ROOT STUDY — These pine trees at Argonne-East were planted between 1953 and 1955, some of the more than one million trees planted on the site to restore the heavily-farmed grounds. Argonne researchers contributed to a new study that shows the potential for soils to soak up atmospheric carbon dioxide is strongly affected by how long roots live.

Roots affect greenhouse gas absorption rate

By Catherine Foster

A new study published in Science indicates that the potential for soils to soak up atmospheric carbon dioxide is strongly affected by how long roots live. Large differences in root replacement rates between forest types might alter current predictions of how carbon absorption by soil will act to reduce global warming from excess human-caused carbon dioxide.

The study, by researchers at Argonne, Duke University, University of Illinois at Chicago and Oak Ridge National Laboratory, was funded primarily by the U.S. Department of Energy’s Office of Science.

The researchers used a novel technique to measure the longevity of roots -- the source of some of the carbon that would be transferred by decay into the soil. They used trees growing in forest plots infused with a computer-controlled flow of carbon dioxide. The flow was metered to maintain the higher atmospheric carbon dioxide levels predicted to occur in the middle of this century. Such an increase in carbon dioxide, caused by the burning of fossil fuels and clearing of the world's forests, underlies the global warming that scientists widely believe to have already begun.

The scientists' measurements revealed that the roots of loblolly pine but not sweetgum trees growing in simulated mid-century air at two experimental sites remained intact far longer and transferred less carbon into soils than scientists had expected.

“Our data showed that fine root replacement varied from 1.2 to 9 years depending on root diameter and forest type,” said Argonne environmental scientist Roser Matamala, lead author of the Science article. Co-author William Schlesinger, Dean of Duke’s Nicholas School of the Environment and Earth Sciences, called the root study results "a huge change from dogma, which says that these roots turn over all the time. This really says the roots can last quite a while.”

“Some forests would do a better job than others in taking up carbon dioxide from the atmosphere and placing it into the soil,” Matamala said. “Pine forests have slow root replacement which decreases the potential to accumulate carbon in the soil in the short-term, while the fast root replacement coupled with increased root production in the sweetgum forest led to a rapid and significant increase in soil carbon.”

Some policy makers expect that the surge of human-produced carbon dioxide will boost plant growth enough to remove much of the extra gas from the atmosphere. The assimilated carbon dioxide, converted into carbohydrates during photosynthesis, would thus be stored in plant tissue for long periods, ameliorating the gas's potential impact on predicted global warming. Under this scenario, significant amounts of residual carbon would ultimately be sequestered in soil particles when roots and other tree parts decay.

“The major implication for greenhouse management strategies is that some forests won’t transfer carbon from the atmosphere to soils at the speed we need them to do it to reduce global warming,” said co-author Miquel Gonzalez-Meler at the University of Illinois at Chicago.

To test how a carbon dioxide-enriched atmosphere will actually affect the environment, the researchers bathed test plots within a growing loblolly forest near Duke and in plots of sweetgum-dominated woodlands in eastern Tennessee with additional carbon dioxide. At both the Duke and Oak Ridge test sites, extra carbon dioxide is released from tower-mounted valves that are computer-controlled to ensure levels of the gas expected in the air worldwide by mid-century.

During the first three years of these continuing seven-year experiments, the extra carbon dioxide boosted overall pine growth by 25 percent and sweetgum production by 21 percent, according to the Science report. However, carbon tracer measurements revealed that the fine roots of the trees at the Duke site lasted significantly longer than plant biologists had previously estimated, implying that they are replaced less often and carbon transfer to soil is slow. The fine roots in the Oak Ridge site, however, have a shorter life, and much more of the extra carbon is transferred quickly to the soil.

The carbon tracer approach used in the study gives scientists a more accurate way to estimate replacement of roots because it documents how long the carbon actually resides in root tissue. The fact that growing roots are so hard to study without killing them or disturbing their growth has led scientists to overestimate how much carbon from extra doses of carbon dioxide might end up in the soil.

