college of forestry

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.

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Thomas Hilker, 541-737-2608

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Overgrazing in Mongolia

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Wild bees thrive after severe forest fires

CORVALLIS, Ore. — Early results from a two-year study in southern Oregon suggest that moderate and severe forest fires create conditions that lead to greater abundance and diversity of wild bees.

Because Oregon’s more than 500 species of native bees are important pollinators of wild plants and crops, the study suggests that fires may promote bee populations that in turn may influence agricultural productivity and overall floral diversity.

In 2016, scientists began trapping bees at 43 sites in forests burned by the 2013 Douglas Complex fire north of Grants Pass. The sites ranged from places where fire severity was low — flames were confined to low-growing vegetation and failed to reach the canopy — to places where severity was moderate and high.

“In low severity spots, if you weren’t looking for the markers of fire, you wouldn’t know that it had burned,” said Sara M. Galbraith, a post-doctoral researcher in the College of Forestry at Oregon State University. “The canopy is completely closed, and the trees are usually older. There isn’t a lot of evidence of fire except for some blackened areas on some of the tree trunks.

“And then, when you go to some of the high-severity fire sites, it’s a completely open canopy. There are a lot of flowering plants in the understory because the light limitation is gone. It just looks completely different,” she added.

In a study led by Jim Rivers, OSU forest wildlife ecologist, Galbraith and a team of field researchers collected bees with blue-vane traps, which attract the insects by reflecting ultra-violet light. “The bees basically think it’s a huge flower,” said Galbraith. “Once they get inside the trap, they are unable to fly out because of the shape of the entrance.”

In addition, researchers recorded the characteristics of each site, such as the types of plants, the degree of forest cover and whether or not logging had taken place after the fire.

Such studies are important, Galbraith said, because the early stages of forest development — what researchers call early seral forests — have become less common. “This research adds to the evidence that there is high biodiversity in early seral forests relative to older stands, and moving forward, this could have an impact on services like pollination in the landscape overall. Without this fundamental information, we can’t be sure of the best management actions to conserve pollinator populations within managed forests.”

The study will conclude this year. It was funded by the federal Bureau of Land Management, the Fish and Wildlife Habitat in Managed Forests Research Program in the College of Forestry, and the Mealey/Boise Cascade/Boone and Crockett/Noble Endowment Fund in the College of Forestry.

Galbraith received a joint Ph.D. from the University of Idaho and CATIE (Centro Agronómico Tropical de Investigación y Enseñanza) in Costa Rica. She will present a paper on the first year of results at the annual conference of the Ecological Society of America on August 10 in Portland. 

Story By: 

 Jim Rivers, jim.rivers@oregonstate.edu, 541-737-6581; Sara M. Galbraith, sara.galbraith@oregonstate.edu

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Bumble bee on fireweed




With support from the state, forest industry, and conservation groups, OSU researchers gather data on threatened seabird

CORVALLIS, Ore. — A multi-year study of the marbled murrelet, a threatened West Coast seabird that nests as far as 50 miles inland, aims to discover the animal’s habitat needs and understand the reasons for the species’ ongoing population decline in the Northwest.

In addition to determining the needs of this elusive bird, the study aims to help forest managers on public and private lands balance habitat conservation with timber land management.

The project is possible because of an increase in funding for research in the College of Forestry at Oregon State University provided by the state Legislature in 2015 with broad support from the timber industry and conservation groups. “We are investing in this project because all interests want to know the breeding habitat requirements of the marbled murrelet, so that land management decisions in our productive coastal forests benefit from the best data and science available,” said Thomas Maness, dean of the college.

“Managing our forests is not just about producing timber. It’s also about habitat. We need to understand where these birds go to nest and the best way to protect this species while actively managing our forests to produce timber revenue that is vital to state and local economies.”

The project is managed through the Institute for Working Forest Landscapes at Oregon State and is a joint effort between researchers at the College of Forestry and the Department of Fisheries and Wildlife in the College of Agricultural Sciences.

