Wood Properties of Norwegian Spruce Grown under Spacing Alternatives
Explore the sawn timber properties of Picea abies from Norway grown under various spacing conditions. Learn about quality factors, knot dimensions, branchiness, and more.
Wood Properties of Norwegian Spruce Grown under Spacing Alternatives
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Presentation Transcript
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
Introduction “ 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
isolation at age ~ 15 years alternative A 350 / ha age 28-29 alternative B 700 / ha age 27-29 alternative FA 1600 / ha age 42 2 trees per site Silvicultural alternatives
stem disc at 1.30 m stem disc at5 m 4 m log, split to 2x2m 2 short logs (1.37 – 2.06 m) 78 laths3 x 6 cm² 44 cants5 x 10 cm² Test material
Roundwood quality down-grading reasons: knots, ring width, compression wood
threshold between grade B and C Branchiness of roundwood alternative A & B: ca. 80% sound knotsalternative FA : 7.5% sound knots
Ring width of roundwood threshold between grade B & C threshold S 7/ S 10 threshold between A & B
26,7 30 22,6 17,8 20 thickest branch [mm] mean diameter of 10 0 A B FA alternative Knot dimension of sawn timber threshold S 10/ S 7 : wide side: 40mm narrow side: 20mm threshold S 13/ S 10: wide side: 20mm narrow side: 10mm
S 0 = reject Knottiness of sawn timber
8 7,2 7,2 6 3,7 4 ring width [mm] 2 0 A B FA alternative Ring width of sawn timber (cants) treshold between S10 & S7 threshold between S13 & S10
S 0 = reject Ring width of sawn timber
Twist of sawn timber S 0 = reject
Quality trend for future? branches ringwidth density juvenile core ??