Reproductive biology and flower-visitor interactions of two bromeliad species from the Brazilian Atlantic Forest

Abstract

Background and aims – The Bromeliaceae family has great importance in the maintenance of neotropical communities. In the Brazilian Atlantic Forest, bromeliads are among the major groups responsible for maintaining the local flora and fauna and participate in important ecological interactions with insects, anurans, and hummingbirds. This work reports on aspects of the reproductive biology and the interactions between two endemic bromeliad species from the Atlantic Forest (Aechmea bruggeri and Quesnelia indecora) and their floral visitors to assess the impact of these relationships on the reproductive success and conservation of these plants.Material and methods – Reproductive phenology, floral biology, pollination experiments, and the reproductive success of both species were investigated. To determine the floral visitors, we made direct observations on flowers and collected floral visitors that could not be identified in the field.Key results – Aechmea bruggeri and Quesnelia indecora presented the individual and population flowering phenological pattern classified as annual with intermediate duration. The species are partially and totally self-incompatible, respectively. Both species presented a varied visitation guild, and although Q. indecora presented flowers with ornitofilous characteristics, no hummingbirds were recorded for this species. The hummingbird Thalurania glaucopis was the main visitor for Aechmea bruggeri and the bee Trigona cf. braueri was the main visitor for Quesnelia indecora. Nectar thieving by lepidopterans was observed for both species. Pollen robbing by beetles and nectar robbing by bees were registered for Aechmea bruggeri and Quesnelia indecora, respectively. Fruit and seed set of both species were highly affected by herbivory, which may negatively affect their reproductive success.Conclusion – Our work highlights the important role of bromeliads in neotropical communities, showing how floral visitors and plants interact by participating in maintaining biological diversity in the studied forest remnant.