In the case of spruce wood, the values of density within the analysed zone increased towards the circumference. Accordingly, larch wood and pine wood were characterised by greater uniformity of properties, compared to spruce wood. This observation has important practical implications, because density is a determinant of many properties that influence the technical quality of wood.

Interrelationships between macrostructural parameters of pine (Pinus sylvestris L.) wood and the propagation velocity of ultrasound waves in the direction along fibres

Moliński W., Marcinkowska A.

Drewno : prace naukowe, doniesienia, komunikaty

2007

vol. 50, nr 177

79-89

The paper analyses the interrelationship between wood macrostructural parameters, width of annual increments and the proportion of latewood in the annual increment of different tissues of pine (Pinus sylvestris L.) wood and the propagation velocity of ultrasound waves in the direction along fibres. On the basis of the measured propagation velocity of ultrasounds waves, the authors calculated the sonic modulus of wood and cell wall elasticity. Experiments were carried out on juvenile, mature and compression wood.

W pracy analizowano wpływ parametrów makrostrukturalnych drewna, szerokości przyrostów rocznych i udziału drewna późnego w przyroście rocznym, różnych tkanek drewna sosny (Pinus sylvestris L.) a prędkością propagacji fal ultradźwiękowych w kierunku wzdłuż włókien. Na podstawie zmierzonej prędkości propagacji fal ultradźwiękowych obliczono soniczny moduł sprężystości drewna oraz ścian komórkowych. Badania przeprowadzono na drewnie młodocianym, dojrzałym oraz naciskowym.