%0 Journal Article
%T Effect of Density on the Natural Resistance of Ten Selected Nigerian Wood Species to Subterranean Termites
%A Iacob Mayowa OWOYEMI
%A Dauda Ishola ALIYU
%A Samuel Oluyinka OLANIRAN
%J Pro Ligno
%D 2013
%I Editura Universitatii Transilvania din Brasov
%X The effect of density on the natural resistanceof ten selected Nigerian wood species to subterraneantermites was investigated. Wood samples obtainedfrom mixed-conversion boards were used such that thesamples contained both sapwood and the heartwood.They were sawn to 35¡Á35¡Á450mm stake and dried at103 ¡À20C till a constant weight was achieved. Densityof the selected wood species was determined. Basedon the observed average density, the wood specieswere classified into high, medium or low density.Graveyard test method was used to assess the naturalresistance of the samples on a site dominated byMacrotermes sybhylinus, a family of subterraneantermites. Weekly visual observations of the stakeswere taken as specified in ASTM D3345-80 Standardsfor 24 weeks. The wood samples were withdrawn atthe 24th week of exposure to termites and weight lossdue to termites¡¯ attack was estimated. Result obtainedshowed the relationship between wood density, weightloss and the ASTM ratings. A strong but negativecorrelation (R2= -0.70) existed between weight lossand wood density while a strong positive correlation(R2=0.83) existed between ASTM values and wooddensity. These results indicated that wood species inthe high density class had a better resistance totermites¡¯ attack. The influence of mixed conversion onthe resistance of wood species to subterraneantermites was also reported, since it is the mostcommon method of conversion in the Nigeriansawmills. The sapwood of high density species are notdurable as revealed in the study thus the preservativetreatment is imperative for long service-life.
%K subterranean termites
%K wood density
%K natural resistance
%K weight loss
%K graveyard test
%U http://www.proligno.ro/en/articles/2013/1/owoyemi_full.pdf