college of agricultural sciences

Oregon posts record $5.2 billion in agricultural sales in 2011

CORVALLIS, Ore. – Oregon's farmers, ranchers and fishing industry grossed a record $5.2 billion in 2011 – thanks to higher commodity prices, according to a report by the Oregon State University Extension Service.

Sales were up 19.1 percent from a revised $4.4 billion in 2010, the largest percentage increase since a 20.6 percent jump in 1979, said Bart Eleveld, the OSU Extension Service economist who compiled the report. It contains estimates for gross farmgate sales for 2011 and revised numbers for 2010 and 2009.

The last sales record was set in 2008 when sales were $4.9 billion. They plunged 15.1 percent in 2009, marking the biggest percentage drop in more than 30 years. Sales rebounded 5.8 percent in 2010.

"After two difficult years, Oregon agricultural sales have recovered from the impacts of the recession," said economist Bill Boggess, the executive associate dean of OSU’s College of Agricultural Sciences. "It was a much needed good year for the state’s farmers and ranchers, who play an increasingly vital role in Oregon’s economy and also keep food on our plates."

Of the 89 commodities identified in the report, 66 increased in sales compared with 2010.

Cattle was again the top commodity, with sales rising 12.8 percent to $799.8 million as droughts in Kansas, New Mexico, Oklahoma and Texas decreased the amount of grass for grazing and forced ranchers in those states to cut back their herds, said Chad Mueller, an OSU cattle expert in Union, Ore. Although U.S. inventories dropped, demand from consumers continued, so prices rose, he said.

Dairy products advanced from third place into the No. 2 slot at $523.9 million with a gain of 10.8 percent, fueled by rebounding milk prices, said Troy Downing, the dairy specialist with the OSU Extension Service.

Wheat moved from fourth place into third place with sales of $521.5 million, up 47.3 percent on a combination of increased acreage and yields, said OSU's wheat breeder, Bob Zemetra.

"It was an excellent year for wheat in terms of weather," Zemetra said. "It was also an excellent year for stripe rust disease, but farmers who applied fungicides or used varieties resistant to it had good crops. Yields were probably 30-40 percent higher than normal in parts of eastern Oregon."

Nursery crops moved down two notches to fourth place, but still managed to eke out a slight 0.7 percent increase to $516.4 million. Continued weakness in new home sales curbed the demand for landscaping, said economist Robin Cross, an OSU research associate who tracks the nursery industry.

Alfalfa hay again finished fifth with a 54.9 percent jump to $272.2 million thanks to higher prices for it, said Mylen Bohle, an agronomist with the OSU Extension Service in central Oregon. He added that with stronger milk prices, dairies were able to afford better quality – and thus more expensive – alfalfa hay.

For the first time, the report included commercial fishing sales, which were $91.5 million and were No. 13 on the list. If they hadn't been included, total sales would have increased 17 percent instead of the 19.1 percent but still would have set a record.

Marion County again led the state, reporting the most sales at $616.9 million, up from $568.2 million in the previous year.

Harvested land statewide totaled 3,184,326 acres in 2011 compared with 3,141,071 acres a year earlier. Of the 2011 total, grains accounted for 1,096,529 acres and hays and forage made up 1,025,764 acres.

The report, "2011 Oregon County and State Agricultural Estimates," is funded by the OSU Extension Service and is online at http://bit.ly/OSU_SR790-11.

The publication and many more estimates, including detailed historical and countywide data from 1976 onward, also are online via the Oregon Agricultural Information Network at http://oain.oregonstate.edu.

To compile the data, each year more than 70 OSU faculty members across the state estimate production based on observations and conversations with producers and others in agricultural businesses.

