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.

1The dynamics of ecological communities have been described by neutral and niche theories that are now 2 increasingly integrated into unified models. It is known that a critical transition exists between these two 3 states, but the spatial aspect of this transition has not been studied. Our aim is to study the spatial aspect of 4 the transition and propose early warning signals to detect it. We used a stochastic, spatially explicit model 5 that spans a continuum from neutral to niche communities, and is driven by the intensity of hierarchical 6 competition. The transition is indicated by the emergence of a large patch formed by one species that 7 connects the whole area. The properties of this patch can be used as early warning indicators of a critical interactions could push them across the transition, however, to a state in which diversity is much lower. 16Thus this new early warnings indicator could be used to monitor high diversity ecosystems that are still 17 undisturbed. 18Short title: A spatial phase transition between neutral and niche communities