WEST LAFAYETTE, Ind., June 1 (UPI) -- An invasive weed causing millions of dollars in damage in western U.S. pastures annually will be a bigger problem with ongoing climate change, researchers say.
Researches at Purdue University in Indiana say the weed, yellow starthistle, will confront land managers with escalating problems as climate changes and it begins to out-compete local grasses.
They found that when exposed to increased carbon dioxide, precipitation, nitrogen and temperature -- all likely results of climate change -- yellow starthistle in some cases grew to six times its normal size while the other grassland species remained relatively unchanged, a Purdue release issued Wednesday said.
"We're likely to see these carbon dioxide concentrations in the second half of this century," Jeff Dukes, a Purdue professor of forestry and natural resources, said. "Our results suggest that yellow starthistle will be a very happy camper in the coming decades."
The weed is a significant problem in the West, especially in California, where it has a longer growing season than native plants and depletes ground moisture, affecting water supplies, researchers said.
"It reduces the quality of the area for animal forage, is toxic to horses and when it forms spines, cattle don't want to eat it," Dukes said. "Many consider yellow starthistle to be the worst grassland weed in the West."