XVI International Botanical Congess
We examined shifts in fruit types, fleshy vs. non-fleshy, in relation to niche shifts, in 50 evolutionary lineages of temperate plants. Each lineage consisted of a sister-group pair of fleshy vs. non-fleshy fruited taxa, and their outgroup. Two niche dimensions were used, based on habitat characteristics, open to closed vegetation, and spatial predictability of disturbance regimes, assumed to reflect the regeneration niche. Results suggest that fleshy fruits are associated with closed habitats where safe sites are spatially unpredictable. A trend was found that shifts from non-fleshy to fleshy fruits are associated with niche shifts to closed habitats. Analyses of phylogenetic patterns are weak tests of process hypotheses, but we suggest the role of evolutionary constraints may have been overestimated in studies of seed dispersal systems.