Yellowstone is in trouble unless we can bring back the beavers
People say that wolf reintroduction saved Yellowstone.
When biologists reintroduced wolves to the park in 1995, the initial effect was promising. Although elk populations did not decline as much as expected, the plants they ate started to regrow. Ecologists theorized that elk altered their behavior when wolves were around and consequently spent less time grazing.
The wolves quickly became the poster child for trophic cascades, how bringing back top predators can restore out-of-whack ecosystems. In recent years, however, ecologists have realized that bringing back wolves hasn’t been enough to restore plant communities in Yellowstone.
“Predators can be important,” Oswald Schmitz, an ecologist at Yale University in New Haven, Connecticut, told Nature, “but they aren’t a panacea.”
Ohhh sure, wolves are all sexy and wild with their howling in the night and dramatic silhouettes. People like George Monblott make viral videos proclaiming their splendor. But guess what has a lumpy silhouette and doesn’t get big fancy supporters? I’ll give you a hint. It starts with a ‘B’.
Thus ecologists have started looking closer at the role beavers play in the ecosystem.
Beavers, too, suffered from the initial decline of wolves and rise of elk, as elk out-competed beavers for food — particularly willow and aspen trees — leading to the near-elimination of beavers and their dams from the park.
As beaver dams disappeared, so did the wetlands and streams they supported — and these are the areas that suffer most today.
“It’s problematic because the willows and beavers have a mutualistic relationship: Beavers eat and cut them down to build their dams, and the dams raise the water tables and bring water up so it’s more available for plants,”
“Without beaver dams creating willow-friendly environments,” Emma Marris, author of the book “Rambunctious Garden: Saving Nature in a Post-Wild World,” told Popular Science, “the willows can’t recover.”
Not only will the willows not recover, but the marshy habitats around them won’t recover either. That includes not only the trees and plants but also the birds, amphibians, and any other creature that needs wetland to survive.
Now it occurs to you that beavers might matter? After we’ve been talking about it for a decade? Well, isn’t that mighty white of you, as they say. I’m sure Dr.’s Hood, Muller-Swarze, Westbrook, Haley and Fouty will be very pleased. More importantly, I’m hoping you take from this that one single answer won’t create a solution. It’s a complicated interweaving of systems, and when you remove one they all suffer. It’s all connected, you know.
(But beavers are STILL more connected than most.)
