We end, I think, at what might be called the standard paradox of the twentieth century: our tools are better than we are, and grow better faster than we do. They suffice to crack the atom, to command the tides. But they do not suffice for the oldest task in human history: to live on a piece of land without spoiling it.
From a modern perspective, Leopold, although insightful and having contributed enormously to the development of ecological ethics and sensibilities, also claimed:
Examine each question in terms of what is ethically and aesthetically right, as well as what is economically expedient. A thing is right when it tends to preserve the integrity, stability, and beauty of the biotic community. It is wrong when it tends otherwise
That’s from his Sand County Almanac (page 262). Read literally, it suggests that biotic communities are capable of stability in the human meaning of the word. But Leopold introduced notions like the trophic cascade which is biological dynamics at its most essential, and, so, instead of biotic communities he should be read as meaning biocoenosis. Accordingly, oscillation in species abundances and even replacement of one species by another, as in forest succession or even invasion would be considered stable. An outline of a modern view is available here.
To his great and practical credit, Leopold also struggled to reconcile Ecology and Economics.