OREGON STATE UNIVERSITY

environment and natural resources

Viruses associated with coral epidemic of “white plague”

CORVALLIS, Ore. – They call it the “white plague,” and like its black counterpart from the Middle Ages, it conjures up visions of catastrophic death, with a cause that was at first uncertain even as it led to widespread destruction – on marine corals in the Caribbean Sea.

Now one of the possible causes of this growing disease epidemic has been identified – a group of viruses that are known as small, circular, single-strand DNA (or SCSD) viruses. Researchers in the College of Science at Oregon State University say these SCSD viruses are associated with a dramatic increase in the white plague that has erupted in recent decades.

Prior to this, it had been believed that the white plague was caused primarily by bacterial pathogens. Researchers are anxious to learn more about this disease and possible ways to prevent it, because its impact on coral reef health has exploded.

“Twenty years ago you had to look pretty hard to find any occurrences of this disease, and now it’s everywhere,” said Nitzan Soffer, a doctoral student in the Department of Microbiology at OSU and lead author on a new study just published in the International Society for Microbial Ecology. “It moves fast and can wipe out a small coral colony in a few days.

“In recent years the white plague has killed 70-80 percent of some coral reefs,” Soffer said. “There are 20 or more unknown pathogens that affect corals and in the past we’ve too-often overlooked the role of viruses, which sometimes can spread very fast.”

This is one of the first studies to show viral association with a severe disease epidemic, scientists said. It was supported by the National Science Foundation.

Marine wildlife diseases are increasing in prevalence, the researchers pointed out. Reports of non-bleaching coral disease have increased more than 50 times since 1965, and are contributing to declines in coral abundance and cover.

White plague is one of the worst. It causes rapid tissue loss, affects many species of coral, and can cause partial or total colony mortality. Some, but not all types are associated with bacteria. Now it appears that viruses also play a role. Corals with white plague disease have higher viral diversity than their healthy counterparts, the study concluded.

Increasing temperatures that stress corals and make them more vulnerable may be part of the equation, because the disease often appears to be at its worst by the end of summer. Overfishing that allows more algae to grow on corals may help spread pathogens, researchers said, as can pollution caused by sewage outflows in some marine habitats.

Viral infection, by itself, does not necessarily cause major problems, the researchers noted. Many healthy corals are infected with herpes-like viruses that are persistent but not fatal, as in many other vertebrate hosts, including humans.

Media Contact: 
Source: 
Multimedia Downloads
Multimedia: 

Coral disease

Coral with white plague


Marine research

Taking samples

Overgrazing turning parts of Mongolian Steppe into desert

CORVALLIS, Ore. – Overgrazing by millions of sheep and goats is the primary cause of degraded land in the Mongolian Steppe, one of the largest remaining grassland ecosystems in the world, Oregon State University researchers say in a new report.

Using a new satellite-based vegetation monitoring system, researchers found that about 12 percent of the biomass has disappeared in this country that’s more than twice the size of Texas, and 70 percent of the grassland ecosystem is now considered degraded. The findings were published in Global Change Biology.

Overgrazing accounts for about 80 percent of the vegetation loss in recent years, researchers concluded, and reduced precipitation as a result of climatic change accounted for most of the rest. These combined forces have led to desertification as once-productive grasslands are overtaken by the Gobi Desert, expanding rapidly from the south.

Since 1990 livestock numbers have almost doubled to 45 million animals, caused in part by the socioeconomic changes linked to the breakup of the former Soviet Union, the report said. High unemployment led many people back to domestic herding.

The problem poses serious threats to this ecosystem, researchers say, including soil and water loss, but it may contribute to global climate change as well. Grasslands, depending on their status, can act as either a significant sink or source for atmospheric carbon dioxide.

“This is a pretty serious issue,” said Thomas Hilker, an assistant professor in the OSU College of Forestry. “Regionally, this is a huge area in which the land is being degraded and the food supply for local people is being reduced.

“Globally, however, all ecosystems have a distinct function in world climate,” he said. “Vegetation cools the landscape and plays an important role for the water and carbon balance, including greenhouse gases.”

