Tropical Savannas


Tropical Savannas Are Characteristic of Semiarid Regions with Seasonal Rainfall


Savanna ecosystem of the Cerrado of South America




Savanna ecosystem of the mulga woodlands of central Australia



  • Warm continental climate with mean temperature usually >18C (64oF)
    • Maximum temperatures occur at the end of the wet season
  • Distinct seasonality in precipitation and large annual variation in total precipitation




  • Savannas have a two-layer vertical structure
    • Grasses
    • Trees or shrubs
  • Characteristics of savanna
    • Occur on land surfaces of little relief
    • Fire-adapted vegetation
    • Woody vegetation is short-lived (less than several decades)
  • Seasonal precipitation controls the yearly cycle of plant activity and productivity in tropical savannas




  • Soils of the savanna
    • Oxisols continuous weathering results in nutrient-poor soil (especially phosphorus)
    • Alfisols common in the drier savannas
    • Entisols associated with the driest savannas