Wood Densities of Mahoganies in Puerto Rican Plantations

Abstract

The wood density of mahogany is a critical determinant of its working properties and strength. The wood densities of the big-leaf and small-leaf mahogany are known principally from old-growth trees rather than from the plantation-grown trees now beginning to enter the market. The wood densities of their hybrid have not been reported. Wood density samples of heartwood of three trees each from six plantations of the two species and their hybrid (54 sample trees) were collected by auger across Puerto Rico. These species tended to be planted in somewhat differing rainfall regimes. Mean annual precipitation of the plantation areas ranged from 810 to 2800 mm yr⁻¹, and the plantation ages ranged from 16 to 59 years. The heartwood densities were analyzed and compared, using analysis of covariance and Tukey’s studentized range test. The class variable, species, and the continuous variable, mean annual precipitation, were significant, but age was not. The means and standard deviations for oven-dry heartwood densities of small-leaf mahogany (0.577 ± 0.059gcm⁻³) and the hybrid (0.546 ± 0.060gcm⁻³) were not significantly different from each other, but were significantly greater than those for big-leaf mahogany (0.470 ± 0.052 gcm⁻³