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. Ciri anatomi kayu gubal dan kayu teras Pseudolachnostylis maprounaefolia dikaji dan dihubungkaitkan dengan ciri fizikal dan mekaniknya. Sampel diambil secara rawak daripada lima batang pokok tanpa mengira kedudukan pada pokok. Kajian ini bertujuan untuk menentukan ciri mekanik P. maprounaefolia, satu spesies kurang digunakan dari Mozambique, dan membandingkannya dengan spesies kayu yang terkenal bagi menilai kegunaan akhirnya serta menyelidiki hubung kait antara anatomi dengan ciri kayu menggunakan korelasi dan regresi. Ciri anatomi digunakan untuk meramal ketumpatan dan ciri mekanik manakala ketumpatan digunakan untuk meramal ciri mekanik. Terdapat perbezaan yang jelas antara ketumpatan dengan prestasi mekanik kayu gubal dan kayu teras. Perbezaan ini disebabkan oleh ketumpatan yang lebih tinggi pada kayu teras (1023.7 kg m-3) berbanding kayu gubal (758.9 kg m-3). Dari segi hubung kait antara anatomi dengan ciri kayu, panjang gentian merupakan ciri anatomi tunggal yang berkorelasi dengan semua ciri yang dinilai. Jadi ketumpatan be