Density and mechanical properties of Scots pine (Pinus sylvestris L.) wood from a seedling seed orchard

Seedling seed orchard (SSO) growing conditions are different to those in the forest. Trees grow in wide spacing with more access to sunlight and competition between trees is less intense causing larger annual rings and limited height growth. The objective of this research was to: 1) determine the density and mechanical properties of Scots pine (Pinus sylvestris L.) wood grown in an SSO and 2) suggest the most suitable use of this wood. Five trees (25-year-old) were selected using the Urich II method. Final samples (from the height of dbh) were cut from pith to bark, in the four cardinal directions. From all five trees, 159 samples were used to determine: 1) the wood density, 2) the compressive strength parallel to the grain, 3) the modulus of rupture, and 4) the strength quality coefficient. For each property the following mean values were obtained: 327 kg m-3, 32 MPa, 59 MPa and 0.10, respectively. The density did not depend on the dbh or mean width of annual ring. At the same time, the mechanical properties depended strongly on the wood density. In all cases, the wood property values of the Scots pine from the SSO were lower in comparison with those published for Scots pine grown in regular stand conditions. Therefore, pine wood from SSOs should be used in the paper industry