Extreme terrestrial environments are often disregarded as ‘curiosities’, of little relevance to understanding the bigger picture of microbial community assembly, diversity, and functions on Earth. However, these environments offer outstanding natural laboratories in which to test and expand our theory and knowledge of microbial survival, community recruitment and succession, and functions and tolerances, which have been mostly developed in more moderate environments.
In this talk, I will present insights from my research group’s work in a range of extreme terrestrial environments, both natural (e.g. salt lakes) and engineered (e.g. mining wastes). Our research has shown that: microbial community succession is relatively slow in extreme environments compared to environments with weaker environmental selection pressures; dispersal limitation is common; and that dust is an important inoculant source (particularly in engineered environments). Ongoing work is interrogating the role of trace gas metabolism as a survival mechanism for microbial inoculants during dust-borne transit from the inoculant source, and as a foundational metabolism during early stages of microbial community establishment and diversification in environments with low or no microbial biomass. These insights have been used to develop new bioremediation technologies to rehabilitate degraded environments and mining wastes, and I will share examples of these here.