NATURAL DURABILITY OF SOME HARDWOODS IMPORTED INTO KOREA FOR DECK BOARDS AGAINST DECAY FUNGI AND SUBTERRANEAN TERMITE IN ACCELERATED LABORATORY TESTS

This study evaluated the natural durability of seven imported hardwoods Bangkirai (Shorea laevis), Burckella (Burckella.), Ipe (Handroanthus.), Jarrah (Eucalyptus marginata.), Kempas (Koompassia malaccensi), Malas (Homalium foetidum) and Merbau (Instia) used for deck boards against decay fungi (Fomitopsis palustris, Gloeophyllum trabeum, Trametes versicolor, and Irpex lacteus) and the subterranean termite (Reticulitermes speratus kyushuensis) in accelerated laboratory tests. Ipe, Jarrah, and Merbau were very durable to fungal attack, with performance comparable to ACQ-treated wood. Bangkirai, Burckella, Kem-pas, and Malas were classified as durable or moderately durable, depending on the fungal species tested. All wood species except for Merbau were highly resistant to termite attack. Termite resistance was similar to ACQ-treated wood. Merbau showed somewhat less than all other species but still significant termite resis-tance. These results indicated that selected naturally durable hardwood species could inhibit fungal and termite attacks as effectively as ACQ treatment. The natural durability of wood species tested in this study is most likely due to the biocidal extractive content of the wood.