OREGON STATE UNIVERSITY

environment and natural resources

OSU Researchers to Visit Site of 2004, 2005 Indonesian Quakes on Groundbreaking Project

CORVALLIS, Ore. – Researchers from Oregon State University and an Indonesian science center are collaborating on a pioneering project to analyze the history of great earthquakes and tsunamis on the Sunda subduction zone, along the western margin of Sumatra and Java – site of one of the most devastating tsunamis in modern history.

Led by OSU marine geologist Chris Goldfinger, the expedition will travel this May to the site of a 2004 Indonesian earthquake and its resulting tsunamis, which devastated nearby Banda Aceh and other coastal cities in the Indian Ocean. They also will visit the site of a second major earthquake that struck west of nearby Nias Island in 2005.

The 43-day research project is funded by the National Science Foundation. It is based on an agreement and collaborative research plan recently developed by Goldfinger and Yusuf S. Djadjadihardja, an official with the Agency for Assessment of Application of Technology in Indonesia.

The project “continues the important cooperation between Indonesia and the United States on potential tsunami and earthquake related natural disasters” that was embodied in a previous hazards research agreement, said John Heffern, United States Embassy Charge d’Affaires.

This will be the first research ship from the United States allowed in Indonesian waters in nearly 30 years, said Goldfinger, a professor in OSU’s College of Oceanic and Atmospheric Sciences. The researchers will take a series of piston core samples from aboard the R/V Roger Revelle, operated by the Scripps Institution of Oceanography. The 32-member scientific team will include at least eight scientists from Indonesia, who will collaborate closely on the analysis of the findings from the cruise.

“The region has had many, many earthquakes in its past, yet we know very little about its seismic history because of its remoteness and access issues,” said Goldfinger, one of the world’s leading experts on subduction zone earthquakes. “Historical records indicate that there were major earthquakes in Padang in 1797 and 1833 in addition to the two more recent quakes, but the evidence beyond that is a little spotty.”

The researchers will leave Phuket, Thailand, on May 7 and cruise to an area in the Indian Ocean west of Banda Aceh, which is on the northern tip of Sumatra, the largest island in Indonesia. From there, they will begin taking a series of core samples – about five to six meters in length – from the seafloor, which is about 4,000 to 6,000 meters below the surface.

They will collect roughly 50 core samples from the ocean along the west coast of Sumatra. From those cores, they will be looking for coarse sediments called “turbidites” that provide evidence of past earthquakes.

When a major offshore earthquake occurs, Goldfinger says, the disturbance causes mud and sand to begin streaming down the continental margins and into the undersea canyons. Sediments run out onto the abyssal plain. The coarser turbidites stand out distinctly from the fine particulate matter that accumulates on a regular basis between major tectonic events.

By dating the fine particles through carbon-14 analysis and other methods, they can estimate with a great deal of accuracy when major earthquakes have occurred.

Goldfinger has used the technique to recreate the seismic history of the Cascadia Subduction Zone off the coast of the Pacific Northwest, where he has documented 34 major earthquakes during the past 10,000 years. At least 19 of those quakes, he says, ruptured along the entire length of the subduction zone – requiring an event of magnitude 8.5 or larger.

Going back further than 10,000 years has been difficult in the Cascadia Subduction Zone because the sea level used to be lower and West Coast rivers emptied directly into offshore canyons, Goldfinger pointed out. Because of that, it was difficult to distinguish between storms debris and earthquake turbidites.

“We hope to create the same kind of history for the Indian Ocean region, which is surprisingly similar to the Cascadia Subduction Zone in structure,” Goldfinger said. “If anything, the Indian Ocean is even better suited for this analysis because there is a huge basin between the rivers and the deep ocean that keeps the terrestrial sediments close to land.”

The researchers will further hone in on the dates of the deposits by studying the fossil record and variations in magnetic north that are recorded in the sediments.

On Dec. 26, 2004, a massive undersea earthquake centered west of Sumatra shook the entire region, generating a series of tsunamis that swamped low-lying coastal areas. Nearly 230,000 persons were killed or are still missing – one of the most devastating natural disasters in history. The earthquake’s magnitude was estimated between 9.1 and 9.3.

In March of 2005, a magnitude 8.7 quake struck an area just to the south, killing an estimated 1,300 people – most on the Indonesian island of Nias. Scientists are unsure whether the second quake was an aftershock or took place because the entire fault has been weakened.

“That’s why it is so important to gather the seismic history of the region,” Goldfinger said.

Eight researchers from OSU – including faculty, technicians and graduate students – will join colleagues from Indonesia as well as researchers from Germany and Japan on the study.

