 |
|
More carbon dioxide may help some trees weather ice storms
August 16, 2006Durham, N.C. - The increased levels of carbon dioxide in the atmosphere predicted for later this century may reduce the damage that future ice storms will cause to commercially important loblolly pine trees, according to a new study.
Researchers working at a Duke University outdoor test facility found that loblolly pines growing under carbon-dioxide levels mimicking those predicted for the year 2050 - roughly one and a half times today's levels - fared somewhat better during and after a major ice storm that hit the area than did loblollies growing under current concentrations of the gas.
The results came as a surprise, the researchers said.
"Before the storm, I was absolutely certain the pines would be more susceptible to ice damage under elevated concentrations of carbon dioxide," said Ram Oren, an ecology professor at Duke's Nicholas School of the Environment and Earth Sciences who directs the test site and participated in the study.
"My impressions were absolutely wrong," he said. "Instead of increasing the sensitivity to ice-storm damage, carbon dioxide decreased the sensitivity."
The researchers reported the findings August 8, 2006, in the Journal of Geophysical Research. The first author of the report is Heather McCarthy, a Nicholas School graduate student. The study was funded by the U.S. Department of Energy and the Forest Service.
Scientists predict that concentrations of carbon dioxide in the air will continue to rise as people continue to burn fossil fuels and clear land for agriculture, and that this rise will help drive global warming. Carbon dioxide is widely thought to play a major role in global warming because it traps solar heat in the atmosphere, much as the glass in a greenhouse traps heat.
At the Free-Air Carbon Dioxide Enrichment (FACE) experiment, located in the Duke Forest research reserve, researchers since 1994 have been studying how this predicted extra gas would affect a typical Southeastern forest ecosystem. At the site, a computer-controlled network of pipes and valves feeds carbon dioxide from elevated towers to trees growing in three different open-air plots. Three other identical "control" plots receive no additional carbon dioxide.
Following the ice storm, which hit in December 2002, the researchers collected and measured ice-felled tree parts in the study area. They found "fewer damaged trees" and "less damage per tree" in plots with elevated carbon-dioxide concentrations, according to their journal report.
"These results suggest that forests may suffer less damage during each ice storm event of similar severity in a future with higher atmospheric carbon dioxide," the researchers said.
Overall, the researchers found that about 20 percent of the trees in plots "treated" with carbon dioxide were damaged, compared with 29 percent of the trees in control plots. Tree tops broken off by the ice in the treated plots also tended to be shorter in length.
In the growing season following the storm, trees in the treated plots recovered better since they had suffered less damage, the scientists found.
The scientists cautioned, however, that they were not able to identify the actual mechanisms that helped to protect the trees grown under elevated carbon-dioxide conditions. "We just couldn't tease out anything obvious," McCarthy said.
They were able to rule out one potentially obvious explanation.
Previous studies at FACE had suggested that new wood grown under elevated carbon-dioxide levels is less dense than normal, so it might be expected that the tops of trees grown under these conditions would be more fragile, Oren and McCarthy said.
But broken-off tree tops collected after the storm from under damaged trees in the treated plots turned out to have normal wood densities, they said. That finding counters the notion that structural weaknesses where tops had broken off are tied to density differences.
As one open possibility, Oren suggested that higher carbon-dioxide levels may have induced the trees to reshape their tops, making them thicker and thus better able to withstand the ice load without breaking.
Whether or not this is the answer will be revealed only when all of the trees are harvested and their individual structures studied in detail, he added.
The test results may hold meaning for the future of commercial pine forests in the Southeast, Oren said. If future studies confirm that loblolly pines growing under higher carbon-dioxide concentrations are better able to resist ice damage, then this might "generate future scenarios in which loblollies could actually migrate farther north," he said.
Ice storms now are major barriers to the northward migration of loblollies, which are susceptible to cold temperatures and ice damage. But according to the results of this study, Oren said, climate changes under global warming would tend to favor the spread of such fast-growing trees.
Duke University
"Before the storm, I was absolutely certain the pines would be more susceptible to ice damage under elevated concentrations of carbon dioxide," said Ram Oren, an ecology professor at Duke's Nicholas School of the Environment and Earth Sciences who directs the test site and participated in the study.
"My impressions were absolutely wrong," he said. "Instead of increasing the sensitivity to ice-storm damage, carbon dioxide decreased the sensitivity."
The researchers reported the findings August 8, 2006, in the Journal of Geophysical Research. The first author of the report is Heather McCarthy, a Nicholas School graduate student. The study was funded by the U.S. Department of Energy and the Forest Service.
Scientists predict that concentrations of carbon dioxide in the air will continue to rise as people continue to burn fossil fuels and clear land for agriculture, and that this rise will help drive global warming. Carbon dioxide is widely thought to play a major role in global warming because it traps solar heat in the atmosphere, much as the glass in a greenhouse traps heat.
