Study indicates climate change could impact dominant Midwest prairie grass

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Study indicates climate change could impact dominant Midwest prairie grass

April 19, 2018, Tim Crosby

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Sara Baer

An important prairie grass could be strongly impacted by climate change during the next 75 years, a team of scientists from the Midwest say. 

Sara Baer, professor of plant biology at SIU, is among a team of researchers that recently published a paper in the journal Global Change Biology on one of the Midwest’s most dominant and economically important grassland plants. Scientists from the Missouri Botanical Garden and Kansas State University also worked on the study. 

Big Bluestem, also known by its scientific name, Andropogon gerardii, is a common grass in natural and restored prairies extending across the central Midwestern region that includes Kansas, Nebraska, Oklahoma, Missouri, Iowa, and Illinois. The plant is an important component of forage for the region’s livestock industry.  It is also commonly used as an ornamental plant, owing to its size and purplish flowers and seed heads. 

Within the Midwest, Big Bluestem can grow to 4 to 6 feet tall, but the researchers found that climate change could reduce height by up to 60 percent during the next 75 years. As a result, the form of Big Bluestem that grows in the central Midwest could come to resemble the form that currently inhabits eastern Colorado on the edge of the species’ range. The tall forms of the Midwest could shift to the Great Lakes region where Big Bluestem is currently smaller and less common. 

Big Bluestem is commonly used in prairie restorations. But because individual plants can live several decades, restoration projects might need to consider the form of plants that would thrive at a site several decades into the future, as well. 

Baer said the study marks the first time researchers have used traits measured from multiple populations of this species across a large geographic area in order to model how the species’ form and corresponding function will respond to climate change. 

“This has important implications for future productivity of tallgrass prairie in the current core distribution of this species, where livestock production is a major agricultural enterprise,” Baer said. “It also has important implications for selecting appropriate sites to restore tallgrass prairie in the future and where to collect seeds to restore prairie communities that will be resilient to climate change.” 

Worldwide, scientists say about 20 percent of plants are already on the brink of extinction with climate change only expected to add pressure on struggling species. This study indicates that common species may also be vulnerable.