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This study aims to investigate whether it is possible to predict the modulus of elasticity (MOE) and modulus of rupture (MOR) of lumber produced from different heights using the stress-wave velocity of standing trees or the dynamic Young's modulus of logs in Siberian larch (Larix sibirica). A total of 190 pieces of lumber (38 by 89 mm in cross section) were cut from 111 logs obtained from 25 standing trees. Significant positive correlation coefficients were found between the stress-wave velocity of standing trees and MOE (r = 0.776) and MOR (r = 0.702) of this lumber. The dynamic Young's modulus of the logs also correlated significantly with MOE (r = 0.745) and MOR (r = 0.584) values. The results obtained in the present study suggest that stress-wave velocity and dynamic Young's modulus are useful for selecting superior trees in tree breeding and sorting logs for producing structural lumber. [ABSTRACT FROM AUTHOR]

The wood properties were examined for Larix sibirica naturally grown in Tosontsengel, Mongolia. The dynamic Young's modulus of the logs ranged from 6.31 to 9.65 GPa. The mean values of wood properties were as follows: water-extracted basic density = 0.44 g cm−3, air-dry density = 0.59 g cm−3, shrinkage at 1% moisture content change in the radial and tangential directions = 0.18% and 0.32%, modulus of elasticity = 11.24 GPa, modulus of rupture = 102.4 MPa, compressive strength parallel to the grain = 53.1 MPa, and mass loss by Fomitopsis palustris and Trametes versicolor = 10.4% and 18.6%. Mass loss in the heartwood was higher than that in the sapwood, indicating that the larger mass loss values in the heartwood of L. sibirica might be related to the larger amount of arabinogalactan. [ABSTRACT FROM AUTHOR]