In 1935, Leopold bought an abandoned farm in southwestern Wisconsin as a hunting reserve. Today known as the Leopold Memorial Reserve, this land, which he and his family dubbed “the shack,” became the site of some of his deepest lessons about the ecological value of predators. In shack journals between 1939 and 1940, he noted that deer were nipping plants and trees down to eighteen inches in height. In a 1940s game survey, he found that humans had eliminated wolves throughout North America, causing an explosion in deer and elk numbers, and resulting degradation of forests through over-browsing. Meanwhile, back at the shack, deer calmly stood their ground in the absence of wolves, chronically browsing tender young saplings to death.
Today ecologists refer to the powerful ecological link between predators, their prey, and the foods prey eat as trophic cascades. We have learned much about the conservation value of keystone predators, which have the ability to touch everything in a food web, thereby creating healthy, resilient ecosystems. Now more than sixty years since Leopold’s death, we are actively restoring these predators to oceans, streams, forests, and prairies worldwide.
Here are some questions to which you can respond via the "Comment" link below.
How do keystone predators structure ecosystems