OREGON STATE UNIVERSITY

environment and natural resources

Invasive parasite destroying fish species in Europe

CORVALLIS, Ore. - Researchers have discovered that a parasite carried by an invasive species of minnow is responsible for the dramatic declines and localized extinctions of a different minnow species in Europe during the past 40 years.

This parasite, which scientists have found can almost totally destroy the spawning success of the small sunbleak minnow, Leucaspius delineatus, may pose threats to the diversity and stability of freshwater ecosystems, and is genetically very similar to a parasite that can be deadly to salmon, researchers say.

The findings were published today in the journal Nature by researchers from Oregon State University, the Centre for Environment, Fisheries and Aquaculture Science in England, Idaho State University, and the Centre for Ecology and Hydrology in England.

"This solves a mystery that fisheries researchers have been studying for decades, about why sunbleak minnows have been disappearing from Europe, where they were once quite common," said Michael Kent, a professor of microbiology and director of the Center for Salmon Disease Research at OSU.

"And to find a parasite that can have such a devastating effect on spawning success is a little alarming," Kent said. "There are still a lot of unanswered questions here, including knowledge of the host range of the parasite. It's unknown if it would be pathogenic to other groups of fishes, such as salmonids."

The minnows involved, both the invasive species and those dying out, are rather small, grey, innocuous fish no more than a few inches long that do not by themselves have any major commercial value, Kent said. But they are an integral part of the biodiversity of freshwater streams and lakes across Europe, and form an important part of the food chain for other fish, he said. The European sunbleak is now listed as a threatened species among European freshwater fish.

"This is another aspect of the concerns about invasive species that you always have to watch for," Kent said. "The new minnows that moved in did not seem to be a big issue by themselves, but the parasite they carried was deadly to the minnows native to these waters."

The invading species, researchers say, was a fish called Asian gudgeon, and it carried parasites closely related to an odd group of fungus-like organisms called choanoflagellates. The Asian gudgeon was first introduced into Romanian ponds and the Danube River in 1960, and has since spread rapidly throughout Europe.

The fungal-like parasite carried by this species can infect the internal organs of fish, causing organ failure, severe anemia and death in susceptible species. The mortality rate of infected fish is very high, and they can get easily infected by direct transmission of the parasite during a free-swimming stage in its life cycle.

"As high as the direct mortality is from this parasite, it's nothing compared to the effect on spawning success," Kent said. "It appears that in sunbleak, infection with the parasite causes near 100 percent failure in successful spawning. Over a few generations that can wipe out a local population."

Other fish in the cyprinid family, including carp, may also be susceptible to this parasite, researchers say. And the parasite is remarkably similar to the "rosette agent" found occasionally in salmon, including chinook salmon, which can also cause mortality.

This is one of the first times that introduction of an invasive fish species has resulted in the almost-total suppression of spawning success in a native species, researchers said. The host fish, Asian gudgeon, is only a carrier and does not appear to be affected by the parasite.

The presence of this parasite in fish may also be a concern in aquaculture trade, they said.

This research was supported by grants from the Centre for Environment, Fisheries and Aquacultural Sciences and the Centre for Ecology and Hydrology in England.

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Michael Kent, 541-737-8652

New edition of popular OSU book introduces trees to know

CORVALLIS - Since its publication in black and white more than 50 years ago, "Trees to Know in Oregon" has become the Oregon State University Extension Service's most-requested publication.

A new revised edition is now available - in full color.

The expanded, 152-page "Trees to Know in Oregon" provides a new generation of youth, hikers, gardeners and foresters with text that combines identification and anecdote with maps and color photographs.

Edward C. Jensen, an OSU forestry professor, is the primary author and principal photographer of the new edition of the book, but he is quick to recognize the contributions of others, especially the book's original author, retired OSU Extension forestry specialist Charles R. Ross.

The new edition has updated sections on ornamental trees, Oregon's forests and record-breaking big trees.

According to the book, Oregon is home to more than 50 national champion trees listed in the American Forestry Association's National Register of Big Trees. They include the nation's largest black cottonwood (370 feet), black walnut (278 feet), and garden plum (a 47-foot giant more than 10 feet around).

