Anatomical, physical and mechanical characterization of the wood of three eucalyptus species: E. camaldulensis Dehn, E. cladocalyx and E. gomphocephala

Abstract

Eucalyptus represents the second largest tree plantation in Algeria after Aleppo pine. However, the valorisation of its wood as lumber and wood products remains unsatisfactory. This study investigates the anatomical, physical and mechanical properties of three eucalyptus wood species (E. camaldulensis Dehn, E. cladocalyx, and E. gomphocephala), which are 35 years old. The obtained results showed that the wood of E. gomphocephala and E. cladocalyxare classified in the high-density category, while the wood of E. camaldulensis is in the medium-density category. The E. cladocalyxwood exhibits strong shrinkage in the volumetric, radial, and tangential directions. Whereas the wood of E. camaldulensis and E. gomphocephalapossesses strong volumetric shrinkage, and mean radial and tangential shrinkages. The wood of E. cladocalyx has lower average values for fiber length, fiber width, lumen diameter, and cell wall thickness, while E. camaldulensis wood exhibits higher average values for both fiber length and lumen diameter, and E. gomphocephala wood has greater average values for both fiber width and cell wall thickness. Moreover, the E. cladocalyxwood possesses the greatest bending strength and hardness, and the lowest modulus of elasticity in flexure and compression strength. Whereas, E. camaldulensis wood has the highest compression strength, and E. gomphocephala wood has the highest modulus of elasticity in bending. In addition, the bending strength, compressive strength, and hardness correlate positively with the wood density at 12% moisture content for three eucalyptus species. There are significant differences (P < 0.05) between the average values of the measured parameters for wood of three eucalyptus species. The results of this study can be used in the field of paper industry, timber structures, and industry of furniture and wood.