PARENT SESSION
Symposium 19: The Role of Plant-Microbe Feedbacks in Plant Invasions
Organized by: K Reinhart and R Callaway
Thursday, August 7. 1:30 PM to 5:00 PM, SITCC Oglethorpe Auditorium.
Degradation of mycorrhizal mutualisms and the success of naturalized plants.
Bever, James*,1, Schultz, Peggy1, Yoshida, Lidia2, Chaudhary, Bala2, Vogelsang, Keith1, Subramaniam, Banu3, 1 Indiana University, Bloomington, Indiana, USA2 University of California--Irvine, Irvine, California, USA3 University of Massachusetts, Amherst, Massachusetts, USA
ABSTRACT- Species characteristics and habitat properties can interact to contribute to successful plant invasions and, in some locations, dominance by naturalized plant species. We suggest that the dominance of naturalized plant species in Southern California is facilitated by the degradation of the mycorrhizal mutualism. Both through examination of floras and experimental tests, we find that naturalized plant species are generally less dependent on arbuscular mycorrhizal (AM) fungi than native plant species. As a result, naturalized plant species would be predicted to have higher success in disturbed habitats. We also find that naturalized plant species are poorer hosts for AM fungi. Therefore, the initial establishment and dominance of an area by naturalized plant species can inhibit the reestablishment of effective mycorrhizal mutualists, thereby inhibiting the reestablishment of native plant species. We find support for this hypothesis of reinforcement in tests of soil community feedback. Native plant species generally grow better with soil communities derived from native dominated sites than from sites dominated by naturalized plant species. Moreover, when the soil community derived from native dominated sites was trained on either native or naturalized plant species, native plant species generally grow better with soil communities previously trained with native plants.
Key words: invasive plant species, feedback, exotic species, mycorrhizae