Wolves Are Essential For A Healthy & Balanced Ecosystem….It’s A Fact!!

Wolves are under fire because ranchers think they threaten livestock, hunters believe they threaten deer and elk populations and they’re a nuisance to outfitters.  But most people see the wolf differently.  The wolf is an icon of freedom in the West.  A top predator that is essential to a healthy ecosystem.  Yet the general public’s opinion doesn’t seem to matter much when it comes to wolf politics.  We get the same tired old arguments about wolves predating on livestock.  Here’s a question?  Why are ranchers allowed to graze their cattle on our public lands and then claim those lands as their own, subjugating the wolf and grizzly to cattle?  The wolf and grizzly have more right to be here then cattle or sheep.  It’s really time to re-examine our priorities.  The ranching and hunting communities are not the only voices speaking out in the West.  It’s not the twentieth century anymore.  It’s a new day and conservationists will not stop until there is a balance of opinion.  The wolf and grizzly have a rightful place here and “wild life managers” should be re-thinking their priorities. The Western lands don’t belong to just ranchers, hunters and outfitters, they belong to all the people, many who believe the wolf and grizzly have a right to live in peace without harrassment.

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Wolves Are Rebalancing Yellowstone Ecosystem

ScienceDaily (Oct. 29, 2003) — CORVALLIS, Ore. – The reintroduction of wolves into Yellowstone National Park may be the key to maintaining groves of cottonwood trees that were well on their way to localized extinction, and is working to rebalance a stream ecosystem in the park for the first time in seven decades, Oregon State University scientists say in two new studies.

The data show a clear and remarkable linkage between the presence of wolves and the health of an entire streamside ecosystem, including two species of cottonwoods and the myriad of roles they play in erosion control, stream health, and nurturing diverse plant and animal life.

The findings of these studies were recently published in Ecological Applications, a journal of the Ecological Society of America, and the journal Forest Ecology and Management.

“In one portion of the elk’s winter range along the Lamar River of Yellowstone National Park, we found that there were thousands of small cottonwood seedlings,” said Robert Beschta, professor emeritus in the College of Forestry at OSU and an expert on streams and riparian systems. “There should also have been hundreds of young trees, but there were none. Long-term elk browsing had been preventing any seedlings from getting taller.”

That pattern was common throughout the study area – lots of seedlings in combination with large cottonwood trees generally more than 70 years old, but little or nothing in between.

Young cottonwoods, willows, and other streamside woody species are a preferred food for browsing elk during the harsh winters in northern Yellowstone, when much of the other forage is buried under snow. But when packs of wolves historically roamed the area, food was not the only consideration for elk, which had to be very careful and apparently avoided browsing in high-risk areas with low visibility or escape barriers.

Wolves were systematically killed in the Yellowstone region and many other areas of the West beginning in the late 1800s. A concentrated effort between 1914 and 1926 finished the job – the last known wolf pack disappeared in 1926.

“I considered a variety of potential reasons that might explain the historical decline of cottonwoods that began in the 1920s and have continued up to the last couple of years,” said Beschta. “I looked at climate change, lack of floods, fire suppression, natural stand dynamics, and numbers of elk. But none of those factors really explained the problem. “Ultimately, it became clear that wolves were the answer.”

While elk populations fluctuated over the decades when wolves were absent, browsing behavior appears to represent an important factor related to streamside impacts. With no fear of wolves, the elk could graze anywhere they liked and for decades have been able to kill, by browsing, nearly all the young cottonwoods. Other streamside species such as willows and berry-producing shrubs also suffered.

That in turn began to play havoc with an entire streamside ecosystem and associated wildlife, including birds, insects, fish and others. Trees and shrubs were lost that could have helped control stream erosion. Food webs broke down.

“Before the wolves came back, it was pretty clear that in some areas we were heading towards an outright extinction of cottonwoods,” Beschta said.

Now, with the recent reintroduction of wolves back into Yellowstone in 1995, streamside shrubs and cottonwoods within the Lamar Valley are beginning to become more prevalent and taller, and were the focus of a second study in the same area. That study outlines how the fear of attack by wolves apparently prevents browsing elk from eating young cottonwood and willows in some streamside zones.

