| Summary: | Across the circumpolar north, the degradation of permafrost in tundra and peatland landscapes has resulted in significant changes to land cover, including an increase in the extent of thermokarst landforms. Climatically-driven changes to soil hydrology and temperature have the potential to impact nutrient cycling biogeochemical processes, which have implications for plant productivity, greenhouse gas fluxes, and surface water quality. Terrestrial and aquatic ecological productivity are often nutrient-limited in subarctic permafrost environments, linking the cycling of bioavailable nutrients to the capacity of the landscape to take in and store carbon. Within these permafrost peatland catchments, the fate of small (< 1 km2) freshwater ponds and lakes has been the subject of scientific interest due to their ubiquity in the landscape, capacity to exchange carbon and energy with the atmosphere, and their potential to inform researchers about past climates through sediment records. High latitude regions are experiencing significant climatic change, including rapid warming and changing precipitation patterns, which may result in changes in nutrient dynamics within terrestrial and aquatic systems and hydrochemical transport dynamics between them. With climate warming, thermokarst lake expansion has the potential to modify the ability of these aquatic systems to maintain these functions through changes to nutrient inputs and cycling. Through seasonal hydrometric and hydrochemical monitoring, laboratory experimentation, and paleolimnological methods, a set of pristine and thermokarst-impacted peatland catchments in the Hudson Bay Lowlands served as the study site to design research questions and methodologies to address several major themes across the pond-peatland interface. Within the peatland catchment, experimental laboratory work was used to examine the climatic controls on mineralization rates across landscape units, which represent potential nutrient contributions along runoff flow paths. Next, seasonal ...
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