Of the truly giant Douglas-firs, the authors describe a tree in Coos County that is taller than a 28-story building with a circumference "larger than two compact cars parked side by side. Its canopy, at high noon, casts a shadow the size of a swimming pool."

The soft-cover book is full of tidbits to help you get to know Oregon trees. For example, the authors point out that lodgepole pine was first named by Lewis and Clark. They describe how whitebark pine and birds called Clark's nutcrackers are highly dependent on each other for survival. And they note that, although more than 1,000 varieties of pears have been named, only a half-dozen varieties are grown commercially.

Far more than just a field guide, "Trees to Know in Oregon" will be a good companion on the trail or on the nightstand, Jensen says.

The book costs $12 per copy and is available from many county offices of the OSU Extension Service.

Or, you may order copies for an additional $4 shipping and handling fee. To order, send your request for EC 1450 with a check or money order for $16 to: Publication Orders, Extension and Experiment Station Communications, Oregon State University, 422 Kerr Administration, Corvallis, OR 97331-2119.

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Edward C. Jensen, 541-737-2519

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OSU Extension has a popular book about trees

Wallowa resources program explores local issues

CORVALLIS - A unique natural resources program taught entirely in Wallowa County will be offered this fall by the College of Forestry and Extended Campus at Oregon State University.

More information about this Wallowa Resources Field Program, which runs from Sept. 12 to Nov. 17, can be obtained on the web at http://ecampus.oregonstate.edu/online-degrees/wallowa

This field studies program is designed for either undergraduate students or professionals, who wish to study community-based forestry and natural resources in a region that's working to manage its forests, grasslands, rivers and ecosystems in a sustainable manner. Instructors will include resource and conservation professionals, community leaders, land managers, and scientists. Students will live in Wallowa County and interact with community residents.

A focus of the course, educators say, will be to explore how both economic and ecological goals can be balanced, and real-world problems and issues dealt with. Registration has begun and more information on the program is now available by contacting OSU Extended Campus, the university's award winning program of extended education, at (800) 235-6559.

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Lisa Templeton, 541-737-1279

OSU Extension to offer well water clinics in Corvallis, Albany

CORVALLIS - The Oregon State University Extension Service will offer monthly well water clinics in Corvallis and Albany through October.

Coordinated through Extension's Well Water Program, they will include free nitrate screening. Jacqueline Fern, Extension's water quality educator, will conduct the screening and be available to answer questions about well and septic systems.

Persons interested in receiving the free nitrate screening should bring about a half-cup of untreated well water in a clean, water-tight container to the clinic. The test takes five to 10 minutes - unless the clinic is exceptionally busy - and persons may wait for the results, stop by before closing, or bring a self-addressed, stamped envelope and be mailed the results.

Each of the regularly scheduled clinics will include a 30-minute presentation beginning at 12:15 p.m. on nitrates and bacteria in well water.

The Corvallis clinics will be held Tuesdays at the Benton County Extension Office, 1849 N.W. 9th St. in Corvallis, from 10 a.m. to 2 p.m. on June 14, July 26, Aug. 16, Sept. 27 and Oct. 18.

The Albany clinics will be held at the Linn County Extension Office, 4th and Lyons in Albany, from 10 a.m. to 2 p.m. on Thursday, June 23; Thursday, July 14; Thursday, Aug. 11; Wednesday, Sept. 7; and Thursday, Oct. 27.

Special clinics will be held from 8 a.m. to noon on June 11 at the Albany Farmers' Market at the downtown riverfront in Albany; and from 9 a.m. to 1 p.m. on July 16 at the Corvallis Farmers' Market, downtown riverfront in Corvallis.

The Oregon Department of Environmental Quality recently designated a portion of the southern Willamette Valley as a Groundwater Management Area, based on elevated nitrate levels.

"While it is especially important for households with pregnant women or newborns to test their well water for nitrates because of a rare type of blue-baby syndrome," Fern said, "all homes with private wells should be aware of their nitrate level."

Additional information on well and septic systems, and the Groundwater Management Area, is available online at http://wellwater.oregonstate.edu, or by calling the Well Water Program at 541-737-6295.

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Jacqueline Fern, 541-737-6295

Study to Examine Carbon Balance in Western U.S.

