The genetic diversity of forest tree species in French Guiana

The reproductive phenology of six tree species, Dicorynia guianensis , Vouacapoua americana , Eperua grandiflora , Carapa procera, Virola michelii and Chrysophyllum sanguinolentum, has been monitored in the Paracou stands over several years. A large variation of flowering rates exists among the species and from year to year. The tallest trees bloom and fruit more frequently than the smallest. The allozyme analysis of parent trees and progenies showed that the studied species are largely outcrossed. However, the individual outcrossing rate is variable among both trees and years in mixed mating species. Although the reproductive success of a logged population can be affected by the loss of effective reproductive trees, changes in flowering pattern, inbreeding and a decrease in seedling viability, impacts of silvicultural treatments were found only in C. procera . This information can be of great interest for the forest manager who must maintain a minimal number of reproductive trees to ensure the regeneration of logged stands.