The research project aims to answer questions about how forests can be managed for both murrelets and timber. “Murrelets prefer mature, late-successional forests, but they may not be restricted to old growth,” said James Rivers, professor of animal ecology in the college and the lead scientist on the project.

“The goal of our project is to determine the murrelets’ requirements for nesting, to learn more about where the birds are located on the landscape and to understand the factors that influence nest success and their relationship to active forest management.” 

The long-lived, dove-sized marbled murrelet spends most of its time in coastal waters dining on krill, other invertebrates and forage fish such as herring, anchovies, smelt and capelin. They nest in mature and old-growth forests and typically produce only one offspring per year, if the nest is successful.

Many seabird species, such as common murres, terns and gulls, tend to nest in colonies, but murrelets are comparatively solitary, nesting in the forest and sometimes within small groups. They typically lay their single egg high in a tree on a horizontal limb that is at least 4 inches in diameter, said Rivers.

Globally, marbled murrelets are one of the few seabirds that nest in this fashion. Scientists don’t know why the birds have evolved this particular habit. “The end goal for these birds is to be very secretive and quiet so predators don’t find their nests and they can produce young,” said Rivers.

“We know we have nesting habitat for murrelets throughout our coastal forests. But we don’t have large sample sizes of nests. If you look at data along the coast from California to Washington, central Oregon has the highest population based on surveys of birds at sea. The Siuslaw National Forest is in that area, and we think the birds may be going in there to nest.”

Only 75 nests have been documented in Oregon since OSU avian ecologist Kim Nelson, a scientist on the project, identified the first one in 1990. “I was on Marys Peak in 1985 when I heard a seabird and wondered what this bird is doing so far from the ocean,” said Nelson. She saw murrelets that year at some of her study sites in the Coast Range.

Three years later, she began a series of systematic murrelet surveys funded by the Oregon Department of Fish and Wildlife and the U.S. Forest Service. Progress was slow, since identifying the birds required people to be physically present at specific locations by dawn for extended periods of time and to listen for the birds’ smooth, high-pitched call. Nonetheless, they found more than 20 active nests and hundreds of occupied sites throughout the Oregon Coast Range.

In a project funded in the 1990s by the Oregon Department of Forestry and the National Council for the Advancement of Air and Stream Improvement, a forest-products industry research organization, Nelson and other scientists climbed about 5,000 trees in a search for murrelet nests. That study identified an additional 45 nests in Oregon and more in Washington, although most of those nests were not active. “Thus, there is limited information about whether those nests were successful and what factors played a role in any nesting failures that may have occurred,” said Rivers.

Along the West Coast, marbled murrelets have been found as far south as Baja California, where they winter, and as far north as the Aleutian Islands. Their populations have been declining by about 4 percent a year in Washington, Oregon and California.

In California, the birds are federally listed as threatened, primarily because of low recruitment of new individuals into the population. The Alaska population is not considered endangered, although population declines have been documented there as well.

The first known murrelet nest was found in the California redwoods in 1974. Based on studies of known nests in the listed range, scientists have found that Steller’s jays and other corvids, such as crows and ravens, are the main predators of murrelet nests.

The researchers aim to learn more about how human activities in the forest affect the risk that predators pose to murrelets. Little is known regarding the effects of logging, camping and the presence of garbage dumps on predator numbers and the chances that predators will find and depredate murrelet nests.

Other unknowns about the birds include how long they live (estimated to be 10 to 15 years), the juxtaposition of nesting to foraging areas and whether individual birds shift their primary feeding areas along the coast from one place to another. 

To answer such questions, members of the OSU research team have been capturing murrelets on the ocean, tagging the birds with miniature VHF radio transmitters and then tracking where they go. Only adult birds with a “brood patch,” a spot with little or no feathers on the breast, are tagged. Such patches indicate that the bird is preparing to breed and incubate an egg.

