Factors affecting log traits and green rotary-peeled veneer recovery from temperate eucalypt plantations

Key message: High levels of percentage green veneer recovery can be obtained from temperate eucalypt plantations. Recovery traits are affected by site and log position in the stem. Of the post-felling log traits studied, out-of-roundness was the best predictor of green recovery.

Context: Eucalyptus globulus and Eucalyptus nitens are widely planted in temperate regions of the globe but few studies of rotary peeling have been documented.

Aims: This study aims to examine differences among sites and log positions in post-felling log traits and green veneer recovery traits and determine the extent to which log traits explain variation in recovery traits.

Methods: Log traits and green rotary-peeled veneer recovery traits from six temperate eucalypt plantations were studied. Selected plantations encompassed different age, site productivity, silvicultural and species classes in south-eastern Australia. Differences in log and recovery traits among sites and between lower and upper logs were examined, as was the extent to which log traits explained variation in recovery traits.

Results: Differences among sites for percentage recovered green veneer were non-significant, despite significant differences for peelable billet volume, roundup loss, residual core diameter and all post-felling log traits: small end diameter, sweep, taper, out-of-roundness, end splitting and dynamic modulus of elasticity (MOE_dyn). The lower log exhibited more sweep, taper and out-of-roundness but lower MOE_dyn and less recovered green veneer. Out-of-roundness was the best predictor of recovery traits (R ² = 13–21 %, P < 0.001).

Conclusion: Recovered green veneer was high across all sites and log positions (78 % overall).