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

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

Abteilung Waldnutzung Silvicultural alternatives 2 trees per site alternative A 350 / ha age alternative B 700 / ha age alternative FA 1600 / ha age 42 isolation at age ~ 15 years

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

Abteilung Waldnutzung Results Roundwood

Abteilung Waldnutzung Roundwood quality down-grading reasons: knots, ring width, compression wood

Abteilung Waldnutzung Branchiness of roundwood alternative A & B: ca. 80% sound knots alternative FA : 7.5% sound knots threshold between grade B and C

Abteilung Waldnutzung Ring width of roundwood threshold between A & B threshold between grade B & C threshold S 7/ S 10

Abteilung Waldnutzung Results Sawn timber

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, ABFA alternative mean diameter of thickest branch [mm] Knot dimension of sawn timber

Abteilung Waldnutzung Knottiness of sawn timber S 0 = reject

Abteilung Waldnutzung Ring width of sawn timber (cants) 7,2 3, ABFA alternative ring width [mm] threshold between S13 & S10 treshold between S10 & S7

Abteilung Waldnutzung Ring width of sawn timber S 0 = reject

Abteilung Waldnutzung Twist of sawn timber S 0 = reject

Abteilung Waldnutzung Wood density, MOE & MOR of sawn timber

Abteilung Waldnutzung Quality trend for future? branches ringwidth density juvenile core ?

Abteilung Waldnutzung grading results according to DIN 4074: Sawn timber quality ABFA S S S 7000 reject rejects due to knot size, ring width and twist

Abteilung Waldnutzung Twist of sawn timber

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

Abteilung Waldnutzung Compression wood of roundwood threshold between grades B and C

Abteilung Waldnutzung Bending strength – MOR Lower bending strength due to larger branches... broader ring width... lower wood density... juvenile wood