For more wonder, rewild the world
Wolves were once native to the US' Yellowstone National Park -- until hunting wiped them out. But when, in 1995, the wolves began to come back (thanks to an aggressive management program), something interesting happened: the rest of the park began to find a new, more healthful balance. In a bold thought experiment, George Monbiot imagines a wilder world in which humans work to restore the complex, lost natural food chains that once surrounded us.
In 1995, wolves were reintroduced into Yellowstone National Park, 70 years after they had been exterminated. Wolves take life, but they also giveth. An unfathomable cascade followed: Deer populations went down, so streamsides and riversides flourished again; trees on the riverbanks quadrupled in height in just six years; bare valleys reverted to aspen and willow; birds and beavers alike flourished; beavers’ dams created habitats for otters, muskrats, fish, frogs and reptiles; and on and on. And a glorious, unexpected side effect: The wolves altered the rivers themselves. The return of trees reduced the rate of erosion and narrowed the width of the streams, meanwhile creating a greater diversity of pools and riffles. Even on the hillsides, vegetation has begun to recover. The Yellowstone wolves demonstrated that a single species, when allowed to pursue its natural behavior, can transform an entire ecosystem.
As a young biologist, Savory was involved in setting aside large swaths of African land as future national parks. This involved removing native tribes from the land to protect animals. Interestingly, as soon as the natives were removed, the land began to deteriorate.
At that point, he became convinced that there were too many elephants, and a team of experts agreed with his theory, which required the removal of elephants to a number they thought the land could sustain. As a result, 40,000 elephants were slaughtered in an effort to stop the damage to the national parks.
Consider the example of whales in the southern oceans. Though the Japanese government has argued that whaling boosts the population of krill and fish, the opposite appears to be true. Declining numbers of whales have an adverse ripple effect on the ocean’s ecosystem. Whales produce an iron-rich manure — “fecal blooms,” as scientists call them — that fertilizes plant plankton; more plant plankton means more zooplankton; more plankton means more food for fish and krill. And, Monbiot suggests, just as wolves have altered the behavior of the Yellowstone rivers, more whales could have changed the composition of the atmosphere for the better, since the plankton fertilized by them absorb carbon and remove it from the atmosphere. It would seem, says Monbiot, there is more and more evidence to support the Gaia hypothesis — that the Earth functions as a coherent and self-regulating system — from an ecological perspective.