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
Darwin's finches have reached their limits on the Galápagos
23.06.2015 | University of Groningen
When Trees Aren’t ‘Green’
15.06.2015 | American Society of Agronomy (ASA), Crop Science Society of America (CSSA), Soil Science Society of America (SSSA)
New technique combines electron microscopy and synchrotron X-rays to track chemical reactions under real operating conditions
A new technique pioneered at the U.S. Department of Energy's Brookhaven National Laboratory reveals atomic-scale changes during catalytic reactions in real...
Think of an object made of iron: An I-beam, a car frame, a nail. Now imagine that half of the iron in that object owes its existence to bacteria living two and a half billion years ago.
Think of an object made of iron: An I-beam, a car frame, a nail. Now imagine that half of the iron in that object owes its existence to bacteria living two and...
A team of scientists including PhD student Friedrich Schuler from the Laboratory of MEMS Applications at the Department of Microsystems Engineering (IMTEK) of...
The three-year clinical trial results of the retinal implant popularly known as the "bionic eye," have proven the long-term efficacy, safety and reliability of...
On June 23, the second Sentinel mission was launched from the space mission launch center in Kourou. A critical component of Aachen is on board. Researchers at the Fraunhofer Institute for Laser Technology ILT and Tesat-Spacecom have jointly developed the know-how for space-qualified laser components. For the Sentinel mission the diode laser pump module of the Laser Communication Terminal LCT was planned and constructed in Aachen in cooperation with the manufacturer of the LCT, Tesat-Spacecom, and the Ferdinand Braun Institute.
After eight years of preparation, in the early morning of June 23 the time had come: in Kourou in French Guiana, the European Space Agency launched the...
25.06.2015 | Event News
16.06.2015 | Event News
11.06.2015 | Event News
30.06.2015 | Physics and Astronomy
30.06.2015 | Physics and Astronomy
30.06.2015 | Materials Sciences