Frugivory in Bromelia Balansae (Bromeliaceae): The Effect of Seed Passage through the Digestive System of Potential Seed Dispersers on Germination in an Atlantic Rainforest, Brazil

Frugivory in Bromelia balansae (Bromeliaceae): the effect of seed passage through the digestive system of potential seed dispersers on germination in an Atlantic Rainforest, Brazil. The Serra do Japi-SP Ecological Reserve is one of the last large areas of continuous forest in the interior of state Sao Paulo, and currently suffers great anthropic pressure due to the urbanization process in its surroundings. The dispersion of seeds by frugivorous mammals has great importance in the regeneration of altered areas and the composition of seed banks. In this work we identified some frugivores of Bromelia balansae and tested the viability of seeds present in their feces. To identify the frugivores were installed "foot traps" near plants with mature fruits. Mammalian feces were collected and analyzed in order to find seeds of B. balansae. Three species of frugivores were identified: Cerdocyon thous, Nasua nasua and Didelphis sp. In captivity, mature fruits of B. balansae were offered to crab-eating foxes and coati to obtain seeds passed through the digestive tract of these animals. The seeds contained in the feces of these mammals were collected for germination experiments in the laboratory. As a control, seeds were extracted directly from mature fruits for germination tests. As main results, we verified that the seeds remained viable and intact after passing through the digestive tract of these two species. Seeds that passed through the digestive tract of N. nasua and C. thous germinated faster than seeds from fruits. Coati gut passage showed significantly higher germinability than both groups of seeds, without pulp and with pulp. But the germinability of seeds with pulp removal was significantly higher than seeds with pulp. However, seeds that were intact after crab-eating foxes gut passage showed germination significantly higher than that seed with pulp, but showed no significant differences when compared to the seeds with removed pulp. Also, our data indicate that the coati gut passage has a higher positive effect on the seed germination of B. balansae than seed from foxes feces and mature fruits treatments. The plant architecture and leaf morphology of B. balansae restricts small size dispersers and favors the access of larger animals to the fruits, such as coatis and crab-eating foxes, ensuring the dispersion of seeds over long distances.