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

Norén, Anna and Persson, Anders (1997). Graded quality of 30-year-old Norway spruce grown on agricultural and forest land. Technical Report. Uppsala: (S), Sveriges lantbruksuniversitet. Studia forestalia Suecica ; 203

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

Authors/Creators:Norén, Anna and Persson, Anders
Title:Graded quality of 30-year-old Norway spruce grown on agricultural and forest land
Series Name/Journal:Studia forestalia Suecica
Year of publishing :1997
Number of Pages:19
Place of Publication:Uppsala
Publisher:Swedish Univ. of Agricultural Sciences
ISBN for printed version:91-576-5553-7
Publication Type:Report
Full Text Status:Public
Subjects:Obsolete subject words > FORESTRY, AGRICULTURAL SCIENCES and LANDSCAPE PLANNING > Plant production > Forestry
Keywords:Fertile land, silviculture, modulus of elasticity, branch properties, basic density, defects, strength grading, export grading
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ID Code:3016
Deposited By: Aina Svensson
Deposited On:22 Jan 2007 00:00
Metadata Last Modified:02 Dec 2014 10:19

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