With the renewed presence of wolves, young cottonwoods and willows have been growing taller each year over the last four years on “high-risk” sites, where elk apparently feel vulnerable due to terrain or other conditions that might prevent escape. In contrast, on “low-risk” sites, they are still being browsed by elk and show little increase in height.

“In one case where a gully formed an escape barrier for elk, the tree height went up proportionally as the gully deepened and formed an increasing barrier to escape,” said William Ripple, a professor with the College of Forestry at OSU. “Where the fear factor of wolves is high, the young trees and willows are doing much better and growing taller.”

Traditionally, “keystone” predators such as wolves were known to influence the population of other animals that they preyed on directly, such as elk or antelope. What researchers are now coming to better understand is the “trophic effect,” or cascade of changes that can take place in an ecosystem when an important part is removed, Ripple said.

The comparatively pristine conditions of a national park allowed this type of research to make “cause and effect” studies more feasible, the scientists point out.

“The removal of wolves for 70 years – and then their return – actually set the stage for a scientific experiment with fairly compelling results,” Beschta said.

In a larger context, the studies also raise valid questions about other complex and poorly understood interactions between plants, animals, and wildlife in disturbed ecosystems across much of the American West, and perhaps elsewhere in the world, the scientists say. In some areas of the West, the disappearance of up to 90 percent of the aspen trees has been documented – another species of plant that is also highly vulnerable to animal browsing when it is young.

“The last period when aspen trees in Yellowstone escaped the effects of elk browsing to generate trees into the forest overstory was the 1920s,” Ripple said, “which is also when wolves were removed from the park.”

But in at least one place – America’s first national park – there is now cause for hope. While it is too early to confirm the widespread recovery of cottonwoods and willows, the reintroduction of wolves appears to have put a stop to major declines in the survival of these plants, the researchers found.

“One point that should not be missed is this is actually great news for the potential recovery of cottonwood trees and mature willows in Yellowstone National Park,” Ripple said. “We now have a pretty good idea why they were in decline and the return of wolves should help pave the way for their recovery.

“Even though it may take a very long time, for a change it looks like we’re headed in the right direction.”

http://www.sciencedaily.com/releases/2003/10/031029064909.htm

 

http://forest.mtu.edu/kidscorner/ecosystems/wolf.html

Yellowstone National Park Wolf Reintroduction is changing the face of the greater Yellowstone ecosystem

By Brodie Farquhar, Yellowstone Journal and YellowstonePark.com

On a quiet spring morning, a resounding “Slap!” reverberates through the air above a remote stream leading to Lake Yellowstone. Over much of the past century, it has been a rarely heard noise in the soundscape that is Yellowstone National Park, but today is growing more common-the sound of a beaver slapping its tail on the water as a warning to other beavers.Yellowstone Wolf Project.

Ten years ago, when the grey wolf was reintroduced into the Greater Yellowstone Ecosystem, there was only one beaver colony in the park, said Doug Smith, a wildlife biologist in charge of the

Today, the park is home to nine beaver colonies, with the promise of more to come, as the reintroduction of wolves continues to astonish biologists with a ripple of direct and indirect consequences throughout the ecosystem.

A flourishing beaver population is just one of those consequences, said Smith.

A beaver’s tale of elk
What happened, said Smith, is that the presence of wolves triggered a still-unfolding cascade effect among animals and plants-one that will take decades of research to understand.

“It is like kicking a pebble down a mountain slope where conditions were just right that a falling pebble could trigger an avalanche of change,” Smith mused.

So how did this avalanche of change work out for the beaver?

To answer that, you have to go back to the 1930s, when the wolf was killed off in Yellowstone. Even though Yellowstone elk were still preyed upon by black and grizzly bears, cougars and, to a lesser extent, coyotes, the absence of wolves took a huge amount of predatory pressure off the elk, said Smith. As a result, elk populations did very well-perhaps too well. Two things happened: the elk pushed the limits of Yellowstone’s carrying capacity, and they didn’t move around much in the winter-browsing heavily on young willow, aspen and cottonwood plants. That was tough for beaver, who need willows to survive in winter.

