Fenologia reprodutiva e interações planta-visitantes florais em espécies de Bromeliaceae da Floresta Atlântica

Abstract

The Bromeliaceae family shows 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 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. 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. Both species presented the individual and population flowering phenological pattern classified as annual with intermediate duration. Aechmea bruggeri and Quesnelia indecora are partially and totally self-incompatible, respectively. Both species presented a varied visitation guild, and although Quesnelia 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, the main visitor for Quesnelia indecora. Nectar thievery by lepidopterans was observed for both species. Pollen robbery by beetles and nectar robbery 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. 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.