Biodiversity not only responds to environmental change, but has been shown to be one of the key drivers of ecosystem function and service delivery. Forest soil biodiversity is also governed by these principles, the structure of soil biological communities is clearly determined by spatial, temporal and hierarchical factors. Global environmental change, together with land-use change and forest ecosystem management, impacts the aboveground structure and composition of European forests. Due to the close link between the above- and belowground parts of forest ecosystems, we know that soil biodiversity is also impacted. However, very little is known about the nature of these impacts; effects they have on the overall level of biodiversity, the functions it fulfills, and on the future stability of forests and forest soils. Even though much remains to be learned about the relationships between soil biodiversity and forest ecosystem functionality, it is clear that better effort needs to be made to preserve existing soil biodiversity and forest conservation strategies taking soils into account must be considered.