At the Free-Air Carbon Dioxide Enrichment (FACE) experiment, located in the Duke Forest research reserve, researchers since 1994 have been studying how this predicted extra gas would affect a typical Southeastern forest ecosystem. At the site, a computer-controlled network of pipes and valves feeds carbon dioxide from elevated towers to trees growing in three different open-air plots. Three other identical "control" plots receive no additional carbon dioxide.
Following the ice storm, which hit in December 2002, the researchers collected and measured ice-felled tree parts in the study area. They found "fewer damaged trees" and "less damage per tree" in plots with elevated carbon-dioxide concentrations, according to their journal report.
"These results suggest that forests may suffer less damage during each ice storm event of similar severity in a future with higher atmospheric carbon dioxide," the researchers said.
Overall, the researchers found that about 20 percent of the trees in plots "treated" with carbon dioxide were damaged, compared with 29 percent of the trees in control plots. Tree tops broken off by the ice in the treated plots also tended to be shorter in length.
In the growing season following the storm, trees in the treated plots recovered better since they had suffered less damage, the scientists found.
The scientists cautioned, however, that they were not able to identify the actual mechanisms that helped to protect the trees grown under elevated carbon-dioxide conditions. "We just couldn't tease out anything obvious," McCarthy said.
They were able to rule out one potentially obvious explanation.
Previous studies at FACE had suggested that new wood grown under elevated carbon-dioxide levels is less dense than normal, so it might be expected that the tops of trees grown under these conditions would be more fragile, Oren and McCarthy said.
But broken-off tree tops collected after the storm from under damaged trees in the treated plots turned out to have normal wood densities, they said. That finding counters the notion that structural weaknesses where tops had broken off are tied to density differences.
As one open possibility, Oren suggested that higher carbon-dioxide levels may have induced the trees to reshape their tops, making them thicker and thus better able to withstand the ice load without breaking.
Whether or not this is the answer will be revealed only when all of the trees are harvested and their individual structures studied in detail, he added.
The test results may hold meaning for the future of commercial pine forests in the Southeast, Oren said. If future studies confirm that loblolly pines growing under higher carbon-dioxide concentrations are better able to resist ice damage, then this might "generate future scenarios in which loblollies could actually migrate farther north," he said.
Ice storms now are major barriers to the northward migration of loblollies, which are susceptible to cold temperatures and ice damage. But according to the results of this study, Oren said, climate changes under global warming would tend to favor the spread of such fast-growing trees.
Duke University
Carbon Dioxide News and Current Carbon Dioxide Events RSSBad sign for global warming: Thawing permafrost holds vast carbon pool
Permafrost blanketing the northern hemisphere contains more than twice the amount of carbon in the atmosphere, making it a potentially mammoth contributor to global climate change depending on how quickly it thaws.
Complex ocean behavior studied with 'artificial upwelling'
A team of scientists is studying the complex ocean upwelling process by mimicking nature - pumping cold, nutrient-rich water from deep within the Pacific Ocean and releasing it into surface waters near Hawaii that lack the nitrogen and phosphorous necessary to support high biological production.
Thawing permafrost likely to boost global warming
The thawing of permafrost in northern latitudes, which greatly increases microbial decomposition of carbon compounds in soil, will dominate other effects of warming in the region and could become a major force promoting the release of carbon dioxide and thus further warming, according to a new assessment in the September 2008 issue of BioScience.
No more big stink: Scent lures mosquitoes, but humans can't smell it
Mosquito traps that reek like latrines may be no more. A University of California, Davis research team led by chemical ecologist Walter Leal has discovered a low-cost, easy-to-prepare attractant that lures blood-fed mosquitoes without making humans hold their noses.
Smoking during pregnancy a 'double-edged sword' in SIDS
Premature infants whose mothers smoked during pregnancy may be at even higher risk for sudden infant death syndrome (SIDS) than preemies whose mothers did not smoke, according to new research out of the University of Calgary.
Why is Greenland covered in ice?
There have been many reports in the media about the effects of global warming on the Greenland ice-sheet, but there is still great uncertainty as to why there is an ice-sheet there at all.
DOE official cites need for major breakthroughs to cope with climate change
Meeting the world's growing energy needs while responding to global warming during the 21st Century will be one of the biggest challenges humanity has ever faced, Raymond L. Orbach, Ph.D., the U.S. Department of Energy's Under Secretary for Science, says in the latest podcast in the American Chemical Society's Global Challenges/Chemistry Solutions series
Future for clean energy lies in 'big bang' of evolution
Amid mounting agreement that future clean, "carbon-neutral", energy will rely on efficient conversion of the sun's light energy into fuels and electric power, attention is focusing on one of the most ancient groups of organism, the cyanobacteria.
