The Arctic and parts of Antarctica are experiencing very rapid climate and environmental changes. Earth system models further predict increasing temperatures and changing precipitation patterns in the 21st century as a result of the polar amplification of global warming. It can be expected that these changes will affect the biodiversity and functioning of polar ecosystems, yet the resilience of these habitats and their vulnerability to change is largely unknown due to the lack of long-term monitoring data and extensive field experiments. This knowledge gap resulted in the development of permanent monitoring stations and field experiments in the framework of international research projects and initiatives such as SCAR ANTOS and Ant-ICON, and the Ny-Ålesund Terrestrial Flagship project.

ExPoSoils is aimed at studying the effects of increased temperature and snow cover on the biodiversity and genetic functional potential of microbial communities in polar desert and tundra soils in the Arctic and Antarctica, and consolidating the long-term monitoring of ecosystem responses to climate change in these regions. Snow fences to increase snow cover and open-top chambers to increase the temperature were installed 5 years ago in Svalbard (High Arctic) and the Sør Rondane Mountains (East Antarctica) and baseline samples were taken. Specifically, the objectives of the project are to (i) develop an integrated database with high-throughput sequencing data of microbial communities in polar desert and tundra soils differing in moisture content and other environmental properties from both the Arctic and Antarctica, (ii) predict the trajectories of these communities in response to future changes in temperature and moisture availability by comparing data from snow fences, open top chambers and measurements of key ecosystem functions (carbon and nitrogen cycling) between the start of these experiments and the present-day, (iii) use a combination of remote sensing and close-range field observation techniques and high-throughput DNA sequencing to detect potential changes in the presence/extent of microbial mat and biological crust communities, and study the diversity and functional potential in natural communities since the start of the monitoring, (iv) isolate, characterize and preserve ‘ex situ’ novel polar microbial diversity that may be threatened by rising temperatures, and (v) establish a long-term monitoring site in Antarctica and put a monitoring scheme in place to identify potential future biological and environmental changes in sites recently proposed to be an Antarctic Specially Protected Area (ASPA) in the Sør Rondane Mountains.