Seed distribution, plant demography and spatiotempporal heterogeneity ofthe environment, by their interactions, determine the ecological and evolutionary landscape inhabited by an organism. A simple hypothesis that quantitatively links these three areas of evolutionary ecology in a new way is proposed. A model of plant population dynamics and forest dynamics predicts that ant-dispersed species will be characterized by a slower rate of demographic change during gap-phase regeneration than bird-dispersed species. Selection for these divergent seed dispersal syndromes (local dispersal vs. long-distance dispersal) will be investigated in a family of understory herbs by comparing changes in demography, light environments and disperser assemblages during gap-phase regeneration. Preliminary data confirmed that the Costa Rican Marantaceae provide an excellent opportunity for the study. The static distribution of plants in forest light habitats was significantly associated with dispersal syndrome, suggesting differences in their dynamic response to intermediate habitats during gap-phase regeneration.
