Portal de Periódicos da CAPES

Peuplement et phénologie des palmiers en forêt guyanaise (Piste de Saint Elie)

1989; Volume: 44; Issue: 2 Linguagem: Inglês

10.3406/revec.1989.5509

0249-7395

P. Sist,

Plant Diversity and Evolution

The palm community of the Piste de St-Elie rain forest, French Guiana, was studied from February 1986 to December 1987, in relation to soil drainage conditions and forest structure. Inventories were carried out on four 2 400-5 000 m2 plots (totaling 1.24 ha) representative of the edaphic conditions of the area (Table I). The minimum size of the area necessary to evaluate palm species richness was shown to be 2 000 m2 (Fig. 1). Within each plot every individual palm, whether seedling, juvenile or adult, was identified and enumerated. The characteristics of the most common species are described, and some of them figured on plates I to III. Eighteen species of palms were found in the 1.24 ha study area, a species richness similar to that of the eastern amazonian rain forest, but much smaller than that of central and western Amazonia. At the Piste de St-Elie, the highest density and lower diversity of palms were found on an hydromorphic soil, the reverse being the case on well drained soils (Tables IV and V). On each plot the community was dominated by a few species (Tables VI and VIII). The distribution of these dominant species was correlated with soil drainage conditions and forest structure (Tables VIII and IX). The phenology of the seven most common palm species was studied every second week (Table X), 30 adult individuals at least being marked on the plots and along 3 forest trails 1 000 to 1 500 m long. The adult stage was defined by morphological characters (Table II). The number of fruits, and the abortion rate of female flowers and fruits, was estimated (Tables X-XII). The pattern of flowering and of fruiting is clearly seasonal in all species (Fig. 3-5, 7-9), and three phenological models can be identified (Table XIII). Most species flower during the dry season (Fig. 10) and produce fruit during the rains (Fig. 11). However, Jessenia bataua subsp. oligocarpa has a different schedule, mast fruiting taking place at the end of the dry season, and occuring every two years because of an alternance of vegetative and reproductive phases (Fig. 5). Nevertheless, ripe palm fruits remain available throughout the year in the Piste de St-Elie rain forest.