OREGON STATE UNIVERSITY

environment and natural resources

Earth-friendly technologies to be discussed at Greener Nano conference

CUPERTINO, Calif – Despite increasing awareness of the demand for environmentally safe consumer products, barriers for commercial production remain – a dichotomy especially severe in the rapidly growing field of nanotechnology.

To address this situation, the Oregon Nanoscience and Microtechnologies Institute (ONAMI) and the Safer Nanomaterials and Manufacturing Initiative (SSNI) will host the Greener Nano 2011 Conference and Workshop May 1-3 in California. The events will be at the Hotel Valencia in San Jose and Hewlett-Packard Co.'s site in Cupertino.

"There is a national push to think about the safe development of nanotech from its conception," said Robert Tanguay, a professor of molecular toxicology in Oregon State University's College of Agricultural Sciences, and a leader in national initiatives for safety in nanotechnology. "There is a shift toward greening the technology right out of the gate, rather than as an afterthought. It's the difference in proactive versus reactive design in safer technologies."

Nanotechnologies have experienced rapid growth in the last decade, and nanoparticles are now found in consumer products ranging from laundry soap to eyeliner. However, their environmental impact is largely unknown, and increasingly controversial.

A recent study from Queen's University found that the silver nanoparticles used in many consumer products may harm beneficial soil bacteria, potentially resulting in a hostile environment for plants. While it remains unclear if these effects were directly caused by silver nanoparticles, it is known that most products in commerce have not had the advantage of being designed from the ground up with a mind toward greener innovation, said Tanguay.

The upcoming workshop and conference will bring together policymakers, industry, students and researchers to discuss advancing a "greener" nanotechnology. Plenary speaker for the conference is  Stanley Williams, senior fellow at Hewlett-Packard Laboratories and founding director of the HP Quantum Science Research Group. He will discuss the sustainable development of nanotechnology in the next decades.

More information on the conference is available at http://oregonstate.edu/conferences/event/greenernano/index.htm

About the Oregon Nanoscience and Microtechnologies Institute: ONAMI is the first Signature Research Center for the advancement of research toward the commercialization of innovative technology within Oregon and the Northwest. It represents an unprecedented collaboration between Oregon's three public research universities - University of Oregon, Oregon State University, Portland State University - and the Pacific Northwest National Laboratory, the state of Oregon, and the region's high-technology industries.

Source: 

Robert Tanguay, 541-737-6514

Bill Gates Sr. to speak at Oct. 19 ARCS Foundation Scholar Awards Luncheon in Portland

PORTLAND, Ore. -- Bill Gates, Sr., co-chair of The Bill and Melinda Gates Foundation, will be the keynote speaker for the ARCS Foundation Portland Chapter’s 2010 Scholar Awards Luncheon Oct. 19 at the Portland Art Museum.

Gates will speak on “Making a Difference: The Value of Philanthropy in Education,” particularly fitting as the Portland Chapter of ARCS (Achievement Rewards for College Scientists) will cross the $1-million mark for awards to graduate students in science and engineering at Oregon Health & Science University and Oregon State University this year.

“Gates has been a long-time supporter of ARCS both in Seattle and nationally,” said Caron Ogg, president of the Portland Chapter of ARCS . “In fact, it was a grant from the Gates Foundation that helped to launch the Portland Chapter six years ago.”

Also speaking will be Clayton Winkler, an ARCS Scholar and Ph.D. candidate in the Department of Neuroscience at OHSU, who will discuss his research on treating progressive neurological disease with a simple sugar.

At the Oct. 19 luncheon, 10 new ARCS Scholar Awards will be given to OHSU students and five to OSU students.  These scholars join 77 outstanding men and women ARCS scholars, collectively, currently studying at both institutions.

“The ARCS Foundation’s engagement with OSU and support of our students has been both gratifying and of great benefit to some very worthy young scholars ,” said Edward J. Ray, president of Oregon State University. “We are proud to be partners with the Portland Chapter and, along with OHSU, to be beneficiaries of the chapter’s vision and generosity in advancing scientific education and innovation.”

The ARCS Foundation was established in 1958 in Los Angeles by a group of women committed to keeping American technologically strong and internationally competitive. There currently are 17 ARCS chapters nationwide – all dedicated to advancing science in America through the provision of financial support to outstanding U.S. citizens completing graduate degrees in natural science, medicine and engineering.

For further information about the ARCS Foundation Portland Chapter or the October 19 luncheon, call (503) 297-8603 or email Portland@arcsfoundation.org.

