Gabriel Bergeron
Ph.D. student
Department of Biology
Laval University

Supervised by:

Pierre Legagneux (Regular member)

Dominique Gravel (Regular member)

Research project description

Dynamics, synchrony and coherence of seasonal food webs in the Canadian High Arctic

Introduction: In highly seasonal ecosystems such as in temperate, boreal, and arctic biomes, the composition of food webs is so changeable that it is imperative to look beyond the seasons to truly understand how species interactions shape the ecosystem. Thus, my project seeks to better understand seasonal ecosystems by looking at food web dynamics over time as well as space. I am using the Arctic tundra ecosystem as a model since this ecosystem undergoes impressive seasonal fluctuations and the small number of species present in the food web facilitates the analysis of the system dynamics. The main objective of the proposed research is to integrate analytical techniques developed in network physics to better understand the evolution and dynamics of food webs with a particular focus on temporal and spatial aspects. Objectives: More concretely, this project will aim to (1) characterize the cyclical fluctuations of a lemming population in time and space at several scales with metrics from the field of network physics. Subsequently, this project will aim to (2) reconstruct the intra- and inter-annual food web of the highly seasonal Canadian high Arctic tundra ecosystem. Finally, the metrics developed in the first objective will be applied to the High Arctic food web to (3) study the assembly rules that appear with the temporal study of a highly seasonal web. Study sites: Field work for this study will take place at the Bylot Island Research Station (Nunavut). The vast majority of Arctic animal species have been monitored for over 10 years through collaboration between several CEN teams. These important field efforts have allowed the accumulation of an impressive database on Arctic biodiversity. Material and methods: This project will use time series of lemming activity on Bylot Island to measure population synchrony and coherence at the plain scale (600 km2). Passive lemming sensors will also be developed and deployed on the site to obtain high resolution spatial and temporal information of lemming activity. To reconstruct the Bylot food web, I will have access to over 15 years of opportunistic wildlife observations. With interpolation techniques, I will be able to reconstruct the composition of the food web on a daily basis. References: Blackman, R. C., Ho, H. C., Walser, J. C., & Altermatt, F. (2022). Spatio-temporal patterns of multi-trophic biodiversity and food-web characteristics uncovered across a river catchment using environmental DNA. Communications Biology, 5(1).

Research Site Coordinates

Scientific Communications

Bergeron, G., Poirier, M., Fauteux, D., 2022. Imprévisibilité climatique, dérèglement des cycles de lemmings et biodiversité nordique. <strong>Le Climatoscope</strong>, 4(1): 81-84.

Poisot, T., Bergeron, G., Cazelles, K., Dallas, T., Gravel, D., MacDonald, A., Mercier, B., Violet, C., Vissault, S., 2020. Environmental biases in the study of ecological networks at the planetary scale. <strong>Journal of Biogeography</strong>, 48(7): 1552-1563. DOI: <a href="" target="_blank">10.1111/jbi.14127</a>.

Bergeron, G., Gravel, D., 2019. Où trouver du sirop d’érable en 2100? <strong>Le Climatoscope</strong>, Septembre 2019(1): 36-39.

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