Wood quality assessment of tree trunk from the tree branch sample and auxiliary data based on NIR Spectroscopy and SilviScan

Abstract

We estimated wood quality parameters for a specific tree trunk using samples of this tree’s branch, and auxiliary samples from other similar species, based on analysis of wood density, modulus of elasticity (MOE), and microfibril angle (MFA), measured with the near-infrared spectroscopy (NIRS) and SilviScan processes.  The measured materials included a branch sample from the subject tree, also known as the smolensk birch¹, and stem analysis disk samples from silver birch (Betula pendula Roth) trees collected in central Poland.  We analyzed and modeled the pith-to-bark and base-to-tip density changes in the silver birch samples, and using developed models estimated the subject tree trunk air-dry wood quality parameters and compared them with published yellow birch (Betula alleghaniensis) and silver birch tabular data.  Then we compared the corresponding surrogated green wood parameters of the subject tree against the standard American utility wood pole parameters, and identified environmental adjustments necessary for a realistic and accurate representation of the final subject tree wood characteristics.  The final conclusions from this study are that the subject tree dry wood parameters are not significantly different (in the statistical sense) from the well-documented yellow birch parameters, which were used as their surrogate, and even without the due reductions in parameters for excessive amount of whorls and branches, and for the height of the tree brake (5 to 7 m above ground), the structural parameters of the subject tree green wood, as applicable to live tree and as surrogated by appropriate yellow birch parameters, are generally weaker than corresponding dry wood parameters for the standard American wood poles and weaker then the southern yellow pine parameters. The adjustments for the whorls and knots and height of the brake may yield some additional 50% reduction in the estimates for the subject tree structural wood parameter values.