Bwa-yo - Société Audubon Haiti

19 Wood Properties and Energy Values
The most widely used product of trees is wood. Though many of the tree species
in Haiti are harvested indiscriminately during land-clearing activities, others are
cultivated because of their wood quality. General utility species combine adequate
form with structural strength and durability. Those harvested for high-quality
craftsmanship are selected for their combination of beauty, working properties and
stability. The best charcoal species are generally those with the densest wood, with
some species achieving high densities at remarkable growth rates. As wood
properties vary, so does the wood quality that determines the species' usefulness to
society.
The information summarized below is arranged in Tables 19.1 and 19.2,
compiling the available information on wood properties and energy values. Each table
is arranged alphabetically by species and should be a helpful guide to the diversity
found in Haiti. Introduced species are included for those that have become naturalized
in Haiti.
Wood Properties: Two-thirds of the tree families and genera known to occur in Haiti
are represented in Table 19.1 for major wood property categories. Data is unavailable
or incomplete for many of the lesser-known and -utilized species, some of which play
an important role in local areas of the country. The information has been compiled
from the literature for the more common, internationally known species. The literature
includes Commercial Timbers ofthe Caribbean by F. R. Longwood (1971); Common
Trees of Puerto Rico and the Virgin Islands, Volume I by E. L. Little, Jr. and F. H
Wadsworth (1964) and Volume II by E. L. Little, Jr., R. O. Woodbury and F. H.
Wadsworth (1974); and Tropical Timbers of the World by M. Chudnoff (1984).
Previously unpublished data from Haiti has been reviewed to broaden the information
base.
Wood characteristics include sapwood (8) and heartwood (H) color, grain, odor,
texture, and other characteristics that describe the wood. Specific gravity is a measure
of wood density calculated as the ratio of oven-dry weight to green volume. Specific
gravity should be stated as a range of values, though it is not uncommon that only an
average value is published in the literature. Durability is a measure of the resistance
of the heartwood to decay fungi, not necessarily to insect attack. It is assumed that the
wood is in contact with the soil. Shrinkage values ate given for radial (R), tangential
(T), and volumetric (V) changes in dimension, as a percentage, from green to
oven-dry conditions. Generally, woods with low shrinkage values exhibit higher
dimensional stability after seasoning. Hardness is a measure of resistance to
indentation and ability to withstand abrasion. Janka side hardness is the pressure, in
pounds, required to embed a 11.3 mm diameter steel ball to a depth of 5.6 mm on the
side-grain of wood dried to 12% moisture content (Chudnoff, 1984).
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