Characteristic of natural regeneration of Aucoumea klaineana (Pierre) in Mayombe rain forest, southern Congo.

This paper presents the analysis of ten natural regenerated stands of Aucoumea klaineana in native monodominant Aucoumea forest located in the Mayombe rain forest (southern Congo). The mean total density was 0.51 ± 0.15 m−2, the main crop density accounted for 46.12% of the total density, the stocking ranged from 18.02% to 78.10% and the spatial pattern was clumped in all stands. The natural regeneration showed a nearly continuous age distribution. The difference of height between consecutive age-classes indicates a high stability of the seedlings height positions. The upper stratum generally corresponds to the oldest seedling, some new individuals had established during late stages of the regeneration phase. Analysis of the saturated models suggested a different pattern in soils with sand content above and below 80%. The model developed showed a positive correlation between the establishment of successful seedlings and soil preparation, and predicts an increase in the number of main crop seedlings from 0.03 to 1.30 seedlings m−2 when soil preparation is made. On the contrary, grasses cover and mean height of hardwood species were negatively correlated with the density of main crop seedlings. Grasses, hardwood and Cecropiaceae species competition were the main factors that explained total density but only in soils with low sand content. Thus, vegetation-control treatments in regeneration areas are highly recommended. In precommercial thinning, the height position of tree could be used as an important criterion in the selection of the remaining trees. [ABSTRACT FROM AUTHOR]