Phenology of neotropical pepper plants (Piperaceae) and their association with their main dispersers, two short‐tailed fruit bats,Carollia perspicillataandC. castanea(Phyllostomidae)

Abstract

To relate differences in phenological strategies of a group of closely related plants to biotic (pollinators, dispersers) and abiotic (water, light) factors, we studied leafing, flowering, and fruiting phenology of 12 species ofPiper(Piperaceae) in a neotropical lowland forest in Panama for 28 months. We asked howPipermay partition time and vertebrate frugivores to minimize possible competition for dispersal agents. Based on habitat preferences and physiological characteristics we discriminate between forestPiperspecies (eight species) and gapPiperspecies (four species). ForestPiperspecies flowered synchronously mostly at the end of the dry season. GapPiperspecies had broader or multiple flowering peaks distributed throughout the year with a trend towards the wet season. Both groups ofPiperspecies showed continuous fruit production. Fruiting peaks of forestPiperspecies were short and staggered. GapPiperspecies had extended fruiting seasons with multiple or broad peaks. Both groups ofPiperspecies also differed in their time of ripening and disperser spectrum. ForestPiperspecies ripened in late afternoon and had a narrow spectrum consisting mainly of two species of frugivorous bats:Carollia perspicillataandC. castanea (Phyllostomidae). Fruits of gapPiperspecies, in contrast, ripened early in the morning and were eaten by a broader range of diurnal and nocturnal visitors, including bats, birds, and ants. We conclude that the differences in flowering phenology of forest and gapPiperspecies are primarily caused by abiotic factors, particularly the availability of water and light, whereas differences in fruiting patterns are mostly influenced by biotic factors. The staggered fruiting pattern of forestPiperspecies may reflect competition for a limited spectrum of dispersers. The long and overlapping fruiting periods of gapPiperspecies are associated with a larger spectrum of dispersers and may be a strategy to overcome the difficulty of seed dispersal into spatially unpredictable germination sites with suitable light conditions.