Iowa, for example, has barely 12,140 hectares remaining of its original 12 million hectares of tall-grass prairie. Tall-grass prairie remains important to ranching in the Osage and Flint Hills of Kansas and in tracts in South Dakota, Oklahoma, and Texas. Because of this ecotonal mixing, the number of plant species found in mixed-grass prairies exceeds that in other prairie types. Mixed-grass prairie in Nebraska Sandhills. Short-grass prairie in Laramie Plain, Wyoming.
Buffalo grass reproduces both sexually and by tillering sprouts from the base of grass clumps.
Unlike the more eastern species, short-grass prairie species remain digestible and retain their protein content when dormant. The mountain plover responds to highly disturbed sites, the chestnut-collared longspur to moderately grazed areas, and the Baird's sparrow to sites with taller grasses. These structures have arisen through the long coevolutionary association between plants and animals with grazing on grasslands. To the south, specifically the Texas high plains, much of the short-grass prairie is now farmland or shrubland invaded by prickly pear cacti and oaks. These areas are largely on the national grasslands managed by the U.S. Forest Service.