Abstract Soils host the most complex communities of organisms, which are still largely considered as an unknown ‘black box’. A key role in soil food webs is held by the highly abundant and diverse group of protists. Traditionally, soil protists are considered as the main consumers of bacteria in soils. However, recent insights obtained using new methodologies, provide clear evidence for the trophic diversity of microbial eukaryotes, showing that non-bacterivorous soil protists (fungivores, omnivores, predators of other protists and nematodes), photosynthetic taxa and plant-as well as animal parasites might be equally important. Here we provide an overview of methodologies to study these important soil organisms. Major gaps of knowledge are highlighted, which can be addressed using a combination of now available methods These studies will undeniably reveal an even higher functional diversity of protists and likely raise awareness of their ecological importance in soils.
- Functional diversity