savana

Savanna, also called savannah, is a mixed grassland ecosystem characterized by dominant grasses with widely spaced trees. It occurs in tropical and subtropical regions between tropical rainforests and deserts and is one of the Earth's major biomes. Savannas experience a seasonal climate with a distinct dry season; annual rainfall ranges roughly from 400 to 1,500 millimeters, and prolonged dry periods contribute to fire regimes that shape vegetation and nutrient cycling.

The vegetation comprises perennial grasses that form dense ground cover, with scattered woody plants such as Acacia species and baobabs. Fire and grazing by large herbivores prevent overgrowth and maintain the open landscape. In wetter regions trees may be more numerous; in drier zones grasses dominate.

Typical fauna includes large herbivores such as zebras, antelopes, gazelles, elephants, and cattle in human-impacted areas; predators include lions and cheetahs. A diverse assemblage of birds, insects, and small mammals also inhabits savannas.

Geographically, classic tropical savannas occur across sub-Saharan Africa, from East to Southern Africa, and extend into the tropical grasslands of South America (Cerrado, Llanos) and parts of Australia. The landscape supports livelihoods such as pastoralism and pastoral agriculture, but is also vulnerable to land conversion, overgrazing, and fire suppression.

Ecology and conservation: Fire is a natural and managed disturbance that maintains the open structure. Conservation efforts focus on protecting habitat heterogeneity, wildlife corridors, and sustainable land use to balance biodiversity with human needs.