Media Contact: 

Bart Eleveld, 541-737-1409

Multimedia Downloads

Oregon cattle

A cow from Oregon State University's Harvey Ranch is herded outside Paisley, Ore. Oregon's ranchers sold $799.8 million of cattle in 2011, up 12.8 percent from the prior year, according to new report by the OSU Extension Service. Cattle was again the top agricultural commodity in terms of farmgate sales. (Photo by Aimee Brown)

Oregon dairy cows
Cows walk through a field at the Double J Jerseys organic dairy farm near Monmouth, Ore. Gross sales of Oregon dairy products increased 10.8 percent to $523.9 million in 2011 compared with the prior year, according to a new report by the Oregon State University Extension Service. Diary products were the second most important agricultural commodity in terms of farmgate sales in 2011. (Photo by Lynn Ketchum)

Economists say that high gas prices triggered the housing crisis in 2007

CORVALLIS, Ore. – A new study by economists at the University of California, Berkeley, and Oregon State University suggests that the U.S. housing crisis that started in 2007 and eventually led to a worldwide financial crisis was triggered by rapidly rising gas prices.

Economic bubbles have a long history – from the Dutch tulip mania in the 1600s to this latest housing bubble – and many factors can cause them to inflate, the researchers say.

But little is known about what actually triggers a bubble to burst.

"The key word is, 'triggered,'" said JunJie Wu, an OSU economist and one of the authors of the paper. "This theory recognizes the role of subprime mortgages and lax lending practices as inflating the housing bubble, but high gasoline prices provided the trigger that burst the bubble."

According to Wu and his fellow authors, Steven Sexton and David Zilberman, both economists from U.C. Berkeley, there is general agreement that the collapse of the housing market initiated the 2007 financial crisis. But there is no consensus on what prompted the housing market collapse.

In their study, the authors show how low gas prices during the housing boom, in combination with easy access to credit and new mortgage products, made suburban houses affordable to a new class of homeowners characterized by low incomes, high leverage, low credit worthiness and long work commutes.

"As a result," Wu said, "housing markets were vulnerable."

When oil prices more than doubled between late 2006 and 2008, sending gas prices to $4.15 per gallon, the calculus of suburban living changed, according to the researchers. High commute costs made suburban homes less valuable and mortgages less affordable for low-income homeowners. Some households could no longer meet mortgage obligations and others walked away from mortgage debt that exceeded the deflated market values of their homes.

"The real-estate mantra is 'location, location, location,'" Wu said. "If you find yourself in a location that is far from your work and transportation costs rise suddenly, that location can lower the value of your house."

The housing boom that began in the late 1990s, and the half-century of suburbanization that preceded it, produced a housing stock that by 2006 was particularly vulnerable to gas price shocks, according to the authors. Cheap and easy credit made owning a home possible for more households of limited means than at any other time in U.S. history.

Many suburban homes were located away from business centers and they tended to be in excess supply. Exurban areas grew twice as fast as metropolitan areas and as a consequence, commute durations grew. From 1970 to 2006, average vehicle miles traveled climbed 177 percent.

The researchers contend that a doubling of gas prices relative to historic averages made mortgage payments unaffordable for some, particularly for low-income households, and that mortgage default rates were higher in commuter towns.

The researchers considered only the impact of rising U.S. gasoline prices in this analysis, and they are quick to recognize many complex influences on the price of gas, including the global rise of the middle class and political unrest in oil-producing nations.

Does their research have implications for the current rise in gas prices?

"I expect that high gas prices will slow the economic recovery in general and the recovery of housing markets in particular," Wu said, "especially for communities tied to high transportation costs."

The paper, "How High Gas Prices Triggered the Housing Crisis: Theory and Empirical Evidence," was published in February 2012 by the University of California Center for Energy and Environmental Economics. View it at: http://www.uce3.berkeley.edu/WP_034.pdf.

Media Contact: 

JunJie Wu, 541-737-3060

Multimedia Downloads


JunJie Wu is an economist at Oregon State University. (Photo by Tiffany Woods)

Oregon students receive state 4-H scholarships

CORVALLIS, Ore. – Sixteen high school students from across Oregon received state 4-H scholarship awards in March through the Oregon State University Extension Service 4-H Youth Development Program.

More than 80 Oregon 4-H members competed for the scholarships, which range from $500 to $4,500. They were evaluated on their high scholastic achievement, 4-H projects and achievements, and personal essay describing their growth in 4-H.

