ABSTRACT
Fungi are the primary source of energy and nutrition for many organisms belowground, and trophic interactions involving fungi affect the diversity and function of soils. Biological diversity in soils is high, and food webs are complex (Moore and Hunt 1988; Bardgett and van der Putten 2014). Unlike aboveground food webs, energy sources in the soil include both living and dead (detrital) plant material (Figure 22.1). Energy from plant photosynthate and roots is conveyed into the soil food web via mycorrhizae, root pathogenic fungi, and other root parasites and pathogens. Detritus and root exudates are consumed by saprophytic fungi and bacteria, communities of which are among the most species-rich on the earth. Energy and nutrients from both living and decomposing plant materials are integrated by soil fauna at higher trophic levels via their trophic interactions with fungi. The primary fauna in the soil that rely, at least in part, on energy derived from fungi are species of nematodes, Collembola, enchytraeids, earthworms, and mites.