Media Contact: 
Source: 

Chris Goldfinger,
541-737-2066

Scientists Link Volcanic Eruption with Historic Major Global Warming Period

CORVALLIS, Ore. – A team of scientists announced today confirmation of a link between massive volcanic eruptions along the east coast of Greenland and in the western British Isles about 55 million years ago and a period of global warming that raised sea surface temperatures by five degrees (Celsius) in the tropics and more than six degrees in the Arctic.

The findings were reported in this week’s edition of Science.

The study is important, experts say, because it documents the Earth’s response to the release of large amounts of greenhouse gases – carbon dioxide and methane – into the atmosphere, and definitively links a major volcanic event with a period of global warming.

“There has been evidence in the marine record of this period of global warming, and evidence in the geologic record of the eruptions at roughly the same time, but until now there has been no direct link between the two,” said Robert A. Duncan, a professor in the College of Oceanic and Atmospheric Sciences at Oregon State University and one of the authors of the study.

Other authors are Michael Storey, from Roskilde University in Denmark, and Carl C. Swisher, from Rutgers University.

The Paleocene-Eocene thermal maximum, or PETM, was a period of intense warming that lasted roughly 220,000 years. In addition to the warming of sea surface waters, this event – characterized by scientists as a “planetary emergency” – also greatly increased the acidification of the world’s oceans and led to the extinction of numerous deep-sea species.

Warming periods in Earth’s history are of interest as analogs to today’s climate change, Duncan said.

The international science team was able to link the PETM with the breakup of Greenland from northern Europe through analyzing the ash layers deposited toward the end of the peak of the volcanic eruptions. Using chemical fingerprints and identical ages, they were able to positively match ash layers in east Greenland with those in marine sediments in the Atlantic Ocean.

“We think the first volcanic eruptions began about 61 million years ago and then it took another 5 million years for the mantle to weaken, the continent to thin and the molten material to rise to the surface,” Duncan said. “It was like lifting a lid. The plate came apart and gave birth to the North Atlantic Ocean.”

The link from the volcanism to the warming period came through correlations with the marine fossil record. Dramatic changes in the carbon-isotopic composition of the ocean, corroded plankton shells, and the extinction of some bottom-dwelling organisms characterize the PETM. This interval occurred about 300,000 years before the ash layer, at the peak of volcanic activity in east Greenland.

The scientists speculate that massive release of greenhouse gases – carbon dioxide and methane – from the “out-gassing” of the lava flows and heating of organic-rich sediments in basins along the east Greenland margin were responsible for the global warming and changes in ocean chemistry.

The breakthrough came from being able to find a marker – the ash eruption – that was distributed all over the North Atlantic, and showed up in the marine record as well, Duncan said.

The volcanic activity that took place in Greenland 55 to 61 million years ago brought up some 10 million cubic kilometers of magma from below the Earth’s surface. These lava flows can be plainly seen today in Greenland, western Scotland and the Faeroe Islands, where they cooled, leaving a layered sequence of lava flows as deep as six kilometers in some places. Duncan said the eruptions are similar in scale with the well-known Deccan Flood Basalts in India.

“They are also about 40 times as big as the Columbia River basalts in Oregon and Washington,” he said.

The Columbia River basalts likely had few global impacts, but the Deccan Flood Basalts, the Siberian Traps, and the Parana Flood Basalts in South America all coincide with periods of global warming or changes in the ocean chemistry, Duncan pointed out. No conclusive links have been established, however, he added.

“Similarly large submarine volcanic events correlate with major marine anoxic events – periods of no oxygen in the deep-ocean water – which we think are triggered by high surface productivity of plankton that have responded to nutrients released into the ocean by hydrothermal activity,” Duncan said.

Media Contact: 
Source: 

Bob Duncan,
541-737-5189

Book Explores Modern Western Silviculture

CORVALLIS, Ore. – Scientists from Oregon State University and the U.S. Forest Service have produced a comprehensive new book on modern silviculture in the West, one of the only books of its type to focus on this specific region, incorporate the newest research findings and explore changing social values.

Titled “Silviculture and Ecology of Western U.S. Forests,” the 440-page book has been published by the Oregon State University Press. It costs $35, and is available at most major web retailers or on the OSU Press website at http://oregonstate.edu/dept/press

“This was written with forest practitioners, students and policy makers in mind, with a clear focus on the forests of the American West,” said John Tappeiner, professor emeritus of forest resources at OSU. “It should be understandable to the lay reader but provide very useful information for forest land owners and managers of all types.”

The book contains chapters on silvicultural systems, differences between federal and private lands, basic ecological principals, ecology of shrubs and hardwoods, tree growth, measures of stand density, use of controlled fire, insects, water stress, and many other topics. It addresses some of the changes in forest values, such as ways to manage lands for timber while maintaining forest health, reducing fire potential, benefiting wildlife and protecting aesthetics.

