Post by: AspenBud on April 30, 2014, 11:12:07 AM
"Questions have also emerged about the well-publicized relationship between wolves and willows. Marshall and two colleagues investigated the controls on willow shrubs by examining ten years’ worth of data from open plots and plots surrounded by cages to keep the elk out. Her team found8 that the willows were not thriving in all the protected sites. The only plants that grew above 2 metres — beyond the reach of browsing elk — were those in areas where simulated beaver dams had raised the water table.
If beavers have a key role in helping willows to thrive, as Marshall’s study suggests, the shrubs face a tough future because the park’s beaver populations have dropped. Researchers speculate that the removal of wolves in the 1920s allowed elk to eat so much willow that there was none left for the beavers, causing an irreversible decline.
“The predator was gone for at least 70 years,” says Marshall. “Removing it has changed the ecosystem in fundamental ways.” This work suggests that wolves did meaningfully structure the Yellowstone ecosystem a century ago, but that reintroducing them cannot restore the old arrangement.
Arthur Middleton, a Yale ecologist who works on Yellowstone elk, says that such studies have disproved the simple version of the trophic cascade story. The wolves, elk and vegetation exist in an ecosystem with hundreds of other factors, many of which seem to be important, he says."
http://www.nature.com/news/rethinking-predators-legend-of-the-wolf-1.14841 (http://www.nature.com/news/rethinking-predators-legend-of-the-wolf-1.14841)
Post by: Broker on April 30, 2014, 03:28:30 PM
Why did you skip over the Aspens Bud?
The reason that Aspens grow taller when they are near water is caused by frequent wolf travel? What kind of expert mind came up with that gem?
Their growth couldn't possibly be attributed to greater access to water could it? No that wouldn't fit the pro wolf style of thinking.
Post by: AspenBud on April 30, 2014, 07:43:36 PM
Cherry pick much? :dunno:
Why did you skip over the Aspens Bud?
The reason that Aspens grow taller when they are near water is caused by frequent wolf travel? What kind of expert mind came up with that gem?
Their growth couldn't possibly be attributed to greater access to water could it? No that wouldn't fit the pro wolf style of thinking.
I cherry picked nothing, I agree with the whole article.
Actually aspens getting chewed down by ungulates can be a big problem. Then again old aspen stands are also a problem since they die and don't regenerate. Fire or clear cutting ensures stands regenerate. If healthy aspen stands are the goal it will take a lot more than wolves down there to reach it. Be it by hunters or wolves, elk needed to die down there in numbers, they were part of the problem.