Groundbreaking research shows DEET's not sweet to mosquitoes
Spray yourself with a DEET-based insect repellent and the mosquitoes will leave you alone. But why? They flee because of their intense dislike for the smell of the chemical repellent and not because DEET jams their sense of smell, report researchers at the University of California, Davis.
MSU's discovery of plant protein holds promise for biofuel production
Scientists at Michigan State University have identified a new protein necessary for chloroplast development. The discovery could ultimately lead to plant varieties tailored specifically for biofuel production.
More Carbon Dioxide News Articles
 | Voluntary Carbon Markets: An International Business Guide to What They Are and How They Work (Environmental Markets Insight Series) by Ricardo Bayon, Amanda Hawn, Katherine Hamilton ** By the end of 2006 the world carbon market will top $30 billion in transactions and the first carbon billionaire may well have emerged** HSBC, Volvo, Avis, Ricoh, and American Express are but a few of the thousands of companies now offsetting their CO2 emissions and becoming "carbon neutral", fuelling a massive international voluntary carbon market that is growing exponentially** This is... |
 | How to Live a Low-Carbon Life: The Individuals Guide to Stopping Climate Change by Chris Goodall That climate change is happening is now all too clear. Many of us want to take action to reduce our carbon dioxide emissions. Yet the lack of a consolidated source of reliable information on how to calculate one’s individual emissions and the difficulty in assessing different options for effectiveness and cost savings has proven to be a major stumbling block. But personal actions to reduce... |
 | Gas Trees and Car Turds: Kids' Guide to the Roots of Climate Change by Kirk Johnson Global warming is a complicated problem. Gas Trees and Car Turds is a fun, fast read about the carbon cycle: trees are made of air and water, electricity is made from coal that is made from trees, gasoline is made from plankton, and all of these things are related to each other and to our climate through carbon dioxide. This colorfully illustrated book makes carbon dioxide, an invisible... |
 | Plan B: Rescuing a Planet under Stress and a Civilization in Trouble by Lester R. Brown A bold new plan for those concerned about rising temperatures, population projections, and spreading water scarcity. Lester Brown notes that if the environmental trends of recent decades continue, the global economy will soon begin to unravel. The food sector, he believes, is the most vulnerable. Record-high temperatures and falling water tables are already taking the edge off grain harvests in... |
 | CO2 Rising: The World's Greatest Environmental Challenge by Tyler Volk The most colossal environmental disturbance in human history is under way. Ever-rising levels of the potent greenhouse gas carbon dioxide (CO2) are altering the cycles of matter and life and interfering with the Earth's natural cooling process. Melting Arctic ice and mountain glaciers are just the first relatively mild symptoms of what will result from this disruption of the planetary energy... |
 | CO2 in Seawater: Equilibrium, Kinetics, Isotopes (Elsevier Oceanography Series) by R.E. Zeebe, D. Wolf-Gladrow Carbon dioxide is the most important greenhouse gas after water vapor in the atmosphere of the earth. More than 98% of the carbon of the atmosphere-ocean system is stored in the oceans as dissolved inorganic carbon. The key for understanding critical processes of the marine carbon cycle is a sound knowledge of the seawater carbonate chemistry, including equilibrium and nonequilibrium properties... |
 | Climate Change and Carbon Markets: A Handbook of Emissions Reduction Mechanisms * Thorough, authoritative explanation of the instruments involved in the carbon trading market being launched through the EU Emissions Trading Scheme, the Kyoto Protocol and other mechanisms* The market for carbon and greenhouse gas permits will be huge --potentially as large as the fossil fuel, (oil, gas and coal] markets it aims to counteract* Essential practical guide and reference for... |
 | Harnessing Farms and Forests in the Low-Carbon Economy: How to Create, Measure, and Verify Greenhouse Gas Offsets by Nicholas Institute for Environmental Policy Solutions As the United States moves to a low-carbon economy in order to combat global warming, credits for reducing carbon dioxide emissions will increasingly become a commodity that is bought and sold on the open market. Farmers and other landowners can benefit from this new economy by conducting land management practices that help sequester carbon dioxide, creating credits they can sell to industry to... |
 | Carbon Capture and Sequestration Integrating Technology, Monitoring, Regulation This book is the first systematic presentation of the technical, legal, and economic forces that must coalesce to realize carbon dioxide capture and geologic sequestration as a viable CO2 reduction strategy. It synthesizes key engineering data and explains the technological and legal conditions that must be in place for carbon sequestration to be... |
 | The Climate Diet: How You Can Cut Carbon, Cut Costs and Save the Planet by Jonathan Harrington We live in a world of excess. We consume too much of everything—food, clothes, cars, bricks and mortar. Our bingeing is often so extreme that it threatens our own health and well being. And we are not the only ones who are getting sick. The Earth—which provides the food, air, water and land that sustains us—is also under severe pressure. Gluttonous consumption of nature's... |
| © 2008 BrightSurf.com |