Les systèmes terrestres

Projets de recherche en cours (2019-2023)

Rapid climate change is driving shifts in the nutritional quality of aquatic food webs across the circumpolar North

The Arctic is warming faster than any other biome on Earth. Increasing temperatures, more snow and wetter summers, and greening catchments are changing circumpolar lakes from cold, low productivity, clear-water environments to warm, productive, turbid ecosystems. The change is happening at an accelerated pace, making lakes sensitive indicators (sentinels) that are vulnerable to climate impacts, with important consequences for cultural and economic ecosystem services of northern peoples. This project brings together a complementary set of nine leading national and international laboratories and their northern datasets in aquatic ecology and biogeochemistry, to synthesize an improved, integrated understanding of nutritional quality of Arctic freshwater food webs and their responses to environmental change. Specifically, we will synthesize information on food web lipids that are of nutritional importance in the North because these health-determining compounds move up through the food web via zooplankton to fish and ultimately humans. An increasing contribution of terrestrial organic material from thawing permafrost will likely decrease the lipid availability in lakes and is expected to have a direct effect on the trophic quality of food webs, and by extension on food quality and security in northern communities. By combining lipid and environmental data from 14 regions that span a wide geographic area, covering 200 degrees of longitude (from Alaska to Russia) and 30 degrees of latitude (from Subarctic to High Arctic), characterised by variation in underlying permafrost extent, modes of thaw, and overall catchment physiography, we aim to evaluate the food web responses to change across the circumpolar North and understand the important nuances of its regional variability.