Session will focus on invited talks from researchers studying microbial diversity in oligotrophic environments, including arid and semi-arid regions, permafrost, acid-mine tailings, volcanic islands, and sub-surface sediments to name a few. The talks will focus on processes employed by microbes to survive in such environments, and the relevant ecosystem functions of such microbial groups. Talks can range from challenges of studying oligotrophic environment, -omics related findings, modeling of such ecosystems to better predict response to climate change scenarios, and role of these microbes in providing soil stability and landscape evolution.