Post-fire recovery in Malpighiaceae species with differing levels of ant-plant associations: the potential role of extrafloral nectaries in the Cerrado

Fire is a key ecological driver in the Brazilian Cerrado, shaping plant traits and influencing biotic interactions such as mutualisms. We assessed how the presence of extrafloral nectaries (EFNs) and associated ant mutualists affects post-fire recovery in three Malpighiaceae species with contrasting ant-plant associations: Peixotoa tomentosa and Banisteriopsis malifolia, which possess EFNs and have strong ant associations, and Byrsonima intermedia, which lacks EFNs and generally exhibits weaker associations with ants. Because ant activity was not measured directly, EFN presence was used as a proxy for mutualistic interactions. We hypothesized that fire would enhance vegetative growth and reproductive output in all species but that the effect would be stronger in species with EFNs. Our results showed that P. tomentosa experienced significant increases in total leaf production, plant height, leaf diameter, and reproductive output (floral buds, flowers, and fruits) in burned areas, along with a reduction in fungal leaf spots. B. malifolia also exhibited higher numbers of floral buds, flowers, and fruits in burned areas, indicating a positive reproductive response to fire. In contrast, B. intermedia showed no significant differences in leaf production or height between burned and unburned areas, and reproductive data were unavailable in this species due to delayed flowering after the fire. These contrasting responses suggest that EFN-bearing species may be better equipped to cope with post-fire conditions. While we did not directly measure ant activity, the observed patterns are consistent with the hypothesis that EFN-mediated mutualisms may contribute to plant resilience. Our findings contribute to the understanding of how species traits associated with ant-plant interactions might influence post-disturbance dynamics in tropical savannas.