A new study looks at a poorly understood process with potentially critical consequences for climate change. Emma Sayer, postdoctoral fellow at the Smithsonian Tropical Research Institute, Jennifer Powers, an assistant professor in the University of Minnesota’s Department of Ecology, Evolution and Behavior, and Edmund Tanner, researcher at Cambridge University, published the findings of their long-term study on the effects of increased plant litter on soil carbon and nutrient cycling in the December 12 edition of PLoS ONE.
As CO2 concentrations in the atmosphere continue to rise, increases in plant productivity – and litterfall – are likely. The study considers the impact of an increase in organic matter on the ground on processes belowground. Results suggest that the balance of carbon stored in the soils (thought to be a long-term sink for carbon) can be changed with the addition of fresh leaf litter. The capacity of soils to store carbon might then diminish if global environmental changes such as CO2 increases and nitrogen deposition boost plant productivity.
Over the course of the 5-year experiment, the fluxes of carbon dioxide from the soil surface to the atmosphere in a tropical forest in Panama were measured. These CO2 fluxes (also called soil respiration) come from two main sources: the respiration of roots and the decomposition of litter and soil organic matter by fungi, bacteria, and other microorganisms.
“To our surprise, the litter addition plots showed substantially higher amounts of soil respiration than would be predicted by the increase in leaf litter,” said Powers. “We suspect that this extra CO2 in the litter addition plots was coming from the decomposition of ‘old soil organic matter’, which was stimulated by adding large quantities of fresh leaf litter.” This effect, the stimulation of the decomposition of old, ‘stored’ organic carbon by the addition of fresh organic matter is known as the ‘priming effect.’ “There are important links between above-and belowground processes and we need to understand these links in order to assess the impact of global change and human disturbance on natural ecosystems” said Sayer.
The study has implications for policy makers considering new approaches to capping carbon emissions such as carbon sequestration. “Our results suggest unanticipated feedbacks to the carbon cycle that must be taken into account when estimating the potential for carbon sequestration in the soil,” Powers said.
Emma Sayer of the Smithsonian Tropical Research Institute and Cambridge University is the lead author of the study. Edmund Tanner, also of Cambridge University, and Jennifer Powers of the University of Minnesota are co-authors.
Citation: Sayer EJ, Powers JS, Tanner EVJ (2007) Increased Litterfall in Tropical Forests Boosts the Transfer of Soil CO2 to the Atmosphere. PLoS ONE 2(12): e1299. doi:10.1371/journal.pone.0001299
Upcycling of PET Bottles: New Ideas for Resource Cycles in Germany
25.06.2018 | Fraunhofer-Institut für Betriebsfestigkeit und Systemzuverlässigkeit LBF
Dry landscapes can increase disease transmission
20.06.2018 | Forschungsverbund Berlin e.V.
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences