Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: Acoustic segregation of Pinus radiata logs according to stiffness. | Ann. For. Sci. 59 2002 471-477 INRA EDP Sciences 2002 DOI forest 2002031 471 Original article Acoustic segregation of Pinus radiata logs according to stiffness A. Colin Mathesona Ross L. Dicksonb David J. Spencera Bill Joec and Jugo Ilicd aCSIRO Forestry and Forest Products PO Box E4008 Kingston ACT 2604 Australia b State Forests of New South Wales Research and Development Division PO Box 46 Tumut NSW 2720 Australia c State Forests of New South Wales Research and Development Division PO Box 100 Beecroft NSW 2119 Australia d CSIRO Forestry and Forest Products Private Bag 10 Clayton South MDC Clayton VIC 3169 Australia Received 16 August 2001 accepted 17 May 2002 Abstract - Wood stiffness varies enormously both within and between trees so it is inevitable that low-grade solid wood products are produced from some trees. Accordingly it would be highly desirable to segregate logs to ensure that only those logs with predominantly high stiffness wood are processed into structural lumber products. This study examined whether sound flight velocity m s-1 could be used as a direct measure of wood stiffness to allow such segregation. Trees of radiata pine were measured before and after harvest with a non-destructive acoustic device stress wave timer to see if there was a relationship between sound wave velocity in either standing trees or logs and machine stress-grades of boards derived from those trees and logs. The speed of sound along logs was sufficiently closely correlated with wood stiffness to allow logs to be sorted into classes. A highly significant and positive relationship was found for acoustic measurements made in logs and a weaker but still significant relationship existed for acoustic measurements made in standing trees. Such segregation of logs according to wave velocity measured in the field may save a large sawmill between A 1-4m each year. Acoustic methods may also be used as an indirect tool for selection provided the heritability of the .
