Icing dynamics in the lake-dominated, discontinuous permafrost Taiga Shield, and effects on fluvial biogeochemistry, carbon cycling and microbial communities ...

• Main Author: Alsafi, Nora
• Format: Text
• Language: unknown
• Published: University of Alberta Library 2023
• Subjects: permafrost; Subarctic; taiga; Taiga shield
• Online Access: https://dx.doi.org/10.7939/r3-bz61-db39; https://era.library.ualberta.ca/items/03a5b4ef-4f5b-4a0a-a699-08ae19de4a69

Climate warming is affecting freshwater systems across the western Canadian subarctic, due to widespread shifts in precipitation regimes, permafrost degradation, and multi-decadal increases in winter baseflow. These changes are significant on the Taiga Shield, which comprises ~20% of North America’s permafrost-covered area, encompassing an area of over 1.3 million km^2. This region is characterized by “fill and spill” hydrology, where runoff is generated by the exceedance of lake basin storage thresholds across the landscape. In response to increasing winter baseflow, hydrologic connectivity between the lakes which dominate this region is also increasing. In addition, taliks, zones of unfrozen ground within or above the permafrost layer, are expanding in spatial extent and occurrence across the Taiga Shield. These changes are expected to alter the export of novel chemical constituents, including dissolved organic matter (DOM), to fluvial networks, with potential implications for carbon cycling and the ...