The seed-dispersers and fruit syndromes of Myrtaceae in the Brazilian Atlantic Forest.

Abstract

Abstract Data on the seed dispersers of 68 Myrtaceae species in the Brazilian Atlantic Forest in São Paulo, Brazil were combined with data on the associated variation in fruit morphology and chemical composition to determine if suites of fruit traits are associated with distinct sets of frugivores. Fruit colour and size, seeds size and mean seed number per fruit were recorded for 32 species. Seed dispersers of 68 species representing 14 genera of Atlantic forest Myrtaceae were identified (i.e., Calycorectes, Calyptranthes, Campomanesia, Eugenia, Marliera, Myrceugenia, Myrcia, Myrcianthes, Myrciaria, Neomitranthes, Plinia, Psidium and Siphoneugena). Birds and monkeys were the most frequent seed dispersers, recorded for 44 and 38 species, respectively (many species were dispersed by both birds and monkeys). Among the 68 Myrtaceae species whose seed dispersers were identified, fruit size varies widely. Fruit shape varies from elongated to markedly depressed. Most genera have few-seeded fruits. Black was the most common colour, followed by yellow, red, orange, grey and green. No significant variation was found between morphological traits and dispersal by birds and monkeys. In contrast to the wide interspecific variation in morphological traits, species were fairly similar in the chemical composition of fruit pulp. Myrtaceae fruits are typically high in water and carbohydrates and low in lipids and proteins. No significant difference were found between fruit species eaten by birds and monkeys in any of the chemical components analysed. Results indicate that size is among the fruit trait most clearly tied to differences in dispersal agents of the Atlantic Forest Myrtaceae.