WASHINGTON, Dec. 5 (UPI) -- A U.S. Energy Department study suggests soil in temperate ecosystems might contribute to partially offsetting rising atmospheric CO2 concentrations.
Because higher CO2 concentrations usually stimulate plant growth, a parallel accumulation of soil carbon derived from decaying roots and other plant material might be expected, researchers said. Yet nearly all elevated CO2 experiments have failed to detect changes in soil carbon against the large and variable background of existing soil organic matter.
Scientists from the Argonne National Laboratory, Oak Ridge National Laboratories, and Kansas State and Texas A&M universities evaluated the collective results of earlier studies and found, on average, elevated CO2 increased soil carbon by 5.6 percent during a two- to nine-year period.
"We were able to see measurable carbon accumulation within a relatively short time period ..." said Argonne's Julie Jastrow, the study's lead author. "We also found over half of the accumulated carbon was associated with soil minerals in stable aggregates, which can protect organic matter from rapid decomposition. This suggests some of the carbon added to these soils could stick around for awhile."
The research appears in the current issue of the journal Global Change Biology.
