Efeito do fogo na fenologia de Syagrus glaucescens Glaz. ex Becc. (Arecaceae)

Abstract

Syagrus glaucescens is an endemic and threatened palm from the rupestrian field of the Espinhaço Range, Minas Gerais, southeastern Brazil. The objective of this study was to evaluate the fire effect on the vegetative and reproductive phenology of S. glaucescens. It was tested the hypothesis that the occurrence of fire can affect the phenological patterns exhibited by this species. The study began after six months of fire occurrence. A total of 40 individuals were marked and observed monthly, 20 in a burned area (Queimado group) and 20 in an unburned adjacent area (Controle group), located in rupestrian fields areas of Serra do Cipó (MG). The analysis of phenophases was performed using the index of activity and the Fournier’s percent index of intensity. Leaf flushing and leaf fall were synchronous among the individuals of the two populations, during the studied period. The production of flowers and fruits on S. glaucescens was asynchronous for the most part of the time. However, in both studied areas most individuals were blooming during the dry season and fruiting in the rainy season. Rainfall seems to be the main factor determining the observed phenological patterns, and was significantly correlated with some phenophases of both burned and control groups. The burned plants flowered and fruited before the control group, and also produced a higher number of flowers and fruits, suggesting that fire may affect the phenology of this palm. Key words: endemic species, fire, rupestrian field, Serra do Cipó.