Climate feedbacks from decomposition by soil microbes are one of the biggest uncertainties facing climate modelers.
A new study from the International Institute for Applied Systems Analysis (IIASA) and the University of Vienna shows that these feedbacks may be less dire than previously thought.
The dynamics among soil microbes allow them to work more efficiently and flexibly as they break down organic matter – spewing less carbon dioxide into the atmosphere than previously thought, according to a new study published in the journal Ecology Letters.
"Previous climate models had simply looked at soil microbes as a black box," says Christina Kaiser, lead author of the study who conducted the work as a post-doctoral researcher at IIASA. Kaiser, now an assistant professor at the University of Vienna, developed an innovative model that helps bring these microbial processes to light.
Microbes and the climate
"Soil microbes are responsible for one of the largest carbon dioxide emissions on the planet, about six times higher than from fossil fuel burning," says IIASA researcher Oskar Franklin, one of the study co-authors. These microbes release greenhouse gases such as carbon dioxide and methane into the atmosphere as they decompose organic matter. At the same time, the Earth's trees and other plants remove about the same amount of carbon dioxide from the atmosphere through photosynthesis.
As long as these two fluxes remain balanced, everything is fine.
But as the temperature warms, soil conditions change and decomposition may change. And previous models of soil decomposition suggest that nutrient imbalances such as nitrogen deficiency would lead to increased carbon emissions. "This is such a big flux that even small changes could have a large effect," says Kaiser. "The potential feedback effects are considerably high and difficult to predict."
Diversity does the trick
How exactly microorganisms in the soil and litter react to changing conditions, however, remains unclear. One reason is that soil microbes live in diverse, complex communities, where they interact with each other and rely on one another for breaking down organic matter.
"One microbe species by itself might not be able to break down a complex substrate like a dead leaf," says Kaiser. "How this system reacts to changes in the environment doesn't depend just on the individual microbes, but rather on the changes to the numbers and interactions of microbe species within the soil community."
To understand these community processes, Kaiser and colleagues developed a computer model that can simulate complex soil dynamics. The model simulates the interactions between 10,000 individual microbes within a 1mm by 1mm square. It shows how nutrients, which influence microbial metabolism, affect these interactions, and change the soil community and thereby the decomposition process.
Previous models had viewed soil decomposition as a single process, and assumed that nutrient imbalances would lead to less efficient decomposition and hence greater greenhouse gas emissions. But the new study shows that, in fact, microbial communities reorganize themselves and continue operating efficiently – emitting far less carbon dioxide than previously predicted.
"Our analyses highlight how the systems thinking for which IIASA is renowned advances insights into key ecosystem services," says study co-author and IIASA ecologist Ulf Dieckmann.
"This model is a huge step forward in our understanding of microbial decomposition, and provides us with a much clearer picture of the soil system," says University of Vienna ecologist Andreas Richter, another study co-author.
Kaiser C, Franklin O, Dieckmann U, and Richter A. 2014. Microbial community dynamics alleviate stoichiometric constraints during litter decay. Ecology Letters. http://onlinelibrary.wiley.com/doi/10.1111/ele.12269/abstract
For more information please contact:
University of Vienna
Department of Microbiology and Ecosystem Science
Tel: +43 (0)1 4277 76663
Mob: +43 6503773428
Ecosystems Services and Management
+43(0) 2236 807 251
IIASA is an international scientific institute that conducts research into the critical issues of global environmental, economic, technological, and social change that we face in the twenty-first century. Our findings provide valuable options to policy makers to shape the future of our changing world. IIASA is independent and funded by scientific institutions in Africa, the Americas, Asia, Oceania, and Europe. http://www.iiasa.ac.at
Katherine Leitzell | EurekAlert!
The causes of soil consumption
14.06.2016 | Schweizerischer Nationalfonds SNF
Fishing prohibitions produce more sharks along with problems for fishing communities
09.06.2016 | Wildlife Conservation Society
Since the completion of the human genome an important goal has been to elucidate the function of the now known proteins: a new molecular method enables the investigation of the function for thousands of proteins in parallel. Applying this new method, an international team of researchers with leading participation of the Technical University of Munich (TUM) was able to identify hundreds of previously unknown interactions among proteins.
The human genome and those of most common crops have been decoded for many years. Soon it will be possible to sequence your personal genome for less than 1000...
3D printing revolutionized the manufacturing of complex shapes in the last few years. Using additive depositing of materials, where individual dots or lines...
R2D2, a joint project to analyze and development high-TRL processes and technologies for manufacture of flexible organic light-emitting diodes (OLEDs) funded by the German Federal Ministry of Education and Research (BMBF) has been successfully completed.
In contrast to point light sources like LEDs made of inorganic semiconductor crystals, organic light-emitting diodes (OLEDs) are light-emitting surfaces. Their...
High resolution rotational spectroscopy reveals an unprecedented number of conformations of an odorant molecule – a new world record!
In a recent publication in the journal Physical Chemistry Chemical Physics, researchers from the Max Planck Institute for the Structure and Dynamics of Matter...
Strands of cow cartilage substitute for ink in a 3D bioprinting process that may one day create cartilage patches for worn out joints, according to a team of engineers. "Our goal is to create tissue that can be used to replace large amounts of worn out tissue or design patches," said Ibrahim T. Ozbolat, associate professor of engineering science and mechanics. "Those who have osteoarthritis in their joints suffer a lot. We need a new alternative treatment for this."
Cartilage is a good tissue to target for scale-up bioprinting because it is made up of only one cell type and has no blood vessels within the tissue. It is...
30.06.2016 | Event News
28.06.2016 | Event News
09.06.2016 | Event News
01.07.2016 | Earth Sciences
01.07.2016 | Medical Engineering
01.07.2016 | Life Sciences