Featured Research

from universities, journals, and other organizations

Lichens Function As Indicators Of Nitrogen Pollution In Forests

Date:
October 17, 2008
Source:
U.S. Forest Service, Pacific Southwest Research Station
Summary:
Scientists have found lichens can give insight into nitrogen air pollution effects on Sierra Nevada and San Bernardino mountain ecosystems, and protecting them provides safeguards for less sensitive species.

Rock covered with lichen.
Credit: iStockphoto/Mark Hatfield

Scientists have found lichens can give insight into nitrogen air pollution effects on Sierra Nevada and San Bernardino mountain ecosystems, and protecting them provides safeguards for less sensitive species.

Their findings are presented this month in the international journal Environmental Pollution and are significant because nitrogen from air pollution causes detrimental chemical and biological effects to terrestrial and aquatic ecosystems. Other harmful effects include elevated nitrate concentrations in streams and groundwater, and weakened California forests more susceptible to bark beetle infestations and fires.

The U.S. Forest Service funded the study, which included the agency's own researchers working with scientists at the University of Arizona and Spain's National Research Center for Energy, Environment and Technology.

According to the scientists, nitrogen pollution that has virtually eliminated lichen species in the Los Angeles Basin and San Bernardino Mountains is now exceeding critical loads over much of the Western Sierra Nevada as far north as Lake Tahoe. Other areas in corridors of polluted air such as the Central Valley are also exceeding nitrogen critical loads.

"Publicity surrounds the carbon cycle and its effects on the environment, but humans have altered the global nitrogen cycle to a greater degree," said Mark Fenn, a Forest Service plant pathologist and one of the study's authors. "There are now significant changes in lichen indicator groups because nitrogen critical loads are being exceeded over much of California."

Scientists involved in the research studied 24 mixed-conifer forest sites exposed to a wide range of atmospheric nitrogen deposition and monitored adverse changes in lichens, among the most sensitive biological indicators of nitrogen effects.

The result is a useful tool for determining critical loads and preventing broader impacts to forests. Protecting lichens also has inherent value because of their complex hydrological, nutrient cycling, wildlife forage and nesting material roles.

"Quantifying nitrogen critical loads helps land managers determine the point at which unacceptable impacts occur to sensitive ecosystems," Fenn said. "This helps bring air quality management that is more firmly rooted in ecosystem protection."

The United Nations' International Cooperative Program on Effects of Air Pollution on Natural Vegetation and Crops has led the largest effort to quantify nitrogen critical loads. Similar coordinated efforts do not exist in the United States. But, U.S. research in critical loads is increasing.


Story Source:

The above story is based on materials provided by U.S. Forest Service, Pacific Southwest Research Station. Note: Materials may be edited for content and length.


Cite This Page:

U.S. Forest Service, Pacific Southwest Research Station. "Lichens Function As Indicators Of Nitrogen Pollution In Forests." ScienceDaily. ScienceDaily, 17 October 2008. <www.sciencedaily.com/releases/2008/10/081006155929.htm>.
U.S. Forest Service, Pacific Southwest Research Station. (2008, October 17). Lichens Function As Indicators Of Nitrogen Pollution In Forests. ScienceDaily. Retrieved September 18, 2014 from www.sciencedaily.com/releases/2008/10/081006155929.htm
U.S. Forest Service, Pacific Southwest Research Station. "Lichens Function As Indicators Of Nitrogen Pollution In Forests." ScienceDaily. www.sciencedaily.com/releases/2008/10/081006155929.htm (accessed September 18, 2014).

Share This



More Earth & Climate News

Thursday, September 18, 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