Even though it was clear that major problems were occurring in Mongolia in the past 20 years, researchers were uncertain whether the underlying cause was overgrazing, climate change or something else. This report indicates that overgrazing is the predominant concern.

Mongolia is a semi-arid region with harsh, dry winters and warm, wet summers. About 79 percent of the country is covered by grasslands, and a huge surge in the number of grazing animals occurred during just the past decade - especially sheep and goats that cause more damage than cattle. Related research has found that heavy grazing results in much less vegetation cover and root biomass, and an increase in animal hoof impacts.

Collaborators on this research included Richard H. Waring, a distinguished professor emeritus of forest ecology from OSU; scientists from NASA and the University of Maryland; and Enkhjargal Natsagdorj, a former OSU doctoral student from Mongolia. The work has been supported by NASA and OSU.

Media Contact: 
Source: 

Thomas Hilker, 541-737-2608

Multimedia Downloads
Multimedia: 

Overgrazing in Mongolia

Grazing in Mongolia


Grazing in Mongolia

Mongolian herders

Iron, steel in hatcheries may distort magnetic “map sense” of steelhead

CORVALLIS, Ore. – Exposure to iron pipes and steel rebar, such as the materials found in most hatcheries, affects the navigation ability of young steelhead trout by altering the important magnetic “map sense” they need for migration, according to new research from Oregon State University.

The exposure to iron and steel distorts the magnetic field around the fish, affecting their ability to navigate, said Nathan Putman, who led the study while working as a postdoctoral researcher in the Department of Fisheries and Wildlife, part of OSU’s College of Agricultural Sciences.

Just last year Putman and other researchers presented evidence of a correlation between the oceanic migration patterns of salmon and drift of the Earth’s magnetic field. Earlier this year they confirmed the ability of salmon to navigate using the magnetic field in experiments at the Oregon Hatchery Research Center. Scientists for decades have studied how salmon find their way across vast stretches of ocean.

“The better fish navigate, the higher their survival rate,” said Putman, who conducted the research at the Oregon Hatchery Research Center in the Alsea River basin last year. “When their magnetic field is altered, the fish get confused.”

Subtle differences in the magnetic environment within hatcheries could help explain why some hatchery fish do better than others when they are released into the wild, Putman said. Stabilizing the magnetic field by using alternative forms of hatchery construction may be one way to produce a better yield of fish, he said.

“It’s not a hopeless problem,” he said. “You can fix these kinds of things. Retrofitting hatcheries with non-magnetic materials might be worth doing if it leads to making better fish.”

Putman’s findings were published this week in the journal Biology Letters. The research was funded by Oregon Sea Grant and the Oregon Department of Fish and Wildlife, with support from Oregon State University. Co-authors of the study are OSU’s David Noakes, senior scientist at the Oregon Hatchery Research Center, and Amanda Meinke of the Oregon Hatchery Research Center.

The new findings follow earlier research by Putman and others that confirmed the connection between salmon and the Earth’s magnetic field. Researchers exposed hundreds of juvenile Chinook salmon to different magnetic fields that exist at the latitudinal extremes of their oceanic range.

Fish responded to these “simulated magnetic displacements” by swimming in the direction that would bring them toward the center of their marine feeding grounds. In essence, the research confirmed that fish possess a map sense, determining where they are and which way to swim based on the magnetic fields they encounter.

Putman repeated that experiment with the steelhead trout and achieved similar results. He then expanded the research to determine if changes to the magnetic field in which fish were reared would affect their map sense. One group of fish was maintained in a fiberglass tank, while the other group was raised in a similar tank but in the vicinity of iron pipes and a concrete floor with steel rebar, which produced a sharp gradient of magnetic field intensity within the tank. Iron pipes and steel reinforced concrete are common in fish hatcheries.

The scientists monitored and photographed the juvenile steelhead, called parr, and tracked the direction in which they were swimming during simulated magnetic displacement experiments. The steelhead reared in a natural magnetic field adjusted their map sense and tended to swim in the same direction. But fish that were exposed to the iron pipes and steel-reinforced concrete failed to show the appropriate orientation and swam in random directions.

