As scientists forecast the impacts of climate change, one missing piece of the puzzle is what will happen to the carbon in the soil and the microbes that control the fate of this carbon as the planet warms.
Scientists studying grasslands in Oklahoma have discovered that an increase of 2 degrees Celsius in the air temperature above the soil creates significant changes to the microbial ecosystem underground. Compared to a control group with no warming, plants in the warmer plots grew faster and higher, which put more carbon into the soil as the plants senesce. The microbial ecosystem responded by altering its DNA to enhance the ability to handle the excess carbon.
"What we conclude from this study is the warming has an effect on the soil ecosystem," said Kostas Konstantinidis, an assistant professor who holds the Carlton S. Wilder Chair in Environmental Engineering at the Georgia Institute of Technology. "It does appear that the microbes change genetically to take advantage of the opportunity given to them."
The study was published online Dec. 27, 2013, in the journal Applied and Environmental Microbiology. The research was sponsored by the Department of Energy, and involved collaboration with several universities, including the University of Oklahoma.
The findings are the culmination of a 10-year study that seeks to understand how the most intricate ecosystem in nature soil will respond to climate change.
A single gram of soil is home to a billion bacterial cells, representing at least 4,000 different species. In comparison, the human gut is home to at least 10 times fewer different species of bacteria. Scientists have little idea what microbes in the soil do, how they do it, or how they respond to changes in their environment, Konstantinidis said. This limits the predictive capabilities of climate models.
"In models of climate change it is a black box what happens to the carbon in soil," Konstant
|Contact: Brett Israel|
Georgia Institute of Technology