Leopolds's teaching is based on the belief that ''the land is one orga
nism.'' Will an ecosystem collapse if a single species is removed, as
would an organism without a single organ? What would happen if all nat
ive plants and the animals that depend on them were replaced by a sing
le introduced species? The answer: a sustainable wheat field, without
which Leopold would not be able to create his ethnic, nor we conduct t
his discourse.