Big Squirreltail Evolves to Fight Off Fiery, Invasive Cheatgrass


Big squirrel tail, left, not to be confused with Big squirreltail, right. Photos via Tomi Tapio and Matt Lavin

Nicknaming plants. Now there's a good job to have. The invasive plant in this tale, called "cheatgrass," is being fought off by a native grass, called "big squirreltail." The battle is playing out in a desert area between the Rocky Mountains and Sierra Nevada and Cascades ranges. Big squirreltail has been evolving to keep cheatgrass from destroying its territory. Big Squirreltail may not sound menacing, but it's holding its own. Scienceline reports that cheatgrass, also known by the less-catchy name of Bromus tectorum, threatens native plants and wildlife along with ranchers and hunters. That's because it sprouts in early March, before native grasses have started growing, soaks up nutrients and water that the native plants need, then dies in April or May, leaving behind what one ecologist likens to "a bunch of tissue paper spread across the landscape."

That's where big squirreltail (aka Elymus multisetus) comes in. Biologist Elizabeth Leger at the University of Nevada has found that pockets of squirreltail are allocating more resources to their root structure, to make a stand against the cheatgrass.

"To gather their data, Leger and her team collected and weighed big squirreltail seeds from invaded and non-invaded areas all over the Intermountain West," Scienceline explains. "Some of the hardiest native plants from invaded areas managed to survive in a hostile environment, and consequently passed along their favorable traits to their seedling offspring."

She's found that the altered version of big squirreltail has been able to increase its nutrient uptake and foil cheatgrass by up to 30 percent.

Leger's research on the bigsquirreltail v. cheatgrass battle has been published in the journal Evolutionary Applications: "Competitive seedlings and inherited traits."

You can read about earlier research, "The Adaptive Value of Remnant Native Plants in Invaded Communities," at her website.

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Tags: Deserts | Evolution | Nevada

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