4:00 pm - 5:00 pm
This seminar has been updated with a new seminar time and link
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 Zachariah Madsen. This seminar is open to the general public to attend.
MSc with Dr. Scott Nielsen.
Zoom Link: https://ualberta-ca.zoom.us/j/92302784818
Thesis Topic: The role of snow and terrain on functional plant composition in an alpine environment
Abstract:
As global temperatures rise, alpine regions are experiencing changes in plant community composition. Understanding how alpine plant communities interact in the face of climate change is essential for predicting future shifts in biodiversity and ecosystem function. Here we aim to investigate how patterns of snow persistence across local terrain features affects functional plant composition. We explore this through two studies, 1) we employ the Grime Competition, Stress-tolerant, and Ruderal (CSR) framework to analyze the effects of snow and directional slope on plant evolutionary strategies and lifeforms, and 2) we develop a causal model describing direct and indirect relationships between terrain, snow, shrubs, and herbs. Our findings reveal that snow persistence is a critical factor structuring local plant composition, especially stress-tolerant strategists, though these effects vary between lifeforms and the direction and steepness of slope. For instance, stress tolerant shrubs grow in late snow beds on cool facing slopes, while stress tolerant forbs grow in late snow beds on warmer facing slopes. The difference in strategy can be explained by our structural equation model, where we found a positive effect of snow on herbaceous species cover and richness, but in the presence of tall evergreen shrubs, the effect was either reduced or reversed the relationship due to the indirect pathway snow shares between shrubs and herbs. Similarly, the effect size of taller deciduous shrubs decreased in the presences of tall evergreen shrubs, due to the indirect effect they share with herb cover and richness. Our results highlight the complex synergism between snow and functional community composition with alpine plants increasingly relying on later snow persistence that is locally modified by the interplay between abiotic and biotic environments. These findings demonstrate the need for ongoing monitoring and management strategies that address the impacts of climate change on alpine ecosystems and ensure their resilience in the face of climate change.
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