9:00 am - 10:00 am
Event details: A graduate exam seminar is a presentation of the student’s final research project for their degree.
This is an ALES PhD Final Exam Seminar by Justine Lejoly. This seminar is open to the general public to attend virtually.
Spread the worm…not!: Impacts of earthworm invasion on soils of the Canadian boreal forest
Exotic earthworms are invading North American forests, where native earthworms were wiped out during the last glaciation. Although earthworms are seen as beneficial for agriculture, their presence might not be desirable in forests that have developed in their absence. While most research on the topic focussed on temperate forests, fewer studies were conducted in boreal forests, which represent the largest terrestrial carbon (C) reservoir. I aimed to determine how invasive earthworms affect boreal forest soils, their C stocks, soil organic matter (SOM) dynamics, and associated microbial communities. To do so, I selected sites to encompass the most common soil types found in the Canadian boreal forest. Invasive earthworms decreased forest floor C stocks, modified the composition and distribution of C in the mineral soil, and contributed to a faster microbial decomposition of SOM. This could alter C sequestration and other ecosystem services of boreal forests in the long term.