Global environmental changes are altering interactions among plant species, sometimes favoring invasive species. Here, we examine how a suite of ﬁve environmental factors, singly and in combination, can affect the success of a highly invasive plant. We introduced Centaurea solstitialis L. (yellow starthistle), which is considered by many to be California’s most troublesome wildland weed, to grassland plots in the San Francisco Bay Area. These plots experienced ambient or elevated levels of warming, atmospheric CO2, precipitation, and nitrate deposition, and an accidental ﬁre in the previous year created an additional treatment. Centaurea grew more than six times larger in response to elevated CO2, and, outside of the burned area, grew more than three times larger in response to nitrate deposition. In contrast, resident plants in the community responded less strongly (or did not respond) to these treatments. Interactive effects among treatments were rarely signiﬁcant. Results from a parallel mesocosm experiment, while less dramatic, supported the pattern of results observed in the ﬁeld. Taken together, our results suggest that ongoing environmental changes may dramatically increase Centaurea’s prevalence in western North America.
Centaurea solstitialis (yellow starthistle); climate change; elevated CO2; grasslands; invasive species; nitrogen deposition; rangelands; weed.
Date of this Version
Dukes, Jeffrey; Chiariello, Nona R.; Loarie, Scott R.; and Field, Christopher B., "Strong Response of an Invasive Plant Species (Centaurea solstitialis L.) to Global Environmental Changes." (2011). Department of Forestry & Natural Resources Faculty Publications. Paper 11.