Nutrient mobility upon permafrost thaw: sources and controlling processes

• Main Authors: Roux, Philippe, Villani, Maëlle, Opfergelt, Sophie, Belgian Science for Climate Action conference
• Other Authors: UCL - SST/ELI/ELIE - Environmental Sciences
• Format: Conference Object
• Language: English
• Published: 2024
• Subjects: Arctic; permafrost; Tundra
• Online Access: http://hdl.handle.net/2078.1/287447

In the Arctic, permafrost thaw in response to warming air temperatures has a profound impact on tundra ecosystems: hydrological flow paths are altered as well as vegetation cover, and previously frozen organic carbon is exposed to microbial decomposition. The implications for the global C cycle put permafrost environment as a climate tipping point by turning them from a carbon sink to a net carbon source. The goal of LIFTHAW is to provide a comprehensive assessment of the nutrient mobility response in permafrost regions subject to thawing. Permafrost thaw unlocks previously frozen soil constituents which become available for biogeochemical reactions. However, it is unclear if this new pool of essential nutrients is primarily available for the more deeply rooted plant species, or whether the change in water table level acts as a nutrient lift. Furthermore, the response of thaw depth to warmer temperature is not uniform at the landscape scale, affecting surface and subsurface water flows, and it is unknown to what extent an increase in connectivity between portion of unfrozen ground controls nutrient mobility. Our poster for the Belgian Science for Climate Action will be designed to present the 3 research questions that the LIFTHAW project aims to answer. (Q1) How does permafrost thaw impact nutrient sources for plant uptake? (Q2) Does permafrost thaw result in nutrient lift with changes in the water table level? (Q3) What is the seasonal effect of permafrost thaw on the lateral transfer of nutrients?