Summary 1We examined among-and within-species effects of seed mass for seedling establishment from seed to 5 years of age in a field experiment at Paracou, French Guiana. 2 Six seeds of each of eight species were weighed and planted into each of 120 plots (1 m 2 ) throughout closed-canopy forest along 12 100-m transects in 1998. 3 We described the microhabitat of each planting site using principal components derived from measurements of light availability, soil moisture, carbon and nitrogen content, and soil phosphorus availability. Although both survival and relative growth rate (RGR) increased with increasing light availability, no other microhabitat variable significantly affected seedling performance. Nor did the magnitude of microhabitat effects on survival or RGR differ among species. 4 Larger-seeded species were more likely to survive from germination to 1 year as well as from 1 to 5 years of age. RGR for seedling height during the first year post-germination was not related to seed mass, but smaller-seeded species did grow slightly faster thereafter. Path analyses revealed that correlations between seed mass and performance were explained in part because larger seeds produced larger initial seedlings, which tended to survive better but grow more slowly. 5 We also analysed within-species effects of seed mass for the larger-seeded Eperua grandiflora and Vouacapoua americana (both Caesalpiniaceae). Larger seeds produced larger seedlings in both species, but larger seeds survived better only for Eperua . Larger seedlings grew more slowly in both species, but did not offset the early ( Eperua ) and later ( Vouacapoua ) positive direct effects of seed mass on RGR that may represent contrasting strategies for reserve deployment. 6 Our results demonstrate that seed size influences performance within and among species in part because of indirect effects of initial seedling size. However, we suggest that traits tightly correlated with seed mass at the species level, such as specific leaf area, leaf longevity and photosynthetic capacity, may also contribute to interspecific performance differences.

A review of literature on seed predation and dispersal by collared peccaries (Pecari tajacu) and white-lipped peccaries (Tayassu pecari) throughout the Neotropics, is provided. A synthesis of the results of 143 studies published between 1836 and 2003 is presented. The ecological implication of seed predation and dispersal by both peccary species, taking into consideration their interactions with 212 plant species are discussed. The different mechanisms of seed dispersal are summarized, and examined whether peccaries play a key role among frugivores by creating a bimodal rather than a typical leptokurtic seed shadow.

This paper discusses the interaction between plants and the rodents that scatterhoard their seeds (i.e. cache seeds individually or in small groups in numerous cache locations) can be viewed as a conditional mutualism that depends in part on two factors that can vary in time and space: (1) the relative abundance of seeds versus scatterhoarders (the seed:scatterhoarder ratio) and (2) the potential recruitment of seedlings that are not handled by scatterhoarders versus recruitment when seeds are handled by scatterhoarders. A simple conceptual model of how the outcome of the scatterhoarder-plant interaction depends on both the relative abundance of each partner and the challenges to recruitment faced by the plant is presented.

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