Natural durability of four TunisianEucalyptusspp. and their respective compositions in extractives

Eucalyptustrees have been adapted to the Tunisian climate. Now, they need to be economically valued. TunisianEucalyptushave great technological properties allowing us to use them as wooden material. However, there is large variability in the natural durability between heartwoodEucalyptusspp. The wood sustainability assessment provides reliable parameters to predict the service life of wood-based products. This study aimed to evaluate the wood deterioration of four North Tunisian fast-growingEucalyptusspp. (Eucalyptus maidenii,Eucalyptus saligna,Eucalyptus camaldulensisandEucalyptus gomphocephala) exposed to basidiomycetes (Coniophora puteanaandTrametes versicolor) and termite (Reticulitermes flavipes) attacks. Among the fourEucalyptuswoods,Eucalyptus gomphocephalapresents the highest decay and termite resistance. The fourEucalyptuswood species are classified as very durable against fungal degradation and durable against termite attacks, expect forEucalyptus salignawhich is classified as sensible against termites. The natural durability ofEucalyptusseems to be mainly caused by extractives, and a lot of compounds are involved. Antifungal and anti-termite properties of these compounds were put in perspective with the natural durability of wood. Gas chromatography-mass spectrometry (GC-MS) analyses highlighted thatEucalyptusdurability is mostly governed by gallic acid, fatty acid glycerides, fatty acid esters, phenolic compounds, sitosterol, catechin and ellagic acid.