Researchers at the University of Illinois at Urbana-Champaign and the University of Bristol Cabot Institute published their findings in the journal Global Change Biology. The findings will be a part of the upcoming Fifth Assessment Report from the Intergovernmental Panel on Climate Change.
“One nutrient can make a huge impact on the carbon cycle and net emissions of the greenhouse gas carbon dioxide,” said study leader Atul Jain, a professor of atmospheric sciences at the U. of I. “We know that climate is changing, but the question is how much? To understand that, we have to understand interactive feedback processes – the interactions of climate with the land, but also interactions between nutrients within the land.”
The carbon cycle is a balance of carbon emissions into the atmosphere and absorption by oceans and terrestrial ecosystems. Carbon is absorbed by plants during photosynthesis and by the oceans through sea-air gas exchange. On the other side of the cycle, carbon is released by burning fossil fuels and by changes in land use – deforestation to expand croplands, for example. While fossil fuel emissions are well-known, there are large uncertainties in estimated emissions from land use change.
“When humans disturb the land, the carbon stored in the plants and the soil goes back into the atmosphere,” Jain said. “But when plants regrow, they absorb carbon through photosynthesis. Absorption or release of carbon can be enhanced or dampened depending on environmental conditions, such as climate and nutrient availability.”
Nitrogen is an essential mineral nutrient for plants, which means that plants need it to grow and thrive. In nontropical regions especially, plant regrowth – and therefore carbon assimilation by plants – is limited by nitrogen availability.
“Most models used to estimate global land use change emissions to date do not have the capability to model this nitrogen limitation on plant regrowth following land use change,” said Prasanth Meiyappan, a graduate student who is a co-author of the study. “This means, for example, they overestimate regrowth and they underestimate net emissions from the harvest-regrowth cycle in temperate forest plantations.”
Jain’s team, in collaboration with Joanna House, a researcher at the University of Bristol’s Cabot Institute, concluded that by not accounting for nitrogen as a limiting nutrient for plant growth, other models might have underestimated the 1990s carbon emissions from land use change by 70 percent in nontropical regions and by 40 percent globally.“This gross underestimation has great implications for international policy,” House said. “If emissions from land-use change are higher than we thought, or the land sink (regrowth) is more limited, then future emissions cuts would have to be deeper to meet the same mitigation targets.”
Next, the researchers are investigating the impacts of other nutrients, such as phosphorus, on the carbon cycle. They also are estimating the carbon stored in the soil, and how much is released or absorbed when the soil is perturbed.
“Soil has great potential to sequester carbon,” Jain said. “The question is, how much that’s being released is being sequestered in the soil? We have to understand how human behavior is changing our environment and interacting with our ecosystems.”
The National Aeronautics and Space Administration, the U.S. Department of Energy and the UK Leverhulme Trust supported this work.
Liz Ahlberg | EurekAlert!
Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
International network connects experimental research in European waters
21.03.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
28.03.2017 | Life Sciences
28.03.2017 | Information Technology
28.03.2017 | Physics and Astronomy