More research is needed to determine exactly what that means for the fish. The loss of their map sense could be temporary and they could recalibrate their magnetic sense after a period of time, Putman said. Alternatively, if there is a critical window in which the steelhead’s map sense is imprinted, and it is exposed to an altered magnetic field then, the fish could remain confused forever, he said.

“There is evidence in other animals, especially in birds, that either is possible,” said Putman, who now works for the National Oceanic and Atmospheric Administration. “We don’t know enough about fish yet to know which is which. We should be able to figure that out with some simple experiments.”

Media Contact: 
Source: 

Nathan Putman, 205-218-5276 or Nathan.putman@gmail.com; or David Noakes, 541-737-1953, David.noakes@oregonstate.edu

Reflections on wilderness featured at Corvallis Science Pub

CORVALLIS, Ore. – Fifty years ago, Congress passed the Wilderness Act, which today protects nearly 110 million acres in the United States. At the June 9 Corvallis Science Pub, Cristina Eisenberg, an Oregon State University conservation biologist, will discuss why intact wilderness areas matter more today than they did in 1964.

The Science Pub presentation is free and open to the public and begins at 6 p.m. in the Majestic Theater, 115 S.W. Second St. in Corvallis.

Eisenberg’s intimate acquaintance with wilderness stems from 20 years of living with her family in a cabin adjacent to the Bob Marshall Wilderness in Montana. At 1 million acres, it comprises the second-largest wilderness area in the lower 48 states.

In her research, she studies interactions among wolves, elk, aspen and fire. In Rocky Mountain ecosystems, she has shown that relatively intact, large tracts of land are essential to create ecologically resilient landscapes. Such landscapes typically consist of extensive protected wilderness.

She will also read and show images from her recently published book, The Carnivore Way, in which she profiles the Crown of the Continent ecosystem, a 28-million-acre wildlife corridor that runs along the mountainous spine of North America.

Sponsors of Science Pub include Terra magazine at OSU, the Downtown Corvallis Association and the Oregon Museum of Science and Industry.

Media Contact: 
Source: 

Cristina Eisenberg, 541-737-7524

Businesses need to plan for, address impacts on biodiversity, new report indicates

CORVALLIS, Ore. – Businesses large and small need to begin the difficult work of assessing and addressing their impact on biodiversity and ecosystem services in order to reduce risk to natural resources in the future, according to a new report from Oregon State University researchers.

Biodiversity and ecosystem services refer to the variety and diversity of plants and animals in the ecosystem and the benefits that nature provides, respectively. They should be part of companies’ strategic planning, said Sally Duncan, director of the OSU Policy Analysis Lab in the School of Public Policy.

“This is an issue of risk management – it has to be part of a strategic plan,” Duncan said. “As one pioneer company leader put it, the greatest risk of all is not doing anything.”

The report, “The New Nature of Business: How Business Pioneers Support Biodiversity and Ecosystems Services,” provides a framework for companies to begin identifying and addressing their potential impacts on the ecosystem.

The report was published this month and is available at www.newnatureofbusiness.org. Partners in the multidisciplinary, international project include Oregon State University and the University of Sydney Business School. Funding comes from the National Science Foundation’s National Socio-Environmental Synthesis Center, with additional support from the University of Sydney Business School.

Biodiversity of plants, animals and microorganisms is essential to a properly functioning ecosystem. Ecosystem services are the benefits of such a system, and include goods such as food and fiber or services such as flood control or pest management.

But biodiversity is threatened by environmental degradation due to things such as habitat destruction and climate change. That, in turn, poses challenges for business leaders, who will have to deal with the ramifications, including pressure from consumers to improve business practices.

“There are many, many companies that have started doing important work on water conservation and energy conservation,” Duncan said. “Biodiversity and ecosystem services are much more complicated. They’re very hard to measure and most companies haven’t even thought about it yet.”

