Phenology and wood density of plants growing in the semi-arid region of northeastern Brazil

The current knowledge about the influence of plant traits and climatic seasonality on the phenology of tropical rain forest plants is insufficient to understand how functional traits can explain mechanisms associated with phenological responses. We hypothesized that the density of the wood and the water stored in stem and root determine presence of phenological groups of trees. Leaf shedding, flushing, and flowering of high wood density species are related to rainfall, due to their low water-storage capacity. In contrast, leaf unfolding and flowering of low wood density species depend on photoperiod, due to their high water-storage capacity. For 12 months, we monitored vegetative and reproductive phases of 281 individuals of 46 tree species in a coastal rain forest in Northeastern Brazil. Data on rainfall, photoperiod, wood density and quantity of water stored in stem and roots were also recorded. Corroborating our hypothesis, wood density and the amount of water stored formed functiona...