Comparison of Productivity, Cost and Chip Quality of Four Balanced Harvest Systems Operating in a Eucalyptus globulus Plantation in Western Australia

Abstract

There have been few comparative harvest system studies to provide a basis to understand the performance and chip quality of harvest systems used in eucalypt plantations. The study compared the CTL – cut-to-length method at the stump, WTM – whole tree method where trees were processed to logs at roadside, IFC-DDC – infield chipping using a debark/delimb/chipper, IFC-F/C – infield chipping using a separate flail and chipper harvest systems on a single site in south-west Western Australia. The WTM and IFC-F/C harvest systems were the most productive. The productivity of the CTL and IFC-DDC harvest systems was about 25% less than that of the other harvest systems. The CTL harvest system produced wood at the highest cost resulting from it having a large number of machines without a correspondingly high productivity level. However, the CTL harvest system has advantages over the other systems through retaining evenly distributed logging residues, low machinery impact on the site and flexibility to add or subtract machines as conditions change. Two limitations of this study were that the harvest systems were only compared at a single mean tree size and operator performance differences may have influenced harvest system productivity. Previous studies have found that the balance of machines in a harvest system can change with changes in mean tree size. This is an area where further research is required. Wood chip samples from three of the four harvest systems did not meet the company chip specifications. However, the deviations from the specifications were minor.