Corporate giants Dow Chemical Co., Pfizer Inc. and Wal-Mart Stores Inc., and smaller organizations such as the Eugene Water and Electric Board, are among the pioneers who are taking steps to address their impacts on biodiversity. Their efforts are highlighted in the report.

Pfizer created a Wildlife Management Team and employees are working to restore and enhance the wildlife on the company’s 2,200-acre manufacturing site in Michigan. Eugene Water and Electric is working with landowners and local government to change land management practices, rather than build a new water treatment plant and charge higher rates.

Researchers developed a decision-making framework to help other companies get started addressing their own impacts on biodiversity and ecosystems services. The hope is that business leaders will use and test the framework and share their experiences on the project website, Duncan said.

“Any change to a big organization is extremely difficult,” Duncan said. “If business leaders see a story on the website that they can relate to, it might seem less scary.”

Developing a tool to measure companies’ impacts on biodiversity and ecosystems services and making that tool available to companies around the world are some of the next steps for the project, she said.

Media Contact: 
Source: 

Sally Duncan, 541-737-9931 or Sally.duncan@oregonstate.edu

OSU again named green college by Princeton Review

CORVALLIS, Ore. – Oregon State University received 95 points out of a possible 99 as a ‘green’ school in the latest edition of “The Princeton Review’s Guide to 332 Green Colleges: 2014 Edition.”

The Princeton Review tallies its Green Rating scores based on institutional data it obtains from colleges in response to survey questions focused on alternative transportation, advancing sustainability, waste-diversion rate and other related topics.

“It’s great to be recognized by Princeton Review for a fourth year in a row,” said Brandon Trelstad, OSU’s sustainability coordinator. “I believe it’s OSU’s diverse and broad sustainability efforts that have gotten us this far.  Student efforts, specifically, have been key in maintaining our leadership role.”

The guide is the only free comprehensive resource of its kind. It can be downloaded at http://www.princetonreview.com/green-guide and http://www.centerforgreenschools.org/greenguide.  It does not rank schools hierarchically, but each school’s green score can be found in their school profile on the main site (http://www.princetonreview.com/).

“Sustainability at OSU is a campus-wide endeavor that includes areas of institutional strength, like research, diversity, affordability, sustainability coordination and governance,” Trelstad said. “We are lucky to have high on- and off-campus community involvement in addressing campus and community sustainability.”

Among OSU’s green highlights were an overall waste diversion rate of 40 percent, its environmentally based degrees including ecological engineering, and the fact that the campus is in the process of bringing online five planned ground-mounted solar electrical arrays that will generate 2.9 megawatts of solar power.

"Best of all, OSU will help you put that academic knowledge into practice; it hosts a Nonprofit Career Day, with significant participation from national and local green groups," the guide states.

The Princeton Review created its "Guide to 332 Green Colleges" in partnership with the Center for Green Schools (www.usgbc.org) at the U.S. Green Building Council (USGBC)), with generous support from United Technologies Corp. (www.utc.com), founding sponsor of the Center for Green Schools.

Media Contact: 
Source: 

Brandon Trelstad, 541-737-3307; Brandon.trelstad@oregonstate.edu

2014 Starker Lectures at OSU to explore “Working Forests”

CORVALLIS, Ore. – The 2014 Starker Lecture Series at Oregon State University will begin on Thursday, Feb. 6, when speaker John Gordon outlines the future of forestry in Oregon. The theme for this year’s series is “Working Forests Across the Landscape.”

Gordon is the Pinchot Professor emeritus and former dean of the Yale University School of Forestry and Environmental Studies. His free public talk, which begins at 3:30 p.m. in Richardson Hall Room 107, is titled “Forestry Diversity: A Key to Oregon’s Future.”

The Starker Lectures are sponsored by the OSU College of Forestry and funded primarily through a donation by the Starker family in memory of T.J. and Bruce Starker, late leaders of the Oregon forest industry, with support from the college and the Oregon Forest Resources Institute. Each year, the lecture series explores forestry issues in the Northwest and beyond.