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Creative writers sought for fall residency at Andrews Forest

CORVALLIS, Ore. – Applications are being sought from writers interested in a one-week fall residency at the H.J. Andrews Experimental Forest.

The residency is part of the Long-Term Ecological Reflections program, which brings together writers, humanists and scientists to create a living, growing record of the forest and the relation of people to the forest.

Creative writers whose work in any genre reflects a keen awareness of the natural world and an appreciation for both scientific and literary ways of knowing are invited to apply. In 2003, the Spring Creek Project at Oregon State University, in collaboration with the Andrews Forest Long-Term Ecological Research Group, began inviting writers to spend weeklong residencies at the forest in order to provide ways of observing the land that complement the ways of science.

Last year’s writer-in-residence, Scott Russell Sanders, wrote an essay called “Mind in the Forest” during his stay. That essay, published in Orion magazine, was recently awarded the John Burroughs Award for an Outstanding Published Nature Essay.

Two earlier pieces of writing inspired by the Andrews Forest residencies also have appeared in Orion: Robert Michael Pyle’s “The Long Haul” (September/October 2004) and Alison Hawthorne Deming’s “The Web” (March/April 2007).

For the Andrews Forest residencies, writers are provided an apartment, access to the ancient forest and well-known research site, interaction with scientists, opportunities to have their writings included in The Forest Log, and an honorarium of $250. Specific dates for week-long residencies during September, October, or November can be negotiated around the writer’s schedule and availability of space. 

The application deadline is May 15. For complete application requirements, go to http://springcreek.oregonstate.edu/residencies.html#AndrewsResidency

Information about the Andrews Experimental Forest is available at http://andrewsforest.oregonstate.edu/

Media Contact: 
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Charles Goodrich, (541) 737-6198

Talk on ‘Where Does Our Food Come From?” held Tuesday, Dec. 1

CORVALLIS, Ore. – Ethno-botanist and author Gary Nabhan and local seed grower Frank Morton will explore the stories and cultural practices of food and seed production during a benefit event, on Tuesday, Dec. 1, beginning 7 p.m. at Mary’s River Grange in Philomath.

In their talk, “Where Does Our Food Come From?”, Nabhan and Morton will talk about what food production and supply systems reveal about a relationship to the land and to food. They also will explore other ways of imagining those relationships.

Their presentation is sponsored by Oregon State University’s Spring Creek Project for Ideas, Nature, and the Written Word, and is a benefit for Ten Rivers Food Web.

Nabhan is an award-winning ethno-botanist, author, poet and local foods advocate who learns from gardening and caring for his heritage breeds of sheep and turkeys. Some of his popular books include, “Arab/American: Landscape, Culture and Cuisine in Two Great Deserts,” Why Some Like It Hot: Food, Genes and Cultural Diversity,” and “Coming Home to Eat: The Pleasure and Politics of Local Foods.” Nabhan is a tenured research social scientist at University of Arizona.

Nabhan will be in Oregon as writer-in-residence at the H.J. Andrews Experimental Forest as part of the Long-Term Ecological Reflections program, with funding from the U.S. Forest Service.

Joining Nabhan will be local seed grower Frank Morton of Wild Garden Seeds. Morton brings almost 30 years of experience growing organic seeds for farmers, gardeners and Gathering Together Farm in Philomath.

Mary’s River Grange is located on Grange Hall Road south of Philomath (near Gathering Together Farm, at 25159 Grange Hall Road, Philomath).

Advance tickets (sliding scale, $7 to $20) are available at Corvallis Brewing Supply, 119 S.W. 4th St., Corvallis; and at GrassRoots Books and Music, 227 S.W. 2nd  St., Corvallis.

Media Contact: 
Source: 

Charles Goodrich, 737-6198

Satellite Studies of Ship Tracks Show Complex Influence of Pollution on Clouds

SAN FRANCISCO – New satellite studies analyzing the impact on clouds from ocean-going ships suggest that airborne particles from pollution or other causes can have a drying effect on some clouds, and a saturating effect on others, complicating global climate change models.

The key difference is what kind of clouds become “perturbed” by the pollution and what the overlying atmospheric conditions may be, the researchers say.

“One significant impact is that our observations suggest clouds affected by haze will offer less reflectivity and less of a cooling effect than most global climate change models suggest,” said Jim Coakley, a professor in the College of Oceanic and Atmospheric Sciences at Oregon State University and principal investigator in the study.

