Evaluation of Physical and Mechanical Properties and Durability of Wood in Traditionally Used Trees in Shiiba Village, Miyazaki Prefecture

Abstract

In Shiiba Village, Miyazaki Prefecture, people have used many trees growing in their living area for their traditional life. We interviewed four elder informants who were expert in wood handling on wood physical and mechanical properties and durability in commonly used trees. The informants discriminated 99 tree species empirically and evaluated their toughness, cleavability, warping, checking, abrasion resistance, hardness, machinability, combustibility and durability. Overall the highest rated species were Torreya nucifera and Sciadopitys verticillata, and the next-best species were Taxus cuspidata and Zelkova serrata. On average, coniferous species were evaluated better than hardwood species, and in hardwood, the arbor trees were evaluated better than shrubs. Air-dry density from previous literature was correlated with empirical toughness, machinability, cleavability, hardness, abrasion resistance and combustibility. Brinell hardness in the literature was correlated with empirical hardness, and decay resistance in the literature was correlated with empirical wood decay and termite resistance.