Sea of Grass

About one quarter of the earth's land is in the grasslands. This biome can be found on every continent except Antarctica. Grasslands exist on either side of two desert belts that circle the earth. Tropical grasslands -- those closest to the equator -- are hot all year long. Those farther from the equator -- such as the U.S. prairies -- have both hot summers and harsh winters. Why do you think the U.S. prairies are often called the "breadbasket of the world?"

Temperate grasslands once covered much of the interior of North America, and they were common in Eurasia and South America as well. Such grasslands are often highly productive when they are converted to agricultural uses. Many of the rich agricultural lands in the United States and southern Canada were originally occupied by prairies, another name for grasslands. In eastern Europe and central Asia, they are called steppes. Whatever name they go by, all grasslands are similar.

The roots of perennial grasses usually penetrate far into the soil, and grassland soil tends to be deep and fertile. In North America, the prairies were once inhabited by huge herds of bison and pronghorns, which were hunted by wolves, bears, and other predators. These herds are almost gone now, and most of the prairies have been converted into the richest agricultural region on earth. They are still grasslands, but are no longer wild.