Graded quality of 30-year-old Norway spruce grown on agricultural and forest land

摘要: Six 30-year-old, fast-grown Norway spruce (Picea abies (L.) Karst.) stands in Sweden, comprising a total of 700 stems, were examined. Four had been planted on agricultural land and two very fertile forest land. The characteristics studied branch properties, defects basic density as well the graded quality timber, assessed by Swedish export grading, modulus elasticity, machine strength grading (EJ. Our aim was to determine how wood properties grown differ from those only differences found between sites concerned defects, especially spike knots. These more common stands, where frequency logs with at least one knot 33.7%, whereas corresponding figure 6.9%. low for boards all according both gradings. Only 7.1% considered be highest grade, u/s. Eighty-two per cent approved structural use, i.e., grade T18 or better. Basic annual ring width characters that explained significant amounts variation EM. A model predicting EM stand is presented. Wood could improved silviculturally thinning regimes technically cross-cutting using butt part tree purposes other than sawing.