New findings on the pollination biology of Mauritia flexuosa (Arecaceae) in Roraima, Brazil: linking dioecy, wind, and habitat.

PREMISE OF THE STUDY: Despite the ecological, economic, and cultural importance of the palm Mauritia flexuosa in Amazonia, knowledge of its reproductive biology is scarce. Previous observations of this species suggested beetles as the probable pollinator, but experimental work to confirm this hypothesis was lacking. •
METHODS: We investigated the floral biology and pollination of M. flexuosa in undisturbed forest, undisturbed savanna/forest ecotone, and fragmented savanna within plantations of the exotic tree, Acacia mangium, in northern Brazilian Amazonia. In each habitat, we examined floral biology, combined floral visitor observations with laboratory analyses, and performed anemophily and exclusion experiments. • KEY
RESULTS: Fruit set was significantly greater in the visitor exclusion treatment than in the wind + visitor exclusion treatment and significantly lower in the wind + visitor exclusion treatment than the open control, but there was no difference in fruit set between the visitor exclusion treatment and the control. We found no significant difference in pollen dispersal among the three habitats. The presence of A. mangium appears to have no immediate effect on pollination of M. flexuosa, although it may indirectly affect other aspects of this native's reproductive ecology. •
CONCLUSIONS: Floral visitors of M. flexuosa are not pollinators. This dioecious palm depends on wind as its primary pollen vector. Wind pollination is not necessarily most effective in open habitats. These findings are important because they re-evaluate traditional assumptions of wind pollination and can improve management strategies of this natural resource in the Amazon.