tropical and subtropical grassland biome with scattered trees
characterized by distinct wet and dry seasons
covers ~20% of Earth's land surface, primarily in Africa, South America, and Australia
dominated by grasses adapted to fire, drought, and grazing
supports large herbivore populations: ungulates, elephants, kangaroos
fire is a key ecological process maintaining the grass-tree balance
soils range from nutrient-poor laterites to fertile volcanic substrates
the Serengeti-Mara ecosystem hosts the largest terrestrial mammal migration
carbon cycle dynamics differ from forests: more carbon stored belowground in roots
transitional biome between tropical rainforest and desert
evolution of grasses (C4 photosynthesis) enabled savanna expansion in the Miocene