The analysis revealed that the pines showed a root carbon turnover of 4.2 years, and the sweetgums showed a carbon turnover of 1.25 years. Plant biologists had previously estimated that such roots would be replaced once every year on average. Based on this analysis, the larger roots would last even longer, said the scientists. Other carbon tracer studies confirmed that the long root turnover rates are changed by carbon dioxide levels.

“These long root lifetimes suggest that root production and turnover in forests have been overestimated and that sequestration of anthropogenic (human-produced) atmospheric carbon in forest soils may be lower than currently estimated,” wrote the paper’s authors.

Other authors are Richard Norby of Oak Ridge National Laboratory and Julie Jastrow (ER).

Symposia to provide update on laser safety

The Environment, Safety, Health/Quality Assurance Division (EQO) will host a laser safety symposium that will be offered in two identical sessions. The first will be Tuesday, Dec. 2, from 10-11:30 a.m. in Argonne-East’s Building 200 Auditorium, while the second will take place on Thursday, Dec. 4, from 2-3:30 p.m. in the Building 402 Conference Center.

The symposium, “Lessons Learned and the Future of Laser Safety at Argonne-East,” is in response to a recent series of serious eye injuries resulting from accidents with research lasers in Department of Energy laboratories. Speakers will reflect on the significance of those accidents and discuss the future of laser safety from the perspective of the U.S. Department of Energy, Argonne and EQO.

“Though the number of laser injuries is relatively small, their severity warrants an effort to be sure we are doing everything possible to prevent any more unfortunate occurrences,” said EQO Laser Safety Officer Bruce Murdoch, who served on an investigation committee for one of the accidents.

Employees working with medium and high-powered lasers are encouraged to attend the symposium, which will focus on ways to promote the heightened sense of teamwork needed to maintain a safe work environment.

Colloquium to focus on national security

Jay C. Davis, a strategic and scientific consultant and member of the University of Chicago Board of Governors for Argonne, will speak on “The Role of Science and Technology in National Security” at a Director’s Special Colloquium Wednesday, Dec. 10, at Argonne-East.

Davis’s talk will begin at 3 p.m. in the Building 402 Conference Center.

Until his retirement in 2002, Davis served as the first National Security Fellow at Lawrence Livermore National Laboratory (LLNL) Center for Global Security Research. Previously, he spent three years as the founding director of the Defense Threat Reduction Agency of the U.S. Department of Defense.

Davis had major operational and scientific responsibilities in two United Nations inspections of Iraq in 1991. He was selected as the only non-U.N. member of the team that briefed the U.N. Security Council on evidence of Iraqi evasion of the inspection process and violation of the non-proliferation treaty.

Davis joined LLNL in 1971 and worked as a research scientist and engineering manager, leading the design of several accelerator facilities. In the 1980s, he became the founding director of the Center for Accelerator Mass Spectrometry.

In 1994, he merged several research organizations at Livermore to create the Earth and Environmental Science Directorate.

‘Women of Manhattan Project’ topic of talk

Argonne retiree Carol Herzenberg will speak on “Women of the Manhattan Project” at the combined November-December meeting of the retirees and the Center for Reactor Information Friday, Dec. 5.

The group will meet at noon for lunch in Argonne-East’s Building 213 Cafeteria, Dining Room B.

Herzenberg is the author of “Their Day in the Sun -- Women of the Manhattan Project” about the role of women in atomic energy research.

Choral group celebrates 23rd season

The Argonne Choral group will sing holiday favorites at three locations at Argonne-East Wednesday, Dec. 10.

The group will perform in the Building 213 Cafeteria at noon, at the Argonne Credit Union at 1:30 p.m. and in the lobby of Building 201 at 2 p.m.

This will be the choral group’s 23rd season. Harry Bell (PFS) has been the group’s only director.

Nanotech instruments go on display

All employees are welcome to see the latest test and measurement solutions for nanotechnology, materials and device research applications when Keithley Instruments visits Argonne-East Tuesday, Dec. 9, from 9 a.m. to 4 p.m. in the Building 213 Cafeteria, Dining Rooms A and B.

More information on Keithley Instruments is online.

