XVI International Botanical Congess

To test the hypothesis that phenology of savanna plants is related to water availability, we studied literfall dynamics, plant water status and flowering and fruiting phenology of 7 species of a savanna in Brasilia. We found an inverse and significant correlation between number of leaves on branches and monthly rainfall. Leaf fall showed a seasonal trend with a significant increase in the dry season. However leaf flushing, flowering and fruiting were also observed in the dry season. Soil water measurements (up to 8 m) showed that plants have access to ground water even in the dry season. Pre-dawn water potential was never below - 0.7 MPa. Water availability is not necessarily the main determinant of phenology in Cerrado vegetation. The high evaporative demand during dry season may constrain water uptake