Coakley presented the findings today at the annual meeting of the American Geophysical Union in San Francisco.

The ships are not necessarily a major cause of pollution, but the particles they emit into the air affect the overlying clouds and these effects can be easily tracked by NASA satellites. The impact of those emissions on the clouds is providing researchers with new information about cloud “behavior.”

Previous studies by Coakley and OSU graduate student Matt Segrin found that particles emitted by ships led to smaller water droplets and a general drying out of the clouds. Yet most models suggested just the opposite – that increasing the number of particles should lead to more liquid in the droplets.

“What we found was that most of those earlier satellite observations were taken off the coast of California and Oregon, where the marine cloud bank was heavy and the air above it comparatively dry,” Coakley said. “The clouds tend to suck down the drier air above them and because the droplets are smaller than normal from the pollution, they evaporate more readily. That evaporation cools the dry air which then sinks, drawing in more air from above, and the pollution clouds end up drying themselves out.

“In our latest studies, using NASA’s Aqua and Terra satellites, we followed the ships past the marine deck and out to where the nearby pristine clouds are dissipating,” Coakley said. “There the ships’ emissions actually create a cloud where clouds would not otherwise appear. We think that the atmosphere above these regions isn’t as dry so that the polluted clouds with their smaller droplets survive, while the nearby unpolluted clouds dissipate because their larger droplets and the support of the relatively moist air aloft grow to form drizzle and fall from the sky.”

When water molecules condense, they attach to a particle and make droplets. When there are few particles in the air, the droplets are bigger and more likely to reach the saturation point and fall as precipitation. Where there is pollution, more particles are in the air and the droplets become smaller, making it harder for them to grow to drizzle-sized droplets.

Because the pollution generates more particles and the water molecules adhere to them, many scientists have speculated that the clouds would become brighter and more reflective. And since burning fossil fuels would likely result in more particles, overall reflectivity would be higher. But the ship track research points out that isn’t necessarily the case. Those same droplets draw in the warmer air above and essentially evaporate, actually lowering the reflectivity to levels below that predicted by climate models.

“Cloud formation and response to pollution and environmental conditions is the weakest part of global climate change studies,” Coakley said. “What we are learning from our studies of polluted clouds is helping us better understand how all clouds behave.”

The researchers use near-infrared radiation to identify exactly where clouds have been polluted from the ships’ emissions then look at either side of the cloud to see the impact of that interaction on the nearby pristine clouds. The ships act as a kind of laboratory, creating tracks of pollution emissions easily visible via satellite imagery.

Ships are not alone in their impacts on clouds, Coakley pointed out, they are merely a convenient tool for research. Coal plants, automobiles and other pollution-causing agents also send particles into the air that can have an effect on cloud formation and behavior.

“You should see the pollution plumes from Los Angeles and San Francisco in the satellite images,” Coakley said. “They are so intense it’s difficult to follow the ship tracks in those locations.”

Coakley has been studying ship tracks and their impacts on clouds for more than 15 years and says the research provides data that should be helpful to climate modelers. It is premature to jump to too many conclusions about how clouds will react to global climate change without more years of research, he emphasized.

“These impacts from the ship tracks are local,” he said, “and we’re just discovering how important the air above the clouds is to their response. There may be many other factors that affect how particles form droplets, how the clouds respond, and what the result is in terms of reflectivity.”

 

Media Contact: 
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Jim Coakley,
541-737-5686

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Ship clouds

This satellite image shows the clear path of a ship. Particles expelled by the ship’s engines pollute the clouds and cause them to have smaller droplets, affecting their reflectivity and behavior.

Condon Lecture to Discuss Reduction of Greenhouse Gases

CORVALLIS – The 2006 Condon Lecture at Oregon State University explores a positive approach to methods of reducing greenhouse gases at their sources.

Professor Lynn Orr of Stanford University will speak on “Technology in the Greenhouse: Changing the World’s Energy Systems” at OSU’s LaSells Stewart Center, on Wednesday, Oct. 4, at 8 p.m. The lecture is free and open to the public.

Orr, a member of the National Academy of Engineering, is director of Stanford’s Global Climate and Energy Project, in which energy and technology companies have come together to fund a project to directly address the global warming crisis. Orr’s talk will address reducing the atmosphere’s carbon dioxide levels by improving energy efficiency, using energy sources other than fossil fuels, and storing carbon dioxide below the Earth’s surface.

