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Abteilung Waldnutzung Wood properties of sawn timber of Norway spruce (Picea abies (L.) Karst.) grown under wide spacing Franka Brüchert, Florian Frisch, Udo H. Sauter IUFRO All Division 5 Conference, Taipei
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Abteilung Waldnutzung If we regard future-crop trees rather as tamed solitaries than as partially unshackled captives, then science must also more intensly address research on solitary trees. ABETZ 1987 Introduction
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Abteilung Waldnutzung Silvicultural alternatives 2 trees per site alternative A 350 / ha age 28-29 alternative B 700 / ha age 27-29 alternative FA 1600 / ha age 42 isolation at age ~ 15 years
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Abteilung Waldnutzung Test material stem disc at 1.30 m stem disc at 5 m 4 m log, split to 2x2m 2 short logs (1.37 – 2.06 m) 44 cants 5 x 10 cm² 78 laths 3 x 6 cm²
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Abteilung Waldnutzung Results Roundwood
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Abteilung Waldnutzung Roundwood quality down-grading reasons: knots, ring width, compression wood
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Abteilung Waldnutzung Branchiness of roundwood alternative A & B: ca. 80% sound knots alternative FA : 7.5% sound knots threshold between grade B and C
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Abteilung Waldnutzung Ring width of roundwood threshold between A & B threshold between grade B & C threshold S 7/ S 10
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Abteilung Waldnutzung Results Sawn timber
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Abteilung Waldnutzung threshold S 13/ S 10: wide side: 20mmnarrow side: 10mm threshold S 10/ S 7 : wide side: 40mmnarrow side: 20mm 26,7 22,6 17,8 0 10 20 30 ABFA alternative mean diameter of thickest branch [mm] Knot dimension of sawn timber
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Abteilung Waldnutzung Knottiness of sawn timber S 0 = reject
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Abteilung Waldnutzung Ring width of sawn timber (cants) 7,2 3,7 0 2 4 6 8 ABFA alternative ring width [mm] threshold between S13 & S10 treshold between S10 & S7
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Abteilung Waldnutzung Ring width of sawn timber S 0 = reject
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Abteilung Waldnutzung Twist of sawn timber S 0 = reject
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Abteilung Waldnutzung Wood density, MOE & MOR of sawn timber
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Abteilung Waldnutzung Quality trend for future? branches ringwidth density juvenile core ?
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Abteilung Waldnutzung grading results according to DIN 4074: Sawn timber quality ABFA S 13000 S 10004 S 7000 reject100 96 rejects due to knot size, ring width and twist
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Abteilung Waldnutzung Twist of sawn timber
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Abteilung Waldnutzung Relation roundwood-sawn timber Features reducing wood quality round woodsawn timber branches ring width reaction wood branches ring width twist curvature broad side curvature narrow side wane reaction wood
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Abteilung Waldnutzung Compression wood of roundwood threshold between grades B and C
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Abteilung Waldnutzung Bending strength – MOR Lower bending strength due to...... larger branches... broader ring width... lower wood density... juvenile wood
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