05Seed Dispersal Ch 5

Seed dispersers play a key role in the ecology and evolution of fleshyfruited plants; especially in tropical forests where from 70% to 90% of all woody species are dispersed by vertebrates (Fleming et al., 1987; Jordano, 2000). Local plant communities with a range of fruit types are assembled under a variety of selection pressures and historical effects. Analyses of community-level variation in fruit traits indicate that they also reflect variations in the composition of the main seed dispersers in the animal community (Mack, 1993; Fleming et al., 1987; Fleming, 1991, 2005). Fruit size is one of the main traits selected by frugivorous vertebrates and has multiple potential influences on seed mass, and therefore on germination and seedling survival (Jordano, 1995). Not unexpectedly, large-scale, community-wide comparisons of fruit traits have reported variation in traits related to fruit size paralleling changes in the frugivore community (see Fleming et al., 1987; Jordano, 2000; Herrera, 2002, and references therein). At a community level, the interactions among plants and frugivores often show high diversity and low specificity (Jordano et al., 2003; Silva et al., Chapter 26, this volume; Forget et al., Chapter 1, this volume). In this context, large-scale comparisons between areas with different faunal assemblages have been widely used to investigate local co-adaptations between plants and frugivores (Snow, 1980; Fischer and Chapman, 1993; Voigt et al., 2004) and are a powerful tool in analyses of ecological convergence at the community level (Schluter, 1988; Corlett and Primack, 2006). However, comparative analyses based on extant communities implicitly ignore the fact that these mutualisms build up on highly