For a while now when I give talks about managing invasive plants, I bring up the subject of the Hippocratic Oath of Land Management: First Do No Harm.
We should choose methods of conducting our work that have the least negative impact—or fewest unanticipated consequences—on the land and habitats we manage.
It means, for example, avoiding unintended disturbance in removing invasive plants since other invasive plants may take advantage of that disturbance.
It means not compacting soil or creating ruts by driving across a wet field, even if it means walking some distance carrying the equipment. It means being thoughtful and aware of the impact of every action. We need to pay attention to the possibility of unintended changes of species composition, hydrology, geomorphology, forest stucture, nutrient availability, etc.
I had thought that applying the medical analogy of the Hippocratic Oath to land management was a unique idea, until I read the cover story in the October – December issue of Conservation In Practice. Entitled "Do No Harm" the article is by Mark Jerome Walters (29-34).
It's mainly about how efforts to save the endangered Hawaii raven actually hampered the species' recovery. "The lure of technology seems to tip the balance toward always 'doing something' rather than erring on the side of doing nothing to minimize the risk of harm" (34). Without the knowlege of how to study the birds without frightening them, researchers disrupted nesting and reproduction. Walters has written a book about what happened: Seeking the Sacred Raven: Politics and Extinction on a Hawaiian Island (Island Press, 2006).
[I call this inability to study something without affecting it (you guessed it!) the "Heisenberg Uncertainty Principle of Nature Study"—based on the quantum physics wave-particle conundrum. Although this is not a proper description of the actual Heisenberg Uncertainty Principle (see the Wikipedia entry) it is worth keeping in mind that researchers often do affect their study subjects.]
I don't mean to imply that we shouldn't study nature or manage our preserves, only that we need to be aware that the things we do may have unanticipated consenquences. And of course, we can't ever anticipate all of the unintended outcomes of our management.
There are also limitations to the medical analogy of the Hippocratic Oath. An ecosystem is not as static as a human body, for example. What we see today, what we take for granted as what a place is, is only a snapshot of a dynamic, ever-changing web of relationships among a changing cast of characters.