Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 
Datenbankrecherche:

 

Warmer soils release additional CO2 into atmosphere; Effect stabilizes over longer term

21.01.2013
Warmer temperatures due to climate change could cause soils to release additional carbon into the atmosphere, thereby enhancing climate change – but that effect diminishes over the long term, finds a new study in the journal Nature Climate Change.

The study, from University of New Hampshire professor Serita Frey and co-authors from the University of California-Davis and the Marine Biological Laboratory, sheds new light on how soil microorganisms respond to temperature and could improve predictions of how climate warming will affect the carbon dioxide flux from soils.

The activities of soil microorganisms release 10 times the carbon dioxide that human activities do on a yearly basis. Historically, this release of carbon dioxide has been kept in check by plants' uptake of the gas from the atmosphere. However, human activities are potentially upsetting this balance.

Frey and co-authors Johan Six and Juhwan Lee of UC-Davis and Jerry Melillo of the Marine Biological Laboratory were curious how increased temperatures due to climate change might alter the amount of carbon released from soils. "While they're low on the charisma scale, soil microorganisms are so critically important to the carbon balance of the atmosphere," Frey says. "If we warm the soil due to climate warming, are we going to fundamentally alter the flux of carbon into the atmosphere in a way that is going to feed back to enhance climate change?"

Yes, the researchers found. And no.
The study examined the efficiency of soil organisms – how completely they utilize food sources to maintain their cellular machinery – depending upon the food source and the temperature under two different scenarios. In the first short-term scenario, these researchers found that warming temperatures had little effect on soils' ability to use glucose, a simple food source released from the roots of plants. For phenol, a more complex food source common in decomposing wood or leaves, soils showed a 60 percent drop in efficiency at higher temperatures.

"As you increase temperature, you decrease the efficiency – soil microorganisms release more carbon dioxide to the atmosphere – but only for the more complex food sources," Frey explains. "You could infer that as the soil warms, more carbon dioxide will be released into the atmosphere, exacerbating the climate problem."

That effect diminishes, however, in the second scenario, in which soils were warmed to 5 degrees Celsius above the ambient temperature for 18 years. "When the soil was heated to simulate climate warming, we saw a change in the community to be more efficient in the longer term," Frey says, lessening the amount of carbon dioxide the soils release into the atmosphere and, in turn, their impact on the climate. "The positive feedback response may not be as strong as we originally predicted."

The research team also examined how changes in soil microorganism efficiency might influence long term storage of carbon in soils as predicted by a commonly used ecosystem model. Models of this type are used to simulate ecosystem carbon dynamics in response to different perturbations, such as land-use change and climate warming. These models generally assume that efficiency is fixed and that it does not change with temperature or other environmental conditions. The team found a large effect on long-term soil carbon storage as predicted by the model when they varied carbon use efficiency in a fashion comparable to what they observed in their experiments. "There is clearly a need for new models that incorporate an efficiency parameter that is allowed to fluctuate in response to temperature and other environmental variables," Six says.

The researchers hypothesize that long-term warming may change the community of soil microorganisms so that it becomes more efficient. Organism adaptation, change in the species that comprise the soils, and/or changes in the availability of various nutrients could result in this increased efficiency.

This study was based on work done at the Harvard Forest Long-Term Ecological Research site in Petersham, Mass., where Frey and Melillo have been warming two sites – one 9 meters square, the other 36 meters square -- with underground cables for two versus 18 years. "It's like having a heating blanket under the forest floor," Frey says, "allowing us to examine how this particular environmental change—long-term soil warming—is altering how the soil functions."

The article, "The Temperature Response of Soil Microbial Efficiency and its Feedback to Climate," is published in the advanced online publication of Nature Climate Change on Jan. 20, 2013. To access the abstract or full text (subscribers only) of the article after the embargo lifts, use the digital object identifier (DOI) number 10.1038/NCLIMATE1796 at this link: http://dx.doi.org/.

This work was supported by an NSF Faculty Early Career Development Award, the NSF Long-term Ecological Research (LTER) Program, a DOE National Institute for Climatic Change Research (NICCR) grant, and a Harvard Forest Bullard Fellowship to Frey.

Photographs available to download:

http://www.unh.edu/news/releases/2013/jan/frey.jpg
Caption: Serita Frey, professor of natural resources at the University of New Hampshire

Credit: Perry Smith, UNH Photographic Services

http://www.unh.edu/news/releases/2013/jan/forestplot.jpg
Caption: Research sites at the Harvard Forest Long-Term Ecological Research site in Petersham, Mass., where Frey and Melillo have been warming two sites with underground cables. The photo was taken during a January thaw on a 50-degree day; the heated plots, which had been snow-covered, melted before the unheated ones.

Credit: Alix Contosa, postdoctoral researcher at UNH

http://www.unh.edu/news/releases/2013/jan/freyinfield.jpg
Caption: Serita Frey (left) collects samples with UMass-Amherst graduate student George Hamaoui at Harvard Forest.

