Using Acoustic Technology as a Means for Improving the Economics of Fuel Reduction Operations through an Integrated Value-Adding Approach

Fuel reduction and/or forest stand health improvement operations are usually associated with high costs of treatment because of social, environmental, and operational requirements, making them financially challenging. An integrated value-adding scenario involving a mixed size/species/quality approach may improve their economics. Acoustic technology has been successfully used as a non-destructive technique for assessing the mechanical quality of various wood products and species based on stiffness. There is a growing interest in incorporating such technologies for measuring internal stem features into a harvester head. Evaluation of hypothetical working procedures for real time measurement of resonance- based acoustic velocity suggested good operational feasibility. For a sample of >3,000 logs from second growth Douglas-fir stands in Western Oregon, a general methodology was developed to estimate relative mill-door breakeven prices of Douglas- fir peeler logs based on acoustic assessment of veneer stiffness differences. Results suggested that stiffness grading based on acoustic velocity measurements could be used as a surrogate measure for potential net returns and hence for an affordable premium price on such logs. The additional value recovered from improved log sorting could partially offset the high costs of fuel reduction/stand health improvement operations.