Last spring, researchers succeeded in capturing and tagging 61 birds. “That was a huge success. We weren’t even sure we’d be able to capture birds on the open ocean,” said Rivers.

Other research methods include the use of infrared cameras to watch nests 24/7, drone-mounted cameras to search for nests in the forest canopy and a customized audio recorder that can record murrelet calls and help researchers document inland movements.

When the birds are stressed by a lack of food, they have been known to forgo reproduction and not lay any eggs, said Nelson. This year, some of the birds that were captured on the central Oregon coast have been tracked to areas south of Cape Blanco where foraging conditions may be better.

Long-term studies such as this enable scientists to understand how birds adjust to unpredictable ocean conditions, which can influence murrelet behavior from year to year. “We will be able to document rare conditions that might not be detected by a typical two- to three-year study,” said Rivers. “Those conditions might have important consequences for the population.”

Other scientists on the project include Dan Roby, ornithologist in the Department of Fisheries and Wildlife. In the College of Forestry, participating researchers include Matt Betts, associate professor and specialist in landscape ecology; Joe Northrup, postdoctoral scientist; and Cheryl Horton and Lindsay Adrean, faculty research assistants.

Story By: 

Jim Rivers, jim.rivers@oregonstate.edu, 541-737-6581; Jennifer Guerrero, 541-737-2063, jennifer.guerrero@oregonstate.edu


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Conserve intact forest landscapes to maximize biodiversity, reduce extinction risk

CORVALLIS, Ore. — A new global analysis of forest habitat loss and wildlife extinction risk published today in the journal Nature shows that species most at risk live in areas just beginning to see the impacts of human activities such as hunting, mining, logging and ranching.

The researchers argue that these intact areas deserve higher priority for limited conservation dollars than areas already impacted heavily by human activity even though species are also threatened in the impacted areas.

“We have seen declines in species in landscapes that have already lost a massive amount of habitat,” said Matthew Betts, lead author and professor in the College of Forestry at Oregon State University. “But we found much more support for what we call the initial intrusion hypothesis. It’s the initial hit caused by roads going into tropical forests and the human activities that follow that is most substantial. These are also the spots with the greatest sheer numbers of species.”

Betts and a team of researchers at Oregon State and BirdLife International, a nonprofit organization, reached their conclusions by analyzing global datasets of forest habitat and species extinction risk. Betts and Christopher Wolf, an Oregon State Ph.D. student in forest ecosystems and statistics along with six co-authors, used forest data assembled by Matthew Hansen at the University of Maryland and categories of extinction risk for 19,432 verterbate species, the so-called Red List, maintained by the International Union for the Conservation of Nature.

Hansen’s data indicate that forest is continuing to be lost at high rates (about 1.5 million square kilometers, or 371 million acres, per year). Most of those changes occur in the tropics. South American rainforests account for nearly half of global forest loss. In total, the new analysis shows that 37 percent of the world’s forests have been converted to other land uses. 

“It should be quite obvious that forest loss increases the risk of species being listed,” said Betts. “But our work provides the first global quantitative link between forest loss and forest species decline.”

However, the question the researchers asked was this: Should conservation efforts be focused on areas where forest habitats have already been lost and species might be reaching a threshold, or on forests that are largely intact and are only just beginning to be affected by development?

At Oregon State, Betts started the Oregon Forest Biodiversity Research Network to use big datasets to answer such questions. In his research in Costa Rica and elsewhere, he has studied the impact of forest clearing on hummingbird pollinators and on other bird species.

It’s likely, Betts added, that heavily impacted areas have already gone through what scientists call an “extinction filter.” Species that are sensitive to development may have previously been eliminated.

High-risk hot spots for forest biodiversity, the researchers wrote, exist in southeast Asia, particularly Borneo, the central-western Amazon and the Congo basin in Africa. Population growth, bushmeat hunting and trapping, and resource extraction in response to consumer demand may fuel future extinction risks in such areas, said Betts.

