RELATIONSHIP BETWEEN MECHANICAL PROPERTIES AND SELECTED ANATOMICAL FEATURES OF NTHOLO (<em>PSEUDOLACHNOSTYLIS</em> <em>MAPROUNAEFOLIA</em>)

Abstract

Uetimane JR E & Ali AC. 2011. Relationship between mechanical properties and selected anatomical
features of ntholo (Pseudolachnostylis maprounaefolia). The anatomical features of the sapwood and heartwood
of ntholo (Pseudolachnostylis maprounaefolia) were studied and interrelated with physico–mechanical properties.
The samples were randomly taken from five trees irrespective of their position within the tree. The objective
was to determine the mechanical properties of ntholo, a lesser-used species from Mozambique, and compare
this species with the most used species in order to assess its end-use as well as to study the anatomy–property
relationship through correlation and regression. Anatomical features were used to predict density and
mechanical properties whereas density, to predict mechanical properties. There were notable differences
between density and mechanical performance of sapwood and heartwood. The higher density of heartwood
(1023.7 kg m^-3) compared with that of sapwood (758.9 kg m^-3) contributed to these differences. In terms of
anatomy–property relationship, fibre length was the only anatomical trait which correlated with all measured
properties and so density correlated with mechanical properties. Apart from modulus of elasticity (MOE)
in sapwood having high predictive power, no other significant regression equations were observed for both
sapwood and heartwood properties. Regression analyses showed that density alone was a poor predictor.
Sapwood properties were mainly influenced by tissue proportions, whereas heartwood properties, by fibre
dimensions and vessel.