Impact of location and forestry conditions on some physical and mechanical properties of northern Tunisian Pinus pinea L. wood

Abstract

Pinea pines have been used and cultivated for their edible pine nuts since prehistoric times. More recently, Pinus pinea L. has been introduced as an ornamental tree in Mediterranean regions, and is now often found in city parks and gardens. However, it has become naturalized outside North African cities to the point that it is now classified as an invasive species there. Its size (more than 15-20 m in height and 30- 40 cm in diameter) makes Pinus pinea a good candidate eco-resource for construction materials in Tunisia. The focus of this study was to analyze the effects of geographical location and forestry conditions on several physical and mechanical properties of Northern Tunisian Pinea pine wood. The Pinus pinea wood samples studied were collected from four different geographical locations, divided into 87 plots according to tree population density and soil fertility class. Density, shrinkage and moisture content were measured and mechanical tests were performed on each wood sample. Preliminary results showed that Tunisian Pinea pine wood has very good dimensional stability in relation to its density. However, the modulus of rupture (MOR) in bending and compression strength is lower than in other Tunisian softwood species, whatever the geographical situation and soil fertility. A linear regression analysis showed that only tree population density seems to have a significant impact on the variability of Pinea wood properties, except for dimensional stability and volumetric shrinkage. Our findings suggest that the growing population density of P. pinea trees is the most important forestry parameter determining its mechanical and physical wood material properties. It could therefore be of interest to improve forestry conditions to obtain better wood quality.