This study demonstrates an unforeseen link between the hunting behavior of a top predator -- the wolf -- and biochemical (nutrient) hot spots on the landscape," said Bump, an assistant professor in Michigan Tech's School of Forest Resources and Environmental Science and first author of the research paper. "It's important because it illuminates another contribution large predators make to the ecosystem they live in and illustrates what can be protected or lost when predators are preserved or exterminated."
Bump and his colleagues studied a 50-year record of more than 3,600 moose carcasses at Isle Royale. They found that soils at carcass sites had 100 to 600 percent more inorganic nitrogen, phosphorus and potassium than soil from surrounding control sites. Carcass sites also had an average of 38 percent more bacterial and fungal fatty acids, evidence of increased growth of bacteria and fungi.
The nitrogen levels (and nutrient quality) in plants growing on the carcass sites was from 25 to 47 percent higher than the levels at the control sites. Since large herbivores, like moose, are attracted to nitrogen-rich plants, the carcass sites become foraging sites, further supplementing soil nutrients from the urine and feces of the animals eating there.
The strong and unexpected connections between wolves, moose and the biogeochemistry of their ecosystem are important to policy makers involved in predator management and to a public increasingly concerned about conservation, Bump suggests.
This reminds me of another ecosystem benefit that wolves were found to convey at Yellowstone: that the return of wolves actually ended up benefiting trout populations.
Huh, you might ask?
Well, trout like cool, shaded streams and eat insects that fall into the water from willows, young cottonwoods, and other plants next to streams. Without wolves around, Yellowstone's elk could pretty much lounge around sipping Pina Coladas and eat all the streamside vegetation they wanted. This reduced amount of shade above streams, as well as habitat for insects that are trout food (fly fishing mimics the falling of insects into the water from trees and shrubs).
Once wolves returned, the elk had to keep on the move, allowing stream-side vegetation to recover, improving trout habitat. With trout fishing being a big industry in the Yellowstone area, there's a considerable economic benefit.
The return of wolves to Yellowstone, in general, has been found to confer a considerable economic benefit to the region. As one story notes:
A two-year study conducted by a Montana economist, and presented at a conference in April 2006, reports that each year tourists visiting Yellowstone hoping to see a wolf spend around $35 million in Montana, Idaho and Wyoming, and that these dollars then turn over in local communities, boosting the regional economic impact to about $70 million a year.