Reproductive phenology of Brazilian savannas and riparian forests: environmental and phylogenetic issues

Abstract

The reproductive phenology of plants is expected to be influenced by climatic factors and by the phylogenetic history of the species. In savannas, the peaks of flowering and fruiting are associated with climate seasonality. However, there is still a controversy about the reproductive phenology of plants in riparian forests, a vegetation type that does not experience a severe water shortage. We tested whether the reproductive peaks in riparian forests are different from those of the savannas. We also tested if the number of species in flower is correlated with rainfall and day length. We sought evidence of phylogenetic signals in the reproductive periods of the species. Most of species in savannas and riparian forests flowered and fruited in the wet season. The number of flowering species was positively correlated with monthly rainfall and day length. However, we did not find phylogenetic signals in the reproductive periods. The phenological pattern of riparian forests was similar to that of savannas. At the community level, the reproductive periods of plants may not be under phylogenetic constraints, as observed in forests under nonseasonal climate. Sun-related variables seem to be the main cues for the reproductive phenology of plants in savannas and riparian forests.