“This is a solid synthesis of 40 years of modern forestry research on western forests, which has never before really been pulled together in this way,” Tappeiner said. “People are now considering different types of silviculture and new options in land management. This text should be invaluable for those purposes.”

Authors of the book include Tappeiner; Douglas Maguire, associate professor of forest science at OSU; and Timothy Harrington, a research forester for the Pacific Northwest Research Station of the USDA Forest Service.

Media Contact: 
Source: 

John Tappeiner,
541-737-3055

Out of Sight, Out of Mind – Deep Mud Seafloors Face Quiet Destruction

CORVALLIS, Ore. – The first study ever done of the effects of bottom trawling on mud seafloors off the West Coast of North America – a huge area that comprises thousands of square miles – suggests that trawling not only reduces fish numbers, but also severely alters communities of organisms inhabiting these deep-sea habitats.

The research compared trawled to untrawled areas 600 to 1,200 feet deep off the southern Oregon coast, and found nearly 20 percent fewer fish overall in the trawled areas, and 30 percent fewer fish species. Certain seafloor dwellers in this type of marine terrain, including sea pens and crabs, were six times more abundant in areas that had not been trawled.

In trawled areas, numerous scavenging species largely replaced the marine life common on undisturbed seafloors.

The study, made by direct observation from small two-person submarine, was just published by scientists from Oregon State University and Washington State University in the Journal of Experimental Marine Biology and Ecology.

This report is the first of its type, scientists say, to examine the effects of a common fishing practice on a rather ordinary but vast ocean floor ecosystem off Washington, Oregon, and California – the mud flats that dominate more than 75 percent of the outer continental shelf.

Bottom trawling, in which large nets are dragged by ships along the seafloor and scoop up pretty much everything in their path, has been done in much of this area. This is one common source, among others, of the sole, lingcod, rockfish and other fish that are common seafood staples in grocery stores and restaurants. In recent years, 94 percent of the continental shelf and slope off Oregon and Washington that was trawled was swept less than once per year, and 6 percent more than once annually, according to a report by the National Academy of Sciences.

Regulatory approaches, including gear modifications and closed areas, have actually steered trawl fisheries toward the mud seafloors, keeping them out of rock or coral areas, because trawls cause less environmental damage on mud. But the long-term implications of fishing with this technology over such a broad area are a concern, according to study authors Mark Hixon, a professor of zoology at OSU, and Brian Tissot, a professor of environmental science at WSU.

“This ecosystem shows striking differences between trawled and untrawled areas,” said Tissot, an expert in seafloor organisms. “Areas that had obviously not been trawled were covered by forests of sea pens and other marine life, and the trawled areas looked like a desert, crisscrossed with trawl tracks.”

Untrawled mud seafloors were dominated by slow-growing but long-lived sea pens in forest-like stands inhabited by crabs, other invertebrates, and 27 species of fish, including soles, poachers, ratfish, and sablefish. In trawled areas, a very different range of scavenger species dominated the disrupted environment – including hermit crabs, sea stars, eelpout, hagfish, and others. These scavenger species may have been attracted to burrowing prey exposed by trawling, Tissot suggested.

“Past overfishing has already led to large and costly cutbacks in the trawl fishing industry,” said Hixon, an expert in marine fishes. “Some have compared bottom trawling to hunting elk by bulldozing forests. It’s very tough on seafloor habitats and larger organisms.

“We really don’t know much about how these systems work, how much trawling they can take, and how resilient they are to this type of damage,” he said. “Mud seafloor ecosystems of the continental shelf may not seem that important, and in the past they have been completely off the radar screen.

“But a question that must be asked is whether we want to sacrifice these ecological communities, not even knowing what the long-term effects of bottom trawling might be, or whether some mud areas on the continental shelf deserve permanent protection.”

The very deep ocean beyond the continental shelf is already protected from bottom trawling, as are certain rocky areas on the shelf. There are also temporary trawl closures on the shelf for rebuilding populations of over-fished rockfishes.

Hook and line, and trap fisheries are far less destructive to seafloor habitat, Hixon noted, but all fishing gears have their pluses and minuses. Bottom trawling has been an efficient means of gathering a huge amount of sea life off the ocean floor, but at the cost of seafloor alteration and wasted bycatch, or discarded, non-seafood species.

Among the species most directly reduced by trawling on deep mud seafloors were sea pens, the research found. Also known as sea whips, these are soft-bodied, erect organisms that anchor in the seafloor and project upwards as much as 3 feet, forming forest-like stands. Sea pens, which can live up to 50 years, were nearly absent on trawled bottoms.

Off Oregon and most of the rest of the West Coast, the continental shelf extends up to 30 miles offshore – a comparatively shallow area before the ocean drops into very deep waters – and is subject to state or federal regulations. Most of the continental shelf is dominated by mud seafloor, with smaller parts covered by rock or sand. A very small number of studies previously had looked at the effects of trawling in other types of marine terrain off Alaska and California, but none studied deep mud floors.

