Doctoral Dissertation Research: Quantifying Lake Metabolism and Carbon Burial in an Agricultural, Drought-prone Sub-Arctic Landscape

Abundant across the Arctic, lakes are hotspots of carbon cycling that influence regional and global carbon budgets. In South Greenland, lakes provide critical resources for sheep farming operations. As the Arctic experiences unprecedented warming, both subsistence and commercial agricultural operations are expected to expand, but it is unclear how these managed landscapes will impact lake ecosystems and carbon cycling. The Qassiarsuk settlement within the Kujataa UNESCO World Heritage Site is a model landscape for understanding the interaction of agriculture with a warmer and drier Arctic. This dissertation project will employ paleolimnological techniques to reconstruct carbon burial, nutrient concentrations, and lake level over the past 200 years to understand lake conditions before the influence of present-day agricultural operations. These measurements will be the first continuous, high-frequency metabolism monitoring within an agricultural region in the Arctic and will incorporate land-use into a framework of Arctic system change. Contemporary intra-annual variability and drivers of lake metabolism will be assessed using high-frequency dissolved oxygen and light sensors and lake level loggers from four lakes that represent hydrological connectivity and land-use patterns found across the Arctic. To quantify how present-day weather patterns influence carbon cycling, researchers will employ year-round, automated sensors to track lake level and lake metabolism to disentangle drivers of carbon burial over the past 200 years. These data will anchor a robust framework for understanding the interactive effect of climate and agriculture on Arctic lakes, filling a gap in our knowledge of landscapes that are of critical importance for communities that rely on lakes for farming operations. Results of this research will be shared with sheep farming communities in South Greenland and presented at interdisciplinary, international science conferences. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.