Healthier willow stands
This created a counterintuitive situation. Back in 1968, said Smith, when the elk population was about a third what it is today, the willow stands along streams were in bad shape. Today, with three times as many elk, willow stands are robust. Why? Because the predatory pressure from wolves keeps elk on the move, so they don’t have time to intensely browse the willow.

Indeed, a research project headed by the U.S. Geological Survey in Ft. Collins found that the combination of intense elk browsing on willows and simulated beaver cuttings produced stunted willow stands. Conversely, simulated beaver cutting without elk browsing produced verdant, healthy stands of willow. In the three-year experiment, willow stem biomass was 10 times greater on unbrowsed plants than on browsed plants. Unbrowsed plants recovered 84 percent of their pre-cut biomass after only two growing seasons, whereas browsed plants recovered only 6 percent.

With elk on the move during the winter, willow stands recovered from intense browsing, and beaver rediscovered an abundant food source that hadn’t been there earlier.

As the beavers spread and built new dams and ponds, the cascade effect continued, said Smith. Beaver dams have multiple effects on stream hydrology. They even out the seasonal pulses of runoff; store water for recharging the water table; and provide cold, shaded water for fish, while the now robust willow stands provide habitat for songbirds.

“What we’re finding is that ecosystems are incredibly complex,” he said. In addition to wolves changing the feeding habits of elk, the rebound of the beaver in Yellowstone may also have been affected by the 1988 Yellowstone fires, the ongoing drought, warmer and drier winters and other factors yet to be discovered, Smith said.

Research bonanza
Biologists are often faced with the grim task of documenting the cascade effects of what happens when a species is removed from an ecosystem, by local extirpation or even extinction. In Yellowstone, biologists have the rare, almost unique, opportunity to document what happens when an ecosystem becomes whole again, what happens when a key species is added back into the ecosystem equation.

“In the entire scientific literature, there are only five or six comparable circumstances,” Smith said. “What we’re seeing now is a feeding frenzy of scientific research.”

Scott Creel, an ecology professor at Montana State University, is hip-deep in that feeding frenzy.

“My research has been in the Gallatin Canyon,” said Creel, where elk inhabit four drainages. Wolves come and go, he said, enabling him to study what elk do in the presence and absence of wolves.

“Elk have proven to be pretty adaptable,” Creel said. “When wolves are around, they’re more vigilant and do less foraging.”

Elk move into heavy timber when wolves are around, Creel added, but return to the grassy, open meadows when wolves go away. Creel and other researchers are still working out what that means in terms of the elk’s diet and whether there are costs associated with this behavior.

Rather surprisingly, elk herd size breaks up into smaller units when wolves are around, said Creel, who had expected herd size to get bigger as a defense mechanism. “I think they’re trying to avoid encounters with wolves,” he said, by being more vigilant, moving into the timber and gathering in smaller herd units.

Food distributors
Researchers have also determined that wolves, in the recent absence of hard winters, are now the primary reason for elk mortality. Before wolf reintroduction, deep snows were the main determinant of whether an elk was going to die.

Researchers from the University of California at Berkeley determined that the combination of less snow and more wolves has benefited scavengers both big and small, from ravens to grizzly bears.

Instead of a boom and bust cycle of elk carrion availability-as existed before wolves and when winters were harder-there’s now a more equitable distribution of carrion throughout winter and early spring, said Chris Wilmers in the on-line journal Public Library of Science Biology. He added that scavengers that once relied on winter-killed elk for food now depend on wolf-killed elk. That benefits ravens, eagles, magpies, coyotes and bears (grizzly and black), especially as the bears emerge hungry from hibernation.

“I call it food for the masses,” said Ed Bangs, wolf recovery coordinator for the U.S. Fish and Wildlife Service. He said he was genuinely surprised by the vast web of life that is linked to wolf kills. “Beetles, wolverine, lynx and more,” he said. “It turns out that the Indian legends of ravens following wolves are true-they do follow them because wolves mean food.”

Brodie Farquhar covers natural resource issues as a freelance writer based in Lander, Wyoming.

 http://www.yellowstonepark.com/MoreToKnow/ShowNewsDetails.aspx?newsid=179

Published in: on September 24, 2009 at 12:17 pm  Leave a Comment  

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