A group of 10 4-H agents and volunteers from counties across the state, led by Mary Arnold, 4-H specialist in research and program evaluation, selected the scholarship winners.

Recipients of the 2012 State 4-H Scholarship Awards are listed below:

 Colton: Heidi Axmaker, Klein-Youngberg Family, $1,250;

Corvallis: Joshua Edwards, CHS Foundation, $1,000; Meredith Truax, Hofer, $1,500;

Eagle Creek: Kayla Cochran, Theiss Memorial, $1,000;

Gold Beach: Denise Craig/Parry, A. Lois Redman, $500;

Grants Pass: Caleb Lennon, Dietz Memorial, $500;

Heppner: Rebecca Jepsen, Myers Memorial, $1,000;

Hillsboro: Matthew Ferguson, O.M. Plummer, $500;

Imbler: Emilee Patterson, Klein-Youngberg Family, $1,250;

Independence: Emma Miller, Oregon 4-H Foundation Memorial, $1,000;

Lake Oswego: Colleen Moore, Martha MacGregor, $4,500; Olivia Vollan, Ellwood Miller Memorial, $1,000;

Madras: Kristin Jasa, Duane Johnson, $500;

Medford: Nicholas Morales, Klein-Youngberg Family, $1,250;

Roseburg: Sarah Gordon, Leeson Memorial, $1,000;

The Dalles: Carly Lowe, Minnick Memorial, $1,000.

 More information about the OSU 4-H Youth Development Program is available at http://oregon.4h.oregonstate.edu/


Helen Pease, 541-737-1314

Oregon Wine Research Institute director moves to research

CORVALLIS, Ore. – The director of Oregon State University's Oregon Wine Research Institute will step down this summer to return to full-time research and teaching at OSU.

Neil Shay joined OSU in 2010 as the first director of the Oregon Wine Research Institute and a professor of food science. His research focuses on how bioactive compounds in fruits and vegetables play a role in modulating chronic conditions such as diabetes and heart disease. Internationally recognized for the impact and significance of his research in nutrition, Shay serves on the editorial board for the Journal of Nutrition, the world's highest-ranked journal for experimental nutrition research.

Shay will continue as director while the university searches for a successor. His return to research will be as a professor in OSU's Department of Food Science and Technology where he will maintain his laboratory program and teach in the department's undergraduate and graduate programs.

"I can understand Neil's desire to continue his outstanding research relating to phytochemicals and once again to be able to share his rich base of knowledge and experience with our students," said Sonny Ramaswamy, dean of the College of Agricultural Sciences. "We appreciate his service as the institute's first director. Given the alignment of much of his research interest with grapes and wine, I expect he will make important additional contributions as a member of the institute's scientific team."

The Oregon Wine Research Institute was established as a partnership among Oregon's robust wine industry, state government and OSU's College of Agricultural Sciences. OSU's College of Business is a participant in the institute as well.

The institute builds partnerships that coordinate a wide range of research across the university and state that are specific to Oregon's wine and grape industry. Faculty in the institute communicate new research-based knowledge to grape growers and winemakers to help ensure that Oregon continues to produce top-quality wines.

As director, Shay led the hiring process for two new OSU faculty, one each in viticulture and enology. A comprehensive five-year strategic plan was developed for the institute and a pilot project grants program was initiated. Along with the Oregon Wine Board, the institute will co-sponsor the 2012 annual meeting of the American Society for Enology and Viticulture this June in Portland.

"The strategic vision for the institute developed under Neil's leadership will continue to guide its important collaborative research and its outreach to the industry," said David Adelsheim, one of the founders of Oregon's grape and wine industry who helped establish the Oregon Wine Research Institute. "We wish Neil well as he returns to the laboratory and classroom, where he has established a noteworthy record during his career."

Media Contact: 

Bill Boggess, 541-737-2331

Multimedia Downloads


Oregon State University's Neil Shay examines vines at OSU's Woodhall Vineyard near Alpine, Ore. (Photo by Lynn Ketchum.)

OSU to host gerontology conference April 11-12

CORVALLIS, Ore. – Oregon State University will host its 36th annual gerontology conference April 11-12, drawing geriatric experts from around the country who will present more than 40 educational workshops for health and human service professionals and the public.

