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17.04.2013 The Fate of the Forests:

The Fate of the Forests: Massive Amounts of Charcoal enter the Worlds Oceans
 
The Fate of the Forests: Massive Amounts of Charcoal enter the Worlds Oceans

An international team of researchers, led by Rudolf Jaffé from Florida International University’s Southeast Environmental Research Center in Miami and Thorsten Dittmar of the Max Planck Institute for Marine Microbiology in Germany, has uncovered one of nature’s long-kept secrets — the true fate of charcoal in the world’s soils. Now they report their findings in Science, one of the most prestigious peer-reviewed journal for general science in the world.
A seemingly ordinary topic, being able to determine the fate of charcoal is critical in helping scientists balance the global carbon budget, which in turn can help understand and mitigate climate change. However, until now, scientists only had scientific guesses as to what happens to charcoal once it’s incorporated into soil. Surprisingly, most were wrong.
“Most scientists thought charcoal was resistant. They thought, once it’s incorporated into the soils, it would stay there,” Jaffé said. “But if that were the case, the soils would be black.”
Charcoal, or black carbon (BC), is a residue generated by combustion sources including wild fires and the burning of fossil fuels. Most of the charcoal in nature is from wild fires and combustion of biomass in general, according to the authors of this study. When charcoal forms it is typically deposited into the soil.
“From a chemical perspective, no one really thought it dissolves, but it does,” Jaffé said. “It doesn’t accumulate like we had believed for a long time. Rather, it is exported into wetlands and rivers, eventually making its way to the oceans.” Thorsten Dittmar, head of the Max Planck Research Group for Marine Geochemistry at the University Oldenburg in Germany, was also tracing the paths of charcoal, only from an oceanography perspective.
Thorsten Dittmar explains: “To understand the oceans we have to understand also the processes on the land, from where the organic load enters the seas. Therefore, our international team took 174 samples from fresh water sites all over the world like the Amazon River, the Congo, the Yangtze and arctic sites. In these water samples we measured dissolved charcoal. Surprisingly, in any river across the world about 10% of organic carbon that is dissolved in the water came from charcoal. With this robust relationship at hand we were able to use older scientific studies regarding organic carbon flux in rivers and estimated the global flux of dissolved charcoal.”
To map out a much more comprehensive picture, the research teams joined forces, along with researchers from Skidaway Institute of Oceanography in Georgia, Woods Hole Research Center in Massachusetts, the USDA Forest Service, and the University of Helsinki in Finland. The collaborative efforts have mapped out the conclusion that charcoal is making its way to the world’s waters. Dittmar comments that “Now, we have shown that fire is probably an integral part of the global carbon cycle”.
This one single discovery, according to Jaffé and co-workers, carries significant implications for bioengineering. The global carbon budget is a balancing act between sources that produce carbon and sinks that remove it. According to the research, the amount of dissolved charcoal transported to the oceans is keeping pace with the total charcoal generated by fires annually on a global scale.
Natural fire of boreal forest. Fotos by Stefan Doerr, Swansea University. Right: Painting called "Kaski" by Eero Järnefelt (1893). The painting is owend by the Finnish National Art Gallery. "Kaski" is a Finnish word, which means slash-and-burn agriculture. Such type of agriculture started in Finland ca. 4 000 years ago and was common to the end 19th century. It generates charcoal that is incorporated into soils.
Critical: Biochar carbon sequestration techniques and Climate Change

While the environmental consequences of the accumulation of black carbon in inland waters and the ocean are currently unknown, Jaffé said the team’s findings mean greater consideration must be given to carbon sequestration techniques. Biochar addition to soils is one such technique. Biochar technology is based on vegetation-derived charcoal that is added to agricultural soils as a means to sequester carbon. Although promising in storing carbon, Jaffé points out that as more people implement biochar technology, they must take into consideration the potential dissolution of the charcoal to ensure these techniques are actually environmentally friendly.
Jaffé and Dittmar agree that there are still many unknowns when it comes to the environmental fate of charcoal, and both plan to move on to the next phase of the research. They have proven where the charcoal goes. Now, they want to answer how this happens and what the environmental consequences are. The authors point out the better scientists can understand the process and the environmental factors controlling it, the better chance they have of developing strategies for carbon sequestration and help mitigate climate change.

More information

Dr. Thorsten Dittmar
Max-Planck-Forschungsgruppe Marine Geochemie
Institut für Chemie und Biologie des Meeres (ICBM)
Carl-von-Ossietzky-Strasse 9-11
D-26129 Oldenburg
Tel.: 0441 798-3602
E-Mail: [Bitte aktivieren Sie Javascript]

Dr. Jutta Niggemann
Max-Planck-Forschungsgruppe Marine Geochemie
Institut für Chemie und Biologie des Meeres (ICBM)
Carl-von-Ossietzky-Strasse 9-11
D-26129 Oldenburg
Tel.: 0441 798-3365
E-Mail: [Bitte aktivieren Sie Javascript]


or contact the press officer

Dr. Manfred Schlösser
Max-Planck-Institut für Marine Mikrobiologie
Celsiusstraße 1, D-28359 Bremen, Tel.: 0421 2028-704
E-Mail: [Bitte aktivieren Sie Javascript]

Original publication
Global Charcoal Mobilization from Soils via Dissolution and Riverine Transport to the Oceans
Rudolf Jaffé, Yan Ding, Jutta Niggemann, Anssi V. Vähätalo, Aron Stubbins, Robert G.M. Spencer, John Campbell, Thorsten Dittmar. Science 2013. DOI: 10.1126/science.1231476

Involved institutions
Southeast Environmental Research Center (SERC), and Department
of Chemistry and Biochemistry, Florida International University (FIU),
Miami, FL 33199, USA.

Max Planck Research Group for Marine Geochemistry, Institute for Chemistry and Biology of the Marine Environment, UniversityOldenburg,
D-29129 Oldenburg, Germany.
Department of Environmental Science, University of Helsinki, 00014 Helsinki, Finland.
Department of Biological and Environmental Science, University of Jyväskylä,
40500 Jyväskylä, Finland

Skidaway Institute of Oceanography, 10 Ocean Science Circle, Savannah, GA 31411, USA.

Woods Hole Research Center, 149 Woods Hole Road, Falmouth,
MA 02540, USA.
U.S. Department of Agriculture Forest Service, Northern Research Station, Durham, NH 03824, USA.
 
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