Numerous studies of bottom trawling done elsewhere in the world have concluded that this fishing practice often reduces habitat complexity, alters seafloor communities, reduces productivity, and has particular impact on fragile species that inhabit the still waters of the deep sea. Although the findings of the Oregon research are based on comparisons of limited scope that are less definitive than experimental studies, the observed patterns are entirely consistent with broader studies worldwide, Hixon said.

This study was funded by the U.S. Minerals Management Service, as part of a regional survey to see what type of sea life was living on rocky seafloors of the outer continental shelf of Oregon. Some of the submarine transects, by coincidence, ran onto mud seafloor areas instead of rocky areas.

Media Contact: 
Source: 

Mark Hixon,
541-737-5364

Multimedia Downloads
Multimedia: 

Mud Seafloors
Mud Seafloors
Mud Seafloors

Mud Seafloors

Arsenic Contamination in Wells Raises Concerns

CORVALLIS, Ore. – Public concerns about high levels of arsenic in well water have prompted a recent and continuing testing program in the area around Sweet Home, Ore., and may raise a warning flag for other areas of the state that could also face problems with this toxin due to geology or land use practices.

In a recent round of testing done near Sweet Home, almost one-fourth of the well water samples showed levels of arsenic now considered unsafe by EPA standards.

Some areas in the Tualatin Basin near Portland; the Ontario region in Eastern Oregon; areas around Creswell and Cottage Grove south of Eugene; and much of the Puget Sound area are also known to have some concerns about high groundwater levels of arsenic.

Officials at Oregon State University who operate the Extension Well Water Program say people should avoid a panic or emotional reaction to the issue of arsenic in water. Levels considered safe have been tightened recently and health risks are still unclear, said Gail Andrews, an assistant professor of bioengineering and OSU water quality educator – but consumers still should be aware and informed on the safety of their water and take action if necessary.

“Arsenic, in particular, is a poison that tends to have an emotional stigma attached to it,” Andrews said. “Probably a third of the calls I get are about this one issue. But there are ways water can be treated, people can drink bottled water, it’s not a problem using this water for bathing and many other uses, and the science is still somewhat uncertain about just how much of a danger arsenic is at very low levels.”

The health concern about arsenic is primarily related to its role as a carcinogen, even at extremely low levels, causing skin and possibly other cancers. Safety levels for public water supplies are measured in parts per billion – a level that’s about 1,000 times more stringent than some other common water contaminants such as nitrates. Recently, the allowed level for public water supplies was lowered from 50 to 10 parts per billion.

“Worth noting is that these are standards for accumulated lifetime exposure, meaning you drink primarily just that water from a single source for your entire life,” Andrews said. “Needless to say, if you moved a lot or had slightly higher levels at something like a vacation home you just visited occasionally, that would be much less of a concern.”

Arsenic is found naturally in some geologic formations, especially in wells that tap into deeper formations, and can vary over time. Sometimes levels are also related to past agricultural practices and use of pesticides. Maps are available outlining areas in the state where arsenic tends to be more of a concern, and it’s been known for some time that the Sweet Home area was one of the hot spots.

At the recent testing around Sweet Home, which was done with the collaboration and support of the local Rotary Club, 84 well water samples were submitted. Arsenic was not detected in 53 samples; found at levels between 4-10 parts per billion in 11 samples; was more than 10 ppb in 15 samples and more than 50 ppb in five samples. The highest level detected was 175 parts per billion.

As a follow up, another program is planned for community education and bringing in well water samples in Sweet Home on Thursday, May 10, from 6-8 p.m. in the meeting room of the Sweet Home School Board. Tests will be done for arsenic, nitrate levels and bacteria.

More information on this and many other well water issues can be obtained on the web at http://wellwater.oregonstate.edu or by calling 541-737-6294.

Many people do not realize, Andrews said, that there are no laws regulating standards for private wells – and often homeowners are not even aware they may have water problems with arsenic or other common contaminants such as nitrates or E coli. The burden is on the individual home owner, landlord or renter to be aware of potential well water risks and take steps to monitor or prevent them. Testing for arsenic is inexpensive, done by many private companies for about $25.

Treatments for arsenic contamination are available but often expensive – they can range from $3,000 to $8,000 for treatments with existing technology. Some new systems for treatment that are far less expensive may soon be available when testing is complete, Andrews said.

Media Contact: 
Source: 

Gail Andrews,
541-737-6294

OSU’s Ed Ray Signs “Presidents Climate Commitment” for Sustainability

CORVALLIS, Ore. – Oregon State University has joined a growing number of universities around the United States in an initiative to make its campus “climate neutral” by establishing policies to limit greenhouse gas emissions and reduce its energy usage.

