“Many of the world’s ecosystems have undergone degradation, and biological diversity has declined as a result. So far, efforts to conserve and manage the earth’s biological diversity have focused on the loss of above-ground species; reductions in soil biodiversity have gone by unnoticed. But as soil biota can have both positive and negative effects on plant production and diversity, it is necessary to understand the mechanisms that relate soil biodiversity and ecosystem functioning to above-ground diversity.”