Grasslands cover about one quarter of the Earth's land, and they have long been valuable to humans.
The soil tends to be nutrient-rich for agriculture, and they provide good grazing space for domestic stock. There is little variation in the structure of this habitat, with the predominant plant species being perennial grasses. They bind the soil and enrich it with nutrients when they die. The grasslands in the USA are sometimes termed as 'America's bread-basket' because they provide much of America's soybean, wheat and corn supply. The transformation of prairies for agriculture means that little natural areas of this biome remain.