OSU President Ed Ray this week signed the American College and University Presidents Climate Commitment pledge.

“This is a commitment that we take quite seriously,” Ray said. “We have on our faculty international leaders in research and education on climate change and its impacts, so we have a sense of responsibility as an institution to become leaders in the operational aspects of sustainability as well.

“We have made some important strides already,” Ray added, “but we can do more.”

The commitment requires OSU to launch a two-year planning process to outline its path toward becoming “climate neutral,” which essentially means that the university will either emit no greenhouse gases, or it will offset its emissions through energy credits and other methods, said Brandon Trelstad, OSU’s campus sustainability coordinator. The most likely solutions, according to Trelstad, will come through a combination of conservation, offsets, and local renewable energy sources.

Part of the planning process will be to determine a realistic date in the future by which this may be accomplished, Trelstad added, and establishing goals for achieving and tracking progress.

“There are a number of interim steps the university can take toward increasing our sustainability, from construction guidelines to travel and purchasing policies,” Trelstad said. “Part of the planning process will be to solicit ideas from students, faculty and staff, and then determine how these might best fit in with the university’s goals and missions.”

The planning process will be led by a university-wide Sustainability Council, which already is in place.

OSU’s primary energy consumption sources are through its antiquated heating plant and electricity usage. Construction is just beginning on a new energy center for the university, which will reduce the amount of energy used to heat and power the campus by an estimated 38 percent, Trelstad pointed out. Much of the university’s electricity originates in Utah from coal-fired power plants.

“By making electricity on campus and efficiently using natural gas, we’ll reduce our global warming gases extensively,” Trelstad said. “The Energy Center also will be configured to easily transition to renewable fuels – like biodiesel, and perhaps someday, even biomass – when these fuels become more financially competitive.”

Trelstad said that OSU’s participation in the Presidents Climate Commitment positions the university to deal with potential future taxes on carbon emissions.

OSU is engaged in several other energy-reducing projects:

  • A project in Bexell Hall, home of the College of Business, will reduce the amount of energy consumed by lighting by approximately 50 percent. Lighting typically represents about 25 percent of the energy used in an office building. Bexell also is implementing new computer use policies and practices that could contribute to a goal of reducing energy use in the building by 50 percent.
  • The university is exploring new software products that would reduce the energy used by campus computers. The idea, Trelstad said, is to adjust the power settings on individual computers to match the needs of users.
  • OSU has a successful sustainability audit program for campus buildings that not only looks at energy consumption, but water and paper use, and even office furniture.
  • The university also is conducting an audit of its outdoor lighting to make sure that lighting is safe for pedestrians at night, but that lights don’t come on too early – especially since the change to daylight savings.
  • Recent campus buildings have been constructed in a more environmentally sustainable manner, exemplified by the 153,000-square-foot Kelley Engineering Center. Designed to be extremely energy efficient, and constructed using sustainable materials and techniques, it received a “Gold” LEED (Leadership in Energy and Environmental Design) certification from the U.S. Green Building Council.

“Oregon State also has been recognized by the Environmental Protection Agency as a ‘Best Workplace for Commuters’ because we have great support for a variety of alternative transportation modes,” Trelstad said. “Since transportation has an obvious and significant impact on global warming, this is important to us as a university – and we’ve been a leader in this area for a long time.”

OSU’s faculty are actively involved in a number of research efforts related to sustainability, including the development of wave energy, passively safe nuclear power, biofuels and other new forms of energy under the Sun Grant initiative; and incorporating these and other new findings into sustainability education throughout the curriculum.

More information on the American College and University Presidents Climate Commitment program is available online at: http://www.presidentsclimatecommitment.org/index.php. Information on OSU’s efforts on sustainability is available at: http://oregonstate.edu/sustainability/

Media Contact: 
Source: 

Brandon Trelstad,
541-737-3307

Predators help shape rivers by affecting grazing behaviors

CORVALLIS, Ore. – Large carnivores not only play a pivotal role in the health of ecosystems, they can also affect the very shape of the landscape, according to recent research by two OSU forestry professors.

Where predators such as wolves and cougars are absent, river channels are apt to widen and erode as deer and other browsers, free of fear, devour and trample streamside vegetation. These riparian plant communities — willows, cottonwoods, sedges — help anchor soils, hold sediments and maintain riverbanks.

OSU researchers William Ripple and Robert Beschta have found evidence, both historical and contemporary, of significant impact from predation on the width, depth and meanders of the Gallatin River in Yellowstone National Park. A story about their research appears in the spring issue of Terra, OSU’s research magazine (on the Web at oregonstate.edu/terra).

Archival photos show dramatic — and deteriorating — changes in the river’s path from the mid-1920s, when wolves were wiped out, through the latter decades of the 20th century. In contrast, an image from the early 2000s, after wolves had once again gained a foothold in the park, show signs of renewal.

