DENVER—New experiments on climate change suggest that shrubs unpalatable to cattle could overtake grasslands if carbon dioxide levels are raised.
Fringed sage increased in bulk by 40 times during climate change experiments conducted by the U.S. Department of Agriculture and Colorado State University, scientists reported last week in the Proceedings of the National Academy of Sciences.
“It was a minor species at the beginning of the study, but by the end of four years, 10 percent of the aboveground cover was this species,” said Jack Morgan, a USDA range scientist in Fort Collins.
“Here’s a plant that may be a winner in a greenhouse future,” Morgan said.
Scientists say the suppression of natural fires to overgrazing, drought and climate change all could be fueling the encroachment of woody shrubs on the 40 percent of Earth’s land covered by grassland.
Research by Morgan and his colleagues show carbon dioxide as a factor.
The researchers set up clear plastic greenhouses around plots of prairie about 40 miles northeast of Fort Collins. Some greenhouses had extra carbon dioxide pumped in, while others had ambient air.
The researchers tracked plant communities in the greenhouses and on normal prairie for four years. Fringed sage increased its aboveground bulk by 40 times in the greenhouses with extra carbon dioxide, the team said.
———
Information from: The Denver Post,
