Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Climate change and permafrost thaw alter greenhouse gas emissions in northern wetlands

13.08.2007
Permafrost – the perpetually frozen foundation of North America – isn’t so permanent anymore, and scientists are scrambling to understand the pros and cons when terra firma goes soft.

Permafrost serves like a platform underneath vast expanses of northern forests and wetlands that are rooted, literally, in melting permafrost in many northern ecosystems. But rising atmospheric temperatures are accelerating rates of permafrost thaw in northern regions, says MSU researcher Merritt Turetsky.

In the report, “The Disappearance of Relict Permafrost in Boreal North America: Effects on Peatland Carbon Storage and Fluxes,” in this week’s online edition of Global Change Biology, Turetsky and others explore whether melting permafrost can lead to a viscous feedback of carbon exchange that actually fuels future climate change.

“The loss of permafrost usually means the loss of terra firma in an otherwise often boggy landscape,” Turetsky said. “Roads, buildings and whole communities will have to cope with this aspect of climate change. What this means for ecosystems and humans residing in the North remains of the most pressing issues in the climate change arena.”

Working closely with researchers from Southern Illinois University, Villanova University and the National Renewable Energy Laboratory, Turetsky, assistant professor of crop and soil sciences and fisheries and wildlife, found that permafrost degradation has complex impacts on greenhouse gas fluxes from northern wetlands.

Their study focused on peatlands, a common type of wetland in boreal regions that slowly accumulates peat, which is an accumulation of partially decayed vegetation. Today, peatlands represent a massive reservoir of stockpiled carbon that accumulated from the atmosphere over many thousands of years. Peat blankets the permafrost and protects it like a thick layer of insulation.

“We find permafrost in peatlands further south than in other boreal ecosystems due to the insulating qualities of peat.So we have argued that these ecosystems serve as a very sensitive indicator of climate change,” Turetsky said. “What will happen to peatlands when climate change disrupts these frozen layers, or perhaps more importantly what will happen to all of that stored carbon in peat, have remained big questions for us.”

Their results were surprising.Turetsky and her colleagues studied areas affected by permafrost degradation across a large region of Canada. They initially expected to find that the melting ice would trigger a release of greenhouse gases to the atmosphere, as previously frozen plant and animal remains became susceptible to decay.

“This could serve as a positive feedback to climate change, where typically warming causes changes that release more greenhouse gases, which in turn causes more warming, and more emissions, and so on,” she said.

But what the researchers actually found is not such a clear-cut climate story.

Permafrost collapse in peatlands tends to result in the slumping of the soil surface and flooding, followed by a complete change in vegetation, soil structure, and many other important aspects of these ecosystems, Turetsky said.The study showed that vegetation responds to the flooding with a boost in productivity. More vegetation sequesters more carbon away from the atmosphere in plant biomass.

“This is actually good news from a greenhouse gas perspective,” Turetsky said.

However, the report also cautions that this flooding associated with collapsing permafrost also increases methane emissions.Methane is an important greenhouse gas, which is more powerful than carbon dioxide in its ability to trap heat in the earth’s atmosphere.

Turetsky said it seems the permafrost degradation initially causes increased soil carbon sequestration, rather than the large releases of carbon to the atmosphere originally predicted.But over time high methane emissions will balance – or outweigh – the reduction of carbon in the atmosphere.

“Not all ecosystems underlain by permafrost will respond the same way,” Turetsky cautioned. “It will depend on the history of the permafrost and the nature of both vegetation and soils.”

What is clear, she said, is that not even northern ecosystems can escape the wide reach of climate change.

The research was funded by the National Science Foundation, the Canadian NSERC, and the Society of Wetland Scientists. Turetsky’s work also is supported by the MSU Michigan Agricultural Experiment Station.

Michigan State University has been advancing knowledge and transforming lives through innovative teaching, research and outreach for more than 150 years. MSU is known internationally as a major public university with global reach and extraordinary impact. Its 17 degree-granting colleges attract scholars worldwide who are interested in combining education with practical problem solving.

Sue Nichols | EurekAlert!
Further information:
http://www.msu.edu

More articles from Ecology, The Environment and Conservation:

nachricht Bioinvasion on the rise
15.02.2017 | Universität Konstanz

nachricht Litter Levels in the Depths of the Arctic are On the Rise
10.02.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

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: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Switched-on DNA

20.02.2017 | Materials Sciences

Second cause of hidden hearing loss identified

20.02.2017 | Health and Medicine

Prospect for more effective treatment of nerve pain

20.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>