Featured Research

from universities, journals, and other organizations

Researchers Find Frozen North May Accelerate Climate Change

Date:
October 12, 2004
Source:
NASA/Goddard Space Flight Center
Summary:
Researchers have found despite their sub-zero temperatures, ecosystems of the frozen north may actually accelerate climate warming.

The UF study suggests that climate warming in the arctic tundra may cause the release of much more carbon dioxide than previously expected. Even though plants grew more, and more carbon was stored in plants and in the surface of the soil, the whole ecosystem did not gain carbon. Instead, it lost a tremendous amount from the deepest soil layers, probably because increased nitrogen accelerated the breakdown of soil carbon.
Credit: Ted Schuur

NASA-funded researchers have found despite their sub-zero temperatures, ecosystems of the frozen north may actually accelerate climate warming.

"The three to seven degree Fahrenheit rise in temperature predicted by global climate computer models could cause the breakdown of the arctic tundra's vast store of soil carbon," said Michelle Mack. She is an ecologist at the University of Florida (UF), Gainesville, Fla., and one of the lead researchers on a study published in last week's issue of Nature. "The rise in temperature would would release more of the greenhouse gas carbon dioxide into the air than plants are capable of taking in," she said.

The study results suggest climate warming in the Arctic tundra may cause the release of much more carbon dioxide than previously expected. This type of positive feedback will make the Earth's climate change even more rapidly.

The findings were collected in a 20-year experiment of the effects of fertilization on the tundra at the Arctic Long-Term Ecological Research site near Toolik Lake, Alaska. The National Science Foundation and NASA provided funding for the research.

One-third of the Earth's soil carbon is locked in northern latitudes, because low temperatures and water-saturated soil slow the decomposition of organic matter by bacteria, fungi and other organisms.

Scientists from UF, the University of Alaska and the Marine Biological Laboratory at Woods Hole, Mass., added nitrogen and phosphorus fertilizer to the soil to simulate the release of nutrients from decomposing soil organic matter.

The scientists hypothesized the fertilizer would stimulate plant growth, remove carbon from the atmosphere and eventually add it to the soil as plants shed dead leaves and roots over time. Thus, the entire ecosystem was thought to be gaining carbon after fertilization.

Mack and her colleagues found exactly the opposite. Even though plants grew more, more carbon was stored in plants and in the surface of the soil, the whole ecosystem did not gain carbon. "Instead, it lost a tremendous amount from the deepest soil layers, probably because increased nitrogen accelerated the decomposition of organic matter by soil organisms, thereby releasing carbon dioxide," Mack said.

The results could have implications for ecosystems in other regions of the world as well, said Edward Schuur, a UF ecologist, project co-leader. Places such as the northeastern United States and Europe, where acid rain has increased the amount of nitrogen deposited into the ecosystem from the atmosphere, also could experience an increased loss of soil carbon in response to higher nitrogen inputs.

"It may be that not just arctic ecosystems, but those in other parts of the world will have a similar decomposition response to increased nitrogen," Schuur said. "Increased nitrogen levels are thought to have caused trees to grow more in many places. These places may experience the same kinds of effects below ground that we've noted," he said.

Few previous studies have assessed fertilization effects on soil carbon pools, because these effects are difficult to detect over short periods of time. The long-term nature of the experiment makes it unique among studies of arctic ecosystems and makes the effects of fertilization large enough to detect.

It has long been thought that global warming would have two opposing effects on Arctic soils. First, would increase the breakdown of soil organic matter, releasing carbon dioxide, the major cause of warming, into the atmosphere. Second, the breakdown of soil organic matter would liberate nutrients that would enhance rates of plant growth, thereby removing carbon dioxide from the atmosphere.


Story Source:

The above story is based on materials provided by NASA/Goddard Space Flight Center. Note: Materials may be edited for content and length.


Cite This Page:

NASA/Goddard Space Flight Center. "Researchers Find Frozen North May Accelerate Climate Change." ScienceDaily. ScienceDaily, 12 October 2004. <www.sciencedaily.com/releases/2004/10/041012092808.htm>.
NASA/Goddard Space Flight Center. (2004, October 12). Researchers Find Frozen North May Accelerate Climate Change. ScienceDaily. Retrieved September 18, 2014 from www.sciencedaily.com/releases/2004/10/041012092808.htm
NASA/Goddard Space Flight Center. "Researchers Find Frozen North May Accelerate Climate Change." ScienceDaily. www.sciencedaily.com/releases/2004/10/041012092808.htm (accessed September 18, 2014).

Share This



More Plants & Animals News

Thursday, September 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

AP (Sep. 18, 2014) Grand the elephant has successfully undergone surgery to remove a portion of infected tusk at Tbilisi Zoo in Georgia. British veterinary surgeons used an electric drill to extract the infected piece. (Sept. 18) Video provided by AP
Powered by NewsLook.com
Chimp Violence Study Renews Debate On Why They Kill

Chimp Violence Study Renews Debate On Why They Kill

Newsy (Sep. 17, 2014) The study weighs in on a debate over whether chimps are naturally violent or become that way due to human interference in the environment. Video provided by Newsy
Powered by NewsLook.com
Some Tobacco Farmers Thrive Amid Challenges

Some Tobacco Farmers Thrive Amid Challenges

AP (Sep. 16, 2014) The South's tobacco country is surviving, and even thriving in some cases, as demand overseas keeps growers in the fields of one of America's oldest cash crops. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

AFP (Sep. 16, 2014) Scientists say a female colossal squid weighing an estimated 350 kilograms (770 lbs) and thought to be only the second intact specimen ever found was carrying eggs when discovered in the Antarctic. Duration: 00:47 Video provided by AFP
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