High nitrate variability on an Alaskan permafrost hillslope dominated by alder shrubs
Rachael E. McCaully,Carli A. Arendt,Brent D. Newman,Verity G. Salmon,Jeffrey M. Heikoop,Cathy J. Wilson,Sanna Sevanto,Nathan A. Wales,George B. Perkins,Oana C. Marina,and Stan D. Wullschleger
Rachael E. McCaully
Earth and Environmental Sciences Division, Los Alamos National
Laboratory, Los Alamos, 87545, United States
Department of Marine Earth and Atmospheric Sciences, North Carolina
State University, Raleigh, 27695, United States
Degrading permafrost and shrub expansion are critically important to tundra biogeochemistry. We observed significant variability in soil pore water NO3-N in an alder-dominated permafrost hillslope in Alaska. Proximity to alder shrubs and the presence or absence of topographic gradients and precipitation events strongly influence NO3-N availability and mobility. The highly dynamic nature of labile N on small spatiotemporal scales has implications for nutrient responses to a warming Arctic.
Degrading permafrost and shrub expansion are critically important to tundra biogeochemistry. We...