A grassland is a biome in which the dominant plants are grasses rather than trees or tall shrubs. Often described as "sea of grass," grasslands cover as much as 25 to 30 percent of the Earth's surface. They are usually found in the interiors of every continent except Antarctica.

Although grasslands vary in climate and the type of plant and animal life they support, most have several things in common. They are covered with grasses, which may be of different heights and varieties. They are usually windy and dry for part of the year. And they occur primarily on flat land or gently rolling hills, although a few are found on mountains where the environment is suitable. Also, grasslands are considered...