Veneer grades, recoveries, and values from 5-year-old eucalypt clones

Abstract

Processing young, small eucalypt logs into veneer is a burgeoning industry across southern China. However, plantations supplying these logs were mostly established for pulpwood; little information is available on variation and selection among commercial eucalypt clones/varieties in regards to suitability for veneer production. Tree growth and log form were assessed on 11 eucalypt clones from a 5-year-old trial in southern China. Logs from these were rotary peeled for veneer; recovery percentages plus a range of quality and value traits were assessed on the outturn. Tree volumes, green veneer recovery ratios (%), veneer quality grades, log value, and value m−3 varied significantly among both clones and log positions up the stem. The clone with the best veneer recovery ratio (50.5 %) provided nearly twice that of the poorest clone (28.4 %). Average veneer value log−1 by clone ranged from RMB 6.7 (US$1) up to RMB 15.1 (US$2) and average value m−3 by clone ranged from 589 RMB m−3 (US$88) up to 925 RMB m−3 (US$139). Overall, sweep was the key factor influencing veneer recovery ratio and value. Knots, especially dead knots, holes and splitting were major factors influencing veneer quality grade. Middle and upper logs had significantly higher veneer recoveries, grades, and values m−3 than the lower logs. Excellent potential exists for selecting among eucalypt clones, and even among log positions within trees, for optimizing veneer production.