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The wood present in trade in Poland named as ‘Siberian larch’, in fact belongs to two tree species: Larix sibirica Ledeb. and Larix gmelinii (Rupr.) Kuzen. The term itself is rather associated with the origin of wood. While Larix sibirica wood is the subject of many research, characteristics of Larix gmelinii still require additions. The main aim of this paper was to describe the technical properties of Dahurian larch wood. We characterised also the microstructure of the wood. Moreover, durability against fungi−caused brown rot was tested. The wood from the Chabarowsk area (Russia) was tested. The properties of wood were determined in accordance with the recommendations of the Polish standards. The obtained results allow to conclude that Dahurian larch wood is characterized by medium shrinkage and typical shrinkage anisotropy (total radial shrinkage was 5.0% and in the tangential direction 7.6%). With the average density of this wood in an air−dry state equal to 620 kg/m³, average mechanical properties are associated – modulus of elasticity 12.5 GPa and Janka hardness on the cross−section of 57 MPa. These values are similar to those of Siberian larch. Dahurian larch heartwoods is characterized by low durability (4th class of natural durability to fungi in a 5−degree scale). It causes that wood used in external environment require special attention and use of wood preservatives.
Siberian yellow pine (Pinus sibirica Du Tour.) has increasingly appeared in the merchant offers on the market of raw wood materials in Poland. However, the knowledge of the technical characteristics of its wood is still insufficient for it is based primarily on the data and experiences from abroad, often from the literature of the former USSR. The main aim of this study was to determine selected physical and mechanical properties of Siberian yellow pine wood such as linear and volumetric shrinkage, compressive strength along the fibers, the tensile strength along the fibers, the tensile strength across the fibers, static bending and modulus of elasticity, flexural dynamic and impact strength, hardness, resistance to splitting and cleavage amd shear strength. Futhermore, the resistance to decay caused by Coniophora puteana (Schum., Fr.) Karst., as well as the examination of the wood structure, assessing the dimensions and arrangement of the structural elements in particular were conducted. The results show that Siberian yellow pine wood has a number of similarities to Scots pine wood in terms of the structure. The wood is very light, with a density of 391 kg/m³ and very soft (Janka hardness on transverse cross section 23 MPa). The mechanical properties of Siberian yellow pine wood are closely related to its density and much lower when compared with Scots pine. Shear strength equalled to 67 MPa, static bending strength – 65 MPa and compression strength along the fibers – 49 MPa. The durability to brown rot fungus of Siberian pine wood is comparable to Scots pine (3rd class according to PN−EN 350−2:2000).
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