Durability of five native Argentine wood species of the genera Prosopis and Acacia decayed by rot fungi and its relationship with extractive content.

The natural durability of four Argentinean species of Prosopis and one of Acacia was evaluated in laboratory tests, according to European standards, using three brown rot and one white rot fungi. These tests were complemented by assessing the wood chemical composition. All the species were from moderately slightly durable to very durable (classes 4-1), and in all cases the heartwood was the most resistant to fungal attack. Chemical extractives content (organic, aqueous, tannic and phenolic) was higher in the heartwood. However, species durability was not related to extractive contents nor with wood density. Instead, it is possible that extractives could contribute to natural durability in different ways, including the effects related to the antioxidant properties of some of them.

Argentinean native wood species: Physical and mechanical characterization of some Prosopis species and Acacia aroma (Leguminosae; Mimosoideae).

One of the problems in marketing the wood of Prosopis and Acacia is the lack of standardization of its qualities. The aim of this paper was to obtain a preliminary detection of some properties of the wood of four species of the genus Prosopis and one species from Acacia grown in Argentina. To accomplish this objective, the content of extractives and some physical and mechanical characteristics were analyzed. The density rho(12) of all the species indicates that these woods range from heavy to very heavy (>or=0.69g/cm(3)). The total volumetric shrinkage values are low, less than 10%, for all species. The parallel compression strength and the shear strength for all the species indicate a very resistant wood (>or=46.93MPa and >or=18.35MPa, respectively). Brinell hardness was higher than 5kg/mm(2) in all cases. The species with less content of extractives is P. ruscifolia (approximately 9% of anhydrous mass) whereas A. aroma was the one with the greatest content (approximately 25% of anhydrous mass in the heartwood).