Abstract:
The natural Radial and axial variations in the resistance
of the wood of Termihalia ivorensis A* Chev, against
damage by subterranean termites were investigated for two
trees from the same locality- The damage was studied in
relation to specific gravity, the modulus of elasticity,
the cross-sectional area of vessels in the wood,, and the
water soluble extractives. The correlation between termite
damage and these physical, mechanical and anatomical
properties have been reported.
It was found that the termite resistance of the wood
varied significantly in the radial direction. The outerheartwood
was less susceptible to damage than the sapwood
and the inner-heartwood, The sapwood was less resistant
to damage than the inner-heartwood. The termite resistance
of the inner-heartwood increased near the top of the tree.
Axial variations in the intensity of termite damage were
not very pronounced.
Termite damage to the wood was inversely correlated
with the specific gravity and cross-sectional area of the
vessels generally. The susceptibility to damage by termites
generally increased with the modulus of elasticity.
The specific gravity, modulus of elasticity and the crosssectional
area of the vessels were inter-correlated and no
one of them could be used alone to predict the termite
resistance of T, ivorensis, The water soluble extractives
appeared not to improve on the resistance of the wood.
The two trees tested showed significant differences
in their resistance to termite attack. This means that
naturally growing trees of T„ ivorensis obtained from
different Forest Reserves in Ghana could be expected to
vary widely in their resistance against attack by subterranean
termites.
