Sixty trees sampled at Yale Myers Forest in northeastern Connecticut contained concentrations of methane that were as high as 80,000 times ambient levels. Normal air concentrations are less than 2 parts per million, but the Yale researchers found average levels of 15,000 parts per million inside trees.
"These are flammable concentrations," said Kristofer Covey, the study's lead author and a Ph.D. candidate at Yale. "Because the conditions thought to be driving this process are common throughout the world's forests, we believe we have found a globally significant new source of this potent greenhouse gas."
The estimated emission rate from an upland site at the Yale forest is roughly equivalent to burning 40 gallons of gasoline per hectare of forest per year. It also has a global warming potential equivalent to 18 percent of the carbon being sequestered by these forests, reducing their climate benefit of carbon sequestration by nearly one-fifth.
"If we extrapolate these findings to forests globally, the methane produced in trees represents 10 percent of global emissions," said Xuhui Lee, a co-author of the study and Sara Shallenberger Brown Professor of Meteorology at Yale. "We didn't know this pathway existed."
The trees producing methane are older—between 80 and 100 years old—and diseased. Although outwardly healthy, they are being hollowed out by a common fungal infection that slowly eats through the trunk, creating conditions favorable to methane-producing microorganisms called methanogens.
"No one until now has linked the idea that fungal rot of timber trees, a production problem in commercial forestry, might also present a problem for greenhouse gas and climate change mitigation," said Mark Bradford, a co-author and Assistant Professor of Terrestrial Ecosystem Ecology at F&ES.
Red maple, an abundant species in North America, had the highest methane concentrations, but other common species, including oak, birch and pine were also producers of the gas. The rate of methane emissions was 3.1 times higher in the summer, suggesting that higher temperatures may lead to increasing levels of forest methane that, in turn, lead to ever-higher temperatures.
"These findings suggest decay in living trees is important to biogeochemists and atmospheric scientists seeking to understand global greenhouse gas budgets and associated climate change," said Covey.
The other co-authors of the paper, "Elevated Methane Concentrations in Trees of an Upland Forest," are Stephen Wood, a Ph.D. student at Columbia University, and Robert Warren, former postdoctoral researcher at Yale and now an assistant professor at Buffalo State (SUNY). The paper can be viewed at www.agu.org/pubs/crossref/pip/2012GL052361.shtml
David DeFusco | EurekAlert!
How do megacities impact coastal seas? Searching for evidence in Chinese marginal seas
11.12.2017 | Leibniz-Institut für Ostseeforschung Warnemünde
What makes corals sick?
11.12.2017 | Leibniz-Zentrum für Marine Tropenforschung (ZMT)
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications
Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...
Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.
The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
11.12.2017 | Physics and Astronomy
11.12.2017 | Earth Sciences
11.12.2017 | Information Technology