Populations of a widespread invader and co-occurring native species vary in phenotypic plasticity

Phenotypic plasticity can promote plant invasions and enhance impacts on native species but little is known about variation in plasticity among invader populations compared to native species. Variation in plasticity among invader populations could inform more precise predictions of invader spread and impacts across heterogeneous resource environments.

 We used a common garden experiment with sun and shade treatments to test for variation in plasticity among 12 populations of an invasive grass, and to determine if the invader exhibited greater plasticity than six native species that co-occur in the Southeast US.

Principal component analysis revealed that invader populations from different native ranges consistently varied from each other and native species in traits linked to more favorable phenotypes under resource limitation. Overall, the invader exhibited greater plasticity than native species, as demonstrated by higher plasticity index values for traits such as plant height, le...