samples of all the main natural regions in the country.

In the 1940s Aldo Leopold understood the need for zapovednik-type reserves: "While even the largest wilderness areas become partially deranged, it required only a few wild acres for J. E. Weaver to discover why the prairie flora is more drought-resistant than the agronomic flora which has supplanted it." The answer was that the wild prairie had a much more complex, and more efficient, root system,