CORVALLIS, Ore. – Researchers at Oregon State University have received a three-year, $1.5 million grant from the North American Carbon Program to determine how climate and human activities affect the terrestrial “carbon balance” in Oregon, Washington and California.

The research will examine areas covered by forests, crops, shrubs, woods and grass, and things that affect carbon sequestration or release, such as wildfire, logging and urbanization.

The work will also consider the effects of climate variation, the interaction between climate and disturbance across very different environments, and the terrestrial carbon uptake relative to human-caused carbon emissions from fossil fuel burning in each state.

“In the Pacific Northwest, we expect that the summers will become dryer and the winters will have more rain,” said Beverly Law, a professor of forest science at OSU and principal investigator on this research. “In this new study, we will examine different responses to climate, in areas that range from coastal forests to arid shrublands and woodlands in the Great Basin. We hope to learn how climate anomalies will affect net carbon uptake and water vapor exchange in the different regions.”

Law also directs three AmeriFlux network sites that use micrometeorological methods to measure the “breathing of the biosphere,” where researchers measure net carbon dioxide, water vapor and energy exchange with the atmosphere. The new study, along with AmeriFlux data from the West Coast, will span ecosystem processes operating over hours to years, and mapping of terrestrial carbon sources and sinks for every kilometer in the region annually over the past three decades.

Scientists expect to find large contrasts in the three-state region, significant differences in the ability of forests to offset fossil emissions, and changes caused by specific events. Carbon sequestration by western Oregon forests, for instance, offsets about 50 percent of the state’s fossil fuel emissions in an average year, but this amount decreased to 30 percent in the year of the historic Biscuit Fire, when wildfire emissions of carbon were significantly higher.

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Beverly Law,
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Workshop to Address Formaldehyde Regulations

CORVALLIS, Ore. – A workshop on formaldehyde regulation will be held July 10-11 in Eugene, Ore., to provide wood product manufacturers information on California’s new regulations in this area.

The event is sponsored by the Oregon Wood Innovation Center at Oregon State University and the Willamette Valley Chapter of the Forest Products Society.

More information on the agenda, speakers, fees, registration and other details can be obtained on the web at http://owic.oregonstate.edu/formaldehyde. Areas of discussion will include the new California Air Resources Board formaldehyde regulations, international regulations, and the perspectives of various professionals in the wood products industry, including people who work with composite panels, hardwood plywood and furniture.

Tours of large testing chambers will help participants see how labs are assessing formaldehyde emissions from wood products.

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Scott Leavengood,
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Wood Science Researcher Receives “Green Chemistry” Award

WASHINGTON, D.C. – An Oregon State University professor who invented a non-toxic adhesive for production of wood composite panels has been recognized with a 2007 Presidential Green Chemistry Challenge Award.

The award is being made today at the National Academy of Sciences in Washington, D.C., by the Environmental Protection Agency, which sponsors this program that honors innovators who have helped reduce waste or toxins in manufacturing processes.

Kaichang Li, one of just seven people or organizations in the nation to be honored, is an OSU professor of wood science and engineering who received the “Greener Synthetic Pathways Award.” Also recognized were Li’s industrial collaborators in the development of this product, Columbia Forest Products of Portland, Ore., and Hercules Incorporated of Wilmington, Del.

During the past 12 years that these awards have been made, the advances they recognize have led to the elimination of over 940 million pounds of hazardous chemicals and solvents, 600 million gallons of water, and 340 million pounds of carbon dioxide, officials say.

Li’s work in developing this new type of alternative adhesive was inspired several years ago by his observation of mussels on the Oregon coast, clinging tightly to rocks despite being pounded by constant waves.

"I was amazed at the time to see these small mussels attach themselves so strongly to rocks," said Li, an expert in wood chemistry and adhesives. "I didn't know of any other type of adhesive that could work this well in water and withstand so much force."

The mussels' byssus, small threads that attach them to rocks and other surfaces, is a protein with a very unusual composition that results in the ability of mussels to stick tightly to surfaces despite being inundated in water.

