ibclogo XVI International Botanical Congess


Abstract Number: 4260
Session = 8.10.1


EVOLUTION OF ANIMAL-DISPERSED TEMPERATE PLANTS: CONSTRAINTS ANDNICHE SHIFTS


O. Eriksson and K. Bolmgren, Dept. of Botany, Stockholm Univ., SE-106 91 Stockholm, Sweden


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.


HTML-Version made 7. July 1999 by Kurt Stüber