Luminescence Data For Floodplain Carbon Storage: Soil Organic Carbon, Surface Age, and Vegetation in an Icy River Corridor

Rivers are some of the most dynamic features of the Arctic landscape, yet their role in the global carbon cycle is poorly understood. Researchers are still unraveling the intricacies of how river dynamics control organic carbon (OC) accumulation, transport, and degradation in riverine systems. The interplay between permafrost thermal state in river corridors, snow and ice-affected hydraulics and channel erosion processes, and ecosystem growth dynamics create unique controls on carbon budgets in Arctic river systems. Fluvial corridors in the Arctic are characterized by a great variety of geomorphic surface types, ranging from peaty sedgelands into which rivers may incise, to abandoned and infilled river avulsions, to shifting sand and gravel bars littered with deposited uprooted willows and blocks of turf. Floodplains are patchworks of surfaces that are crafted by the dynamic disturbance regime of rivers. Quantifying the stock and accumulation history of OC on these surfaces is vital for improving carbon inventories in these often-overlooked regions of the Arctic. The changing Arctic climate will significantly affect the hydrologic and thermal regimes of fluvial systems, altering riverine carbon budgets in the process. To better understand the organic carbon stocks on braided Arctic river floodplains, I examine surfaces along the Canning River on Alaska’s North Slope.