Enemies of Disruption
ALDO LEOPOLD enjoyed a practical turn of mind. As he discovered ecological principles or learned them from researchers like Elton, he was fond of applying them to history or to practical management. In 1933, just before he published his pioneering work of applied ecology, Game Management, he wrote:
A harmonious relation to the land is more intricate, and of more consequence to civilization, than the historians of progress seem to realize. Civilization is not, as they often assume, the enslavement of a stable and constant earth. It is a state of mutual and interdependent cooperation between human animals, other animals, plants, and soils, which may be disrupted at any moment by the failure of any of them. Land spoilation has evicted nations, and on occasion can do it again. . . .
All civilization seems to have been conditioned upon whether the plant succession, under the impact of occupancy, gave a stable and habitable assortment of vegetative types, or an unstable and uninhabitable assortment. The swampy forests of Caesar's Gaul were utterly changed by human use--for the better. Moses' land of milk and honey were utterly changed--for the worse. . . .
Unforeseen ecological reactions not only make or break history in a few exceptional enterprises--they condition, circumscribe, delimit, and warp all enterprises, both economic and cultural, that pertain to land. . . . In short, the reaction of land to occupancy determines the nature and duration of civilization. . . .
[On the other hand] within the limits of the soil and plant succession we also rebuild the earth--but without plan, without knowledge of its properties, and without understanding of the increasingly coarse and pow-