11:00 am - 12:00 pm
Event details: A graduate exam seminar is a presentation of the student’s final research project for their degree.
This is an ALES MSc Final Exam Seminar by Elena Schaefer. This seminar is open to the general public to attend.
MSc with Dr. Justine Karst and Dr. Catherine Gehring
Thesis Topic: Mycorrhizas and root traits of the riparian tree species Populus fremontii
Forests in arid regions are not uncommon, however trees in these areas must budget carbon as a limited resource, suggesting carbon allocation to root systems and mycorrhizal fungi could be important for overall tree fitness. I tested the influence of mycorrhizal type on root traits, including fine root carbon flux, using provenances of Populus fremontii that vary in dominance of two mycorrhizal types. I confirmed not only that P. fremontii forms two mycorrhizas simultaneously, but depending on provenance and environment, individuals also preferentially associate with one mycorrhizal type. Mycorrhizal type, however, did not affect fine root carbon flux in either experiment. Overall, I measured extremely low fine root carbon-flux rates. Additionally, root traits were variable and disconnected from mycorrhizal type, revealing context-dependent patterns. These results suggest that P. fremontii minimizes exudation of carbon across a range of environments, and the distinct effects of mycorrhizal type on root traits are nuanced.