Prairies in Missouri and southern Illinois could look shorter by the end of the century, according to a study from the Missouri Botanical Garden and Kansas State University.
Researchers reported in the journal Global Change Ecology that tall varieties of the big bluestem grass that covers much of Midwestern prairies could be taken over by shorter forms of the plant over the next several decades. That's because climate change could reduce rainfall in many parts of the region, leading to drier conditions.
Big bluestem grasses that grow up to 8 feet tall in Missouri are less tolerant of dry conditions than the 2-foot tall big bluestem grasses that live in Colorado and western Kansas.
After studying big bluestem grasses of various heights in a greenhouse, scientists concluded that the short forms of the plant could spread eastward. The shift could significantly affect wildlife, said Loretta Johnson, a plant ecologist at Kansas State University.
"The prairies will be very different if you've got low biomass and low productivity," Johnson said. "Because that plant productivity is what animals are depending on."
Scientists don't know the extent to which the change in height could affect the prairie ecosystem, said Adam Smith, a researcher at the Missouri Botanical Garden. However, it's likely that it will affect farmers who feed big bluestem grasses to their livestock.
"[Big bluestem] is also an important forage crop," Smith said. "It's part of the basis of the region's $10 billion livestock industry. If your animals are dependent on eating a lot of it, then they would have to eat something else."
Researchers are studying the big bluestem's genes to further understand the effects of climate change on Midwestern prairies. Only 4 percent of the United States' historic grasslands currently remain.
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