Alaskan Active Layer and Permafrost Laboratory Mixing Experiment

A laboratory mixing experiment was conducted to assess how microbial communities are affected by the mixing of active layer and permafrost soils when the terrain thaws. Active layer soil and permafrost collected from two sites in interior Alaska were mixed in five different ratios and incubated for 100 days at 10 degrees C. Samples were collected, thawed, and pooled into active layer (AL), transition zone (TZ), and permafrost (PF) based on the active layer depth measurements collected at the sites during the time of sample collection. For the incubation study, permafrost and active layer soils were mixed in five ratios, 100%AL, 90%AL+10%PF, 50%AL+50%PF, 10%AL+90%PF, and 100%PF, as well as a separate 100%TZ sample to represent the permafrost-active layer boundary where the AL and PF soil layers meet in the field.