Topics will include nutrition, dementia, diabetes, health care law, medications, hospice, Parkinson’s disease and alternative medicine.

Author and former social worker Wendy Lustbader will give the keynote speech at noon on the opening day. She teaches at the University of Washington and lectures nationally on chronic illness, aging and the needs of family caregivers. She co-authored "Taking Care of Aging Family Members" and wrote "Counting on Kindness: The Dilemmas of Dependency."

Albert Starr, a Portland surgeon who co-invented and implanted the world's first successful artificial heart valve, will be the keynote speaker at noon on the second day. Starr is a special adviser to the dean of medicine and the president at Oregon Health & Science University.

To register for the conference, go to www.osugero.org or call 541-737-9300. Attendees can also register at the door. Cost is $105 for one day and $195 for both days for those who sign up on or before April 5. The on-site registration fee is $130 for one day and $220 for two days. Discounts are offered for students, OSU employees and members of the OSU Retirement Association. Continuing education units are available for nurses, pharmacists, social workers, adult home care providers and nursing home and assisted living administrators.

The conference will take place at the CH2M HILL Alumni Center. The event is presented in part by the OSU Extension Service.

Media Contact: 

Sunita Vasdev, 541-737-2261

Two agriculture-inspired exhibits to feature Betty LaDuke this spring

CORVALLIS, Ore. – Two agriculture-inspired exhibits will be on display this spring at Oregon State University.

Giclée prints of paintings by Ashland artist Betty LaDuke will be featured March 20 through May 3 in the OSU Memorial Union building concourse. In addition, the OSU College of Agricultural Sciences will sponsor its 30th annual Art About Agriculture exhibition, the invitational "Cultivating the Land for a Harvest of Art," in the Giustina Gallery of the OSU LaSells Stewart Center, April 2-27.

In connection with the Art About Agriculture exhibit, LaDuke will give a talk, "Celebrating Slow Food: Drawings, Paintings and Wood Panels from Latin America, Asia, Africa and Oregon, USA." The talk runs from 2:30 to 4 p.m. on April 5 in the OSU LaSells Stewart Center Construction and Engineering Hall. It is sponsored in part by the Benton County Cultural Coalition and the Oregon Cultural Trust.

LaDuke has studied people on several continents since 1972. Her detailed sketches are rendered while she interacts with communities and farmers in their tasks of planting, growing and harvesting crops, tending livestock and marketing products. Her work celebrates Heifer International, a global nonprofit that provides cattle and other livestock to families in developing nations.

The artist will meet with OSU students in the MU concourse April 5 from 9:15 to 10:45 a.m. for a gallery talk. In conjunction with the exhibit, Heifer International’s documentary, "Dreaming Cows: Betty LaDuke," will be continually aired April 2–5 on a LCD screen located across from the MU Lounge.

LaDuke and friend Maribeth Collins donated two paintings by LaDuke to the Art About Agriculture permanent collection. An inaugural public display at the LaSells Stewart Center will feature the paintings concurrently with the annual show.

A set of primitive, hand-made tools from Indonesia, Central America and other locations will be on display in the Construction and Engineering display case at LaSells. They were donated by Leslie Burrill, widow of the late Larry Burrill, who was a professor in the OSU crop and soil science department and collected the tools in his research and travels.

Artists invited to display their work in the 2012 Art About Agriculture show are:

 Athena: Amy Rogers

Corvallis: Elaine Greene

Pendleton: Hiroko Cannon, Shari Dallas

Portland: Mary Josephson

San Rafael, Calif.: Lara Mehling

Holualoa, Hawaii: Cliff Johns, John Mydock

Hayden, Idaho: Kyle Paliotto

Bellingham, Wash.: Susan Bennerstrom

Spokane, Wash.: Mary Farrell

Walla Walla, Wash.: Mare Blocker


Shelley Curtis, 541-737-5534

Publication explains how to stop spread of Sudden Oak Death

CORVALLIS, Ore. – A newly updated publication outlines how the public can help stop the spread of a disease that has killed more than a million oak and tanoak trees in 14 coastal counties in California and thousands of tanoaks in Curry County, Ore.

