Microbial diversity in arctic freshwaters is structured by inoculation of microbes from soils

A 12-year sample archive of DNA from Alaskan arctic tundra ecosystems are available to the Earth Microbiome Project for comparison of microbial diversity across a range of arctic environments from soils to water to sediments. These samples were preserved and extracted using a method that differs from that of the EMP. Therefore, we must test how the extraction method used to extract our archived samples compares with those methods used by the EMP. The samples for this test were collected during the summer of 2011 at the Toolik Field Station. Each site was sampled in triplicate and samples were divided and preserved for extraction using our standard protocol (three replicates), and for extraction using the EMP protocol (three replicates). Half of the samples are from the epilimnion and hypolimnion of ultra-oligotrophic Toolik Lake collected over the course of the summer, and the rest are from different environments associated with a headwater stream that lies upslope of Toolik Lake. The data from these samples will allow us to test whether our extraction protocol yields results that are similar to the EMP extraction protocol, to investigate how replicates compare, and to determine how the microbial community and its metagenome changes over the course of the summer in Arctic tundra waters. LTRB, Long Term Ecological Research. The samples from this study were provided to the EMP for amplification with the EMP protocols