Savanna

A savanna is a tropical or subtropical ecosystem dominated by grasses, with trees and shrubs scattered across the landscape. It develops where there is enough warmth for plant growth but a pronounced dry season limits the formation of dense, closed forests. Rainfall varies considerably among savannas, so some are relatively dry while others receive much more seasonal rain. Fires, grazing, browsing and the availability of water all influence the balance between grasses and woody plants.

Soil conditions also vary from one region to another. Savannas occur in parts of Africa, South America and Australia, as well as in other warm regions. Their vegetation is adapted to seasonal drought and, in many places, to recurring fires. Grasses can regrow from their roots after fire or grazing, while some trees have thick bark or other adaptations that help them survive. Savannas support diverse communities of plants and animals.

In Africa, for example, large herbivores such as zebras, antelopes and elephants interact with predators, birds, insects and many smaller organisms. Elsewhere, the species present depend on local climate and vegetation. Seasonal changes strongly affect life in these ecosystems: during the rainy season, plants grow rapidly and water becomes more available, while the dry season can reduce food and water resources.

Many savanna regions are also used for livestock grazing and agriculture, depending on local conditions. Intensive farming, overgrazing, changes in fire patterns, invasive species and habitat conversion can disturb these ecosystems. Protecting natural vegetation, managing fire and grazing carefully, and preserving water sources can help maintain the ecological processes that allow savannas to function.