Argonne musicians to perform in concert

Several Argonne and University of Chicago employees will display their musical talents when the Hinsdale-based West Suburban Symphony Orchestra (WSSO) performs holiday favorites Sunday, Dec. 7.

Members of the WSSO include IPD Director and violinist Kathy Macal, French horn player Liz Moog (XFD), violist Marvin Tetenbaum (CMT), violinist Margret Chang (C&PA) and cellist and orchestra president Rich Lukes (University of Chicago).

The concert is scheduled to begin at 3:30 p.m. at Hinsdale Central High School, 55th and Grant Streets, with a pre-concert conversation with conductor Peter Lipari to take place at 2:45 p.m. Tickets, available at the door, are $17 for adults, $12 for seniors, and $5 for teens, with kids 12 and under free.

The program will include classical works such as Tchaikovsky’s “Nutcracker Suite” and Mannheim Steamroller adaptations of select carols. In addition, the orchestra will feature a guest performance by The Agape Ringers -- Chicago’s premiere handbell ensemble.

Founded in 1947, the West Suburban Symphony Orchestra is made up of more than 100 volunteer musicians from the greater Chicagoland area, who come together to share classical and popular music with the public.

“While suburban musical groups give highly professional performances, most of our members don’t earn a living as players or vocalists,” said Macal. “We have day jobs that pay the bills and volunteer to play after-hour gigs that we hope are as rewarding for our audiences as they are for us.”

More information about the orchestra and the concert is online.

Guest House plans annual Beaujolais dinner

The Argonne Guest House will celebrate the arrival of the 2003 Beaujolais Nouveau wine Friday, Dec. 5, with a special dinner from 5-8 p.m.

Beaujolais Nouveau is young wine, made from the fast-fermenting Gamay grape, traditionally released in France on the third Thursday of every November.

The menu for the Beaujolais Nouveau dinner will include items like garlic roasted rack of pork, undressed beef Wellington, seared tuna, roast rack of lamb, braised beef short ribs and monkfish and oxtails. Beaujolais Nouveau will be available for $12 per bottle or $4 per glass.

The full menu will be posted online.

Guest House to close for events

The Argonne Guest House will not serve lunch Friday, Dec. 12, or Friday, Dec. 19, due to special events.

Breakfast and dinner will be available both days

Retirement plan questions can be answered

The laboratory’s retirement vendors will send representatives to Argonne-East during December to meet individually with employees to answer questions about retirement plans and retirement plan assets. For an appointment, call the number listed.

Fidelity -- Tuesday, Dec. 2, and Tuesday, Dec. 9. Call the appointment desk at (800) 642-7131.

TIAA-CREF -- Monday, Dec. 15, and Tuesday, Dec. 16. Call (800) 842-2005.

Santa seeks help for breakfast

Argonne employees can help make the Argonne Club’s “Breakfast with Santa” holiday party a success.

Volunteers are needed to collect tickets, run games and greet children while in costume. Volunteers can be as young as 16 years old, so children of employees can participate.

The event will be held Saturday, Dec. 6, from 9 a.m. to 3 p.m.

For more information, call Loretta Phillips at ext. 2-6934 or e-mail lmphillips@anl.gov.

Leukemia research topic of talk

“Focus on Acute Myeloid Leukemia” will be presented by Elizabeth Eklund Friday, Dec. 12, at 1:30 p.m. in Argonne-East’s Building 362 Auditorium.

Eklund is an associate professor of medicine in the Division of Hematology and Oncology at Northwestern University’s Medical School and the Robert H. Luire Comprehensive Cancer Center. Her leukemia research is partly funded by the Leukemia and Lymphoma Society, an Argonne Combined Appeal agency.

The lecture is sponsored by the Argonne Combined Appeal, the Energy Systems Division and the Biosciences Division.

For more information, call Sandra Biedron (ES) at ext. 2-1162.

Club hosts ‘Rudolph Romp’

The Argonne Running Club will host the “Rudolph Romp” holiday run and walk Thursday, Dec. 4.

The three-mile run and two-mile walk will start at the Advanced Photon Source Gallery at noon. Employees of all ability levels are invited to participate.