PATTERN, ADAPTATION, AND CONSTRAINT IN FRUITING SYNCHRONY WITHIN VERTEBRATE-DISPERSED WOODY-PLANTS

Patterns of within-plant fruit ripening synchrony were examined for 12 woody species in SE Michigan. Flowering was more synchronous than fruiting in all individuals tested, suggesting that flowering may constrain fruiting synchrony, but flowering and fruiting synchrony were not positively correlated among individuals of Amelanchier arborea or Prunus virginiana and only weakly correlated among 9 species, indicating that selection may act independently on the 2 phenological events. Contrary to the frugivore availability hypothesis, summer fruiting species were not less synchronous than autumn fruiters. Species in which fruits undergo a dual color change during ripening tended to have more asynchronous ripening, but this pattern was confounded by a phylogenetic pattern. Two species in the Ericaceae had the most asynchronous flowering and fruiting; among the remaining species the strongest pattern was that trees were more asynchronous than shrubs. -Author