Study: Predator effect clouded in ‘cascades’

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Perhaps the most-told ecological success story about the Greater Yellowstone Ecosystem is bringing back wolves, which sparked a trickle-down effect on the web of life around them that researchers are still debating.

The premise of wolf reintroduction’s effects, known as a “trophic cascade,” is that the return of a large canines cut into numbers of herbivore populations like elk, and in turn influenced vegetation like willows and the smaller species that depends on the shrubbery, like songbirds. But some scientists who have kept an eye on Yellowstone since wolves were brought back 24 years ago say the narrative has been too simplified, and charge that a new University of Wyoming research supports.

“Conventional wisdom in ecology is that trophic cascades are reversable,” University of Wyoming PhD ecology candidate Jesse Alston told the News&Guide. “So when you reintroduce a predator to an ecosystem where they existed, it’s going to reverse back to a historic state.”

Because of some “theoretical reasons,” Alston and some lab mates suspected that the relationship wasn’t so neat. Their hunch was that factors like the effects of climate change, incomplete historical records and smaller “mesopredators” filling vacant ecological niches weren’t being fully accounted for.<<<Read More>>>