An ongoing debate among scientists and policymakers focuses on whether conservation programs should prioritize forests already affected by development. “Granted that there’s no such thing as a place that hasn’t been touched by humans in some way due, for example, to a changing climate,” said Betts. “But then there’s the view that humans can quite tightly co-exist with nature assuming that we undertake certain ameliorative measures, that as long as we’re softer on the Earth, we can still have productive landscapes for agriculture. Our paper suggests that we would be helped by having these intact forest landscapes well protected.”

Dedicating some areas to intensive production may allow other areas to be preserved as habitat, said Taal Levi, co-author and assistant professor in Fisheries and Wildlife at Oregon State. “There are many potential benefits to concentrating our environmental impact by intensifying drivers of land-use change, such as agriculture and forestry, in exchange for gazetting large remote undisturbed reserves. A disproportionately large impact arises from the first disturbance to forests.”

Co-authors included William Ripple, Kimberly Millers, Adam Duarte and Ben Phalan at Oregon State; and Stuart Butchart at BirdLife International.

Funding support was provided by the Institute for Working Forest Landscapes professorship at Oregon State.

Story By: 

Matt Betts, 541-737-3841, matthew.betts@oregonstate.edu; Chris Wolf, christopher.wolf@oregonstate.edu, 971-645-0936  

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Seismic experiments will test performance of innovative cross-laminated timber structure

CORVALLIS, Ore. — Engineering researchers are putting an innovative two-story structure made of cross-laminated timber panels through a series of seismic tests to determine how it would perform in an earthquake.

The tests are being conducted at the Natural Hazards Engineering Research Infrastructure at University of California San Diego (NEHRI@UCSD) site, which is funded by the National Science Foundation (NSF). They will produce data that can be used in the design of a new generation of wood-frame high-rises, such as a four-story parking structure designed for Springfield, Oregon, and the 12-story Framework building in Portland. Scheduled to open in 2018, the 90,000-square-foot Framework structure will be the tallest mass-timber building in the United States.

A consortium of universities, agencies and engineering firms is conducting the tests with funding from the NSF, Katerra, Simpson Strong-Tie, Tallwood Design Institute, DR Johnson Lumber Co., the Forest Products Laboratory, City of Springfield, the Softwood Lumber Board and MyTiCon Timber Connectors.

“The overarching goal of the project is to propose a design methodology for seismic loading for large panels subjected to large in-plane loading, including some consisting of a composite made of concrete and cross-laminated timber (CLT),” said Arijit Sinha, associate professor of renewable materials in the College of Forestry at Oregon State University

“Several tests will be conducted at different shaking intensities,” said Andre Barbosa, assistant professor of structural engineering in the College of Engineering at Oregon State. “The three different phases of testing include designs for locations in San Francisco, Seattle and Berkeley.”

Barbosa, Sinha and Christopher Higgins, professor of structural engineering in the OSU College of Engineering, are leading the test of the building’s horizontal elements. The three researchers are affiliated with the Tallwood Design Institute at Oregon State, a collaboration between OSU and the University of Oregon.

The tests reflect a range of stresses associated with a variety of earthquake and wind conditions. “Just for reference, the shake-table motions on one of the tests are calibrated to what is expected to occur in a magnitude 9.0 subduction earthquake zone event in Seattle,” Barbosa added.

Researchers will collect data through more than 300 channels in three phases of testing on the 22-foot-tall structure. Data will be generated at pre-selected points to measure how the CLT panels bend and how the panels move relative to each other. Researchers are particularly interested in a system that allows the building to rock in response to an earthquake and how the walls and floors interact during shaking.

In a so-called “rocking wall system,” vertical walls are connected to a steel footing by post-tensioned rods that run up next to a CLT wall and special U-shaped brackets on the side of the wall. The rods allow the wall to rock during an earthquake and snap back into its original upright position, minimizing the impact and resulting structural damage.

