High-resolution proxies for wood density variations in Terminalia superba

Area of Science:

• Forestry and Wood Science
• Materials Science
• Biophysics

Background:

• Wood density is critical in forest science, with traditional gravimetric methods being destructive and time-consuming.
• Faster, semi- to non-destructive indirect methods are sought for efficient wood density evaluation.

Purpose of the Study:

• To compare the efficacy of various indirect methods for determining wood density profiles.
• To evaluate high-resolution X-ray computed tomography as a tool for wood density assessment.

Main Methods:

• Wood density variations were analyzed using one-dimensional resistance drillings, 2D neutron scans, and 3D neutron and X-ray scans.
• Methods were applied to Terminalia superba (limba), an African pioneer species.

Main Results:

• X-ray tomography provided direct wood density estimates with high correlation (R(2) = 0.995) to gravimetric data.
• X-ray densities showed a strong linear relationship with neutron attenuation (R(2) = 0.986) but a weak one with drilling resistance (R(2) = 0.243).
• All methods identified similar density trends, with variations attributed to tree ring orientation and method characteristics.

Conclusions:

• High-resolution X-ray computed tomography is a promising technique for wood core research.
• Further investigation is needed for limba noir density variations and resistance drilling refinement.