Some Physical … Elaieb et al.
J. Chem. Bio. Phy. Sci. Sec. B, February 2017 – April 2017, Vol. 7, No. 2; 537-549.
During the colonial period, the Tunisian forest area significantly decreased by human and climatic
aggressions. Indeed, the Tunisian forest area decreased from 1.096 million ha to 844.000 ha between1912
and 1952 illustrating 23% loss during 40 years1.
In a reforestation program with the help of the Food and Agriculture Organization (FAO) after the
independence, quite few Eucalyptus species were planted in different areas of Tunisia. In order to test
their compatibility to climate and soil, many arboreta were settled 2. The objective of this project at the
beginning was for pulp production but the wood produced was then reoriented for industrial use such
particle board MDF and energy. These species were very well adapted to the Tunisian conditions 3,4. In
recent decades, Eucalyptus trees are increasingly used for their essential oils 5 and for honey production.
Nevertheless, in Tunisia, the valorization of Eucalyptus wood remains under estimated and very little
research has been done 6. However the Eucalyptus wood becomes a subject of interest as raw material
for composite panels in many tropical and subtropical countries including Thailand, Chile, Brazil
and Malaysia 7.
According to the FAO, the reforestations based on Eucalyptus covers a surface of 28535 ha in pure
stands and 39000 ha mixed with other species, with an estimated annual Eucalyptus wood production of
120.000 m32. These great efforts of reforestation were undergone in all Tunisia in order to overcome the
land degradation and improve the forest production.
In order to fill the lacks of information concerning Eucalyptus wood properties, the aim of this study is to
characterize the physical (specific gravity, dimensional changes, Fibers Saturation Point) and mechanical
properties (hardness, compression and bending strengths) of two Eucalyptus wood species: Eucalyptus
loxophleba and Eucalyptus salmonophloia, from the arboretum of El Hanyalocated near Sousse in the
east and the semi-arid climate (400 mm rainfall). The results may be useful in reforestation objectives
and forest management strategies.
2. MATERIALS AND METHODS
2.1. Trees selection and sampling:
Eucalyptus loxophleba and Eucalyptus salmonophloia wood species of 50 and 53 years old respectively
were chosen, in this study, to estimate the physical and mechanical properties of Tunisian reforestation
Eucalyptus wood species. 3 trees of each wood species were collected in the “El Hanya” arboretum in the
Sousse region (35°49′ N, 10°38′ E). According to Oger and Lecerq8, the sampling for the determination
of physical and mechanical properties is optimal when the number of sampled trees is comprised between
1 and 5, and should be healthy, free from defects and alteration and have an almost perfectly straight.
The studied site is characterized by a semi-arid bio climate, an annual rainfall of 327 mm/year and
average annual temperatures varying from 14.9 °C to 18.5 °C. The average of maximum temperature of
the warmest month can reach more than 35 °C and the average maximum of the coldest month is around
4 °C. The soil is poorly developed in coastal dunes and leached brown forest in the mountains 9.
2.2. Physical properties
2.2.1. Moisture content, specific gravity and shrinkage: To perform physical and mechanical tests, a
disk 50 mm thick was cut at breast height from each selected tree (Figure 1).The samples were free of