Stand structure, species diversity and regeneration of an endemic palm forest on the Seychelles

Abstract

The ‘Vallée de Mai’ on the island of Praslin in the Seychelles group is a World Heritage Site because of its unique forest vegetation dominated by the palm Lodoicea maldivica. However, despite its great conservation importance, the stand structure, species diversity and regeneration of this forest have not previously been studied. Moreover, the conservation value of the reserve is currently threatened by invading alien plants and limited regeneration of some native species. The species composition of the forest was studied in six permanent plots (1985 and 1998) and along seven trail transects (1997). To explain potential variation in tree regeneration, the light climate within all plots was investigated using hemispherical photographs. The results reveal little change in forest structure, species diversity and regeneration in the permanent plots over the 13‐year period, but some regeneration of most woody species, presence of some alien species and a relatively high species turnover. We found no significant influence of local light climate upon forest structure, species diversity or regeneration. Although the stand characteristics seem to be relatively stable, the permanent plots and transects should be monitored in order to detect future changes in stand structure and to optimize the protection of this unique forest reserve.

Dramatic changes in leaf development of the native Capsicum chinense from the Seychelles at temperatures below 24°C

“…The granitic islands are of Pre-Cambrian age (Miller and Mudie 1961) and, because of their long isolation, they are classified as 'Oceanic islands' although of continental origin (Baker and Miller 1963). The flora of the granitic islands of the Seychelles comprises many endemic species (Swabey 1970;Fleischmann et al 2005).…”

Conservation of oceanic island floras: Present and future global challenges

“…Such species may be less vulnerable to short-term demographic stochasticity, and their longevity and naturally low regeneration over long periods may result in underestimates of population viability where only adult tree counts are used for population estimates (e.g. Fleischmann et al, 2005). However, life history and demography vary considerably among oceanic island plants: not all are slow-growing and long-lived (e.g.…”

Sustainable harvesting of coco de mer, Lodoicea maldivica, in the Vallée de Mai, Seychelles

“…The first, a re-survey of six permanent monitoring plots (20 m × 20 m; see Fleischmann et al, 2005) showed that over a period of 24 years eight of 35 L. maldivica died, resulting in a annual mortality rate of ca. 1%.…”

“…As an estimate of fecundity (annual contribution of each female palm to the next generation), we used data for 407 female trees in six permanent monitoring plots (Fleischmann et al, 2005) and along transects (total length 3.48 km) spanning the entire VM (Fleischer-Dogley, 2006). In the model, mean annual nut production (1.2 nuts/tree) was adjusted for germination success, loss due to harvesting and for the dioecious nature of the palm.…”