Pollination and fruit set in the main neotropical mangrove species from the Southwestern Caribbean

Abstract

To increase our understanding of pre-dispersal reproduction of neotropical mangrove species we studied pollination effectiveness of flower visitors (potential to be pollen vector and to induce fruit development), pollination specialization and fruit set. Rhizophora mangle exhibited ambophilous pollination, a fruit set of 7.2%, and a highly effective pollinator, the hoverfly Copestylum sp. 1. Laguncularia racemosa had three highly effective pollinators, a fruit set of 7.9%, and the most specialized pollination system among the three species. Avicennia germinans showed the least specialized pollination, with four highly effective pollinators. This species showed the highest recruitment potential, with a fruit set of 29%. Although R. mangle is considered to be predominantly wind pollinated, our results indicate that the role of insect pollination has been underestimated. Likewise, our findings show that A. germinans has effective pollinators and vectors in several taxonomic groups. On small islands, where low insect diversity is expected, the level of pollination generalization found in R. mangle and A. germinans is higher than previously suggested. Competition for pollination resources appears to be low among the species studied.