Phenology and its relation to precipitation in the Brazilian savanna

Vegetation phenology is influenced by the photoperiod, precipitation, soil, air temperature and solar illumination, and as such varies greatly along geographic gradients, vegetation types and climatic zones. In this work, focused in the Brazilian savanna, we analyzed the phenology of the main physiognomies and its relation to precipitation. Along the 13 years of analysis (2000 to 2012). As our results showed, the time lag between precipitation and vegetation response was of about one month at both the beginning and end of the growing season. A clear dependence on time lag extension and ENSO phenomenon was also observed. During El Niño years the start of the wet season occurred earlier in August and the duration of the growing season was longer. As opposed, La Niña events tend to cause a later start of the season and shorter growing seasons.