Physical and Mechanical Strength Properties of Resin Tapped Pinus caribaea Timber

Resin tapping on Pinus caribaea Morelet (P. caribaea) is an activity that is proven to yield multiple economic benefits to pine growers. However, there is uncertainty as to whether extracting gum resin from P. caribaea trees compromises its timber strength properties for structural applications. In this study, the effects of resin tapping on the basic density and strength properties of timber from P. caribaea of different ages (one, three, and five years) were investigated. Tests were done on small, clear specimens from P. caribaea trees whose resins were tapped, with control samples obtained from an untapped tree. The samples were prepared using the British standard (BS 373:1957) and tested for their basic density, modulus of elasticity, modulus of rupture, shear strength parallel to grain and compressive strength parallel to grain test following the American Standards Testing Methods. The chemical composition of turpentine tapped from the trees was determined using gas chromatography/mass spectrometry. The results showed that basic densities and strength properties of P. caribaea timber tended to increase with an increase in the age of the resin tapped trees, which were significantly different from the samples of the untapped tree (P<0.05). These results suggest that resin tapping of P. caribaea using the Chinese method does not have negative effects on the strength properties of its timber. However, further studies are required to understand the effects of resin tapping on timber properties, especially for P. caribaea trees that are tapped for more than five years.