Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Wildfire and an example of its important link to the ecosystem

01.06.2012
A dilemma is smouldering, even as several wildfires top the headlines: new findings highlighting the practice of aggressive fire suppression

Traveling the western U.S. state of Nevada in the 1860s, a young American writer named Mark Twain heard a "world of talk" about the beauty of Lake Tahoe and so set out one August day to see the lake perched high in the Sierra Nevada Mountains. Determined to make the 11-mile journey on foot, Twain and his companions became briefly discouraged after toiling up one mountain and then another to no avail. But they trudged on until "at last the Lake burst upon us," Twain wrote in his 1872 book, Roughing It.


Wildfires used to be a natural part of Sierran ecosystems, with minor fires sweeping through at intervals of 10 to 25 years. Credit: Photo courtesy of Dale Johnson and Soil Horizons/Soil Science Society of America

One hundred and fifty years later, visitors to this border region between California and Nevada still marvel at Lake Tahoe, but sadly the "jewel of the Sierra" is not the same gem it was in Twain's time. Boating on the lake during his trip, Twain said he could see rocks at least 80 feet below the surface—a degree of clarity that scientists attribute to "ultra-oligotrophic" conditions, meaning exceptionally nutrient-poor and pure. Since the 1960s, however, Lake Tahoe's renowned water quality has been in slow decline, and exactly why "is the $64,000 question," says soil scientist Dale Johnson of the University of Nevada in Reno.

Damaging blazes sweep the Tahoe region regularly, and by the time Johnson teamed up with his University of Nevada colleague, Wally Miller—an expert on Tahoe's water quality—scientists already knew how catastrophic fires could affect downstream streams and lakes. Wildfire can leave slopes bare of vegetation and unprotected from erosion. Burning also releases nitrogen, phosphorus, sulfate, and other biochemicals locked in plants, wood, and soils, allowing the nutrients to run off downslope or seep into groundwater. But when Miller and Johnson began their studies, they discovered something that few, if anyone, had suspected: Not only could a major disturbance like fire affect Lake Tahoe, but so too could a lack of disturbance—the absence of fire. "The results were very surprising and therefore very hard to publish," Johnson says. "No one believed it."

But the findings also lead to a dilemma. On one hand, wildfire is beneficial in that it burns away decades of accumulated organic material, which Johnson and Miller have shown can potentially be a slow but significant source of nutrients to Lake Tahoe. On the other hand, severe wildfire can also deplete forests of nitrogen and send pulses of nutrients downstream—not to mention the damage it does to timber and private property.

"So what do you do?" Miller asks. The answer lately embraced by forest managers is to mimic the natural, Sierran fire regime that existed before aggressive fire suppression began. Managers will purposely light small, controlled fires to burn away accumulated woody debris. Or they'll remove wood with harvesting equipment or chip it on site.

But managers don't want to remove too many nutrients from the system, since they're needed to support future generations of trees. So Miller and Johnson have been studying the practices' impacts on nutrients and on water quality, just as they earlier investigated catastrophic wildfire and fire suppression.

Teri Barr | EurekAlert!
Further information:
http://www.agronomy.org

Further reports about: Johnson Lake Baikal Sierra Nevada Wildfire ecosystem water quality

More articles from Ecology, The Environment and Conservation:

nachricht Safeguarding sustainability through forest certification mapping
27.06.2017 | International Institute for Applied Systems Analysis (IIASA)

nachricht Dune ecosystem modelling
26.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

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: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>