Distribution of Extrafloral Nectaries in Different Vegetation Types of Amazonian Brazil

Abstract

Summary This paper reports for the first time data on the taxonomic distribution and abundance of woody plants with extrafloral nectaries (EFNs) in plant communities occuring in the Amazon region, Brazil. Surveys were carried out in four vegetation types: ‘terra firme’ forest, successional forest, ‘buritirana’ (palm vegetation) and ‘shrub canga’ (savanna). EFNSs were present in 30 plant species belonging to 22 genera and 14 families. Nectary species represented 17.6 to 53.3% of the species sampled in different areas, with local abundances varying from 19.1 to 50.0%. The percentage of species with EFNs was greater in the flora of the shrub canga than in the terra firme and successional forests. Nectary plants were more abundant in the shrub canga and successional forest. The data for proportion and abundance of nectary species in Amazonian vegetation types were in general much higher than those obtained in temperate habitats, and support the hypothesis that EFNs tend to be more common in tropical environments. It is suggested that the high abundance of EFNs in the surveyed areas may be the result of intense foraging activity by ants on plants, leading to the formation of facultative mutualisms.