This research project aimed to understand permafrost stability in Alaskan landscapes susceptible to freeze-thaw cycles. Arctic warming is exposing thawing permafrost to repeated freeze-thaw, a disruptive process that can alter soil biogeochemistry and physical structure. To investigate the impact of permafrost exposure to freeze-thaw, soil response was tested across three scales: 2.5 cm3 aggregates, a forested permafrost hillslope, and two Alaskan sites at contrasting latitudes with underlying permafrost. X-Ray Computed Tomography (XCT) imaging was employed to investigate pore deformation while Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) informed comparisons of soil organic carbon chemistry at the soil horizon, hillslope, and site levels. Soil permafrost cores from the National Ecological Observatory Network (NEON) were used to set up freeze-thaw experiments at OSU. Findings indicated that a combination of freeze-thaw history and soil properties may dictate soil response to future freeze-thaw cycles, introducing heterogeneity into physical and biogeochemical soil responses following permafrost thaw.
The U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research (BER) under contract DE-AC05-76RL01830 (PNNL).|The National Science Foundation award for the National Ecological Observatory Network (NSF#1724433).