Credit: Brian Godbois, research assistant at UNH

http://www.unh.edu/news/releases/2013/jan/freysoil.jpg
Caption: Collecting soil samples.
Credit: Courtesy of Serita Frey
Watch Serita Frey describe her research: http://www.youtube.com/watch?v=h0XpJdPRROw&list=PLAAADC61677E4780B&index=12

The University of New Hampshire, founded in 1866, is a world-class public research university with the feel of a New England liberal arts college. A land, sea, and space-grant university, UNH is the state's flagship public institution, enrolling 12,200 undergraduate and 2,300 graduate students.

Beth Potier | EurekAlert!
Further information:
http://www.unh.edu

More articles from Earth Sciences:

nachricht Clouds and climate in the pre-industrial age
30.05.2016 | Goethe-Universität Frankfurt am Main

nachricht Researchers find higher than expected carbon emissions from inland waterways
25.05.2016 | Washington State University

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: PTB-Forscher können Ertrag von Solarzellen unter realen Bedingungen bestimmen

An einem neuartigen Messplatz messen die Wissenschaftler Referenzsolarzellen mit bisher unerreichter Genauigkeit

Solarzellen werden im Labor bisher unter einheitlich festgelegten Bedingungen getestet. Da die realen Bedingungen, wie die Temperatur oder der Einfallswinkel...

Im Focus: Tiroler Technologie zur Abwasserreinigung weltweit erfolgreich

Auf biologischem Weg und mit geringem Energieeinsatz wandelt ein an der Universität Innsbruck entwickeltes Verfahren in Kläranlagen anfallende Stickstoffverbindungen in unschädlichen Luftstickstoff um. Diese innovative Technologie wurde nun gemeinsam mit dem US-Wasserdienstleister DC Water weiterentwickelt und vermarktet. Für die Kläranlage von Washington DC wird die bisher größte DEMON®-Anlage errichtet.

Das DEMON®-Verfahren wurde bereits vor elf Jahren entwickelt und von der Universität Innsbruck zum Patent angemeldet. Inzwischen wird die Technologie in rund...

Im Focus: Worldwide Success of Tyrolean Wastewater Treatment Technology

A biological and energy-efficient process, developed and patented by the University of Innsbruck, converts nitrogen compounds in wastewater treatment facilities into harmless atmospheric nitrogen gas. This innovative technology is now being refined and marketed jointly with the United States’ DC Water and Sewer Authority (DC Water). The largest DEMON®-system in a wastewater treatment plant is currently being built in Washington, DC.

The DEMON®-system was developed and patented by the University of Innsbruck 11 years ago. Today this successful technology has been implemented in about 70...

Im Focus: Optische Uhren können die Sekunde machen

Eine Neudefinition der Einheit Sekunde auf der Basis von optischen Uhren wird realistisch

Genauer sind sie jetzt schon, aber noch nicht so zuverlässig. Daher haben optische Uhren, die schon einige Jahre lang als die Uhren der Zukunft gelten, die...

Im Focus: Computational High-Throughput-Screening findet neue Hartmagnete die weniger Seltene Erden enthalten

Für Zukunftstechnologien wie Elektromobilität und erneuerbare Energien ist der Einsatz von starken Dauermagneten von großer Bedeutung. Für deren Herstellung werden Seltene Erden benötigt. Dem Fraunhofer-Institut für Werkstoffmechanik IWM in Freiburg ist es nun gelungen, mit einem selbst entwickelten Simulationsverfahren auf Basis eines High-Throughput-Screening (HTS) vielversprechende Materialansätze für neue Dauermagnete zu identifizieren. Das Team verbesserte damit die magnetischen Eigenschaften und ersetzte gleichzeitig Seltene Erden durch Elemente, die weniger teuer und zuverlässig verfügbar sind. Die Ergebnisse wurden im Online-Fachmagazin »Scientific Reports« publiziert.

Ausgangspunkt des Projekts der IWM-Forscher Wolfgang Körner, Georg Krugel und Christian Elsässer war eine Neodym-Eisen-Stickstoff-Verbindung, die auf einem...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

IHR
JOB & KARRIERE
SERVICE
im innovations-report
in Kooperation mit academics
Veranstaltungen

Wie sieht die Schifffahrt der Zukunft aus? - IAME-Jahreskonferenz in Hamburg

27.05.2016 | Veranstaltungen

Technologische Potenziale der Multiparameteranalytik

27.05.2016 | Veranstaltungen

Umweltbeobachtung in nah und fern

27.05.2016 | Veranstaltungen

 
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

Atome mit dem gewissen Twist

30.05.2016 | Physik Astronomie

Durchbruch in der zahnmedizinischen Bildgebung

30.05.2016 | Medizintechnik

Umweltfreundlicher Autolack aus Maisstärke soll Kratzer von selbst reparieren

30.05.2016 | Materialwissenschaften