The effect of leaf phenology of overstory trees on the reproductive success of an understory shrub, Staphylea bumalda DC

The effects of the leaf phenology of canopy trees on the reproductive success of an entomophilous, self-incompatible shrub, Staphylea bumalda DC. were examined in a deciduous broad-leaved forest in northern Japan. The amount of light reaching a particular understory shrub from spring to early summer was determined by the leafing date of surrounding canopy species. Variation in leafing date of canopy species affected flower and fruit production by the understory shrub. These results suggest that reproductive success of understory shrubs depends in part on the leaf phenology of canopy trees.Key words: phenology, deciduous broad-leaved forest, fruit set, resource limitation.