“It appears that the presence or absence of this apex predator can impart important effects upon lower trophic levels: first to elk, then to willows and finally to … processes associated with floodplain systems,” professors Robert Beschta and William Ripple explain in the journal Earth Surface Processes and Landforms (May 2006).

The ecological consequences of catastrophic channel transformations are profound. As their banks crumble, rivers flow faster and sediments get finer, while water temperatures grow warmer and water tables sink deeper. Plant communities shift from moisture-loving to dry-land species. On the over-browsed sections of the Gallatin floodplain, for instance, shrubby cinquefoil and lodgepole pines replaced the lush willow thickets and dense sedges characteristic of healthy riparian zones.

Animal communities across the food web — from birds to aquatic insects, butterflies, fish, frogs, toads and lizards — shrink or disappear along with the vegetation they depend on.

Beavers are another casualty of the top-down “trophic cascade.” Their dam-and-pond systems play a critical role in maintaining plant, vertebrate and invertebrate diversity and biomass in riparian ecosystems, the researchers stress. One Wyoming scientist found about 75 times more waterfowl in streams with beaver ponds than in similar streams devoid of the industrious rodents, Beschta and Ripple note.

In studies across the West, the researchers have been amassing evidence of the predator-vegetation-biodiversity link. The stream channel study takes the linkage still further, connecting the carving of landscapes by river systems to the prowling of these landscapes by large carnivores.

“The heavy annual browsing of willow communities after the loss of wolves ultimately generated major changes in floodplain functions and channel morphology,” they say. “To the best of our knowledge, we are the first to connect a large, highly interacting carnivore to the characteristics of a river floodplain and its channel.”

Wolves and cougars could, under certain circumstances, be important management tools for restoring riparian zones — essentially, reviving the natural stasis of a system that has been out of balance since predators were extirpated, the researchers suggest.

Read more about the research of Beschta and Ripple in the spring 2007 issue of Terra, OSU’s research magazine, oregonstate.edu/terra.

Source: 

Bill Ripple,
541-737-3056

Slow but Reasonably Sure: Burned Forest Lands Regenerate Naturally

CORVALLIS, Ore. – A new study of forest lands that burned in the 1990s in northern California and southwestern Oregon has concluded there is a “fair to excellent” chance that an adequate level of conifers will regenerate naturally, in sites that had no manual planting or other forest management.

The research, to be published Wednesday in the Journal of Forestry by scientists from Oregon State University, examined the recovery of conifers on 35 plots that had burned in wildfires from nine to 19 years ago, and generally found a high level of naturally regenerating tree seedlings.

Although the abundance of natural regeneration appeared to be variable and growth often slow, there was no evidence of recent conifer mortality or suppression leading to seedling death.

Total conifer density and the types of tree species varied quite a bit depending on elevation, but the density of surviving conifer seedlings was as much or more than typical densities in 60- to 100-year-old stands in this region, which is about 100 to 1,000 trees per acre. Traditional old growth forests of this region, with trees 250 or more years old, often had as few as 20-40 large trees per acre.

About 10 percent of the plots studied already had larger trees that were considered “free to grow” by forestry standards. The scientists said the height of competing shrubs had “quite likely” slowed after one or two decades, and “we predict that conifer mortality will remain low and height growth will accelerate as individuals continue to emerge above the shrub layer.” The study also showed that trees would regenerate at considerable distances from seed sources.

“The natural regeneration on many of these sites is actually much higher than needed to restore a forest,” said Jeff Shatford, a senior faculty research assistant in the OSU Department of Forest Science. “We expect that the high density of young trees we observed will thin out naturally over time.”

The authors said in their report that “assertions that burned areas, left unmanaged, will remain unproductive for some indefinite period, seem unwarranted.” Short-term delays in conifer regeneration and a broader range of recovering plant and animal species may also have benefits in terms of varied tree size, plant biodiversity, and wildlife habitat.

“When left to natural regeneration in this region, it appears that conifers may come back more slowly and with more variation than with conventional forest management, but in most cases they do come back,” said David Hibbs, co-author of the report and a professor of forest ecology and silviculture in the OSU Department of Forest Science. “There may be some cases, especially on the lowest, hottest, south-facing slopes, where that is not true.

“But at most elevations and in most situations, natural conifer regeneration appears to be working.”

Whether lands should be planted and weed competition controlled is more a question of short-term timber production, tree species control and forest management goals than the regeneration of the forest, the scientists said.

The sites picked for this study all met several criteria: They had gone through a hot, canopy-replacing wildfire from nine to 19 years ago, more than 90 percent of the trees were killed in the fire, and there was no post-fire salvage logging or tree planting. The sites were on the Klamath, Rogue/Siskiyou or Umpqua National Forests.