Li began his research through chemical modifications of soybean protein using mussel adhesive protein as a model. He later developed a unique curing agent that is able to convert inexpensive, abundant, and readily available soybean flour to a superior adhesive for bonding wood. In collaborative work with private industry, a strong, environmentally friendly, cost-competitive adhesive was used to replace toxic urea-formaldehyde resin in commercial production of wood composite panels, such as plywood and particleboard.

Last year, Columbia Forest Products converted all its plywood plants to the new adhesive, replaced the use of more than 47 million pounds of the conventional formaldehyde-based adhesive, and at each of its plants reduced emissions of hazardous air pollutants by 50-90 percent. Continued commercial development and expanded use of the new adhesive is anticipated.

This award program was created after passage of the 1990 Pollution Prevention Act, which made it national policy to reduce pollution at its source whenever feasible. It encourages scientific solutions to real-world environmental problems associated with the design, manufacture, and use of chemicals.

Participants in the award ceremony included representatives of the White House Council for Environmental Quality, National Academy of Sciences, American Chemical Society, Small Business Administration, and EPA.

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Richard Engler,
202-564-8587

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A Six-Inch Tall Tree: Researchers Demonstrate Way to Control Height

CORVALLIS, Ore. – Forest scientists at Oregon State University have used genetic modification to successfully manipulate the growth in height of trees, showing that it’s possible to create miniature trees that look similar to normal trees – but after several years of growth may range anywhere from 50 feet tall to a few inches.

This is a “proof of concept” that tree height can be readily controlled by genetic engineering techniques. It opens the door to a wide variety of new products for the ornamental and nursery industries, experts say, if regulatory hurdles can be overcome – a big “if.”

The findings were recently published in the journal Landscape Plant News.

“From a science perspective, this is a very interesting accomplishment and there’s no doubt it could be made to work,” said Steven Strauss, a professor of forest science at OSU.

“But further development may be precluded by social, legal and regulatory obstacles,” he said. “Clearly there would be concerns whether the market for specialty tree products such as this would be strong enough to make it worth the large investments of time, money and testing that current regulation of genetically modified organisms would require, at least in the U.S.”

That aside, he said, it appears that with further research and development programs, it would indeed be possible to create an elm tree – which ordinarily would grow to 100 feet or more – that is only five feet tall at maturity, a charming addition that would fit nicely on a backyard deck. Or a 30-foot version that might be a better fit on urban streets. Or, in fact, just about any height in between. Other changes can also affect foliage shapes or color in very attractive ways, and some might have value in cleaning up environmental pollution.

In their studies, OSU scientists were able to create young poplar trees, which grow rapidly and can reach a mature height of 150 feet or more, that were anywhere from about 15 feet to a few inches tall after two years of growth. The smallest of them could be difficult to even find, tiny little “shrublets” among the flowers in the field site.

The manipulation of height growth was achieved by insertion of certain genes, mostly taken from the model plant Arabidopsis, which inhibited the action of a class of plant-specific hormones known as gibberellic acids. These compounds are also used as sprays to control the size and fruiting of orchard trees. In trees, the compounds promote the elongation of plant cells – when they are inhibited, the cells do not fully elongate, and plants remain short and stocky.

“It’s really interesting that these genes from Arabidopsis, which is a small plant in the mustard family, have been conserved through 50-100 million years of evolution and can perform more or less the same function in poplar trees,” Strauss said. “The modified trees themselves look pretty much normal, just a lot smaller, and a little more compact or bushy.”

Altogether, the researchers used seven distinct kinds of genes and more than 160 different types of genetic insertions to create about 600 genetically modified trees. All caused decreased signaling by gibberellic acids. They were grown in the field with USDA approval, and assessed several times for variation in size and appearance.

Other than reduced size, there appeared to be striking variation in foliage color and leaf shape, some of which might have significant ornamental value. Root development also appeared to be very strong, which might provide increased stress tolerance and have value where extensive root development is needed, such as in bioremediation of polluted soils or in very windy, limited soil moisture situations.

From an environmental viewpoint, the researchers said, dwarfed trees such as this are unlikely to be any kind of threat to spread, because they would compete very poorly with normal or wild trees. In virtually all tree species, low height is a disadvantage as trees compete for sunshine. Another possible value, from that perspective, is that this trait might be used to help control the spread of exotic and potentially invasive trees that are commonly sold by nurseries.