"Stop the Spread of Sudden Oak Death" (EC1608) is available for free online at http://bit.ly/OSUESec1608 . Sudden Oak Death is the common name for the disease caused by a pathogen, Phytophthora ramorum.

"No one knows where the pathogen came from or how it was introduced in Oregon," said Dave Shaw, an Oregon State University plant pathologist. He and Ellen Goheen, plant pathologist with the U.S. Forest Service, are authors of the publication.

Other hosts for the disease are California black oak, Douglas-fir, grand fir, coast redwood, Pacific madrone, Pacific rhododendron, evergreen huckleberry, and many other tree and shrub species common in Oregon and Washington forests. The disease also causes branch and shoot dieback and leaf spotting on a large number of woodland and nursery plant species.

Hosts in the nursery trade include varieties of rhododendron, camellia and Pieris. A complete host list is at http://1.usa.gov/ybkqzQ

P. ramorum spreads naturally when mist and rain move spores within forest canopies – from treetops to stems and shrubs below, or across landscapes from treetop to treetop.

"Humans help spread the disease when they transport infected plants, plant parts or infested soil," Shaw said. "State and federal inspectors survey forests and nurseries in Oregon regularly to detect the disease. Infected plants and adjacent host plants are destroyed to slow spread of the disease."

State and federal quarantine regulations minimize the risk of new infections and prevent human-assisted spread. Complete texts of these regulations (ORS 603-052-1230 and 7 CFR 301.92) are on the Oregon Department of Agriculture and the U.S. Department of Agriculture websites.

People can spread Phytophthora ramorum across long distances by moving infected plants either purchased at a nursery or collected in the wild, or by moving infected wood, leaves, stems or soil.

The authors say there are things persons living, working, or visiting in the quarantined portion (map printed in publication) of Oregon's Curry County can do to help stop the spread. These include:

         • Become familiar with the most recent regulations on Sudden Oak Death (websites in publication).

         • Do not collect and remove host plants or plant parts from the forest.

         • Do not collect or remove soil.

         • Stay on established trails and respect trail closures.

         • Before leaving infested areas, clean and disinfect equipment such as saws, shovels and pruning equipment you used in infested areas; wash soil off tires, wheel wells and the undercarriage of your vehicle; clean soil off shoes, mountain bikes, horse hooves and pet paws.

         • For best protection, use a 10-percent bleach solution for cleaning.

         • Buy healthy plants from reputable nurseries.

For more information, contact the OSU Extension foresters in local county offices, or a forester working with a state or federal agency.

OSU Extension, Curry County, 29390 Ellensburg (Hwy 101), Gold Beach, OR 97444

541-247-6672 or 1-800-356-3986 http://extension.oregonstate.edu/curry/

Oregon Department of Forestry, http://egov.oregon.gov/ODF/

USDA Forest Service, Pacific Northwest Region, http://www.fs.usda.gov/goto/r6/fhp


Dave Shaw, 541-737-2845

OSU dean is tapped to lead top federal agency for food and agriculture

CORVALLIS, Ore. – Sonny Ramaswamy, dean of the College of Agricultural Sciences and director of the Oregon Agricultural Experiment Station at Oregon State University, has been named by President Obama to lead the National Institute of Food and Agriculture (NIFA) in Washington, D.C.

NIFA is the lead agency within the U.S. Department of Agriculture that supports research, education and extension programs in the nation's Land-Grant University System and partner organizations. NIFA impacts local communities through a national network of researchers and extension educators who respond to public inquiries and conduct informal, noncredit educational programs.  NIFA helps states respond to areas of public concern that affect agricultural producers, small business owners, youth, families, and communities and by providing grants to land-grant universities and researchers.

Oregon State University is Oregon's only land-grant university.

Ramaswamy joined Oregon State in 2009 and led the college during a time of decreasing state investments and a need for increasing extramural support for research and teaching. During his tenure, OSU's agricultural research programs grew to almost $60 million in grants and contracts. Private support for the College and student programs grew to $77 million.

