Important Trees of Haiti

Bwa Pie 19
Biomass Studies: Ehrlich (1985) developed total and fuelwood biomass tables for C.
arborescens, sampled from a stand oftrees located near Morne-a-Cabrit. The estimates
are based on diameter-at-breast-height (DBH) and stump diameter measurements.
Another set ofbiomass equations was developed on a drier site in the Northwest near
Nan Marron in 1990. The 5-year-old stand had a narrow stem diameter range from 3-7
cm. These equations estimate total and wood(> I cm) dry weights on the basis of stem
diameters measured at 0.3 m above ground level. The set of equations for C.
arborescens is given in Table 2.1.
Table 2.1 Equations used to estimate biomass components (kg dry weight) of C. arborescens
in Haiti.
COMPONENT REGRESSION EQUATION l R 2 DIAMETER SITE
RANGE (CM)
Total aboveground biomass 0.25(DBH)2 0.98 3.0-12.5 Morne-a-Cabrit
Usable wood weight 0.204(DBH)2 0.98 3.0-12.5 Morne-a-Cabrit
Total aboveground biomass 0.Q33hLd n 2 0.99 2.8-6.6 Nan Marron
Usable wood weight 0.027hLdn 2 0.99 2.8--6.6 NaI).Marron
1 DBH=Stem diameter at 1.3 m above ground level, in em. d =Stem diameter at 0.30 m above ground level, in em. h
=Total tree height, in m. n =Number of stems at 0.30 m above ground level.
Growth Performance: The oldest trials of C. arborescens were established by the FAO
project in the mid-I 970s. Later in the 1980s, several trials were established by the
USAID Agroforestry Outreach and AFII projects and the World Bank Projet Forestier
National. Table 2.2 compiles the growth rates and yield information available for several
of the trials. The species failed at the highest elevation site (Tranquille) as well as
on the coastal sites that receive severe drought, such as Cabaret and Jean Rabel.
However, Nan Marron is probably the driest site and the species is performing well,
being thesame small-leafvariety that is common in the area. The Haut Camp and Lapila
sites have an adequate rainfall distribution, but the soils are extremely shallow and
rocky. In contrast, the fastest growth occurs on alluvial, lowland sites such as Fauche,
near Grand Goave, and Roche Blanche, near Croix-des-Bouquets. Early height growth
of 2.5 m yr- 1 has been observed. The O'Gorman trial, located only 5 Ian east ofRoche
Blanche, is also an alluvial site, but with a combination ofless rainfall, poorer soils, and
perhaps a poorly-adapted provenance. Moortele (1979) indicates that the source of the
seed was from Grenier, a much higher (el. 800 m) and wetter location than the trial site.
Figure 2.10 summarizes the height growth ofthe species in Haiti.
Tree Improvement: There are distinct varieties in the species that are adapted to a wide
range of growing conditions in Haiti. Farmers growing in moist and wetter sites prefer
the taller and faster large-leaf variety for timber wood; the small-leaf variety is adapted
.to shallow and rocky soils common to the dry regions ofHaiti under 1000 mm rainfall.
The first priority in the improvement ofthis species was to focus on the large-leafvariety
for the moist regions ofHaiti where the species is most developed as a timber tree.
The establishment ofseed orchards is the surest method to guarantee the harvest ofpure
large-leaf varieties and to achieve the uniformity in seedling performance that the
farmer is seeking.