The initial studies were done with poplar, Strauss said. Similar results should be possible in any tree species, but are limited by the lack of research into gene transfer methods for most ornamental and forest trees. However, usable methods are already available for sweet gum, elm, black locust and pines. The current successful modification with poplar could be just “the tip of the iceberg,” the researchers said in their report.

Dwarf trees and crop plants created with traditional cross-breeding or horticultural techniques are already widely used in fruit trees, the ornamental tree industry and agriculture.

The advances for cereals have been part of the “Green Revolution,” in which plants such as rice or wheat were created that directed less energy to height growth and more to development of stout stems and plentiful seed. In orchards, semi-dwarf fruit trees produce more fruit that is easier to harvest. The improvements in cereal yields have been credited with preventing the starvation of millions.

The research was funded by the U.S. Department of Agriculture.

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Steven Strauss,
541-737-6578

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Human Activities Increasing Carbon Sequestration in Forests

CORVALLIS, Ore. – Human-caused nitrogen deposition has been indirectly “fertilizing” forests, increasing their growth and sequestering major amounts of carbon, a new study in the journal Nature suggests.

The findings create a more complex view of the carbon cycle in forests, where it was already known that logging or other stand-replacement events – whether natural or not – create periods of five to 20 years when there is a net release of carbon dioxide from forests to the atmosphere, instead of sequestration as they do later on.

The end result is a highly variable forest carbon cycle that appears to be heavily influenced by the footprint of humans, one way or another. It’s a complicated process with powerful driving forces that were poorly understood, said scientists from 10 institutions in the United States, Canada and Europe.

Until this report, researchers had never quantified the effect of continuous low levels of nitrogen deposition to spur net carbon uptake by forests and actually offset a significant amount of greenhouse gases into the atmosphere.

This broad study analyzed the carbon balance across a network of forest sites that represent nitrogen deposition in most of Western Europe and the continental United States. Until now, it has been difficult to separate the effects of nitrogen deposition on forests from the many other variables that affect their carbon release or sequestration – things like forest age, logging, wildfires, disease or insect epidemics, or other causes. This study attempted to do that, and found that the net carbon sequestration by temperate and boreal forests was overwhelmingly determined by nitrogen inputs.

“What is surprising is that the net sequestration is quite large for a relatively low level of nitrogen addition,” said Beverly Law, a professor of forest science at Oregon State University, co-author of the study and director of the AmeriFlux monitoring network in North and South America.

“Through our forests, fertilization by nitrogen deposition is to some degree offsetting our carbon dioxide emissions – at least right now,” she said.

It was first recognized in the 1980s that human activities, by releasing unprecedented amounts of active nitrogen into the atmosphere, were not just altering the global nitrogen cycle but also causing the eutrophication of large parts of the biosphere, the researchers said in their report. Nitrogen – produced by automobile engines, factories, and intensive agriculture – is often a key, limiting nutrient in forests and other ecosystems.

Early forest growth puts a severe nitrogen stress on the ecosystem initially, and then the forest continues to grow and remove carbon from the atmosphere for the rest of the management or life cycle, accumulating wood at a high rate on the small additional nitrogen inputs.

This growth and sequestration is achieved without applications of fertilizer that would likely result in nitrous oxide emissions, another greenhouse gas, that would offset the benefits to the atmosphere of carbon removal.

However, it’s known that large additions of nitrogen to ecosystems can also be damaging above a certain threshold, researchers say, and it’s unclear how long this process will continue.

“The results demonstrate that mankind is ultimately controlling the carbon balance of temperate and boreal forests, either directly through forest management or indirectly through nitrogen deposition,” the study authors said.

Ultimately, mature forests, at least in northern latitudes, absorb and sequester substantial amounts of carbon from the atmosphere. Forest protection and management options have been viewed as one mechanism to absorb carbon dioxide from the atmosphere and reduce concerns about the greenhouse effect and global warming.

This work was supported by the European Commission, the US Department of Energy, and other national programs.

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Beverly Law,
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Salvage Logging, Replanting Increased Biscuit Fire Severity

CORVALLIS, Ore. – The Biscuit Fire of 2002 burned more severely in areas that had been salvage logged and replanted, compared to similar areas that were also burned in a 1987 fire but had been left to regenerate naturally, a new study concludes.

