Arctic biodiversity faces several threats, including habitat degradation caused by human activities, ecosystem modification resulting from global warming, as well as colonization by non-native species. The influence of these threats is not uniform and depends heavily on the biotic, topographical, and climatic conditions specific to the local ecosystem, as well as on human use. In addition, there is a lack of fundamental knowledge about the structure and functioning of arctic ecosystems, as well as an absence of temporal reference on the state of biodiversity, which decreases our ability to understand and mitigate current and future changes. My doctoral project taking place near Canadian Force Station (CFS) Alert (Nunavut), will develop new knowledge and understanding of biodiversity from the polar desert, will create biodiversity baselines, and will develop local biodiversity management plans.
My project aims to (1) establish an updated inventory of vascular plants in Alert, (2) map the habitats by classifying them into major physiognomic types: xeric habitats, mesic habitats and wetlands, (3) determine the habitats used by dominant animal species (e.g. muskox and arctic hare) and species with conservation status (e.g. Peary caribou and Red knot), (4) assess the ecological role of snowbanks, which slow summer melting irrigates and maintains adjacent wetlands, thus creating essential habitats for flora and fauna, (5) identify the sites most likely to be colonized by non-native plant species, and finally (6 ) develop and present to the Department of National Defense a biodiversity management plan with measures to protect local biodiversity and allow the recovery of species with conservation status.
My study site (170 km2) is located at the northern end of Ellesmere Island, in the polar desert surrounding CFS Alert. CFS Alert, the most northerly permanently inhabited site on the planet, has been operational since the 1950s and accommodates 50-200 people depending on season. The use of heavy off-road machinery and the weekly staff rotations increase the risk of habitat degradation and introduction of non-native species. This arctic site, already subject to global warming, includes several species with conservation status that are protected under the Species at Risk Act and the Migratory Birds Convention Act.
To achieve my objectives, I will (1) sample the vegetation in quadrats placed according to a stratified sampling plan, (2) generate a vegetation map based on vegetation indices calculated by remote sensing from a high resolution satellite picture, (3) identify habitats used by dominant animal species and species with conservation status, by using species distribution models based on data from visual observations, camera traps and feces, (4) compare plant production and wildlife presence between areas irrigated and not irrigated by snowbanks, using plant biomass estimation, faeces sampling, camera traps, arthropod traps, and visual observations (5) inventory the presence of non-native species along transects near human infrastructures, and finally (6) propose management recommendations based on the above new information.
Based on my preliminary data and observations, (1) at least 58 species of vascular plants are found at the study site, (2) five plant communities can be identified at CFS Alert, including one xeric community, one mesic community and three wet communities, (3) herbivores mainly use wetlands while shorebirds use shallow ponds, (4) wetlands irrigated by snowbanks show a denser plant cover, a lower plant richness, a higher arthropod density, and a greater use by herbivores than the surrounding xeric and mesic environments, and finally (5) very few, if any, non-native species are present around CFS Alert.
Desjardins, É., Lai, S., Payette, S., Dubé, M., Sokoloff, P.C., St-Louis, A., Poulin, M.-P., Legros, J., Sirois, L., Vézina, F., Tam, A., Berteaux, D., 2021. Survey of the vascular plants of Alert (Ellesmere Island, Canada), a polar desert at the northern tip of the Americas. Check List, 17(1): 181–225. DOI: 10.15560/17.1.181.