Yellowstone: Ecologists do not cry wolf.

What do wolves and aspen trees have to do with one another? Nature is an entangled mesh of complicated relationships. Thus seemingly disparate parts and niches of nature tend to interact with one another.

In the late 1930’s all wolves where hunted to extinction in Yellowstone park. It was considered a victory over nature.

Aldo Leopold was a park ranger who reformed his views on the culling of predators. At the time he wrote in his journal:

In those days we had never heard of passing up a chance to kill a wolf. In a second we were pumping lead into the pack, but with more excitement than accuracy; how to aim a steep downhill shot is always confusing. When our rifles were empty, the old wolf was down, and a pup was dragging a leg into impassable side-rocks.

We reached the old wolf in time to watch a fierce green fire dying in her eyes. I realized then, and have known ever since, that there was something new to me in those eyes—something known only to her and to the mountain. I was young then, and full of trigger-itch; I thought that because fewer wolves meant more deer, that no wolves would mean hunters’ paradise. But after seeing the green fire die, I sensed that neither the wolf nor the mountain agreed with such a view.”
— Aldo Leopold

With the disappearance of the wolf from Yellowstone, the Elk flourished. In fact, they flourished to the point where aspen saplings never got over 5 feet as they were fed upon by the elk. There has been no growth of aspen in Yellowstone in 70 years.

Douglas (Doug) W. Smith led the Gray Wolf Restoration project which reintroduced the wolf to Yellowstone in 1995. Since then the aspen are beginning to show signs of recovery.