a b s t r a c t The seed dispersal system of Attalea geraensis (Arecaceae), an acaulescent palm, was investigated during one year in two Cerrado fragments in the state of Sa˜o Paulo, southeastern Brazil. A. geraensis had inflorescences and infrutescences throughout the year. Two scatter- hoarding rodents (the spiny rat, Clyomys bishopi and agoutis, Dasyprocta azarae) were identified as seed predators/dispersers, able to move seeds up to 30m from the palms, although most of the fruits (57.5%) were dispersed less than 2 m. The removal rates were high and after 20 days, 97.2% of the fruits were removed. Fruit fate was not related to fruit mass, length and diameter. The application of Morisita’s index showed a more clumped distribution of adults in the smaller fragment, probably because of the absence of agoutis. Higher seed removal by rodents in the large Cerrado remnant may decrease seed predation by beetles. ª 2007 Elsevier Masson SAS. All rights reserved. 1. Introduction Seed dispersal is a central demographic process to plant populations (Harper, 1977; Jordano, 2000; Levine and Murrell, 2003). Seed dispersal curve can set if seedlings will be more or less aggregated and whether they will reach or not favourable patches (Janzen, 1970; Barot et al., 1999a). Therefore, seed dispersal is related to demographic parameters, such as seed or seedling survival (Barot et al., 1999b). In tropical regions, animals are the main seed dispersers of most plants and their foraging behavior may have strong effects on plant distribution (Jordano, 2000). In Cerrado, a savanna-like vegetation, the most common dispersal mode is zoochory, which can involve up to 68% of all woody species (Gottsberger and Silberbauer-Gottsberger, 1983; Vieira et al., 2002). One of the most common plant families in the Cerrado, in terms of individuals, is the Arecaceae. The seed dispersal system of the Arecaceae is chiefly zoochoric (Zona and Henderson, 1989), with the seeds representing a very important component of the diets of mammals, especially in periods of fruit scarcity (Terborgh, 1986; Peres, 2000; Silvius, 2002). The importance of palms may be even higher in highly seasonal ecosystems, such as savannas. In the Cerrado, peak fruit production has been recorded between November and February, the most * Corresponding author. Laborato´ rio de Fisiologia Vegetal, Departamento de Botaˆ nica, Universidade Federal de Minas Gerais (UFMG), Avenida Antoˆ nio Carlos, 6627, Pampulha, 31270-901 Belo Horizonte, MG, Brazil. E-mail address: bonjorne@gmail.com (L. Bonjorne de Almeida). available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/actoec1146-609X/$
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