Savanna

Savanna is a type of landscape characterized by persistent grasses and scattered small trees. Like tropical forests, the tree canopy does not cover the entire ground; sunlight reaches the soil, which allows grass to become the dominant vegetation.

Savannas are mostly found in regions between tropical forests and deserts. They occur in Africa, South America, India, and northern Australia. The most distinctive feature is the regular alternation of wet and dry seasons each year.

Climate and rainfall

Savanna climate is tropical, with distinct wet and dry seasons. Temperatures remain high throughout the year; the greatest variation is linked to rainfall, not temperature. Most rain falls in a few months, while the remainder of the year is dry.

Vegetation and fire

Savanna grasses have deep roots and can regenerate after burning or grazing. Fire is common during the dry season; it prevents trees from taking over the entire landscape. Some trees, such as cork oaks, have thick bark that resists fire.

Animals

African savannas are known for grazing animals that move in herds, such as zebras, wildebeest, and antelopes, and for predators that follow them, such as lions and hyenas. Most animals are migratory, moving to areas where rain has fallen and new grass has grown.

Humans and change

Many savannas are inhabited by pastoralists and farmers. Overgrazing, repeated fires, and agricultural expansion alter the pattern of vegetation. Scientists debate the extent to which savannas are natural landscapes or the result of human activity over a long period.