Variation in natural durability of seven Eucalyptus grandis x Eucalyptus urophylla hybrid clones

Abstract

Programs aimed at developing clones of hybrid trees are commonly established in Brazil to meet the demands of various forest-based industries. These programs have continually improved the quality of eucalyptus wood, which has the potential to reduce deforestation by lowering demand for other high-value species. This is particularly true in the lumber market, but little is known about the resistance of eucalyptus wood to biodegradation. This study evaluated variation in natural resistance of seven Eucalyptus grandis x Eucalyptus urophylla hybrid clones to decay by four wood-rot fungi and feeding by subterranean termites. In addition to mass loss, the relationship between density and durability was also examined. Results showed significant differences among the various clones in density as well as in resistance to fungi and termites, although none of the clones were resistant to Trametes versicolor. Mass loss in wood specimens ranged from 9 to 61 percent in the fungal tests and from 6.9 to 20.5 percent in termite tests. Average density measurements among clone groups were calculated to be between 461 and 659 kg/m³. Among the clones, five of the seven showed resistance to fungal decay and termite feeding, which was correlated with increased wood density. Based on these results, we suggest that certain clones, particularly those with higher density values, may be considered for production of various lumber products.

Citation

Franca, F.J.N.; Franca, T.S.F.A.; Arango, R.A; Woodward, B.M.; Vidaurre, G.B. 2017. Variation in natural durability of seven Eucalyptus grandis x Eucalyptus urophylla hybrid clones. Forest Products Journal. 67(3/4): 230-235.