Savannas are grasslands with scattered trees, and they are found in Africa, South America, and northern Australia (Figure 20.18). Savannas are hot, tropical areas with temperatures averaging from 24oC –29oC (75oF –84oF) and an annual rainfall of 51–127 cm (20–50 in). Savannas have an extensive dry season and consequent fires. As a result, scattered in the grasses and forbs (herbaceous flowering plants) that dominate the savanna, there are relatively few trees (Figure 20.20). Since fire is an important source of disturbance in this biome, plants have evolved well-developed root systems that allow them to quickly re-sprout after a fire.
Figure 20.20 Although savannas are dominated by grasses, small woodlands, such as this one in Mount Archer National Park in Queensland, Australia, may dot the landscape. (credit: "Ethel Aardvark"/Wikimedia Commons)