Drylands represent the most dominant terrestrial biome as they cover over 45% of the Earth's terrestrial surface. Furthermore, with the increasing global temperatures we are experiencing in relation with climate change, their surface is expanding via a land degradation process termed desertification. As a result, it is crucial to understand how these major and yet fragile ecosystems function, particularly at the microscale. Indeed, in such an environment, where the presence and diversity of macroorganisms is limited, microorganisms represent key driving force of nutrient cycling. Consequently, this presentation will show how dryland microbial communities from many niches are surprisingly diverse and fully functional despite drylands’ polyextreme conditions and also how these could be used in climate change mitigation strategies.