Changes in Icelandic soil microbiomes from the forefield of retreating glaciers revealed by Illumina and MinION sequencing

Abstract

Climate change is affecting the sub‐Arctic landscape more than mid‐latitude locations on Earth. This is especially evident in Iceland where glaciers are now receding at a rapid pace. As glaciers retreat, newly exposed land undergoes primary succession. The soil microbiome is a critical component of succession; microbial communities often act as first colonizers and are key players in soil neogenesis. Warming‐related changes in the composition of soil microbes may increase the amount of gasses such as methane and CO2 produced by soil bacteria, as well as expose potentially new pathogens. Therefore, it is important to collect long‐term data sets from diverse locations throughout the Arctic and sub‐Arctic to form a clearer picture of how climate change affects these areas. We are developing a chronosequence of soil microbiome data and extent mapping at two outlet glaciers on the South coast of Iceland (Sólheimajökull and Kvíárjökull). During our work, we have optimized a field‐based soil extraction protocol for remote DNA extraction. We compare microbiome communities between multiple sampling locations to understand how the organismal composition changes as the land recovers. We hypothesize that microbial populations will change in composition as we move farther away from the glacier’s margin. We also compare Illumina and MinION sequencing results on the same samples. We expect that MinION sequencing will be able to produce species‐level identification but may produce a different yet overlapping population set when compared with Illumina sequencing data. In addition to population‐level changes (such as nitrogen pathway development) we are searching the data to identify antibiotic resistances. The data gathered in this first‐pass analysis expands our current knowledge of soil microbiomes in the sub‐Arctic and provides a foundation for a long‐term study of the region.