Electrical anisotropy in wood

Electrical admittance measurements were made on "green" (freshly felled, undried) samples from two species (Monterey pine and shining gum) of forestry trees at frequencies between 10 kHz and 40 MHz. Differences were noted between measurements along the three axes. The results are consistent with structurally-limited ionic conductivity and are also in accordance with the established morphology: the axial direction having few barriers, but the tangential many more. However, the radial conductivity was also high, especially in pine, and a structural reason for this has still to be elucidated.