Procedures for Scanning Radiata Pine Stem Dimensions and Quality on Mechanised Processors

摘要

Four simulated procedures for scanning and bucking of 75 pruned and 75 unpruned radiata pine (Pinus radiata) trees were evaluated on the basis of productivity, costs, and value recovery. The procedures evaluated were: (a) a conventional scan where quality changes and bucking decisions were input by the machine operator, (b) a fully automated scan of the stem prior to optimisation and bucking, (c) a 6 m automated scan with 6.2 m forecast ahead, and (d) a 4.7 m automated scan with 7.5 m forecast ahead before optimal bucking took place. Cutting patterns for export and domestic markets were used in the simulations for optimally bucking each tree. After subtracting costs, net value recovery for the automated scanning methods was 5 to 8% higher than for a conventional scan. Based on the stand types and market conditions used in the analyses, breakeven capital investment costs for new scanning and optimisation equipment on mechanised processors could range between US$240,000 and US$450,000.