Permafrost is one Earth’s largest reservoirs of soil organic carbon, and across the Arctic, it is thawing rapidly. As it thaws, microbial processes convert soil organic matter to greenhouse gasses such as CO2, CH4, and possibly N2O. The enivronmental impact of permafrost thawing will depend greatly on the microbial metabolic processes that drive those transformations, and the relative quantities of greenhouse gasses produced vs organic preserved or exported. In this project, which has been recommended for funding by the Department of Energy, we will use a broad spectrum of techniques, including metagenomics, proteomics, metabolomics, thawing experiments, and geochemical modeling to understand the microbial and biogeochemical dynamics of thawing permafrost in Svalbard. The project team is lead by Karen Lloyd of the University of Tennessee Department of Microbiology, and includes Drew Steen and Tatiana Vishnivetskaya, also of UT-K, Tullis Onstott of Princeton University, Robert Hettich of Oak Ridge National Laboratory, and John Cliff of Pacific Northwest National Lab. Additionally, James Bradley of Queen Mary University, London, Julia Boike of the Alfred Wegener Institute, Potsam, and Andrey Abramov of the Russian Academy of Sciences, Puschchino are our international collaborators.
The Steen Lab’s responsibility in this project is to study organic matter-microbe interactions in thawing permafrost using two techniques. First, we will perform assays of extracellular enzymes in experimentally-thawed permafrost soil, which will then be compared to genes encoding extracellular enzymes in the soil communities. Simultaneously, we will create a microbially-informed geochemical model to describe biogeochemical processes in thawing sediments.
