Featured Research

from universities, journals, and other organizations

Tropical Rainforest Nutrients Linked To Global Carbon Dioxide Levels

Date:
June 22, 2006
Source:
National Science Foundation
Summary:
Extra amounts of key nutrients in tropical rain forest soils cause them to release more carbon dioxide into the atmosphere, according to research conducted by scientists at the University of Colorado (CU) - Boulder.

Carl Bern samples canopy foliage in Costa Rica.
Credit: CU-Boulder

Extra amounts of key nutrients in tropical rain forest soils cause them to release more carbon dioxide into the atmosphere, according to research conducted by scientists at the University of Colorado (CU) - Boulder.

Results of the research, conducted by Cory Cleveland and CU scientist Alan Townsend, are published this week in the journal Proceedings of the National Academy of Sciences.

"The large change in carbon dioxide emissions from tropical forest soils due to soil nutrients is a new dimension in understanding these important ecosystems," said Martyn Caldwell, program director in the National Science Foundation's (NSF) Division of Environmental Biology, which funded the research.

"Tropical rainforests have received considerable attention related to the global carbon balance, but that has largely revolved around rainforest vegetation and its ability to 'take up' carbon dioxide," said Caldwell. "This is a new look at tropical rainforests and their relationship to carbon dioxide levels on Earth."

The study showed that when phosphorus or nitrogen -- which occur naturally in rain forest soils -- were added to forest plots in Costa Rica, they caused an increase in carbon dioxide emissions to the atmosphere by about 20 percent annually, said Cleveland.

"The study is important because human activities are changing the amount of phosphorus and nitrogen in ecosystems all over the globe, including the tropics," Cleveland said. "Tropical rain forests play a dominant role on Earth in regulating atmospheric carbon dioxide."

One big question, said Cleveland, "is how tropical rain forests are responding to climate change. What we have demonstrated is that even small changes in nutrients could have a profound impact on the release of carbon dioxide from tropical forest soils."

The study, which took place in 2004 and 2005 in Costa Rica's Golfo Dulce Forest Reserve, included a series of 25 meter-square plots that were fertilized with phosphorus, nitrogen, or a combination of the two.

Tropical forests contain up to 40 percent of the carbon stored on Earth's continents and account for at least one-third of the annual exchange of carbon dioxide between the biosphere and the atmosphere, said Cleveland. Earth's soils are believed to store several times more carbon than all the planet's vegetation.

"This is the first time anyone has taken a close look at how changes in key nutrients may alter soil carbon dioxide emissions in tropical forests," said Cleveland. "Processes in the tropics affect what is happening around the globe, so this study has some big implications."

Phosphorus is known as a "limiting nutrient" because its availability can govern the growth rate of many organisms. While slash-and-burn agriculture in the tropics often reduces soil phosphorus in the long run, the practice can initially make more phosphorus available to tropical soil microbes, increasing their metabolism and the amounts of carbon dioxide they emit.

Phosphorus and many other nutrients are regularly transported around the Earth by global wind patterns, sometimes riding on huge transcontinental dust clouds, said Townsend. "There is strong evidence that humans are increasing the size of these dust clouds as changes occur in both land-use patterns and climate, which in turn can alter the availability of nutrients to forests," he said.

Nitrogen pollution also is increasing around the world, including in tropical forests, a result of fossil-fuel combustion and crop fertilization activities, said Townsend.


Story Source:

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


Cite This Page:

National Science Foundation. "Tropical Rainforest Nutrients Linked To Global Carbon Dioxide Levels." ScienceDaily. ScienceDaily, 22 June 2006. <www.sciencedaily.com/releases/2006/06/060621084137.htm>.
National Science Foundation. (2006, June 22). Tropical Rainforest Nutrients Linked To Global Carbon Dioxide Levels. ScienceDaily. Retrieved September 16, 2014 from www.sciencedaily.com/releases/2006/06/060621084137.htm
National Science Foundation. "Tropical Rainforest Nutrients Linked To Global Carbon Dioxide Levels." ScienceDaily. www.sciencedaily.com/releases/2006/06/060621084137.htm (accessed September 16, 2014).

Share This



More Earth & Climate News

Tuesday, September 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Man Floats for 31 Hours in Gulf Waters

Man Floats for 31 Hours in Gulf Waters

AP (Sep. 16, 2014) A Texas man is lucky to be alive after he and three others floated for more than a day in the Gulf of Mexico when their boat sank during a fishing trip. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Researchers Explore Shipwrecks Off Calif. Coast

Researchers Explore Shipwrecks Off Calif. Coast

AP (Sep. 16, 2014) Federal researchers are exploring more than a dozen underwater sites where they believe ships sank in the treacherous waters west of San Francisco in the decades following the Gold Rush. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Isolated N. Korea Asks For International Help With Volcano

Isolated N. Korea Asks For International Help With Volcano

Newsy (Sep. 16, 2014) Mount Paektu volcano in North Korea is showing signs of life and there's not much known about it. 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