EXAMINATION OF WOOD PROPERTIES OF PLANTATION-GROWN PERNAMBUCO (CAESALPINIA ECHINATA)

摘要

Caesalpinia echinata (pernambuco or pau-brasil), is recognized as the premier wood for manufacturing stringed instrument bows. Owing to limited supplies and concerns regarding species survival, interest exists in establishing pernambuco plantations toprovide future bow-quality wood. For native forest- and plantation-grown woods we examined several wood properties considered important in determining bow quality including basic density, modulus of elasticity (MOE), modulus of rupture (MOR) measured using static bending samples, air-dry density, microfibril angle (MFA), and stiffness using SilviScan. Color, extractives content and loss tangent (tan b) were measured for a subsample of the static bending samples. Finally, the samples were also ranked based on their potential for manufacturing high-quality bows (0 = poor, 1 = good and 2 = excellent) by an experienced bow maker. No evidence of differences between means for density, MOE and MOR for native, and 25- and 30 -year-old plantation-grown pernambuco was observed; however, when sorted based on quality, the excellent group had higher density, MOE and MOR. MFA and tan 6 were low, especially for native forest samples. Extractive contents were low for plantation samples; 5.7% and 12.7% respectively for the 25- and 30-year-old samples, compared to the native forest samples (set 1 = 23 %, set 2 = 22.5 %) and few samples had heartwood. Overall, plantation-grown samples provided promising results in terms of their quality.