Other events in the 2014 series include:

  • Feb. 27 Lecture – “A Luxuriant Landscape: Oregon’s Working Forest Landscapes, an Ecological Perspective,” by Tom Spies, a research forester with the U.S. Forest Service’s Pacific Northwest Research Station (3:30 to 5 p.m., Richardson Hall 107);
  • April 24 Lecture – “Beyond Boundaries: Social Challenges and Opportunities in Forest Landscape Management,” by Paige Fischer, a research social scientist with the U.S. Forest Service’s Western Wildland Environmental Threat Assessment Center (3:30 to 5 p.m., Richardson Hall 107);
  • May 29 Capstone Field Trip – A tour of the Cool Soda All Lands Collaborative Project in Linn County, led by representatives of Cascade Timber Consulting, South Santiam Watershed Council, U.S. Forest Service, and the Sweet Home Ranger District (9 a.m. to 4 p.m.). Registration is required by May 20.

More information on the Starker Lectures is available at: http://starkerlectures.forestry.oregonstate.edu/

Media Contact: 
Source: 

Jessica Fontaine, 541-737-3161; Jessica.fontaine@oregonstate.edu

Climate center at OSU gets major grant to study forest mortality

CORVALLIS, Ore. – Oregon State University has received a five-year, $4 million grant from the United States Department of Agriculture to investigate increasing impacts of drought, insect attacks and fires on forests in the western U.S., and to project how the influence of climate change may affect forest die-offs in the future.

The researchers will also enhance an earth system model to allow them to predict when forests are becoming vulnerable to physiological stress and then create strategies to minimize impacts of climate, insects and fire.

“The western United States has gone through two decades of devastating forest loss and we don’t even fully know why it happened, much less how to predict these events,” said Philip Mote, director of the Oregon Climate Change Research Institute at OSU and a principal investigator on the grant. “Certainly wildfire, bark beetle infestation and drought play a role, but the intersection of these factors with forest management decisions hasn’t been well-explored.

“A change in severity of drought, for example, can make the difference between trees losing some needles and wiping out the entire stand,” added Mote, a professor in the College of Earth, Ocean, and Atmospheric Sciences at OSU. “The margin between life and death in the forest can be rather small.”

Other lead investigators from OSU on the project include Beverly Law, a professor in the Department of Forest Ecosystems and Society, who will focus on modeling forest processes with the Community Land Model; and Andrew Plantinga, a professor in the Department of Applied Economics, whose expertise is on the economics of land use, climate change and forests.

“Climate variation and extremes can impact trees differently depending on species-specific traits that determine how they compete and respond to environmental conditions,” Law said. “We know little about how physiological limits vary by species, and have not incorporated such knowledge in earth system models.”

The OSU researchers note that forest management decisions could potentially play a role during periods of drought, for example. Drought-stressed trees become vulnerable when they experience vapor pressure deficits – and cannot take in enough water to sustain them, or to remain vigorous enough to help repel invading bark beetles, said Law, who is co-lead principal investigator on the project.

An excess of trees in an area of limited water might benefit from targeted thinning so fewer trees remain to compete for the same amount of water, Law noted. However, forests that already have low densities “are not expected to respond well,” she said.

“What we don’t know,” Mote said, “is what the threshold is between stress and mortality, which trees to thin and how many, and whether such a strategy not only works, but is economically feasible for landowners.”

Law said the intervention strategies “should not result in potentially harmful ecological impacts on habitat and soil quality.”

Among the goals of the project are to:

  • Improve the ability of a leading land surface model to predict tree mortality;
  • Map the vulnerability of western forests to mortality under present and future climate conditions,  particularly in Oregon, Washington, California and Idaho;
  • Apply forest vulnerability data to forest sector models to help land managers better predict ecological and economic outcomes, including timber production, forest recreation and water use.

As part of the study, the researchers will run computer models that will utilize a crowd-sourced computing effort called Weatherathome.net, through which a network of thousands of volunteers will use their home computers to run climate model scenarios. Such a network can equal or exceed the output of a supercomputer.

The OSU grant is part of the inter-agency Decadal and Regional Climate Prediction Using Earth System Models Program, which is coordinated by the National Science Foundation and includes USDA and the Department of Energy.

