Assessment of genetic diversity of economically and ecologically important tropical tree species of Central America and the Caribbean:
Implications for conservation, sustainable utilization and management

Logging significantly decreased the genetic diversity of mahogany populations (Swietenia macrophylla) from Central America. Thus, it is important that logging within the remaining mahogany populations is strictly controlled, or valuable genetic resources will be lost. Results of this project submitted to government committees have contributed directly to the conservation of this species and mahogany species are now protected in Costa Rica and Nicaragua where further cutting is prohibited.

Populations of Spanish cedar (Cedrela odorata) from the Atlantic regions of Costa Rica were genetically distinct from those from Pacific regions. Future conservation strategies should seek to conserve in situ populations from both regions of the country.

The density of Tabebuia heterophylla trees in natural populations significantly influenced levels of interbreeding between trees. It was also found that outcrossing rates differed significantly on different sides of the canopy of the same tree. Thus the species has the capacity to reproduce under both high and low density conditions, and has consequences for the reproductive success of the species in fragmented populations. This information led to the design of an indoor seed orchard producing seed of superior genetic quality.

Populations of Tabebuia from the northern islands of the Caribbean are more genetically diverse than those from southern islands. Results indicate that there is little geneflow between islands, which appear to behave as isolated units. Thus any conservation strategy should treat populations from each island as separate management units. The results obtained have already inspired concrete actions to preserve genetic diversity and additional genebank collections have been made.