The Condon Lectureship was established to honor Thomas Condon, a pioneer in Oregon geology. Its purpose is to help interpret the results of significant scientific research for non-specialists.

Source: 

OSU Department
of Geosciences,
541-737-1244

‘Aquatic Invaders’ Educational Program Receives Coastal America Partnership Award

CORVALLIS, Ore. – “Aquatic Invaders” – an educational program that demonstrates simple steps to avoid the spread of invasive species – was honored by Coastal America during a recent national meeting of the Association of Zoos and Aquariums.

The project is a partnership between the association and the national Sea Grant network.

"Through this outstanding team effort, nearly 140 million people annually may learn how to protect our environment from aquatic invasive species, which cost our nation nearly $138 billion per year to control,” said Timothy R.E. Keeney, the U.S. Dept. of Commerce’s deputy assistant secretary for oceans and atmosphere.

Keeney presented the 2006 Coastal America Partnership Award to the Aquatic Invaders Toolkit Team, on behalf of President Bush and the 12 federal agencies of the Coastal America Partnership.

Samuel Chan, an Oregon Sea Grant Extension faculty member, was part of the science team.

Chan’s science team collaborated with zoo and aquarium educators to incorporate and package the materials into a format that will be adapted by zoo and aquaria educators for their public audiences.

Funded by a grant from the National Oceanic and Atmospheric Administration’s National Sea Grant College Program, "Aquatic Invaders" is a 20-minute program that includes audience participation. During the program the audience sees how one person can bring invasive species to an ecosystem. The program is designed for all ages and can be presented indoors or outdoors.

“The educators and audience members identify specific steps to take – such as cleaning boats immediately after they are taken out of the water, and properly caring for home aquariums and water gardens,” said Katie Mosher, North Carolina Sea Grant communications director and project coordinator.

The Coastal America Partnership was established in 1992 to protect, preserve and restore coastal watersheds by integrating federal actions with state and local government and non-governmental efforts. Federal partners include the Departments of Agriculture, Air Force, Army, Commerce, Defense, Energy, Housing and Urban Development, Interior, Navy, State and Transportation, as well as the Environmental Protection Agency and the Executive Office of the President.

Source: 

Samuel Chan,
503-679-4828

Conference to Explore Hydrologic Issues

CORVALLIS, Ore. – About 100 leading hydrologists from around the world are at Oregon State University today through Oct. 19 for an international workshop, “Towards a Community Action Plan for the Hydrological Sciences.”

The workshop explores ways to improve hydrologic predictions, reduce uncertainty in how watersheds function and learn how they can be better managed.

The event is one part of a decade-long initiative of the International Association of Hydrological Sciences called “PUB: Prediction in Ungauged Basins,” an effort to more effectively predict things like stream flow, sediment and water quality in places where they are not physically measured. Improved knowledge and systems in this area should allow for more effective and sustainable river basin management, experts say.

“These issues are of special importance to Oregonians, where much of the state is poorly gauged for water resources,” said Jeffrey McDonnell, who holds the Richardson Chair in Watershed Science in the OSU Department of Forest Engineering. “In addition, it’s poorly understood how water resources will change in response to climate and land use change.”

The workshop, which is designed for science professionals, is sponsored by the National Science Foundation, the OSU Institute for Water and Watersheds, and the Consortium of Universities for the Advancement of Hydrologic Science.

Meetings will explore such topics as estimating uncertainty, fiber optic hydrology, watershed classifications, new modeling approaches, remote sensing, and many other issues.

For two years, McDonnell will coordinate the PUB initiative among the researchers involved in the International Association of Hydrological Sciences, including the efforts of its 3,500 members, 65 member countries and three agencies of the United Nations.

Media Contact: 
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Jeffrey McDonnell,
541-737-8720

Researchers Discover Rich Methane Field off India, But Energy Potential Still Unknown

CORVALLIS, Ore. – An international team of scientists looking for gas hydrates off the coast of India has discovered a pair of methane hydrate reservoirs buried in the sediment below the Bay of Bengal, and though the idea of a new energy source is tantalizing, researchers say the technology does not yet exist to make these reservoirs commercially feasible.

A similar field of gas hydrates was found off the coast of Oregon a few years ago, said Marta Torres, a marine geochemist at Oregon State University and an investigator on the India and Oregon expeditions.

