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A domination of generalist predators in soil communities suggests a wide overlap in their prey spectra, resulting in a probability of tense trophic relationships within the predator complex, in particular during the periods of prey scarcity caused by natural community reorganisations or anthropogenic disturbance. It has been argued that soil physical structure (e.g. pore size and connectivity) can limit interactions between the potential trophic competitors facilitating their coexistence (Erktan et al., 2020). Another possible mechanism of coexistence of generalist predators would be a variation in their life history traits resulting in a certain partitioning of their trophic niches. On an example of a field experiment studying soil mesofauna succession in decomposing plant remains, we compared potential trophic spectra of the abundant predators (firstly, gamasid mites), outlined by significant correlations of their densities with densities of other members of the community. A wide variation of potential prey objects was revealed for the major predators which thus should be treated as generalist feeders with activities spanning over several trophic levels. At the same time, the predators were characterised by individual spectra of the potential prey taxa and a low interspecific similarity between these spectra. The results suggest a certain differentiation of trophic niches in the mesofauna predatory complex. In addition, the prey spectra underwent temporal changes in the course of mesofauna succession, indicating possible switching of predators between the prey objects in response to environmental changes during the decay process. [ABSTRACT FROM AUTHOR]

A striking feature of predatory complex in soil communities is a domination of generalist predators and a wide overlap in the prey spectra of the major predators, combined with usual intraguild predation and cannibalism. This suggests a probability of tense trophic relationships between the major predator taxa, in particular during the periods of community reorganisations and/or prey scarcity caused by natural or anthropogenic disturbance. On an example of a field experiment modelling the process of mesofauna community development after the ploughing of an organic fertiliser into soil, dynamics of major predators (Mesostigmata and trombidiform mites, insect larvae) was followed in detail. It was shown that patterns of population dynamics of the dominant predatory taxa markedly differed and their density peaks were distinctly separated. A preliminary explanation suggests that this differentiation was determined to a large extent by the interactions between the predatory taxa (like partitioning of prey objects and/or avoidance of intraguild predation). [ABSTRACT FROM AUTHOR]