- Saranpää, Pekka
Finnish Forest Research Institute METLA, Vantaa, Finland
Northern softwood is valuable raw material for both timber and pulp. Slow growth results in rather uniform quality. However, the rotation time is long. Wood quality can be dived into two classes: 1) the external quality of wood includes stem volume, straightness and the quality of branches; 2) the internal quality of wood can be determined on the basis of basic density, annual ring width, knot size, amount of heartwood, fibre length and cell wall thickness. Wood properties of a certain species are influenced by several factors. Within-tree and tree-to-tree variation of wood properties is fairly large. More information is needed of wood properties and the relationship between external and internal quality of wood before one is able to evaluate the wood quality of a certain stand. The effect of environmental factors and forest management on the wood properties and quality of Norway spruce and Scots pine will be discussed.