Savanna is grassland with scattered individual trees. Savannas cover almost half
the surface of Africa and large areas of Australia, South America, and India.
Climate is the most important factor in creating a savanna. Savannas are found in
warm or hot climates where the annual rainfall is about 20 to 50 inches (50–130
cm) per year concentrated in six to eight months of the year, followed by a long
period of drought when fires can occur.
The soil of a savanna is porous, with rapid drainage of water and a thin layer
of humus, which provides the vegetation with nutrients.
The predominant vegetation consists of grasses and small broad-leaved
plants that grow with grasses. Deciduous trees and shrubs are scattered across
the open landscape. Savannas have both a dry and a rainy season, and seasonal
fires play a vital role in the savanna’s biodiversity.
Animals (which do not all occur in the same savanna) include giraffes,
zebras, buffaloes, kangaroos, mice, moles, gophers, ground squirrels, snakes,
worms, termites, beetles, lions, leopards, hyenas, and elephants.
Environmental concerns include poaching, overgrazing, and clearing of the
land for crops.
Figure 4.28 Savanna food webTemperate Grassland
Grasses are the dominant vegetation while trees and large shrubs are absent.
Examples of temperate grasslands include the veldts of South Africa, the pampas
of Argentina, the steppes (short grasses) of the former Soviet Union, and the