"Three concepts – preeminence, purpose, impact – have framed Dr. Ramaswamy's leadership of the college and the Experiment Station," said OSU president Ed Ray. "His work in support of research and outreach will be particularly valuable as he moves into his new position as director of NIFA."

As an entomologist, Ramaswamy has studied the reproductive biology of insects and plant-insect interactions affecting wheat, cotton, beans, and other crops. Before coming to OSU, Ramaswamy led agricultural research programs in many agricultural settings, including Indiana, Kansas, and Mississippi.

At OSU, Ramaswamy helped establish the Leadership Academy, a program for undergraduates in the colleges of Agricultural Sciences and Forestry that helps develop career-ready skills in leadership and communications.

OSU's agricultural sciences programs include teaching, extension and research in food, agriculture, and natural resources throughout the state. Programs in fisheries, wildlife, botany and plant pathology, agricultural and resource economics, and environmental and molecular toxicology are ranked among the top in the nation.

"The vision and progressive thinking that Sonny has brought to the College of Agricultural Sciences has helped position Oregon State as one of the leading land grant universities in the nation," said Carl Casale, president of CHS Inc., a leading energy, grains and foods company.

Ramaswamy is the second OSU faculty member to be tapped for high-ranking positions in the Obama administration. In 2009, Jane Lubchenco was named as the under secretary of commerce for oceans and atmosphere and administrator of the National Oceanic and Atmospheric Administration, the nation's top science agency for climate, oceans, and the atmosphere.

Ramaswamy begins his new job later this spring. OSU's Office of the Provost will announce plans for leadership transition over the next few weeks.

Media Contact: 

Todd Simmons, 541-737-0790

Multimedia Downloads

Sonny Ramaswamy
Sonny Ramaswamy

Another mechanism discovered by which sulforaphane prevents cancer

CORVALLIS, Ore. – Researchers in the Linus Pauling Institute at Oregon State University have discovered yet another reason why the “sulforaphane”compound in broccoli and other cruciferous vegetables is so good for you – it provides not just one, but two ways to prevent cancer through the complex mechanism of epigenetics.

Epigenetics, an increasing focus of research around the world, refers not just to our genetic code, but also to the way that diet, toxins and other forces can change which genes get activated, or “expressed.” This can play a powerful role in everything from cancer to heart disease and other health issues.

Sulforaphane was identified years ago as one of the most critical compounds that provide much of the health benefits in cruciferous vegetables, and scientists also knew that a mechanism involved was histone deacetylases, or HDACs. This family of enzymes can interfere with the normal function of genes that suppress tumors.

HDAC inhibitors, such as sulforaphane, can help restore proper balance and prevent the development of cancer. This is one of the most promising areas of much cancer research. But the new OSU studies have found a second epigenetic mechanism, DNA methylation, which plays a similar role.

“It appears that DNA methylation and HDAC inhibition, both of which can be influenced by sulforaphane, work in concert with each other to maintain proper cell function,” said Emily Ho, an associate professor in the Linus Pauling Institute and the OSU College of Public Health and Human Sciences. “They sort of work as partners and talk to each other.”

This one-two punch, Ho said, is important to cell function and the control of cell division – which, when disrupted, is a hallmark of cancer.

“Cancer is very complex and it’s usually not just one thing that has gone wrong,” Ho said. “It’s increasingly clear that sulforaphane is a real multi-tasker. The more we find out about it, the more benefits it appears to have.”

DNA methylation, Ho said, is a normal process of turning off genes, and it helps control what DNA material gets read as part of genetic communication within cells. In cancer that process gets mixed up. And of considerable interest to researchers is that these same disrupted processes appear to play a role in other neurodegenerative diseases, including cardiovascular disease, immune function, neurodegenerative disease and even aging.

The influence of sulforaphane on DNA methylation was explored by examining methylation of the gene cyclinD2.

This research, which was published in the journal Clinical Epigenetics, primarily studied the effect on prostate cancer cells. But the same processes are probably relevant to many other cancers as well, researchers said, including colon and breast cancer.