Other collaborating researchers include Shiling Pei of the Colorado School of Mines, John van de Lindt of Colorado State Universit, Jeffery Berman of the University of Washington, Dan Dolan of Washington State University, James Ricles and Richard Sause from Lehigh University, and Keri Ryan from University of Nevada Reno. Also participating in the tests are representatives of KPFF Consulting Engineers and WoodWorks, an initiative of the Wood Products Council.

Researchers plan to evaluate larger buildings in the future, including a 10-story tall CLT structure by 2020.

Ongoing activity at the outdoor shake-table of the Natural Hazards Engineering Research Infrastructure facility is live-streamed by webcam at http://nheri.ucsd.edu/video/

Story By: 

Andre Barbosa, andre.barbosa@oregonstate.edu, 541-737-7291; Arijit Sinha, arijit.sinha@oregonstate.edu, 541-737-6713  

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Pacific Northwest forests are at a crossroads, scientists argue in new book

CORVALLIS, Ore. – The Pacific Northwest faces two stark choices for managing its forests, scientists suggest in a new book. One choice leads to stagnant or declining rural communities and risks to some native species, and the other leads to environmental benefits and increases in employment.

In “People, Forests, and Change: Lessons from the Pacific Northwest,” forestry scientists at Oregon State University, the USDA Forest Service and other universities and research organizations offer a detailed look at the region’s forest management as well as its history, new science discoveries and projections for the future. The book has been published by Island Press.

“We wanted to provide a synopsis of Northwest moist coniferous forests – where we are now, how we arrived at this point and directions into the future,” said Deanna “Dede” Olson, co-editor with Beatrice Van Horne. Both are forest scientists with the U.S. Forest Service.

Northwest forests will face an important potential pivot point in the next few years, said Olson. The Northwest Forest Plan is due to be evaluated, and the results will lead to renewed plans in each of the region’s national forests and lands supervised by the Bureau of Land Management. Also, collaborative groups are gaining recognition for contributing to forest governance on lands managed by a variety of public and private entities.

Other factors driving forest management include habitat requirements for sensitive species and strategies that produce a greater variety of forest conditions including both young and mature stands (more than 80 years old). Forest managers need to address the need for forest resilience in the face of climate change and fire and new forest products that can come from younger trees.

The Northwest Forest Plan mandates a one-size-fits-all management approach, said Thomas Maness, dean of the College of Forestry and co-author.

“Yet we know that northwest forests are exceedingly diverse and fragmented. We have an opportunity to actively manage for the desired characteristics of the landscape, while at the same time producing revenue to support communities and pay for management," he added. "Collaboration and building trust are the keys to achieving this goal.”

A shift in relationships among forest landowners, communities and other organizations may herald such an approach, Olson noted. “There is increased recognition that fragmented federal lands have limitations for maintaining ecosystem integrity. A new definition of sustainability seems to be developing, and what that will be is being crafted by the decisions that will come around these various issues.”

“We hope to inspire new conversations about how these topics are emerging as priorities in several places and contexts, and both bottom-up inspiration and top-down motivation can address them.” 

Story By: 

Deanna H. Olson, 541-750-7373, dedeolson@fs.fed.us

Beatrice Van Horne, 541-750-7357, bvhorne@fs.fed.us

Thomas Maness, 541-737-4603, thomas.maness@oregonstate.edu


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OSU President Ed Ray

OSU President Ed Ray



Forestry Dean Thomas Maness

New era of western wildfire demands new ways to protect people, ecosystems

CORVALLIS, Ore. — Current wildfire policy can’t adequately protect people, homes and ecosystems from the longer, hotter fire seasons climate change is causing, according to a report published today in the Proceedings of the National Academy of Sciences.

Efforts to extinguish every blaze and to reduce the buildup of dead wood and forest undergrowth are becoming increasingly inadequate on their own.

Instead, the authors — a team of wildfire experts from eight universities and a nonprofit research group — urge policymakers and communities to embrace policy reform that will promote adaptation to increasing wildfire and warming.

