Savann

Savanna, also spelled savann, is a biome characterized by a grassy ground layer with widely spaced trees or shrubs. It occurs in tropical and subtropical regions where seasonal rainfall produces distinct wet and dry seasons. The open canopy allows extensive grass growth, while fire and grazing historically help keep woody cover in check and maintain the ecosystem’s characteristic balance between grass and trees.

Climate and soils: Savannas typically receive 500 to 1,500 millimeters of rain per year, concentrated in the wet season. Fires, often ignited by lightning or humans, are a natural disturbance that sustains the open landscape. Soils tend to be shallow and nutrient-poor, making them sensitive to erosion and compaction when degraded.

Flora: The plant community is dominated by grasses such as Themeda, Hyparrhenia, and Andropogon, with scattered trees including Acacia and Baobab in many regions. Fire-resistant traits and rapid regrowth characterize many plants, enabling recovery between dry seasons.

Fauna: Savannas support large herbivores—zebras, wildebeests, gazelles, and antelopes—along with predators such as lions, cheetahs, and hyenas. The ecosystem also hosts diverse birds, insects, and in some regions migratory species that follow rainfall and forage availability.

Human use and conservation: Human communities practice extensive grazing and pastoralism in savannas. Agriculture and urban expansion threaten natural cover. Conservation measures emphasize fire management, sustainable grazing, and protected areas to preserve biodiversity, ecosystem services, and regional climate regulation. Ongoing research addresses the impacts of climate change on rainfall patterns and fire regimes in savanna landscapes.