Featured Research

from universities, journals, and other organizations

Nitrogen Loss Threatens Desert Plant Life, Study Shows

Date:
November 9, 2009
Source:
Cornell University
Summary:
As the climate gets warmer, arid soils lose nitrogen as gas, reports a new study. That could lead to deserts with even less plant life than they sustain today, say the researchers.

The Mojave Desert. As the climate gets warmer, arid soils lose nitrogen as gas, reports a new Cornell study. That could lead to deserts with even less plant life than they sustain today, say the researchers.
Credit: Image courtesy of Cornell University

As the climate gets warmer, arid soils lose nitrogen as gas, reports a new Cornell study. That could lead to deserts with even less plant life than they sustain today, say the researchers.

"This is a way that nitrogen is lost from an ecosystem that people have never accounted for before," said Jed Sparks, associate professor of ecology and evolutionary biology and co-author of the study, published in the Nov. 6 issue of Science. "It allows us to finally understand the dynamics of nitrogen in arid systems."

Available nitrogen is second only to water as the biggest constraint to biological activity in arid ecosystems, but before now, ecologists struggled to understand how the inputs and outputs of nitrogen in deserts balance.

By showing that the higher temperatures cause nitrogen to escape as gas from desert soils, the Cornell researchers have balanced the nitrogen budget in deserts. They stress that most climate change models need to be altered to consider these findings.

Sparks and lead author Carmody McCalley, a graduate student, warn that temperature increases and shifting precipitation patterns due to climate change may lead to further nitrogen losses in arid ecosystems. That would make arid soils even more infertile and unable to support most plant life, McCalley warned. Although, some climate models predict more summer rainfall for desert areas, the water, when combined with heat, would greatly increase nitrogen losses, she added.

"We're on a trajectory where plant life in arid ecosystems could cease to do well," she said.

In the past, researchers focused on biological mechanisms where soil microbes near the surface produce nitrogen gas that dissipates into the air, but McCalley and Sparks found that non-biological processes (abiotic) play a bigger role in nitrogen losses. They used instruments sensitive enough to measure levels of nitrogen gases in parts per trillion that had never before been applied to soil measurements.

The researchers covered small patches of soil in the Mojave Desert with sealed containers to measure nitrogen oxide (NO), NOy (a group of more than 25 different compounds containing oxidized nitrogen) and ammonia gases that escape from desert soils. To rule out the role of light in this process, McCalley kept light constant but varied the temperatures in lab experiments.

"At 40 to 50 degrees Celsius [about 100-120 F], we found rapid increases in gases coming out of the soil" regardless of the light, McCalley said. Midday ground temperatures average about 150 F and can reach almost 200 F in the Mojave Desert.

"Any place that gets hot and dry, in all parts of the world, will likely exhibit this pattern," said Sparks.

In addition, the researchers note, more nitrogen oxides in the lower atmosphere creates ozone near the ground, which contributes to air pollution and increases the greenhouse effect that warms the planet.

With deserts accounting for 35 to 40 percent of the Earth's surface and arid and semiarid lands being the most likely areas for new human settlements, air quality issues, loss of soil fertility and further desertification need to be considered as the climate warms, the researchers said.

The researchers also point out that most climate modelers now use algorithms that only consider biological factors to predict nitrogen gases coming from soils.

"The code in climate models would have to change to account for abiotic impacts on this part of the nitrogen budget," McCalley concluded.

The research was support in part by the National Science Foundation and Cornell's Andrew Mellon Student Research Grants.


Story Source:

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


Cite This Page:

Cornell University. "Nitrogen Loss Threatens Desert Plant Life, Study Shows." ScienceDaily. ScienceDaily, 9 November 2009. <www.sciencedaily.com/releases/2009/11/091106145308.htm>.
Cornell University. (2009, November 9). Nitrogen Loss Threatens Desert Plant Life, Study Shows. ScienceDaily. Retrieved April 18, 2014 from www.sciencedaily.com/releases/2009/11/091106145308.htm
Cornell University. "Nitrogen Loss Threatens Desert Plant Life, Study Shows." ScienceDaily. www.sciencedaily.com/releases/2009/11/091106145308.htm (accessed April 18, 2014).

Share This



More Plants & Animals News

Friday, April 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Vermont Goat Meat Gives Refugees Taste of Home

Vermont Goat Meat Gives Refugees Taste of Home

AP (Apr. 18, 2014) Dairy farmers and ethnic groups in Vermont are both benefiting from a unique collaborative effort that's feeding a growing need for fresh and affordable goat meat. (April 18) Video provided by AP
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
Little Progress Made In Fighting Food Poisoning, CDC Says

Little Progress Made In Fighting Food Poisoning, CDC Says

Newsy (Apr. 18, 2014) A new report shows rates of two foodborne infections increased in the U.S. in recent years, while salmonella actually dropped 9 percent. Video provided by Newsy
Powered by NewsLook.com
The Great British Farmland Boom

The Great British Farmland Boom

Reuters - Business Video Online (Apr. 17, 2014) Britain's troubled Co-operative Group is preparing to cash in on nearly 18,000 acres of farmland in one of the biggest UK land sales in decades. As Ivor Bennett reports, the market timing couldn't be better, with farmland prices soaring over 270 percent in the last 10 years. Video provided by Reuters
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