Reproduction of Byrsonima sericea (Malpighiaceae) in Restinga Fragmented Habitats in Southeastern Brazil

Abstract

Habitat fragmentation may affect the reproductive success of plant populations in many different ways. Thus, negative, neutral, or positive plant responses can be observed, according to the balance of the different interactions. Variables related to mutualistic and antagonistic interactions (pollinator activity and gall occurrence, respectively) were measured on Byrsonima sericea populations of a fragmented seashore area (restinga) in southeastern Brazil. Pollinator visits to the oil-bearing flowers, insect gall occurrence on stems and inflorescences, and fruit set of B. sericea were compared between three small (up to 0.3 ha) and three large (14.0–99.0 ha) fragments. MANOVA showed differences between fragment classes. Nevertheless, a posteriori univariate ANOVA showed that the pollinator visit frequency was more than twofold higher in small fragments, and that gall occurrence and fruit set did not show significant differences between small and large fragments. These results suggest that the habitat fragmentation does not affect the female reproductive success of B. sericea in the studied restinga areas because resource availability seems to be a more important factor for fruit set than pollen limitation due to pollination failure. This is the first work assessing the effects of habitat fragmentation in restinga areas, which are intensely impacted by urbanization, so that no generalization about the fragmentation consequences can still be made for this ecosystem.