Wood density, annual ring width and latewood content in larch [Larix sp.] and Scots pine [Pinus silvestris]
2005
Karlman, L.(Swedish Univ. of Agricultural Sciences, Umea (Sweden)) | Moerling, T. | Martinsson, O.
The wood density, annual ring width and latewood content in five different species of larch (Larix Mill.) and in Scots pine (Pinus sylvestris L.) were investigated using direct scanning X-ray densitometry. In total 106 trees were investigated. Old, 120-150 year, Siberian larch (Larix sibirica Ledeb, and Larix sukaczewii Dyl.) grown in Krasnoyarsk and Archangelsk and 105 year-old European larch (Larix decidua Mill.) grown in Sweden had on an average 20-25% higher wood density than Swedish Scots pine. The variation in density between different trees of the same species was big. Average wood density of larch trees was 618 (535-670)kg/cubic m in old Siberian larch and 621 (550-665)kg/cubic m in mature European larch timber grown in Sweden. Average wood density for the young, 30-35 years-old, larch trees was 536 (515-560)kg/cubic m for European larch, 451(410-490) kg/cubic m for hybrid larch (L. x eurolepis Henry) and 452 (420-490) kg/cubic m for Japanese larch (L. kaempferi Lamb.). Corresponding figures for mature Scots pine was 504 (475-555) kg/cubic m. The density within the mature zone of the heartwood was 20-40% higher than in the juvenile wood zone. The density in mature European and Siberian larch heartwood, usually reached 650 kg/cubic m after 25-30 annual rings from the pith. The density of larch heartwood increased with annual ring width up to 2.5 mm and decreased with annual ring with wider than 3 mm. On an average the latewood content was 40-50% in old European larch, around 40% in mature Siberian larch and 20-40% in young hybrid larch. The latewood content of mature Scots pine was approximately the same as in mature European larch. The density of 35 year old European larch with narrower ring widths than 4 mm was higher than in old, slow growing Scots pine.
Показать больше [+] Меньше [-]