“With these processes, the key is balance,” Ho said. “DNA methylation is a natural process, and when properly controlled is helpful. But when the balance gets mixed up it can cause havoc, and that’s where some of these critical nutrients are involved. They help restore the balance.”

Sulforaphane is particularly abundant in broccoli, but also found in other cruciferous vegetables such as cauliflower and kale. Both laboratory and clinical studies have shown that higher intake of cruciferous vegetables can aid in cancer prevention.

The research was supported by the National Institutes of Health and the OSU Environmental Health Sciences Center.

Media Contact: 

Emily Ho, 541-737-9559

Multimedia Downloads



Study: Forested riparian zones important to nitrogen control, stream health

CORVALLIS, Ore. – Human activities from agriculture to fossil fuel consumption have resulted in high levels of nitrates in many streams and rivers; now a new study suggests that nurturing riparian zone forests may be a key in maintaining healthy waterways.

Streams flowing through urban areas and agricultural lands may have some of the same ability to process nitrates as healthy forest streams – if they have adequate forest buffer zones along their banks, the researchers say.

Results of the research were just published the professional journal, Ecosystems.

“There are many important ways in which streamside trees help maintain healthy river systems,” said lead author Daniel Sobota, who conducted the research as part of his doctoral studies at Oregon State University. “The shade they offer may reduce the amount of sunlight reaching the stream, preventing excessive algae growth.

“Additionally, the leaves and woody debris generated by streamside forests hold the nitrogen and prevent it from being released downstream all at once,” added Sobota, whose Ph.D. was in fisheries and wildlife at OSU. “This ability of a stream to ‘take up’ the nitrogen can help reduce the impacts of nitrogen enrichment in human-altered river basins.”

In the study, which was funded by the National Science Foundation, Sobota and his colleagues looked at nine streams in Oregon’s Willamette Valley that flowed through forest, agricultural or urban landscapes. Among their goals was to discover how much nitrogen was absorbed by the streams near the source, and how much went downriver.

In tests in Willamette Valley streams, the researchers discovered that 21 to 72 percent of nitrates entering the waterway could be stored in leaves, wood and aquatic mosses within one kilometer downstream.

The inability of a stream or river to hold nitrogen can cause “eutrophication,” or excess algae growth that can die and lead to low-oxygen waters. Eutrophication has caused significant problems in the Gulf of Mexico where the Mississippi River drains, as well as in the Chesapeake Bay.

“Forested riparian buffers can help delay nitrogen from going downstream so there isn’t a large influx at one time that could trigger harmful algal blooms,” Sobota said. “From a management perspective, that is a desirable trait.”

Rivers also can process nitrogen naturally through a process called “denitrification.” When oxygen levels in the water are low, bacteria will consume nitrogen instead and release it into the atmosphere – mostly as a harmless gas, Sobota pointed out. However, previous studies by researchers at OSU and the U.S. Forest Service found that the Oregon streams in their study have lower-than-average rates of denitrification.

The reason is a combination of high-gradient streams, oxygenated water and porous streambeds, which are not conducive to denitrification, said Sherri Johnson, a research ecologist with the U.S. Forest Service and a courtesy professor of fisheries and wildlife at OSU.

“A lot of streams in Oregon have subsurface water flowing beneath the streambed through the gravel,” said Johnson, also an author on the Ecosystems article. “This ‘hyporheic’ flow intermixes with the river water and limits the anaerobic processes.”

Linda Ashkenas, a senior faculty research assistant in the Department of Fisheries and Wildlife at OSU and an author on the study, said maintaining complex river channels is also important to stream health.

“Human impacts on rivers have eliminated many of the braids and channels that existed naturally, causing water to flow downstream faster, carrying nitrates with it,” Ashkenas said. “River systems that are more complex slow the water down and give organisms time to filter out the nitrogen.”

Sobota is working with the U.S. Environmental Protection Agency office on the OSU campus as a National Research Council post-doctoral researcher. The Ecosystems study is part of a large, multi-institution project called Lotic Intersite Nitrogen Experiment II, or LINX II.

Media Contact: 

Daniel Sobota, 541-754-4833