Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tracking sulfur and nitrogen in snow provides clues to acidification

18.02.2008
Scientists investigate accumulated sulfate and nitrate in snow in New Hampshire and follow it after the snow melts.

In forests of the northeastern United States, sulfate and nitrate are the dominant dissolved forms of sulfur and nitrogen in precipitation. In winter, these acidic agents accumulate in the snowpack and are released to groundwater and streams over a short period of time during spring snowmelt.

This pulsed release of sulfate and nitrate in snowmelt can cause episodic acidification in poorly buffered soils, ultimately threatening the health of acid-sensitive biota.

There have been recent studies showing that biological cycling of sulfur and nitrogen persists in cold weather, despite below freezing air temperatures. Much of this activity occurs in soils, where an insulating snow layer keeps soil temperatures warm enough for a range of biological processes. Despite the growing awareness of winter’s role in sulfur and nitrogen cycling, many questions remain unanswered. In particular, there is much uncertainty about how sulfate and nitrate are retained or transformed in forest soils during cold weather.

In the November-December 2007 issue of the Soil Science Society of America Journal (SSSAJ), scientists from the U.S. Forest Service, SUNY-ESF, University of Calgary, and Cary Institute of Ecosystem Studies tracked the movement of sulfate and nitrate deposited in snow. A solution containing isotopically enriched sulfate and nitrate was sprayed on the surface of the snowpack during mid winter. The isotopic values of the labeled sulfate and nitrate were well above background levels and served as a tracer to follow the movement and transformation of these compounds in the ecosystem.

The researchers found that almost all of the labeled sulfate and nitrate deposited on the surface of the snow was recovered in snowmelt water, indicating that there were no significant transformations of sulfate and nitrate in the snowpack. In contrast, about half of the sulfate and nitrate was retained or transformed in the forest floor, suggesting that organic soils are a sink for these compounds during winter. For sulfate, the amount retained or transformed in the forest floor was nearly equal to the amount released, resulting in no significant net gains or losses. A significant amount of ammonium was produced in the forest floor indicating that N mineralization can be important, even when soil temperatures are near freezing. By contrast, net nitrification rates were very low during winter. Tracer results indicated that microbes did not immobilize snowpack nitrate and that other processes such as plant uptake, denitrification, and abiotic nitrate retention were probably more important factors affecting nitrate during snowmelt. More information on controls on nitrogen and sulfur cycling during winter is critical to our understanding of long-term trends and will help us predict how forest ecosystems will respond to future disturbances and global change processes.

The full article is available for no charge for 30 days following the date of this summary. View the abstract at: http://soil.scijournals.org/cgi/content/abstract/71/6/1934

Soil Science Society of America Journal, http://soil.scijournals.org, is a peer-reviewed international journal published six times a year by the Soil Science Society of America. Its contents focus on research relating to physics; chemistry; biology and biochemistry; fertility and plant nutrition; genesis, morphology, and classification; water management and conservation; forest, range, and wildland soils; nutrient management and soil and plant analysis; mineralogy; and wetland soils.

The Soil Science Society of America (SSSA) www.soils.org is an educational organization based in Madison, Wisconsin, which helps its 6,000+ members advance the disciplines and practices of soil science by supporting professional growth and science policy initiatives, and by providing quality, research-based publications and a variety of member services.

Sara Uttech | EurekAlert!
Further information:
http://www.soils.org

More articles from Ecology, The Environment and Conservation:

nachricht Scientists on the road to discovering impact of urban road dust
18.01.2018 | University of Alberta

nachricht Gran Chaco: Biodiversity at High Risk
17.01.2018 | Humboldt-Universität zu Berlin

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Let the good tubes roll

19.01.2018 | Materials Sciences

How cancer metastasis happens: Researchers reveal a key mechanism

19.01.2018 | Health and Medicine

Meteoritic stardust unlocks timing of supernova dust formation

19.01.2018 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>