The last couple of days, I’ve spent some time reading and studying more about ecosystems, looking at different theories on how best to care for and/or manage them. Just yesterday I published an article called, “Natural Regulation of Wildlife and Lands“, providing links to various stories that can better explain about “natural regulation” management as opposed to scientific management by man.
One scientist I referenced, Dr. Valerius Geist, and linked to a previous story of his, “Beware of Natural Wildlife Management”, responded in email to the story by George Dovel in the latest edition of The Outdoorsman, “The Truth about Our Wildlife Managers’ Plan to Restore “Native†Ecosystems“.
Dr. Geist’s email says that “The misconception of “balance” in an ecosystem is actually quite simple to debunk.” Here’s what he said.
In an individual’s body all functions are closely controlled or balanced, by negative feedback. If your blood sugar rises, insulin is secreted and excesses are removed into fat-storage, liver or are burned. If it is too low, glucagon is secreted raising the blood sugar level. That level is set by specialized cells in the hypothalamus, that is, the brain stem. And so it goes with all functions and organs. If you cut off a piece of liver, the liver will grow back to exactly its old size. If twin rats are joined by a common blood supply and the liver of one is removed, the liver of the second grows to exactly twice its former size. Here you see control in action.
An ecosystem is a collection of populations that compete with one another, coveting at least some of the same basic resources. Hold one population back and other populations will increase to fill the vacuum – as best as they can. The tendency to grow, to take up space and resources to the limit of one’s ability, is an example of positive feedback. The population grows till it runs out of resources, and each population does it. When there is a stalemate, its similar to two wrestlers locked against one another in a deadlock. That’s not control! It may be followed by the collapse of one, and victory of another. Many populations locked in deadly competition, one against the other, do generate the kind of stability described for the wrestler, but only a temporary one, as little collapses here and there lead to new short-term stability. And so it goes on. That is, ecosystems are constantly in change – one reason a given species exists on earth only a given time and then dies out, unable to competed as its adaptations were fit for competition to past ecosystems.
Positive versus negative feed back! Ecosystems run by positive feedback, individuals by negative feedback! Balance happens under negative feedback, not under positive feedback. Gridlock is not balance!
Enter man the manager. By selectively cutting back one population or another, or enhancing such, he can, indeed, create true “balance”. But that’s a human artifact.
A “let it be” philosophy by romantics, the “nature knows best” arguments are not rooted in science or scholarship. Nor is the common notion that pre-Colombian North America was a “Wilderness”. It was not. “Wilderness” is a post-Colombian artifact of European colonization based initially on the almost total collapse of native American populations from European/Asiatic/African disease. When the heavy hand of red man came off the continent (an example of negative feed back!) “Wilderness” erupted. That’s positive feed back.
Cheers, Val Geist
Dr. Valerius Geist, Professor Emeritus of Environmental Science at the University of Calgary in Alberta, is a renowned expert in wildlife management and conservation practices. In addition to teaching, writing about, and lecturing on the subjects, Dr. Geist has performed years of in-the-field research on big game species. He has authored 16 books, seven documentary films and contributed 40 entries to various encyclopedias.
Tom Remington
