Bwa-yo - Société Audubon Haiti

44 Fwenn
Height growth has never been observed to exceed 2 m yr- 1 for either species (see
Fig. 5.7 and Fig. 5.8). The fastest growth has been measured at the Fauche site (1.8 m
yr- 1 for S. glauca; 1.6 m yr- 1 for S. berteroana), with the average for the species close to
a meter per year. The oldest trial at O'Gorman in the Cul-de-Sac plain was measured at
9 years and showed a mean annual height increment of 0.5 m and stem-diameter increment
of 0.6 cm for S. berteroana. S. glauca exhibited height increments of 0.7 m and
stem-diameter increments of 0.6 cm in the same trial. However, the O'Gorman site is
not typical of the growing conditions where S. glauca is commercially exploited for
lumber. Fauche and La Jeune are typical sites where the native population is vigorous
and the species is regarded as a valuable shade and timber species. These trials should
be observed carefully to estimate the profitability of growing the species for timber.
Tree Improvement: The selection ofS. glauca provenances for superior wood properties
has been examined in Africa, based in part on seed collected in Haiti (Ergo and
Deschamps, 1984). A great deal of heterogeneity was found among the seed sources
throughout its native range in the Caribbean and Central America. Most variability was
attributed to genetic differences, indicating the potential oftree improvement within the
species.
Between 1988 and 1991, a selection ofsuperior phenotypes was conducted in areas
of Haiti where significant populations occur: La Jeune area of the Plateau Central,
Maniche area ofthe southwest, the Grand-Anse, and areas ofBainet and Jacmel. A total
of 79 plus trees were selected, ofwhich 35 trees were harvested for seed and propagated
for establishment in seedling seed orchards, progeny trials, and arboreta. The same
approach was employed for the endemic S. berteroana. Nine of 14 selected trees were
harvested and established in orchards and progeny trials. Some of the orchards of the
Table 5.1 Site and growth parameters of S. glauca var. latifolia trials in
Haiti.
SITE ELEVATION ANNUAL AGE SURVIVAL HEIGHT DBUZ
(m) RAINFALL (yr) (%) M.A.!.l M.A.I.
(mm) (m) (em)
Laborde 2 90 1875 1.0 92 0.5
La Jeune 400 1145 2.0 88 1.2
Paillant 600 1300 2.0 69 0.4
Tranquille 76-11 900 1450 2.9 41 0.2
Bombard 480 948 3.0 75 0.8 0.8
Fauche 1436 3.0 77 1.8 2.0
HautCamp 180 2280 3.0 82 0:4 0.5
Marmont 280 1450 3.0 48 0.9 0.8
Roche Blanche 130 1030 3.0 84 1.6 2.0
Terrier Rouge 20 1293 3.0 57 0.7 0.8
Lapila 2 350 1145 3.2 52 0.7 0.9
Lapi1a 1 350 1145 3.4 90 1.2 1.3
a'Gorman 76-10 70 830 5.3 85 0.9 0.8
a'Gorman 76-9 70 830 5.3 74 1.2 0.5
a'Gorman 76-6 70 830 9.0 41 0.7 0.4
Vaudreuil 75-1 55 830 10.0 53 1.0 1.2
I M.A.I. = Mean annual increment. 2 DBH =Stem diameter at 1.3 m above ground level.