Mating system of a Guiana tropical forest tree, Dicorynia guianensis Amshoff (Caesalpiniaceae)

Mating system of a Guiana tropical forest tree, Dicorynia guianensis Amshoff (Caesalpiniaceae). The mating system of a tropical rain forest tree Dicorynia guianensis (Caesalpiniaceae) was studied using allozyme analyses and the multilocus mixed mating programme of Ritland. Open-pollinated progenies were collected in 1993 and 1995 on logged and control plots of a sylvicultural trial in Paracou (French Guiana). D. guianensis exhibited a high outcrossing rate (trn) for the global population which was remarkably stable in spite of a high variation of the flowering rate between the 2 years. The individual outcrossing rates (ti) varied, but significant relations were not found between tm or ti and the density of flowering. Heterogeneity of pollen clouds existed at the patch and individual level, but not at the population level. Spatial autocorrelation statistics were used to investigate spatial structures of pollen clouds: there were not any significant spatial correlation. Pollen dispersion distances of up to 190 m were detected with rare allozymes. There was no significant difference between outcrossing rate when computing separate estimates for trees located on logged plots and control plots. (C) Inra/Elsevier, Paris