Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Global warming's ecosystem double whammy

18.09.2008
DRI study shows 1 abnormally warm year suppresses carbon dioxide uptake for 2 years

Plants and soils act like sponges for atmospheric carbon dioxide, but new research finds that one abnormally warm year can suppress the amount of carbon dioxide taken up by some grassland ecosystems for up to two years. The findings, which followed an unprecedented four-year study of sealed, 12-ton containerized grassland plots at DRI is the cover story in this week's issue (September 18) of the journal Nature.

"This is the first study to quantitatively track the response in carbon dioxide uptake and loss in entire ecosystems during anomalously warm years," said lead author Jay Arnone, research professor in the Division of Earth and Ecosystem sciences at DRI. "The 'lagged' responses that carry over for more than one year are a dramatic reminder of the fragility of ecosystems that are key players in global carbon sequestration."

The plants and soils in ecosystems help modulate the amount of carbon dioxide (CO2) in the atmosphere. Plants need CO2 to survive, and they absorb most CO2 during spring and summer growing seasons, storing the carbon in their leaves, stems and roots. This stored carbon returns to the soil when plants die, and it is released back into the atmosphere when soil bacteria feed on the dead plants and release CO2.

The four-year DRI study involved native Oklahoma tall grass prairie ecosystems that were sealed inside four, living-room-sized environment chambers. The dozen 12-ton, six-foot-deep plots were extracted intact from the University of Oklahoma's prairie research facility near Norman, Okla., in order to minimize the disturbance of plants and soil bacteria. Inside the DRI's sunlit-controlled EcoCELL chambers, scientists replicated the daily and seasonal changes in temperature, and rainfall that occur in the wild.

In the second year of the study, half of the plots were subjected to temperatures typical of a normal year, and the other half were subjected to abnormally warm temperatures -- on the order of those predicted to occur later this century by the Intergovernmental Panel on Climate Change. In the third year of the study, temperatures around the warmed plots were turned down again to match temperatures in the control plots. The CO2 flux -- the amount of carbon dioxide moving between the atmosphere and biosphere -- was tracked in each chamber for all four years of the study.

DRI's EcoCELL facility gave the scientists an unprecedented degree of control over the enclosed ecosystems. Not only could they create the same air temperature conditions from year-to-year, they could also independently control the soil temperature in each chamber -- a key feature that enhanced the ecological relevance of the results. Each containerized ecosystem also sat on "load cells," the type of scales used to weigh trucks on highways. Scientists used the scales to track the amount of water that was taken up and lost by the plants and soil in both normal and abnormal years. Thus, each containerized ecosystem served as a weighing lysimeter, an instrument that's used to measure the water and nutrients that percolate through soils.

The scientists found that ecosystems exposed to an anomalously warm year had a net reduction in CO2 uptake for at least two years. These ecosystems trapped and held about one-third the amount of carbon in those years than did the plots exposed to normal temperatures.

"Large reductions in net CO2 uptake in the warm year were caused mainly by decreased plant productivity resulting from drought, while the lack of complete recovery the following year was caused by a lagged stimulation of CO2 release by soil microorganisms in response to soil moisture conditions," explained co-author Paul Verburg, also from DRI.

Numerous studies have found that the Earth's atmospheric CO2 levels have risen by about one-third since the dawn of the Industrial Age. CO2 helps trap heat in the atmosphere, and political and economic leaders the world over are debating policy and economic reforms to reduce the billions of tons of CO2 that burned fossil fuels are adding to the atmosphere each year.

"Our findings confirm that ecosystems respond to climate change in a much more complex way than one might expect based solely on traditional experiments and observations," said study co-author James Coleman, vice provost for research and professor of ecology and evolutionary biology at Rice University. "Our results provide new information for those who are formulating science-based carbon policies."

Greg Bortolin | EurekAlert!
Further information:
http://www.dri.edu
http://www.rice.edu

More articles from Ecology, The Environment and Conservation:

nachricht Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel

nachricht Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)

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: Attoseconds break into atomic interior

A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.

In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...

Im Focus: Good vibrations feel the force

A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.

By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...

Im Focus: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Basque researchers turn light upside down

23.02.2018 | Physics and Astronomy

Finnish research group discovers a new immune system regulator

23.02.2018 | Health and Medicine

Attoseconds break into atomic interior

23.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>