Featured Research

from universities, journals, and other organizations

Plants' fungi allies may not help store climate change's extra carbon

Date:
August 30, 2012
Source:
Penn State
Summary:
Fungi found in plants may not be the answer to mitigating climate change by storing additional carbon in soils as some previously thought, according to plant biologists.

Fungi found in plants may not be the answer to mitigating climate change by storing additional carbon in soils as some previously thought.
Credit: Alexandr / Fotolia

Fungi found in plants may not be the answer to mitigating climate change by storing additional carbon in soils as some previously thought, according to an international team of plant biologists.

The researchers found that increased carbon dioxide stimulates the growth of arbuscular mycorrhizal fungi (AMF) -- a type of fungus that is often found in the roots of most land plants -- which then leads to higher decomposition rates of organic materials, said Lei Cheng, post doctorate fellow in plant science, Penn State. This decomposition releases more carbon dioxide back into the air, which means that terrestrial ecosystems may have limited capacity to halt climate change by cleaning up excessive greenhouse gases, according to the researchers.

"Prior to our study, there have been few studies on whether elevated levels of carbon dioxide would stimulate organic carbon decomposition through AMF," said Cheng.

To study the effect of higher levels of carbon dioxide on AMF-mediated decomposition, the researchers conducted four experiments, two in greenhouses and two in fields to mimic Earth's expected North American atmospheric levels of carbon dioxide. They studied plots of a wild oat species, which is native to Eurasia and now common in North American grasslands, and wheat.

In the experiments, one plot was treated with AMF, the other did not have the fungus. Both plots were exposed to higher than currently existing carbon dioxide levels. After a ten-week gestation period, the sample of plants with AMF had 9 percent less carbon in the soil than the plot that was not treated with AMF, indicating that the carbon was released back into the atmosphere.

"Basically, we showed that elevated carbon dioxide increases carbon allocation to AMF to increase plant nitrogen uptake, and higher AMF facilitate organic residue decomposition which releases carbon dioxide into the air," said Cheng.

Elevated levels of carbon dioxide did significantly increase the size of the AMF colonies and carbon allocation underground, according to the researchers, who released their findings in the Aug. 30 issue of Science. However, the storage of carbon is offset by the role of AMF in facilitating decomposition.

"We used to think that this excess carbon would be sequestered in the soil," said Cheng. "So, that could help mitigate climate change, but it doesn't appear to be so."

They also studied the effect on a wheat and soybean field. In this experiment, Cheng said elevated levels of carbon dioxide increased both the size of AMF colonies and decomposition.

AMF colonies, which are found in the roots of 80 percent of land plant species, play a critical role in Earth's carbon cycle. The fungus receives and stores carbon -- a byproduct of the plant's photosynthesis -- from its host plant in its long vein-like structures. A plant stores about 20 percent of its carbon in AMF, according to Cheng.

AMF also help the plant capture nutrients, such as phosphorus and nitrogen.

"We found that, under elevated carbon dioxide levels, AMF supply more nitrogen to their host plants by acquiring ammonium directly from decomposing residues," Cheng said. "So the good news is that AMF's role in the plant's nitrogen uptake may open up the possibility of keeping carbon in the soil."

When there are higher carbon dioxide levels, the plant's ability to take in nitrates is inhibited and it then adds more carbon to fungi like AMF to acquire ammonium, said Cheng. The management of soil nitrogen transformations may provide a promising strategy of restoring levels of carbon sequestration under higher carbon dioxide conditions.

Cheng worked with Fitzgerald L. Booker, plant physiologist and professor of crop science, and Kent O. Burkey, plant physiologist and professor of crop science and botany, both of North Carolina State University and the U.S. Department of Agriculture-Agricultural Research Service; Thomas W. Rufty, Bayer Distinguished Professor, department of crop science, Shuijin Hu, associate professor of plant pathology, H. David Shew, professor of plant pathology, and Cong Tu, research specialist, all of North Carolina State University, and Lishi Zhou, department of plant pathology, North Carolina State University and State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Science.

The USDA supported this work.


Story Source:

The above story is based on materials provided by Penn State. Note: Materials may be edited for content and length.


Journal Reference:

  1. L. Cheng, F. L. Booker, C. Tu, K. O. Burkey, L. Zhou, H. D. Shew, T. W. Rufty, S. Hu. Arbuscular Mycorrhizal Fungi Increase Organic Carbon Decomposition Under Elevated CO2. Science, 2012; 337 (6098): 1084 DOI: 10.1126/science.1224304

Cite This Page:

Penn State. "Plants' fungi allies may not help store climate change's extra carbon." ScienceDaily. ScienceDaily, 30 August 2012. <www.sciencedaily.com/releases/2012/08/120830141345.htm>.
Penn State. (2012, August 30). Plants' fungi allies may not help store climate change's extra carbon. ScienceDaily. Retrieved April 21, 2014 from www.sciencedaily.com/releases/2012/08/120830141345.htm
Penn State. "Plants' fungi allies may not help store climate change's extra carbon." ScienceDaily. www.sciencedaily.com/releases/2012/08/120830141345.htm (accessed April 21, 2014).

Share This



More Earth & Climate News

Monday, April 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ocean Drones Making Waves in Research World

Ocean Drones Making Waves in Research World

AP (Apr. 21, 2014) Two California companies are developing unmanned watercraft to study the ocean. The ocean drones can stay at sea for months to gather scientific data, patrol borders and protect endangered reefs. (April 21) Video provided by AP
Powered by NewsLook.com
Drought Concerns May Hurt Lake Tourism

Drought Concerns May Hurt Lake Tourism

AP (Apr. 18, 2014) Operators of recreational businesses on western reservoirs worry that ongoing drought concerns will keep boaters and other visitors from flocking to the popular summer attractions. (April 18) Video provided by AP
Powered by NewsLook.com
Man Claims He Found Loch Ness Monster With... Apple Maps?

Man Claims He Found Loch Ness Monster With... Apple Maps?

Newsy (Apr. 18, 2014) Andy Dixon showed the Daily Mail a screenshot of what he believes to be the mythical beast swimming just below the lake's surface. Video provided by Newsy
Powered by NewsLook.com
First Ever 'Female Penis' Discovered In Animal Kingdom

First Ever 'Female Penis' Discovered In Animal Kingdom

Newsy (Apr. 18, 2014) Not only are these newly discovered bugs' sex organs reversed, but they also mate for up to 70 hours. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins