Yellowstone National Park has recently seen the effects of wolves being brought back into its borders. The animals have slowly shaped the landscape around them, being the key to the entire ecosystem’s recovery, even its rivers.
Wolves were absent from Yellowstone for decades following an extermination campaign that happened over a hundred years ago. Without any predators, the elk population exploded. This had repercussions for the landscape as elk started overgrazing on many essential plant species.
The wolves of Yellowstone have a trophic cascade on their environment, which means they influence not just themselves but multiple levels of the food chain. After they were driven out of the landscape, the park’s biodiversity and many other factors were negatively impacted.
A Knock On Effect
Elk’s quickly noticed their predator’s absence, and quickly took advantage of it, grazing boldly on grass from grasslands and the edge of rivers where they would normally be more cautious. Once wolves were introduced decades later, the elk adjusted back to their old lifestyle.
Stream-side regions are important for biodiversity. Species like the willow crown aid in water retention and soil health. This allows rivers to run deeper, allowing more species to inhabit their waters. With the elk population controlled, willows and other vegetation could thrive.
With the return of vegetation, other species came back to the park, including birds and insects, as well as small mammals that use the srubbery as shelter. Once biodiversity is re-established, the whole ecosystem can recover.
Wolves Saved The Rivers
As plants recover around rivers due to the elk population being controlled by wolves, their root systems increase the strength of the soil, reducing its degradation. This means that small ponds can develop and rivers become straighter. With healthier waterways, more ecosystems can thrive.
Willow crown played the biggest role in the ecological recovery of Yellowstone’s rivers. The species had been severely diminished by overgrazing until fairly recently.
Although Yellowstone has shown an amazing effort in its recovery, it still has a way to go, and this further recovery will take time. Plants are only just starting to recover from the elk population, and many more animals are yet to return in strong numbers.
Keystone Predators
The ecological that the wolves have had on Yellowstone is undeniable and show that keystone predator species as essential to an ecosystem’s health. Other ecosystems that have lost their keystone predators could recover similarly to the way that Yellowstone has.
Willow crowns aren’t the only plants that have started to recover. Aspens, alders, and shrubs have all strengthened their numbers. Each of these species is important in unique ways, such as providing shelter and food for critical species.
A Successful Recovery
As wolves strengthen the environment around them, their numbers are expected to keep increase. Wolves are considered an endangered species and need a recovery of their own. With conservation looking after the area, their population should be more resilient than before.
Yellowstone’s recovery was due to the conservation efforts that moved a small wolf population in the 90s to its borders. The results have been promising, with these wolves keeping the environment balanced for the foreseeable future.
