Application of the Fourier analysis to determine the demarcation between juvenile and mature wood

Juvenile wood produced in the crown has features that distinguish it from the older, more mature wood of the bole. Juvenile wood has important wood quality attributes because, depending on the species, it can have lower density and has shorter tracheids, thin-walled cells, larger fibrial angles, high – more than 10% – lignin and hemicellulose content, and a slightly lower cellulose content than mature wood. Wood juvenility can be established by examining a number of different physical or chemical properties. Juvenile wood is not desirable for solid wood products because of warpage during drying, low strength properties, and other factors considered critical for producing high-stiffness veneer. Fourier transformation is an extremely useful mathematical tool that has been applied in the quantitative analysis of many physical processes. Fourier transformation can be represented as a series of sine and cosine functions. Density spectra derived from X-ray imaging provide new information in the nondestructive testing of wood. Until recently, testing for wood juvenility required wood samples to be milled, dissolved in acids, and painstakingly analyzed for certain anatomical features. The new method proposed in this report opens a new possibility for minimizing the time required to analyze wood formation. The main purpose of this report is thus to demonstrate how to distinguish juvenile wood from mature wood by Fourier analysis of density distribution curves. It is also the first study to employ Fourier analysis-assisted assays of the boundary line between juvenile and mature wood.