“We know we need to learn to live with fire. And when we add climate change to the equation, all signs point to urgent shifts in policies and philosophies of fire in our natural and built landscapes,” said Meg Krawchuk, co-author on the report and an assistant professor in the College of Forestry at Oregon State University.

There is no one-size-fits-all path for adapting to fire in the Pacific Northwest, added Krawchuk, who studies the mosaic of burned and unburned areas left behind by wildfire. “It’s key that we respect the core elements of geography: people and place. Inland dry forests and rangelands face very different environmental pressures and futures from the coast.”

Scientists say this also means accepting wildfire as an inevitable part of the landscape.

“Wildfire is catching up to us,” said lead author Tania Schoennagel, a research scientist at the University of Colorado-Boulder’s Institute of Arctic and Alpine Research. “We’re learning our old tools aren’t enough and we need to approach wildfire differently.”

The western United States has seen a 2-degree-Celsius rise in annual average temperature and lengthening of the fire season by almost three months since the 1970s. Both elements contribute to what the authors refer to as the “new era of western wildfires.” This pattern of bigger, hotter fires, along with the influx of homes into fire-prone areas — more than 2 million since 1990 — has made wildfire vastly more costly and dangerous.

“For a long time, we’ve thought that if we try harder and do better, we can get ahead of wildfire and reduce the risks,” said Schoennagel. “We can no longer do that. This is bigger than us, and we’re going to have to adapt to wildfire rather than the other way around.”

As part of this adaptation process, the authors advocate for actions that may be unpopular, such as allowing more fires to burn largely unimpeded in wildland areas and intentionally setting more fires, or “controlled burns,” to reduce natural fuels like undergrowth in more developed areas. Both these steps would reduce future risk and help ecosystems adapt to increasing wildfire and warming.

They also argue for reforming federal, state and local policies that have the unintended consequence of encouraging people to develop in fire-prone areas. Currently, federal taxpayers pick up the tab for preventing and fighting western wildfires, a cost that has reached some $2 billion a year. If states and counties were to bear more of that cost, it would provide incentive to adopt planning efforts and fire-resistant building codes that would reduce risk.

Re-targeting forest-thinning efforts is another beneficial reform suggested by the authors. The federal government has spent about $5 billion since 2006 on thinning dense forests and removing fuel from 7 million hectares (17 million acres) of land, often in remote areas. But these widespread efforts have done little to reduce record-setting fires. Directing thinning projects to particularly high-risk areas, including communities in fire-prone regions and forests in particularly dry areas, would increase adaptation to wildfire, the authors said.

Additionally, as climate change forces species to move their ranges, some species may vanish entirely. Familiar landscapes will disappear, a fact that makes many people balk. But such changes, including those caused by wildfire, could be necessary for the environment in the long run, says Max Moritz, co-author and fire scientist at the University of California Cooperative Extension. “We need the foresight to help guide these ecosystems in a healthy direction now so they can adjust in pace with our changing climate,” he said. “That means embracing some changes while we have a window to do so.”

Critical to making a policy of adaptation successful, said Schoennagel, will be education and changing people’s perception of wildfire. “We have to learn that wildfire is inevitable, in the same way that droughts and flooding are. We’ve tried to control fire, but it’s not a control we can maintain. Like other natural disasters, we have to learn to adapt.”

Story By: 

Meg Krawchuk, 541-737-1483, meg.krawchuk@oregonstate.edu; Tania Schoennagel, 303-818-5166, tania.schoennagel@colorado.edu


As more of the Pacific Northwest burns, severe fires change forest ecology

CORVALLIS, Ore. — Over the last 30 years, the landscape annually affected by forest fires has slowly increased across the Pacific Northwest, and in some regions, severe blazes account for a higher proportion of the area burned than in the past.

As a result, the ecology of some of the region’s forests is changing in unprecedented ways.

Scientists calculated that less than one-half of 1 percent of the region’s forest is subject to fire in any given year. But in a project using satellite imagery and ground-based tree inventories, they also found that, in areas historically dominated by low- and mixed-severity fires, nearly a quarter of the burned landscape was subject to patches of high-severity fires that often exceeded 250 acres in size.