Media Contact: 
Source: 

Phil Mote, 541-737-5694

Multimedia Downloads
Multimedia: 

Dying trees

Forest die-off

Of bears and berries: return of wolves aids grizzly bears in Yellowstone

CORVALLIS, Ore. – A new study suggests that the return of wolves to Yellowstone National Park is beginning to bring back a key part of the diet of grizzly bears that has been missing for much of the past century – berries that help bears put on fat before going into hibernation.

It’s one of the first reports to identify the interactions between these large, important predators, based on complex ecological processes. It was published today by scientists from Oregon State University and Washington State University in the Journal of Animal Ecology.

The researchers found that the level of berries consumed by Yellowstone grizzlies is significantly higher now that shrubs are starting to recover following the re-introduction of wolves, which have reduced over-browsing by elk herds. The berry bushes also produce flowers of value to pollinators like butterflies, insects and hummingbirds; food for other small and large mammals; and special benefits to birds.

The report said that berries may be sufficiently important to grizzly bear diet and health that they could be considered in legal disputes – as is white pine nut availability now - about whether or not to change the “threatened” status of grizzly bears under the Endangered Species Act.

“Wild fruit is typically an important part of grizzly bear diet, especially in late summer when they are trying to gain weight as rapidly as possible before winter hibernation,” said William Ripple, a professor in the OSU Department of Forest Ecosystems and Society, and lead author on the article. “Berries are one part of a diverse food source that aids bear survival and reproduction, and at certain times of the year can be more than half their diet in many places in North America.”

When wolves were removed from Yellowstone early in the 1900s, increased browsing by elk herds caused the demise of young aspen and willow trees – a favorite food – along with many berry-producing shrubs and tall, herbaceous plants. The recovery of those trees and other food sources since the re-introduction of wolves in the 1990s has had a profound impact on the Yellowstone ecosystem, researchers say, even though it’s still in the very early stages.

“Studies like this also point to the need for an ecologically effective number of wolves,” said co-author Robert Beschta, an OSU professor emeritus. “As we learn more about the cascading effects they have on ecosystems, the issue may be more than having just enough individual wolves so they can survive as a species. In some situations, we may wish to consider the numbers necessary to help control overbrowsing, allow tree and shrub recovery, and restore ecosystem health.”

As wolves help reduce elk numbers in Yellowstone and allow tree and shrub recovery, researchers said, this improves the diet and health of grizzly bears. In turn, a healthy grizzly bear population provides a second avenue of control on wild ungulates, especially on newborns in the spring time.

Yellowstone has a wide variety of nutritious berries – serviceberry, chokecherry, buffaloberry, twinberry, huckleberry and others – that are highly palatable to bears. These shrubs are also eaten by elk and thus likely declined as elk populations grew over time. With the return of wolves, the new study found the percentage of fruit in grizzly bear scat in recent years almost doubled during August.

Because the abundant elk have been an important food for Yellowstone grizzly bears for the past half-century, the increased supply of berries may help offset the reduced availability of elk in the bears’ diet in recent years. More research is needed regarding the effects of wolves on plants and animals consumed by grizzly bears.

There is precedent for high levels of ungulate herbivory causing problems for grizzly bears, who are omnivores that eat both plants and animals. Before going extinct in the American Southwest by the early 1900s, grizzly bear diets shifted toward livestock depredation, the report noted, because of lack of plant-based food caused by livestock overgrazing. And, in the absence of wolves, black bears went extinct on Anticosti Island in Canada after over-browsing of berry shrubs by introduced while-tailed deer.

Increases in berry production in Yellowstone may also provide a buffer against other ecosystem shifts, the researchers noted – whitebark pine nut production, a favored bear food, may be facing pressure from climate change. Grizzly bear survival declined during years of low nut production.

Livestock grazing in grizzly bear habitat adjacent to the national park, and bison herbivory in the park, likely also contribute to high foraging pressure on shrubs and forbs, the report said. In addition to eliminating wolf-livestock conflicts, retiring livestock allotments in the grizzly bear recovery zone adjacent to Yellowstone could benefit bears through increases in plant foods.

