THE EFFECT OF SITE ON SAWN TIMBER QUALITY OF NORWAY SPRUCE AND SCOTS PINE

摘要

The aim of the study was to clarify the effect of site fertility of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) on the quality and usability of sawn timber. Especially the availability of the high quality joinery timber was studied. The effect of felling time on sawn timber drying was also clarified. The study material was collected from four different thinning stands of Norway spruce and Scots pine. Two of the stands were first thinnings that were delayed and two of them were later thinnings. About 32 - 40 stems per stand were felled and processed to sawn timber. Sawn timber was sorted according to the grading rules of Nordic Timber. The share of high quality Norway spruce timber was greatest in the less fertile later thinning stand and in the small and middle-sized trees of the more fertile later thinning stand and the less fertile first thinning stand. The quality and value lowering twist developed in drying were most common in sawn timber from the first thinning stands. The quality of Scots pine: timber was low in all the stands. The amount of high quality sawn timber was reaspnable only in the less fertile later thinning stand. The amount of knotty sawn timber, knotty-pine, was high in the biggest trees of the more fertile stands. The quality lowering checks developed in drying appeared only in sawn timber from the later thinning stands and mostly in that from the less fertile site.