Journal of Tropical Ecology



Seed fate of two Sapotaceae species in a Guianan rain forest in the context of escape and satiation hypotheses


Stéphanie Chauvet a1c1, François Feer a1 and Pierre-Michel Forget a1
a1 Muséum National d'Histoire Naturelle, Département Ecologie et Gestion de la Biodiversité, UMR 8571 CNRS-MNHN, 4 Avenue du Petit Château, F-91800 Brunoy, France

Article author query
chauvet s   [PubMed][Google Scholar] 
feer f   [PubMed][Google Scholar] 
forget p-m   [PubMed][Google Scholar] 

Abstract

Seed removal by rodents was investigated for Manilkara huberi and Chrysophyllum lucentifolium in a French Guianan forest. According to the escape hypothesis, seed survival was expected to be greater in populations of low conspecific adult density, while on the contrary, under the satiation hypothesis, it was expected to be greater in populations of high density. The two plots under study showed opposite densities for the two studied tree species. Therefore, according to both hypotheses, seed survival at each plot was expected to be opposite between species. To assess seed fate, seeds were thread-marked in order to relocate them after removal and to determine whether they were consumed or scatterhoarded by rodents. Contrary to what was expected, our results showed that both M. huberi and C. lucentifoliumhad better survival in the same plot. This suggests that seed fate for both study species was not influenced by the density of conspecific adult trees, but was rather affected by other habitat characteristics, likely the global resource abundance. Variation in seed predation rates of both species seemed largely related to their respective fruiting period, while scatterhoarding rate seemed more affected by intrinsic seed characteristics.

(Accepted December 2 2002)


Key Words: Chrysophyllum lucentifolium; escape hypothesis; French Guiana; Manilkara huberi; rodents; satiation hypothesis; scatterhoarding; seed dispersal; seed predation.

Correspondence:
c1 Corresponding author. Present address: Umeå University, Department of Ecology and Environmental Science, SE-901 87 Umeå, Sweden. Email: chauvet_st@hotmail.com