Temporal Patterns of Energy Balance for a Brazilian Tropical Savanna under Contrasting Seasonal Conditions

The savanna of Central Brazil (locally known as cerrado) has a long history of land cover change due to human activity. These changes have led to the degradation of cerrado forests and woodlands, leading to the expansion of grass-dominated cerrados and pastures. Thus, the aim of this study was to evaluate the temporal variation in energy flux in areas of degraded, grass-dominated cerrado (locally known as campo sujo) in Central Brazil. The amount of Rn partitioned into H declined as monthly rainfall increased and reached a level of approximately 30% during the wet season, while the amount of Rn partitioned into Le increased as monthly rainfall increased and reached a level of approximately 60% during the wet season. As a result, H was significantly higher than Le during the dry season, resulting in a Bowen ratio (β = H/Le) of 3-5, while Le was higher than H during the wet season, resulting in a β≈1. These data indicate that the energy partitioning of grass-dominated cerrado is relatively more sensitive to water availability than cerrado woodlands and forests, and have important implications for local and regional energy balance