Trophic resources of the edaphic mesofauna: a worldwide review of the empirical evidence

Ecosystem sustainable use requires reliable information about structure and functioning. Accurate knowledge of trophic relations is central for the understanding of ecosystem dynamics, essential to develop sustainable use practices. This review gathers the information available worldwide about the trophic resources within the soil mesofauna. From over 130000 hits of the initial search on soil mesofauna, only a total of 78 published works relate particular species, genera, and families to particular trophic resources, the majority of them dealing with soils of the Paleartic region. Thirteen trophic resource categories were identified for six of the main orders of soil Acari and Collembola, using a combination of eight different methodologies. Out of 2717 records relating specific taxonomic groups to their trophic resources, 515 mention saprophytic fungi as a food resource, 381 cite nematodes, 308 mention bacteria, 286 litter and 256 cite mychorrizae. The available information is also highly skewed, for 68.16% of all the available information comes from Acari, and within these, 44.5% correspond just to Sarcoptiformes. For Collembola, the information available in the literature is much scarce the majority of it from Arthropleona. This review shows the general lack of information relating species, genera, and families of the soil mesofauna to specific trophic resources, with Collembolans largely unexplored in this regard. It also highlights the studies mostly come from European soils, with the use of trophic resources by the mesofauna of majority of the soils in most of the world still largely unknown.