Ellen Nelson has battled invasive plants that out-compete native grasses on her grass-fed beef ranch near Bellvue, Colo. Some climate studies suggest that fight will worsen in the coming decades. (Luke Runyon/Harvest Public Media)
Feb. 25, 2014 Luke Runyon Reporter Luke Runyon is Harvest Public Media’s reporter based at KUNC in northern Colorado.
Most climate models paint a bleak picture for the Great Plains a century from now: It will likely be warmer and the air will be more rich with carbon dioxide. Though scientists don’t yet know how exactly the climate will change, new studies show it could be a boon to some invasive plant species.
A growing problem
Ask most Midwestern and Rocky Mountain ranchers about the weeds currently causing them to pull out their hair and be prepared for a long list. It could be cheat grass in Nebraska, or red brome in Utah, or yellow starthistle in California. Depending on the plant, cattle either don’t want to eat it or could get sick if they ingest it. And getting rid of these plants is expensive.
But could climate change exacerbate an already thorny problem for ranchers? In 2005, U.S. Department of Agriculture researcher Dana Blumenthal set out to document what effect climate change will have on large swathes of grassland, focusing in on a noxious weed called Dalmatian toadflax.
For about eight years Blumenthal and his team simulated a possible future climate in the Wyoming grassland. A heating apparatus kept test plots warmer than normal. Pipes pumped carbon dioxide into the air surrounding the toadflax. The warming and CO2 weren’t set at doomsday levels, but rather conservative levels Blumenthal says the plains could see within a century. Under those conditions, Dalmatian toadflax flourished, growing in size 13-fold and producing more seeds.
“The simplest reason that invasive species are likely to do well under future conditions is that they are pretty much by definition good at dealing with change,” Blumenthal said.