Soil carries out functions that are crucial for theenvironment and life on earth and is therefore an essential non renewableresource for mankind. Recently, the European Soil Framework Directive proposalindicated that soil is under increasing environmental pressure mostly due tothe intensification of human activities, which are damaging the capacity ofsoil to continue to perform in full its broad variety of crucial functions.Most of these soil functions are depending on micro-organisms inhabiting the soil.The diversity of soil micro-organisms is the highest on earth with estimates ofseveral thousand to several million different genomes per gram of soil. Howeverfundamental knowledge of the diversity and ecology of microbial communitiescarrying out soil functions is still limited. Understanding the impact ofanthropogenic activities on microbial communities and how this relates to soilfunctioning is therefore a major challenge in soil microbiology. The revolutionin the techniques available to date offer exciting opportunities for a betterunderstanding of the relationships between microbial diversity and soilfunctions. This talk will focus on the novel insights into the impact of humanactivities on microbial communities and potential consequences for ecosystemprocesses.