s of eight feet at times. Between lies the mid-grass prairie dominated by side-oats grama and wheatgrass, with a mixture of shortgrass prairies in dry sites and tallgrass in wetter sites. The prairie is well known for its fauna. Some authors have estimated that there were between 30-60 million bison roaming the prairies. Elk, deer, and antelope also grazed in astounding numbers. Large predators preying on the grazers included the grizzly bear and wolf. Hoards of smaller wildlife from birds to pocket gophers were inhabitants adapted to this unique ecosystem.
Man discovered the rich soils that exist in the prairies about 150 years ago. Finding the prairie soils outstanding for crop production, they plowed the prairie everywhere they could for the production of wheat, corn, and other domestic crops. Today, the most fertile and well-watered region, the tallgrass prairie, has been reduced to but 1% of its original area. This makes it one of the rarest and most endangered ecosystems in the world. The largest remaining area still left unplowed is in the rocky and hilly region of Kansas called the Flint Hills. This physiographic region averages 60 miles wide and stretches from the Nebraska border, south into northern Oklahoma.
Fires sweep across the prairie consuming everything in its path. On top of this there is a barrage of organisms feeding on these plants as fast as they grow. The secret to the survival of the prairie plants in such a hostile environment is that 75-80% of the prairies biomass, or plant material, is underground. The visible plants seen on the landscape are merely the photosynthetic leaves gathering sunlight for a much larger community underground. Just beneath the surface lies the main stems or rhizomes, running horizontally. Here they lie protected from drying, grazing, trampling, fire, and frost. Tough fibrous roots descend from these rhizomes deep into the ground. Roots of some plants such as dotted gayfeather have been reported to go 10 to 15 feet deep. On these roots, are microscopic "rootlets" numbering in the billions and utilized by the plant. Even smaller than rootlets are mycorrhizae that support plant growth by drawing in nutrients too little for even rootlets to obtain. The roots of plants are so numerous, that were one plant's roots placed end to end they would stretch for miles. The competition for nutrients and resources is fierce, so thickly interwoven are plant roots that early settlers were able to cut bricks out of the sod to build homes and schools.