Density of juvenile and mature wood of selected coniferous species

Abstract

The objective of research was to determine the density of juvenile (JW) and mature wood (MW) of selected coniferous species growing in the Czech Republic. The research included the wood of Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.) and European larch (Larix decidua Mill.). The juvenile wood density close to the pith was 410 kg·m<sup>–3</sup> for spruce, 391 kg·m<sup>–3</sup> for pine and 573 kg·m<sup>–3</sup> for larch with 12% water content. Mature wood in the peripheral parts had the higher density in all species – spruce 516 kg·m<sup>–3</sup>, pine 552 kg·m<sup>–3</sup> and larch 652 kg·m<sup>–3</sup>. The highest difference, the difference of 161 kg·m<sup>–3</sup>, between juvenile and mature wood was found out in Scots pine. The large difference in the wood density of pine is caused by a considerable difference in the mean ring width of its juvenile and mature wood. Further, it was proved that wood density decreases with the increasing ring width while wood density increases with the increasing proportion of latewood.