NATURAL REGENERATION OF RAIN-FOREST IN FRENCH-GUYANA - SPATIAL-DISTRIBUTION OF 3 SPECIES, QUALEA-ROSEA AUBLET, EPERUA-FALCATA AUBLET, SYMPHONIA-GLOBULIFERA LINNAEUS F

A natural regeneration survey concerning a systematic sampling of 1% of the area was carried out from 1986 to 1988 on 33 species from the French Guyana rainforest in the Paracou sylviculture and research area. The present study has focused on spatial distribution modeling of 3 species: Qualea rosea Aublet, Eperua falcata Aublet and Symphonia globulifera Linnaeus f. Abundance and dispersion parameters were as follows: seedling density, relative precision, dispersion index. The latter showed the presence of clusters. Two mathematical methods were applied for spatial structure (variograms and non-parametric indices). Three different patterns were found: tight agregates, loose agregates and patches. These structures were related to mature tree distribution. It was found that interaction between mature trees and young seedlings could lead to partial mortality of seedlings. Species distribution was also related to environment, particularly topography and frequency of gaps. The patch structure observed for Eperua falcata Aublet corresponded to the rapid "turnover rate" focused on the poorest sites.