About a quarter of the earth’s total land surface is grassland. They are known by different names in different continents. Except Antarctica, they are found in every other continent. They are basically a sea of grass extending for miles which receives more rains than deserts but not enough for many trees.
Prairie is the term used for the grasslands that cover much of the western United States and Canada. The largest uninterrupted grassland in the world is the steppe that extends from central Europe Far East into Siberia. Rivers flowing through the mountains are the source of water in the grasslands. Water is stored in depressions that get formed either naturally or are man-made. At the end of winter, the melting snow during the rainy season soaks the soil and creates temporary streams and shallow ponds.
Many birds live on the grasslands. Trees do not occur in all these grasslands but may occur in moist places. This is because of rainfall which is not enough for the growth of trees but sufficient for grasses to grow even as tall as 12 feet high. Hence the birds build their nests on the ground. Still more interesting is that eagles who nest only on trees, nest on the ground in Siberia. Most of the huge birds like Ostriches of Africa, rheas of South America and emus of Australia live in the grasslands.
Some grassland may be studded with widely spaced scrubby trees and bushes looking like a park. Wind is also one of the factors that help in maintaining grassland. They are given different names depending on where they are.
If grassland is dotted with trees, it is called savanna. There are huge savannas in hot parts of the world. There are North American prairies, South American Pampas, South African Veldt (veld), Asian steppes, African Savanna and Australian rangeland.