When you take away the predators from an ecosystem, you’ll damage the ecosystem as a whole, and not just the predator/prey aspect.
This is the finding from a report published online in the journal European Journal of Wildlife Research, which examined 42 studies written over the past 50 years.
The study found that the loss of major predators from a forest ecosystem allows the game animal populations to increase dramatically.
Good news, right?
Wrong.
As those game animals increase, so does the amount of food they need to eat. As a result, trees and shrubbery decline, and small trees are eaten before they get a chance to grow, leading to a crippled ecosystem as well as deforestation and a loss of carbon sequestration potential.
A wolf in Yellowstone National Park
“These issues do not just affect the United States and a few national parks,” said William Ripple, an OSU professor of forestry and lead author of the study. “The data from Canada, Alaska, the Yukon, Northern Europe and Asia are all showing similar results. There’s consistent evidence that large predators help keep populations of large herbivores in check, with positive effects on ecosystem health.”
The report showed that densities of large mammalian herbivores were six times greater where there were no wolves than in those areas where wolves were present. The researchers, from Oregon State University, also found that combinations of predators can create important synergy for moderating the size of large herbivore populations.
“Wolves can provide food that bears scavenge, helping to maintain a healthy bear population,” said Robert Beschta, a professor emeritus at OSU and co-author of the study. “The bears then often prey on young moose, deer or elk – in Yellowstone more young elk calves are killed by bears than by wolves, coyotes and cougars combined.”
The same can be said for the coexistence of wolves and lynx in Europe.
“In systems where large predators remain, they appear to have a major role in sustaining the diversity and productivity of native plant communities, thus maintaining healthy ecosystems,” said Beschta. “When the role of major predators is more fully appreciated, it may allow managers to reconsider some of their assumptions about the management of wildlife.”
A grizzly bear in Yellowstone National Park
Idaho and Montana in the U.S. both see hundreds of wolves being killed in an attempt to reduce ranching conflicts and increase game herd levels; both very selfish human concerns that bear little to no thought for anything beyond the human sphere of influence.
The new analysis makes clear that the potential beneficial ecosystem effects of large predators is far more pervasive, over much larger areas, than has often been appreciated.
The study shows that large predators help maintain native plant communities by keeping the number of large herbivore animals in check, allowing small trees to survive and grow, reduce stream bank erosion, as well as contributing to the health of forests, streams, fisheries, and other wildlife.
Additionally, the report found that human hunting is not as effective in preventing the increase of large herbivores as the natural method is.
This is partly “because hunting by humans is often not functionally equivalent to predation by large, wide-ranging carnivores such as wolves,” the researchers wrote in their report.
“More studies are necessary to understand how many wolves are needed in managed ecosystems,” Ripple said. “It is likely that wolves need to be maintained at sufficient densities before we see their resulting effects on ecosystems.”
“The preservation or recovery of large predators may represent an important conservation need for helping to maintain the resiliency of northern forest ecosystems,” the researchers concluded, “especially in the face of a rapidly changing climate.”
Source: Oregon Stat University
I'm a Christian, a nerd, a geek, a liberal left-winger, and believe that we're pretty quickly directing planet-Earth into hell in a handbasket! I work as Associate Editor for the Important Media Network and write for CleanTechnica and Planetsave. I also write for Fantasy Book Review (.co.uk), Amazing Stories, the Stabley Times and Medium. I love words with a passion, both creating them and reading them.
