Effect of permeability and extractives on the decay rate of southern pine sapwood in above grund exposure
D D Nicholas, T Schultz, L Sites, D Buckner
The effects of wood permeability and hydrophilic and hydrophobic extractives on the decay rate of southern pine sapwood in above ground exposure were investigated. Permeability was determined by water sorption measurements, and the effect of extractives was studied by pre-extracting the test samples prior to outdoor exposure using water to extract hydrophilic extractives or sequential methanol/cyclohexane extractions to remove hydrophobic extractives. Initial water permeability of the wood prior to outdoor exposure was highly correlated to decay rate, with the more permeable samples decaying more rapidly. Removal of the hydrophilic extractives prior to exposure decreased the decay rate, but the effect was not statistically significant at the 0.05 level. Conversely, removal of the hydrophobic extractives significantly increased the rate of decay, even though it had no effect on the initial water permeability.