The analysis, one of the first to ever quantify the effect of salvage logging and replanting on future fire severity, is being published this week in Proceedings of the National Academy of Sciences, a professional journal, by scientists from Oregon State University and the Pacific Northwest Research Station of the USDA Forest Service.

It found that fire severity was 16 to 61 percent higher in logged and planted areas, compared to those that had burned severely and were left alone in a fire 15 years earlier. The study was done in areas that had burned twice – once in the 1987 Silver Fire, and again in the massive 2002 Biscuit Fire, one of the largest forest fires in modern United States history.

“Many forest managers in the past have assumed that salvage logging after a severe forest fire, along with replanting new trees, will reduce future fire severity,” said Jonathan Thompson, a doctoral student at OSU in the Department of Forest Science, and lead author on the study. “This is based on the assumption that removing dead trees reduces fuel loads and planting conifers hastens the return of fire-resistant forests.”

“However, those assumptions have never really been tested,” Thompson said. “This analysis showed that, after accounting for the effects of topography, Silver Fire severity and other environmental variables, the Biscuit Fire severity was higher where they had done salvage logging and planting.”

It’s not completely clear from these data, Thompson said, what the causative mechanism is – the tree removal, the addition of more fine fuels to the forest floor during the logging operation, or the growth of new trees that for several decades may be very vulnerable to new fires.

The study is not, researchers said, an indictment of salvage logging – it may still have value for economic purposes or to assure the establishment of desired tree species. However, “the hypothesis that salvage-logging, then planting, reduces re-burn severity is not supported by these data,” the scientists said in their report.

“Young forests in this region are susceptible to recurring severe fires,” Thompson said. “Compared to an older forest with branches high above the forest floor, young trees are very vulnerable, whether they are planted or naturally regenerated.”

However, in the aftermath of a wildfire, removal of large dead trees followed by planting conifer seedlings does not appear to lessen the risk of severe fires in the first 10-20 years, Thompson said. This may be because the logging process leaves more available fuel on the forest floor; the dense, homogenous replantation of young trees provides a good setting for fire; or some combination of these factors over time.

“Dead woody fuel . . . is only part of the fire risk story, and it may not be the most important after a few years,” the study noted.

By contrast, natural regeneration of forests, he said, appears to result in at least slightly – and sometimes significantly – less risk of severe future fires. This could be because the regenerating trees are patchier, have open gaps, more species diversity, or other factors. But the study showed that total consumption of tree crowns in a recurring fire situation is more severe in the managed stands than the natural ones, at least when there are one to two decades between fires.

This research was done with satellite data, government agency records and aerial photography, in the mixed-conifer, mixed-evergreen hardwood zones of the Siskiyou Mountains. It analyzed burn severity patterns with a commonly used metric of fire damage on almost 45,000 acres of the Biscuit Fire that had also burned 15 years earlier.

Among its conclusions:

  • Areas that burned severely in 1987 tended to re-burn at high severity in 2002.
  • Areas unaffected by the initial fire tended to burn at the lowest severities in 2002.
  • The findings are consistent with studies that show site history influences fire severity, and that conifer plantations are associated with high severity fire.

There are some potential environmental and management implications of the research, Thompson said.

“If we do have a warmer climate that leads to increasing frequency of wildfire in this region a positive feedback of high severity re-burns may favor plant species more able to deal with that regime – manzanita, ceanothus or tan oak – that could displace conifer forests,” he said.

Managers may have few options to reduce the risk of future high severity fire within areas that have experienced recent severe burns.

Typical fuel treatments such as thinning do not have much effect on fire risk in young forests, Thompson said. There are ongoing experiments within the Biscuit Fire region to test the effectiveness of fuel breaks for slowing the spread of severe fires.

Co-authors on this study were Thomas Spies, principal investigator of the project and a research forester with the Pacific Northwest Research Station of the USDA Forest Service, and Lisa Ganio, an associate professor with the OSU Department of Forest Science.

The study was funded by the Joint Fire Science Program, a partnership of six federal wildland, fire and research organizations, established in 1998 to provide scientific information and support for fuel and fire management programs.

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Jonathan Thompson,
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