Perennial redox potential dynamics in Alaskan degraded and non-degraded permafrost soils

Abstract

The redox status of permafrost soils is a decisive factor for their nutrient cycling, organic matter decomposition, and greenhouse gas emissions. Although being associated with a variety of processes, data availability of continuous redox measurements in permafrost soils is scarce. Here, we provide a unique dataset covering three years of soil redox potential measurements, obtained from a monitoring approach at three research sites near Fairbanks, Alaska. Redox potential pattern in the permafrost soil active layer showed large seasonal differences, with reducing conditions in the short summer/autumn to largely oxidizing conditions in winter and spring. However, conditions for methane production were at no time recorded in the three years. Especially the freezing and thawing had substantial impact on the redox status, highlighting that assessment of redox conditions in permafrost soils should be extended beyond the typical summer observation periods.