The research was supported by private, state and federal agencies, including the U.S. Geological Survey.

Media Contact: 
Source: 

William Ripple, 541-737-3056

Multimedia Downloads
Multimedia: 

Grizzly bear
Grizzly bear


Serviceberry

Serviceberries

Global warming to cut snow water storage 56 percent in Oregon watershed

The study this story is based on is available online: http://bit.ly/13ZLzl1

CORVALLIS, Ore. – A new report projects that by the middle of this century there will be an average 56 percent drop in the amount of water stored in peak snowpack in the McKenzie River watershed of the Oregon Cascade Range -  and that similar impacts may be found on low-elevation maritime snow packs around the world.

The findings by scientists at Oregon State University, which are based on a projected 3.6 degree Fahrenheit temperature increase, highlight the special risks facing many low-elevation, mountainous regions where snow often falls near the freezing point. In such areas, changing from snow to rain only requires a very modest rise in temperature.

As in Oregon, which depends on Cascade Range winter snowpack for much of the water in the populous Willamette Valley, there may be significant impacts on ecosystems, agriculture, hydropower, industry, municipalities and recreation, especially in summer when water demands peak.

The latest study was one of the most precise of its type done on an entire watershed, and was just published in Hydrology and Earth System Sciences, with support from the National Science Foundation. It makes it clear that new choices are coming for western Oregon and other regions like it.

“In Oregon we have a water-rich environment, but even here we will have to manage our water resources differently in the future,” said Eric Sproles, who led this study as a doctoral student at OSU.

“In the Willamette River, for instance, between 60-80 percent of summer stream flow comes from seasonal snow above 4,000 feet,” he said. “As more precipitation falls as rain, there will more chance of winter flooding as well as summer drought in the same season. More than 70 percent of Oregon’s population lives in the Willamette Valley, with the economy and ecosystems depending heavily on this river.”

Annual precipitation in the future may be either higher or lower, the OSU researchers said. They did calculations for precipitation changes that could range 10 percent in either direction, although change of that magnitude is not anticipated by most climate models.

The study made clear, so far as snowpack goes, that temperature is the driving force, far more than precipitation. Even the highest levels of anticipated precipitation had almost no impact on snow-water storage, they said.

“This is not an issue that will just affect Oregon,” said Anne Nolin, a professor in the College of Earth, Ocean, and Atmospheric Sciences, and co-author of the study. “You may see similar impacts almost anywhere around the world that has low-elevation snow in mountains, such as in Japan, New Zealand, Northern California, the Andes Mountains, a lot of Eastern Europe and the lower-elevation Alps.”

The focus of this study was the McKenzie River, a beautiful, clear mountain river that rises in the high Cascade Range near the Three Sisters volcanoes, and supplies about 25 percent of the late summer discharge of the Willamette River. Researchers said this is one of the most detailed studies of its type done on a large watershed.

Among the findings of the study:

  • The average date of peak snowpack in the spring on this watershed will be about 12 days earlier by the middle of this century.
  • The elevation zone from 1,000 to 1,500 meters will lose the greatest volume of stored water, and some locations at that elevation could lose more than 80 days of snow cover in an average year.
  • Changes in dam operations in the McKenzie River watershed will be needed, but will not be able to make up for the vast capability of water storage in snow.
  • Summer water flows will be going down even as Oregon’s population surges by about 400,000 people from 2010 to 2020.
  • Globally, maritime snow comprises about 10 percent of the Earth’s seasonal snow cover.
  • Snowmelt is a source of water for more than one billion people.
  • Precipitation is highly sensitive to temperature and can fall as rain, snow, or a rain-snow mix.

The model developed for this research, scientists said, could be readily adapted to help other regions in similar situations determine their future loss of snow water in the future.

Media Contact: 
Source: 

Eric Sproles, 541-729-1377

Multimedia Downloads
Multimedia: 

McKenzie River watershed

McKenzie River watershed


McKenzie River

McKenzie River