Conifer trees that naturally regenerated were dominated by Douglas-fir and ponderosa pine at lower elevations, and true firs at higher elevations. There was considerable variation in the regeneration process. Some sites filled in immediately. Others had a few years delay, then rapid filling; some were slow but constant; and a few sites never filled. Surprising to researchers was that up to 19 years after a fire, there was still some new and locally dominant conifer regeneration.

Seed was provided by patches of surviving trees or nearby unburned forest, which were rarely more than a few hundred yards from fire-killed trees. The relationship of shrub competition with tree seedlings also was surprising. On low and middle elevation sites, there were actually more conifers where there was more shrub and hardwood cover; what favored one group also seemed to favor the other. At higher elevations, shrub cover was less of an issue and the abundance of conifer regeneration was conspicuously high. At some high-elevation sites, trees continued to establish in great numbers – even many years after the fire.

In continued research, OSU scientists said they plan to study more specifically what sites will grow into mature forests and what species will persist there, and also more directly compare the progress of natural regeneration with that of managed sites.

This study was funded by the Joint Fire Science Program, a partnership of six federal wildland, fire and research organizations.

Fire suppression and fuel buildups, among other possible causes, have led to an increasing frequency and severity of forest fire in the western United States, the researchers said. Between 1970 and 2004, more than 600 wildfires burned more than 20 million acres in Oregon and California. The 2002 Biscuit Fire, in terrain similar to where this research was done, was one of the largest fires in Oregon’s recorded history.

The recovery of burned lands after wildfire, and whether active management is necessary, has become a point of considerable interest and controversy in recent years. Some studies have argued that, in the absence of aggressive management, burned areas might turn into unproductive shrub fields that could persist for decades or centuries.

“In contrast to expectations, we found natural conifer regeneration to be generally abundant across a variety of settings,” the scientists wrote in the new study. “Management plans can benefit greatly from utilizing natural conifer regeneration, but managers must face the challenge of long regeneration periods, and be able to accommodate high levels of variation across the landscape of a fire.”

Media Contact: 
Source: 

David Hibbs,
541-737-6077

Multimedia Downloads
Multimedia: 

Doug fir burn
Eleven years after the Pony Fire, a young Douglas-fir tree pokes its way through brush fields in one of the plots surveyed by a new Oregon State University study on the natural recovery of conifers in areas previously hit by wildfire. Daniel Irvine, an OSU environmental science student, worked on the project in this part of the Klamath National Forest in northern California in 2006. (Photo courtesy of Oregon State University)

Insect Attack May Have Been Death Knell for Dinosaurs

CORVALLIS, Ore. – Asteroid impacts or massive volcanic flows might have occurred around the time dinosaurs became extinct, but a new book argues that the mightiest creatures the world has ever known may have been brought down by a tiny, much less dramatic force – biting, disease-carrying insects.

An important contributor to the demise of the dinosaurs, experts say, could have been the rise and evolution of insects, especially the slow-but-overwhelming threat posed by new disease carriers. And the evidence for this emerging threat has been captured in almost lifelike-detail – many types of insects preserved in amber that date to the time when dinosaurs disappeared.

“There are serious problems with the sudden impact theories of dinosaur extinction, not the least of which is that dinosaurs declined and disappeared over a period of hundreds of thousands, or even millions of years,” said George Poinar Jr., a courtesy professor of zoology at Oregon State University. “That time frame is just not consistent with the effects of an asteroid impact. But competition with insects, emerging new diseases and the spread of flowering plants over very long periods of time is perfectly compatible with everything we know about dinosaur extinction.”

This concept is outlined in detail in “What Bugged the Dinosaurs? Insects, Disease and Death in the Cretaceous,” a book by George and Roberta Poinar, just published by Princeton University Press.

In it, the authors argue that insects provide a plausible and effective explanation for the slow, inexorable decline and eventual extinction of dinosaurs over many thousands of years. This period is known as the famous “K-T Boundary,” or the line between the Cretaceous and Tertiary Period about 65 million years ago. There is evidence that some catastrophic events, such as a major asteroid or lava flows, also occurred at this time – but these provide no complete explanation for the gradual decline of dinosaur populations, and even how some dinosaurs survived for thousands of years after the K-T Boundary.

Insects and disease, on the other hand, may have been a lot slower, but ultimately finished the job.

“We don’t suggest that the appearance of biting insects and the spread of disease are the only things that relate to dinosaur extinction,” Poinar said. “Other geologic and catastrophic events certainly played a role. But by themselves, such events do not explain a process that in reality took a very, very long time, perhaps millions of years. Insects and diseases do provide that explanation.”

