The new evidence supports an emerging view that although forests remove a substantial amount of carbon dioxide from the atmosphere, much of the carbon is being stored in living woody biomass rather than as dead organic matter in soils.
Richard P. Phillips, lead author on the paper and an assistant professor of biology in the IU College of Arts and Sciences, said that after nearly two decades of research on forest ecosystem responses to global change, some of the uncertainty has been lifted about how forests are storing carbon in the wake of rising carbon dioxide levels."It's been suggested that as trees take up more carbon dioxide from the atmosphere, a greater amount of carbon will go to roots and fungi to acquire nutrients, but our results show that little of this carbon accumulates in soil because the decomposition of root and fungal detritus is also increased," he said.
The authors also report that nitrogen cycled faster in this forest as the demand for nutrients by trees and microbes became greater under elevated CO2.
"The growth of trees is limited by the availability of nitrogen at this site, so it makes sense that trees are using the 'extra' carbon taken up under elevated CO2 to prime microbes to release nitrogen bound up in organic matter," Phillips said. "What is surprising is that the trees seem to be getting much of their nitrogen by decomposing root and fungal detritus that is less than a year old."
The two-fold effects of microbial priming, where microbes are stimulated to decompose old soil organic matter via an increase in new carbon and other energy sources, and the faster turnover of recently fixed root and fungal carbon, are enough to explain the rapid carbon and nitrogen cycling that is occurring at the Duke Forest FACE site.
"We call it the RAMP hypothesis -- Rhizo-Accelerated Mineralization and Priming -- and it states that root-induced changes in the rates of microbial processing of carbon and nitrogen are key mediators of long-term ecosystem responses to global change," Phillips added.
"Most ecosystem models have limited representations of roots, and none of them include processes such as priming. Our results demonstrate that interactions between roots and soil microbes play an underappreciated role in determining how much carbon is stored and how fast nitrogen is cycled. So including these processes in models should lead to improved projections of long-term carbon storage in forests in response to global environmental change'" he said.
"Roots and fungi accelerate carbon and nitrogen cycling in forests exposed to elevated CO2" -- by Phillips; IU and University of Gottingen (Germany) post-doctoral researcher Ina C. Meier; Emily S. Bernhardt of Duke University, A. Stuart Grandy and Kyle Wickings of the University of New Hampshire; and Adrien C. Finzi of Boston University -- was published July 9 in the online early addition of Ecology Letters. Free access to the research article will be available until October.
Funding for this work was provided by the U.S. Department of Agriculture and the U.S. Department of Energy. Phillips and his research team in March received a $398,000 National Science Foundation grant to fund testing of the RAMP hypothesis in mixed hardwood forests of Indiana.
To speak with Phillips or for more information, please contact Steve Chaplin, IU Communications, at 812-856-1896 or email@example.com. Tweeting IU science news: @IndianaScience; blogging at Science at Work.
Steve Chaplin | Newswise Science News
Dune ecosystem modelling
26.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
Understanding animal social networks can aid wildlife conservation
23.06.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
26.06.2017 | Agricultural and Forestry Science
26.06.2017 | Life Sciences
26.06.2017 | Health and Medicine