“No one yet knows how to extract methane for energy from such sources,” said Torres, an associate professor in OSU’s College of Oceanic and Atmospheric Sciences. “We’re still learning how much gas hydrate is in the sediment and we need to learn more about how much energy is required to mine it, as well as look at environmental concerns and possible hazards associated with extracting gas from these deposits.”

Since that Oregon cruise, scientists have learned a lot about the processes that form such reservoirs, according to Anne Trehu, a professor of oceanography at OSU, who was the lead scientist on the Oregon expedition.

“We now have a good understanding of how methane is generated and how it moves from deep sediments to the shallow areas where massive hydrate is formed,” Trehu said.

The India research cruise aboard the vessel JOIDES Resolution, funded by the Indian government, began in May and continued for more nearly four months. Project coordinator Timothy Collett, from the U.S. Geological Survey, assembled a team of scientists from various institutions and agencies in the United States to provide the expertise and equipment for the project. OSU, which has been involved in gas hydrate research for nearly a decade, was joined by the U.S. Department of Energy, the Scripps Institute of Oceanography, the University of Rhode Island and the University of New Hampshire. Some 40 U.S. scientists worked with colleagues from India, Canada and England on the research.

Gas hydrates are crystalline substances that look like packed snow, or ice. They form when water and methane are combined at high pressure and low temperature. Commonly found along the continental margins, they are created from the natural gas that occurs after decomposition of organic material deep within ocean sediments.

Though scientists remain unsure about the overall abundance of methane hydrates in the world’s marine sediments, many believe it is a significant fossil fuel reservoir – perhaps the most abundant untapped fossil fuel. However, mining of methane hydrate has been problematic because of its instability.

“When you bring it up from deep water, it just melts,” Torres said. “As soon these methane chunks get warm, or the pressure eases, they disappear and the methane escapes into the ocean or atmosphere, unless it is trapped and confined.”

Working around the temperature and pressure problems is feasible, she added, because scientists can preserve small methane hydrate samples in liquid nitrogen or cooled pressure chambers. However, finding a way to bring vast amounts of methane hydrates to the surface profitably and safely has yet to be discovered.

There are also questions about the amount of methane stored in these hydrates, scientists say. Some of the early estimates about methane content are probably too high, Torres says, because remote sensing techniques had not been calibrated. One of the goals of gas hydrate research at OSU is to use a suite of tools, including thermal imaging and measurements of electrical resistance, to identify how much methane is contained in the sediments of hydrate reservoirs.

The 9-meter sediment cores they extracted from a site near the Andaman Islands at the southern edge of the Bay of Bengal were comprised predominately of clay, which typically included 1 to 3 percent hydrate. However, in the more permeable ash layers, it wasn’t unusual to find sediment samples that contained 30 to 60 percent hydrates – and samples reached as high as 87 percent.

“The technicians had to be extremely careful with the core samples so they didn’t explode,” Torres said.

In their research, the scientists first mapped large areas of the Arabian Sea and the Bay of Bengal. On the western side of India, they found little evidence of methane hydrate – in large part because there was very little organic matter. However, in the Krishna-Godawari Basin, where the margin is more fractured, they found a large area filled with hydrates that were relatively shallow. Here the methane is pushed closer to the surface through cracks and results in near-surface deposits similar to those found off the shore of Oregon and parts of Canada.

Later in the cruise, they found another site bear gas hydrate near the Andaman Islands in a volcanic arc, where layers of ash acted as a reservoir to trap the methane and form hydrates.

One of the intriguing things about methane hydrate as an energy source, Torres noted, is that in some situations it could be renewable at a much faster rate than other fossil fuels, although still in a time scale long enough to be formidable.

“The Oregon hydrate field is relatively young – about a thousand years – and produces some big chunks of methane hydrate,” Torres noted. “We’re just beginning the work on the data from India. But organic material is being buried at a fast rate, so the process of creating methane is continual.”

Media Contact: 
Source: 

Marta Torres,
541-737-2902

Cougar Predation Important in Wildland Ecosystems

CORVALLIS, Ore. – The general disappearance of cougars from a portion of Zion National Park in the past 70 years has allowed deer populations to dramatically increase, leading to severe ecological damage, loss of cottonwood trees, eroding streambanks, and declining biodiversity.

This “trophic cascade” of environmental degradation, all linked to the decline of a major predator, has been shown in a new study to affect a broad range of terrestrial and aquatic species, according to scientists from Oregon State University.

The research was just published in the journal Biological Conservation and – like recent studies outlining similar ecological ripple effects following the disappearance of wolves in the American West – may cause land managers to reconsider the importance of predatory species in how ecosystems function.

