Big bluestem grass — one of the most important forage grasses in the Midwest for cattle — is predicted to drop as much as 60 percent drop in stature and growth over the next 75 years due to climate change, according to a study published in the journal Global Change Biology.
“In the Midwest, big bluestem can grow to 4 to 6 feet tall,” but if the researchers’ predictions hold true, “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 grass could shift to the Great Lakes region where big bluestem is currently less common,” say the study’s authors at the University of Kansas.
Most of the size reductions were blamed on changes in rainfall, rather than higher temperatures. And it wouldn’t just be cattle that would be hurt, but a much larger network of prairie species. “Because big bluestem is currently a dominant grass species of the Great Plains and makes up to 70 percent of the plant biomass in places, how the ecosystem works could be affected by predicted changes in growth of this species,” said Loretta Johnson, a biology professor at the University of Kansas.