Studies of fires prior to 1900 suggest that severe fires occurred over smaller patches of forest and accounted for a much smaller proportion of the total burned area than they do today.

To reach their conclusions, researchers analyzed images taken by the LANDSAT satellite between 1985 and 2010. The study evaluated burned area and fire severity in seven different ecosystems, ranging from high-elevation subalpine forests to those dominated by western hemlock, ponderosa pine and Douglas fir. Since high-severity fire kills trees outright, the scientists were able to link fire-related tree mortality to changes in images from year to year.

They published their findings in the journal Ecosphere.

“Large fires can have significant social and economic costs, but they are also playing an important role in the ecology of our forests,” said Matthew Reilly, lead author and a post-doctoral researcher in the College of Forestry at Oregon State University.

“From a regional biodiversity perspective, they are enhancing diversity by creating early seral habitats (the first stage of forest development dominated by grasses, forbs and shrubs). These provide important habitats for species that depend on open conditions and fire-killed trees (or snags). Such habitats are very rare and dispersed across the region but are concentrated in hotspots of high-severity fire like southwest Oregon, Santiam Pass in central Oregon, the North Cascades in Washington and more recently the Blue Mountains, following the Canyon Creek Complex fire near John Day.”

About 98 percent of forest fires are put out before they have a chance to grow, said Reilly.

“Our study is really about the other 2 percent that tend to burn during the hottest, driest, windiest conditions,” he said. “Suppression tends to be more effective when it’s cool and wet.”

More high-severity fires occur in hotter, drier years, the scientists said. But in dry areas east of the Cascades, fires burn a smaller portion of the landscape than they did before 1900. Consequently, forests are becoming denser as vegetation accumulates, creating what scientists call a “fire deficit.”

“In the ponderosa pine forests in eastern Oregon, we estimated it would take about 380 years at the current rate for fire to cover the whole region,” said Reilly. “But historically, we know that those forests were subject to fire every 12 to 28 years.”

The scientists’ results are consistent with other studies that document a fire deficit in the forests of the western United States, but this is the first study to document how recent fires vary in different ecosystems across the Pacific Northwest.

“There’s no one out there who thinks that fire will play the historical role that it used to. We just can’t really have that,” Reilly said. “But we need to figure out how to let the low- to moderate-severity fires burn in forests where fire was frequent historically. There is growing consensus among scientists that use of managed wildfire may be one way to do this, especially in cool, wet years.” 

Researchers at the University of Vermont, the USDA Forest Service and the College of Earth, Ocean, and Atmospheric Sciences at OSU were co-authors on the paper. Funding for the study was provided by the USDA Forest Service.

Story By: 

Matthew Reilly, matthew.reilly@oregonstate.edu, 706-338-1372


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Workshop to explore bees, birds and other forest pollinators

CORVALLIS, Ore. — Fires, harvesting and other forest disturbances can affect the birds and insects that pollinate plants in Oregon and worldwide.

The College of Forestry at Oregon State University will offer a look at research on forest pollinators in a workshop at the CH2MHill Alumni Center on the OSU campus on Thursday, March 30. It will be from 9 a.m. to 4 p.m. and is free and open to the public.

Registration is required by March 20 at http://cpe.forestry.oregonstate.edu/PollinatorWorkshop.

“Our goal is to communicate what we know about how forest management affects pollinators,” said Brianna Beene, workshop organizer and program coordinator in the office of continuing and professional education. “We will also seek input from land managers about what kinds of research would be most useful to them.”

Speakers from Oregon State, Washington State, Montana State and the U.S. Department of Agriculture will address a variety of topics, including the influence of wildfire severity, salvage logging, herbicides and practical ways to augment blooms for native bees.

Story By: 

Brianna Beene, brianna.beene@oregonstate.edu, 541 737 3740