Supervised by:

Dominique Berteaux (Regular Member (Co-researcher))

Co-supervised by:

François Vézina (Regular Member (Co-researcher))

Research project description

Fine-scale study of biodiversity hotspots in the polar desert.

Introduction

Polar deserts, characterized by low temperatures, low precipitation and

Objectives

Fine-scale biodiversity hotspots are often clearly identifiable in the field, as the vegetation is more luxurious than in the surrounding area. The hypothesis put forward to explain their presence is that they are initiated by the behavior of predatory vertebrates who choose them as perches or territorial boundary markers. This use leads to the deposition of faeces, urine or pellets, which enriches the adjacent soil, encouraging vegetation, which in turn attracts small herbivores (arthropods, lemmings), generating a positive feedback loop. I am going to test the main components of the above hypothesis, which has never been done formally. This is of great interest because the hypothesis provides an original conceptual framework linking geomorphology, animal behavior, soil ecology and plant ecology.

Study Sites

My research fieldwork will be completed from June to August 2025 on a 170 km2 study area at Canadian Forces Station Alert, on Ellesmere Island, less than 820 km from the North Pole. I will be co-supervised by Prof. Berteaux and Prof. Vézina (UQAR), both specialists in Arctic vertebrates. I will be working closely with PhD student É. Desjardins (UQAR), who is a specialist of plants, soils and invertebrates found in Alert. My supervisory team has been working at Alert since 2018 thanks to an agreement with the Department of National Defence, which guarantees access to the site and the required logistics.

Material and methods

A systematic search for biodiversity hotspots over 5 km2 will first assess their dependence on micro-relief (habitat selection analyses). Then, 40 hotspots will be compared with 40 control sites according to the following variables: 1) Predator abundance and behaviour (automatic cameras), 2) Faeces and pellet counts; 2) Soil nitrogen (N), carbon (C) and phosphorus (P) concentrations, 3) Plant diversity, biomass and productivity (quadrats); 4) Arthropod diversity and biomass (pitfall traps) and lemming abundance (burrows).

References

Rantanen, M., A. Yu. Karpechko, A. Lipponen, K. Nordling, O. Hyvärinen, K. Ruosteenoja, T. Vihma, and A. Laaksonen. (2022). The Arctic has warmed nearly four times faster than the globe since 1979. Communications Earth & Environment, 3:168. Berteaux, D., Réale, D., McAdam, A. G., and S. Boutin. (2004). Keeping pace with fast climate change: can arctic life count on evolution?. Integrative and Comparative Biology, 44(2), 140-151. Johnson-Bice, S., Gable, T., Roth, J., and J. Bump. (2023). Patchy indirect effects: predators contribute to landscape heterogeneity and ecosystem function via localized pathways. Authorea Preprints. Monk, J. D., and O. J. Schmitz. (2022). Landscapes shaped from the top down: predicting cascading predator effects on spatial biogeochemistry. Oikos, 2022(5), e08554. Jones, C. G., Lawton, J. H., and M. Shachak. (1996). Organisms as ecosystem engineers. Ecosystem management: Selected readings (pp. 130– 147). New York, NY: Springer. Coggan, N. V., Hayward,

Research Site Coordinates