Abstract Detail

Mycological Section

David, Aaron [1], Seabloom, Eric [1], May, Georgiana [1].

Roles of root-associated fungal symbionts on invasion success of a coastal beachgrass in primary successional dunes.

Fungal symbionts play important roles in shaping plant communities, and may facilitate the establishment of invasive plants. Arbuscular mycorrhizal fungi (AMF), for instance, may give an invasive species an advantage over resident plant species if they provide the invasive with greater access to nutrients. Alternatively, fungi may play a limited role in invasion, particularly in primary successional habitats where fungal abundance and diversity is relatively low. We evaluated the role of AMF and root endophytes in facilitating invasion of a coastal beachgrass, Ammophila breviligulata, in the Pacific Northwest, USA, as well as the role of disturbance. We conducted a field experiment in which individuals of the invading A. breviligulata, an established invasive congener A. arenaria, and a native Elymus mollis were planted into plots that manipulated disturbance in the young successional foredunes and older backdunes. We measured AMF and root endophyte colonization using a combination of microscopy, culturing, and Illumina environmental sequencing techniques, and analyzed how AMF and root endophytes contributed to plant biomass. We found that the native E. mollis harbored greater colonization of AMF than either invasive Ammophila species. A. breviligulata more frequently associated with dark septate root endophytes than did the other plant species. AMF and root endophyte presence were generally poor predictors of plant performance. We did find strong evidence that the three plant species responded differently to disturbance; E. mollis and A. arenaria achieved higher biomass in disturbed plots than undisturbed plots, while A. breviligulata biomass did not differ with the disturbance treatment. This result suggests that the success of the invading A. breviligulata is not dependent on disturbance while both an established invasive and a native species may depend more on disturbance. Our results fail to find a strong role of AMF or DSE in facilitating the invasion of A. breviligulata, and instead support the idea that the species’ reliance on disturbance plays a large role. Our study contributes to our general understanding of the roles fungi play in altering plant communities, and suggests that in our primary successional system, they may play a reduced role.

1 - University of Minnesota, Ecology, Evolution, and Behavior, 1987 Upper Buford Cir, Saint Paul, MN, 55108, United States

Keywords:
dark septate endophyte
arbuscular mycorrhizal fungi
Ammophila
coastal dunes
invasive species.

Presentation Type: Oral Paper:Papers for Sections
Session: 22
Location: Salon 1/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 4:45 PM
Number: 22005
Abstract ID:1205
Candidate for Awards:MSA Best Oral Presentation Award by a Graduate Student