Global warming, soil decomposition studied

ATHENS, Ga., Oct. 29 (UPI) -- U.S. scientists say they've found elevated temperatures created by global warming don't result in persistent elevated levels of decomposing organic matter.

University of Georgia researchers say current models of global climate change predict warmer conditions will increase the rate by which bacteria and other microbes decompose organic matter -- a scenario that pumps even more heat-trapping carbon into the atmosphere.

But the scientists say their new findings show that while the rate of decomposition increases for a brief period, it does not persist.

"There is about two and a half times more carbon in the soil than there is in the atmosphere, and the concern right now is that a lot of that carbon is going to end up in the atmosphere," said Assistant Professor Mark Bradford, the study's lead author. "What our finding suggests is that a positive feedback between warming and a loss of soil carbon to the atmosphere is likely to occur, but will be less than currently predicted."

Those findings, Bradford said, help resolve a long-standing debate about how unseen soil microbes respond to and influence global climate change.

The research is reported in the early online edition of the journal Ecology Letters.