Savannah...

A savannah, is a tropical grassland ecosystem characterized by the trees being sufficiently small or widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of C4 grasses.

Some classification systems also recognize a grassland savannah from which trees are absent. It is often believed that savannahs feature widely spaced, scattered trees, however in many savannah communities tree densities are higher and trees are more regularly spaced than in forest communities.

Savannahs are also characterized by seasonal water availability, with the majority of rainfall being confined to one season of the year. Savannahs can be associated with several types of biomes. Savannahs are frequently seen as a transitional zone, occurring between forest and desert or prairie. They cover 20% of the globe not including oceans. The largest amount of Savannah is in Africa.