Phenology and pollination and dispersal modes of Fabaceae in a riparian forest, Chapada Diamantina, Northeastern Brazil

Abstract

Phenological patterns have been described based on frequency, period and duration of the events and analyzed as a function of biotic and abiotic factors with the vegetative and reproductive cycles of plant species commonly related to the precipitation and day length. In this work, we describe the phenological strategies of 11 Fabaceae species present in gallery forests along the Lençóis River, Chapada Diamantina, Bahia State, Brazil, and investigate the environmental factors influence and pollination and dispersal modes on the phenological patterns. Observations of vegetative (leaf flushing and leaf fall) and reproductive (bud, flower, immature fruit and mature fruit) phenology were made among a group of 75 individuals based on Fournier index (24 months). Interspecific synchrony was determined based on the presence or absence of each phenophase in the individuals. Multiple linear regression analyses were conducted to investigate the influence of environmental variables on the phenophases, and Pearson correlation analysis between vegetative and reproductive events. Pollination and dispersal syndromes were defined based on field observations and literature. The species demonstrated non-seasonal vegetative and reproductive events, different of the expected for the family. However, the flowers and mature fruits (i.e., resources for pollinators and dispersal agents) were seasonal. The correlation with precipitation was positive to the leaf flush and negative to leaf fall and diaspore propagation. The leaf flushing, flowering and fruit maturation are correlated to day length. Our study reveals the occurrence of different groups of Fabaceae with distinct flowering and fruiting peaks related to pollination and dispersal syndromes, which minimize the niche overlapping among them.