Reproductive phenology of Euterpe edulis Mart. in two altitudinal classes in the Brazilian Atlantic forest

Abstract

Euterpe edulis Mart. is an endangered palm tree. This species is of high ecological importance because it produces flowers and fruits in large quantities for pollinators and dispersers. Phenological studies help to understand the periods of availability of these resources, as well as allowing relating the species reproductive cycles with environmental variables such as altitude, precipitation, temperatures and relative humidity. Knowing that altitude influences meteorological variables, this study aimed to follow the reproductive phenology of E. edulis in two altitudinal classes and to verify if there is a difference in the phenological pattern due to the altitudinal difference. The study was conducted in Salto Morato Nature Reserve, a protected area located in the Brazilian Atlantic forest, more specifically, in the city of Guaraqueçaba, Paraná state. Monthly activity and intensity data were collected for the following phenophases: flowering, aborted bunches, immature fruits, green fruits and ripe fruits. Meteorological stations collected hourly temperature and relative humidity data on the altitudinal classes. Meteorological and phenology intensity data were correlated by Spearman correlation. There was a delay in the onset of phenophases in class II (200 to 400 m a.s.l) compared with class I (20 to 100 m a.s.l). In both altitude classes, ripe fruits were negatively correlated with temperature, indicating that they are available in a period of scarce forest resources. However, the amount of months that ripe fruits were available was different for each altitudinal class. We conclude that altitude influences the reproductive phenology of E. edulis, making this species even more important for feeding the fauna.