Prairies are vast open areas dominated by grasses.
These ecosystems arise in areas that are too dry to support forests but too wet to be deserts. Prairies are extremely diverse, containing hundreds of species of grasses, wildflowers, low woody shrubs, and lichens. The prairie pothole lakes and other waters are important waterfowl habitat and the grasslands themselves provide key nesting habitat for many other birds. More than 99 percent of the original tall-grass prairie of the Great Plains in the United States has disappeared. It has been converted to agriculture and ranching.