Recent studies with invasive species have revealed that evolution plays an important role in the successful invasion of new habitats. For plant species involved in continent-wide invasions, the expectation is that the well known north-south increase in the number of herbivore species should favor the rapid evolution of increased resistance to herbivores at lower latitudes. This prediction will be tested using the common reed, Phragmites australis. The common reed is widely distributed across European and North American marshes; in the past 100 years a European variety of this species has invaded and rapidly spread throughout North America. The first objective is to test whether the common reed has undergone rapid evolution to form a north-south gradient in traits associated with anti-herbivore defense. The second objective is to quantify differences in plant defenses between native and invasive varieties of the common reed that occur together in the same marshes and on separate continents, and to evaluate how these differences may affect invader success.
This will be the first study to test whether herbivores influence the evolution and the invasion success of invasive species at the scale of whole continents. This research will provide invaluable data regarding the potential negative effects that the invasive common reed variety is having on the less common varieties that are native to North America. The PIs will provide research experience, mentorship and training for two graduate and up to four undergraduate students. The PIs will also participate in a variety of programs that promote undergraduate research and public awareness of the detrimental effects of invasive species.