Poinar and his wife, Roberta, have spent much of their careers studying the plant and animal life forms found preserved in amber, using them to re-create the biological ecosystems that were in place millions of years ago. They are also authors of “The Amber Forest: A Reconstruction of a Vanished World.”

As a semi-precious gem that first begins to form as sap oozing from a tree, amber has the unique ability to trap very small animals or other materials and – as a natural embalming agent – display them in nearly perfect, three-dimensional form millions of years later. This phenomenon has been invaluable in scientific and ecological research, and among other things, formed the scientific premise for the movie Jurassic Park, for the "dinosaur DNA" found in mosquitoes.

“During the late Cretaceous Period, the associations between insects, microbes and disease transmission were just emerging,” Poinar said. “We found in the gut of one biting insect, preserved in amber from that era, the pathogen that causes leishmania – a serious disease still today, one that can infect both reptiles and humans. In another biting insect, we discovered organisms that cause malaria, a type that infects birds and lizards today.

“In dinosaur feces, we found nematodes, trematodes and even protozoa that could have caused dysentery and other abdominal disturbances. The infective stages of these intestinal parasites are carried by filth-visiting insects.”

In the Late Cretaceous, Poinar said, the world was covered with warm-temperate to tropical areas that swarmed with blood-sucking insects carrying leishmania, malaria, intestinal parasites, arboviruses and other pathogens, and caused repeated epidemics that slowly-but-surely wore down dinosaur populations. Ticks, mites, lice and biting flies would have tormented and weakened them.

“Smaller and separated populations of dinosaurs could have been repeatedly wiped out, just like when bird malaria was introduced into Hawaii, it killed off many of the honeycreepers,” Poinar said. “After many millions of years of evolution, mammals, birds and reptiles have evolved some resistance to these diseases. But back in the Cretaceous, these diseases were new and invasive, and vertebrates had little or no natural or acquired immunity to them. Massive outbreaks causing death and localized extinctions would have occurred.”

In similar fashion, the researchers suggest, insects would have played a major role in changing the nature of plant life on Earth – the fundamental basis for all dinosaur life, whether herbivore, omnivore or carnivore. As the dinosaurs were declining, their traditional food items such as seed ferns, cycads, gingkoes and other gymnosperms were largely being displaced by flowering plants, which insects helped spread by their pollination activities. These plants would have spread to dominate the landscape. Also, insects could have spread plant diseases that destroyed large tracts of vegetation, and the insects could have been major competitors for the available plant food supply.

“Insects have exerted a tremendous impact on the entire ecology of the Earth, certainly shaping the evolution and causing the extinction of terrestrial organisms,” the authors wrote in their book. “The largest of the land animals, the dinosaurs, would have been locked in a life-or-death struggle with them for survival.”

The confluence of new insect-spread diseases, loss of traditional food sources, and competition for plants by insect pests could all have provided a lingering, debilitating condition that dinosaurs were ultimately unable to overcome, the researchers say. And these concerns – which might have pressured the dinosaurs for thousands of years – may have finished the job, along with the changing environment, meteor impacts and massive lava flows.

“We can’t say for certain that insects are the smoking gun, but we believe they were an extremely significant force in the decline of the dinosaurs,” Poinar said. “Our research with amber shows that there were evolving, disease-carrying vectors in the Cretaceous, and that at least some of the pathogens they carried infected reptiles. This clearly fills in some gaps regarding dinosaur extinctions.”

Media Contact: 
Source: 

George Poinar, Jr.,
541-737-5366

Multimedia Downloads
Multimedia: 

Burmese termite

Burmese termite

Burmese tick

Tick found in Burmese amber.

Mountain Logging Conference at OSU

CORVALLIS, Ore. – The 13th International Mountain Logging and Pacific Northwest Skyline Symposium will be held at Oregon State University on April 1-6, attracting experts from around the world to explore the latest innovations and approaches to mountain logging.

The professional conference, at the CH2M-Hill Alumni Center on the OSU campus, will include field tours, eight workshops, a poster and vendor session, and multiple presentations.

Participants are expected from Canada, Austria, Germany, France, Japan, Turkey, South Africa, Sweden and other nations, in addition to forestry professionals from much of the United States in academia, industry and government. The conference theme this year is “Global Competitiveness: Implications and Sustainable Approaches for Mountain Forest Harvesting.”

Focus topics include logging innovations to reduce cost or improve value; forest road and transportation management; harvest planning; environmental quality in mountain logging; biomass utilization for energy and biofuels; and workforce issues.

Mountain forests – such as those that dominate much of the Pacific Northwest – are valuable sources of wood, water, wildlife habitat, recreational opportunities and scenic quality. The latest knowledge in forest engineering techniques is necessary to meet societal demands for wood products while protecting and enhancing other forest features. This conference is of considerable value in achieving those goals, organizers say.

Media Contact: 
Source: 

Lesley Nylin,
541-737-1349