Gabrielle Côté
Université du Québec à Rimouski
M.Sc. candidate
Supervisor: Dominique Berteaux
François Vézina
Start: 2024-05-01
M.Sc. candidate
Supervisor: Dominique Berteaux
François Vézina
Start: 2024-05-01
Project
Fine-scale study of biodiversity hotspots in the polar desert.Polar deserts are characterized by low temperatures, low precipitation and low vegetation cover (<5%). As polar deserts are difficult to access, little is known about their structure, functioning and evolution, which poses two problems. Firstly, because of polar amplification, the climate there is warming faster than elsewhere on earth, but the current and future ecological effects of this warming are poorly understood. Secondly, mining and military activities are expanding rapidly, but knowledge is lacking to accompany these developments with effective biodiversity conservation plans. It is in this context that my project proposes to better understand an important component of polar deserts, namely fine scale biodiversity hotspots (BH). BHs, which are often clearly identifiable in the field because the vegetation is more luxurious than in the surrounding area, are generally located on small knolls or around large rocks. The hypothesis put forward to explain their presence is that they are initiated by the behavior of predatory vertebrates who choose them as perches (jaegers, snowy owls, gulls) or territorial boundary markers (foxes, wolves, ermines). This use results in the deposition of faeces, urine or pellets which enrich the adjacent soil, encouraging vegetation, which in turn attracts small herbivores (arthropods, lemmings), thus generating a positive feedback loop. The aim of my research project is to test the main components of this hypothesis, which has never been formally done. My study will take place from June to August 2025 on a 170km2 study area at Canadian Forces Station Alert on Ellesmere Island, less than 820 km from the North Pole. During this period, 40 BHs will be compared with 40 control sites according to: 1) Predator abundance and behavior (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). The hypothesis tested provides an original conceptual framework linking geomorphology, animal behaviour, soil ecology and plant ecology. In addition, the hypothesis suggests the presence of processes that may be linked to the ecosystem engineer concept. The ecosystem engineer concept was established over 20 years ago to describe the role of certain species in the physical modification of habitats, leading to changes in the abundance, distribution and diversity of other species. But to my knowledge, the concept has never been applied to a community of species, in this case the guild of vertebrate predators in the polar desert. The relevance of this study is therefore manifold. It is fundamental to a better understanding of polar desert ecology and to clarifying the concept of ecosystem engineer. It is also applied, as it will be used to inform a Biodiversity Management Plan, which is underway at Alert and requires an analysis of the spatial distribution of biodiversity hotspots.
