PADRÃO GEOGRÁFICO DE PLANTAS COM NECTÁRIOS EXTRAFLORAIS EM BIOMAS BRASILEIROS

Abstract

Extrafloral nectary plants (EFN-plants) are very common in Brazil, but it seems that most studies investigate plants from the Cerrado biome. This might create a bias in our understanding of EFN-plants and avoid generalizations in the ant-plant mutualistic systems. In order to deeply understand ant-plant interactions it is necessary to know where EFN-plants occur. In this study we investigated the geographical distribution of EFN-plants in Brazilian biomes (Cerrado, Atlantic Forest, Caatinga, Amazon, Pantanal and Pampa). Data were retrieved from published literature and only EFN-plants that interacted with ants were considered in our data. A total of 166 EFN-plant species in 91 genera and 34 families are known from four Brazilian biomes: Cerrado, Atlantic Forest, Caatinga and the Amazon (the Pantanal and Pampas have no record of EFN-plants interacting with ants). Most publications of Brazilian EFN-plants investigate the Cerrado flora, and this biome stand out in the richness of these plants (72 species e 19 families). The most studied plant was Caryocar brasiliense (Caryocaraceae), a Cerrado native species. Fabaceae was the richest family with 59 species, and it was the richest family in the Cerrado, Atlantic Forest and Caatinga. In the Amazon, the Bignoniaceae was the richest family. Only the Fabaceae and Euphorbiaceae were found in all four biomes. The flora dissimilarity was high, because only 8 (out of 166 species) were found in more than one biome; however, no plant species was found in all biomes concomitantly. Our study shows that our understanding of the Brazilian EFN-plant flora is geographically limited, as most plants belong to the Cerrado biome. Ant-plant mutualistic interactions are conditional over space, which means that ants can have different roles in their plant-partners along geographical scales. Studies of plant biodiversity and distribution can be a first step to infer key processes to the maintenance of interactions and to permit assumptions of biogeographical and macroecological hypotheses.