The findings are consistent, researchers say, with predictions made more than half a century ago by the famed naturalist Aldo Leopold, often considered the father of wildlife ecology.

“When park development caused cougar to begin leaving Zion Canyon in the 1930s, it allowed much higher levels of deer browsing,” said Robert Beschta, an OSU professor emeritus of forest hydrology. “That set in motion a long cascade of changes that resulted in the loss of most cottonwoods along the streambanks and heavy bank erosion.”

“But the end result isn’t just loss of trees,” he said. “It’s the decline or disappearance of shrubs, wetland plants, amphibians, lizards, wildflowers, and even butterflies.”

Until recently, ecologists had a poor understanding of how the loss of an important predator, such as wolves or cougar, could affect such a broad range of other plant and animal species. But the evidence is now accumulating that primary predators not only have direct effects in influencing the population sizes of native grazing animals such as deer and elk – they also have indirect effects in changing their foraging behavior, in what has been called “the ecology of fear.”

That phenomenon, the scientists say, has been shown as vividly in Zion National Park as any other location they have ever studied. In Zion Canyon, which since the early 1900s has been a popular tourist attraction, cougars are virtually absent, mostly just scared off by the huge influx of human visitors.

With their natural enemy gone, growing and ravenous deer populations ate young cottonwood trees almost as quickly as they sprouted, robbing streambanks of shade and erosion protection.

As a result, the soils and vegetation of floodplains began to erode away. Other types of vegetation and the animal species dependent on them suffered. And unless something is done, cottonwoods in Zion Canyon may ultimately disappear in areas accessible to deer, the researchers said.

By contrast, a nearby roadless watershed has similar native ecology but is sufficiently remote that it still has an intact cougar population and far fewer mule deer. In contrast to Zion Canyon, streambanks in this watershed have nearly 50 times more young cottonwood trees as well as thriving populations of flowers, lizards, butterflies, and several species of water-loving plants that help stabilize stream banks, provide food-web support, and protect floodplains for use by many other animal species.

“The documentation of species abundance that we have in this study is very compelling,” said William Ripple, a professor in the OSU Department of Forest Resources and lead author on the study. Researchers did a systematic survey of channel dimensions, streambank condition, vegetation and species presence along each study site.

“These two canyons, almost side by side, have a similar climate and their ecosystems should be quite similar,” Ripple said. “But instead they are very different, and we hypothesize that the long-term lack of cottonwood recruitment associated with stream-side areas in Zion Canyon indicates the effects of low cougar and high deer densities over many decades.

"It's a great research setting and a great opportunity to assess the potential importance of a key predator,” he said. “We hope to conduct additional research in Zion National Park to further explore the findings of this initial study."

It’s important to remember, the researchers said, that the ultimate driver behind all of these changes is humans – in the case of Zion Canyon, simply by their presence. That canyon receives nearly three million human visitors a year, the adjacent North Creek a stray handful of hikers. Cougars in Zion Canyon were not intentionally killed or removed, they just left due to the increased presence of humans.

As findings such as this – the way cougars affect deer and wolves affect elk – continue to mount, land managers may have to acknowledge the potentially enormous impact of these grazing animals on other ecosystem processes, scientists say. This could open the way to new management options once the role of herbivores such as deer, elk, or other grazing animals is more fully understood.

In systems with wild ungulates, the sustainability of riparian habitats and biodiversity may require both predation on these herbivores as well as the fear of predation to further affect their behavior, the researchers concluded.

Ripple and Beschta considered other factors that may have played a role in loss of cottonwood trees in Zion Canyon, such as climate fluctuations or human interventions to stream channels, but concluded that those impacts could not have caused the enormous loss of trees and associated impacts to other biota that were found in the canyon.

The findings of this study may be relevant to other ecosystems in the U.S. and around the world where key predators have been removed, the researchers said, and high populations of native herbivores such as deer or elk – or domestic grazers such as cattle or sheep – affect native biodiversity.

This research was funded by the National Park Service.

Media Contact: 
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Robert Beschta,
541-737-4292

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cougar

A new study by researchers from Oregon State University found that cougars in Zion National Park have a profound impact on other aspects of the ecosystem, primarily by controlling deer populations and the ecosystem alterations related to deer browsing. (Photo by Washington Department of Fish and Wildlife)

Cougar effect graphic

Cougars are a top predator in this ecosystem, and their impact is outlined in this graphic