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

[摘要] 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 ascampo sujo) in Central Brazil. The amount ofRnpartitioned intoHdeclined as monthly rainfall increased and reached a level of approximately 30% during the wet season, while the amount ofRnpartitioned intoLeincreased as monthly rainfall increased and reached a level of approximately 60% during the wet season.As a result,Hwas significantly higher thanLeduring 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 aβ≈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.

[学科分类] 地质学