Tropical grasslands, also known as savannas, are a type of biome characterized by a combination of grasses and scattered trees. These grasslands are found in tropical regions, primarily in Africa, South America, Australia, and India. They are known for their diverse wildlife and unique ecological features.

I. Definition of Tropical Grasslands
- Tropical grasslands are vast stretches of land dominated by grasses with scattered trees and shrubs.
- They are characterized by a distinct wet and dry season, with a high temperature throughout the year.
- The grasses in these regions are adapted to fire and drought, which are common occurrences in savannas.

II. Other Names for Tropical Grasslands
- Prairies: Prairies are temperate grasslands found in North America, primarily in the central part of the continent. They are different from tropical grasslands in terms of climate and vegetation.
- Steppes: Steppes are semi-arid grasslands found in Eurasia. They have a colder climate compared to tropical grasslands and are dominated by grasses with few trees.
- Velds: Velds are grasslands found in Southern Africa, particularly in South Africa, Zimbabwe, and Botswana. They are similar to savannas but have some distinct characteristics.

III. Reasons for Tropical Grasslands being called Savannas
- The term "savanna" originated from the Spanish word "sabana," which means a treeless plain or a grassy meadow.
- It accurately describes the open grassy landscape with scattered trees that is characteristic of tropical grasslands.
- The word "savanna" is commonly used to refer to this specific type of grassland, distinguishing it from other grassland types such as prairies, steppes, and velds.

IV. Characteristics of Tropical Grasslands
- Dominated by tall grasses with some scattered trees and shrubs.
- Have a distinct wet and dry season, with most rainfall occurring during the wet season.
- Support a diverse range of wildlife, including large herbivores like elephants, zebras, and giraffes, as well as predators like lions and cheetahs.
- Adapted to fire and drought, with grasses having underground rhizomes or bulbs that allow them to survive and regrow after fires.

In conclusion, tropical grasslands are known as savannas due to their distinct characteristics of grasses, scattered trees, and a wet and dry season. While other names like prairies, steppes, and velds may also refer to grasslands, the term savanna specifically describes the tropical grassland biome.