Climate change allows invasive weed to outcompete local species

Climate change allows invasive weed to outcompete local species

May 31, 2011

WEST LAFAYETTE, Ind. - Yellow starthistle already causes millions of dollars in damage to pastures in western states each year, and as climate changes, land managers can expect the problem with that weed and others to escalate.

When exposed to increased carbon dioxide, precipitation, nitrogen and temperature – all expected results of climate change – yellow starthistle in some cases grew to six times its normal size while the other grassland species remained relatively unchanged, according to a Purdue University study published in the early online edition of the journal Ecological Applications. The plants were compared with those grown under ambient conditions.

"The rest of the grassland didn't respond much to changes in conditions except nitrogen," said Jeff Dukes, a Purdue associate professor of forestry and natural resources and the study's lead author. "We're likely to see these carbon dioxide concentrations in the second half of this century. Our results suggest that yellow starthistle will be a very happy camper in the coming decades."

The study is one of the first comparing the growth of invasive species versus their local competitors under future climate scenarios. Dukes believes the results indicate problems land managers and crop growers could see in the coming decades, and not just with yellow starthistle.

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