DOI: 10.5061/dryad.bcc2fqzgj
title: Data from: New perspectives on soil animal trophic ecology through the lens of C and N stable isotope ratios of oribatid mites

description: Knowledge of the trophic ecology of soil animals is important for
 understanding their high alpha diversity as well as their functional role
 in soil food webs and systems. In the last 20 years, the analysis of
 natural variations in stable isotope ratios (15N/14N, 13C/12C) has
 revolutionized our view on soil animal trophic ecology. Here, we review
 the state of the art of the trophic ecology of a highly abundant and
 diverse soil animal taxon, oribatid mites (Oribatida), investigated by
 stable isotope analyses. The review is based on 25 papers reporting stable
 isotope data of 292 oribatid mite taxa from 30 different sites. Four main
 findings emerged. (1) Oribatid mites cluster into six trophic groups, i.e.
 moss feeders, lichen feeders, primary decomposers, fungal
 feeders/secondary decomposers, predators/scavengers and marine algal
 feeders, plus one additional group, which incorporates CaCO3 in their
 cuticle for defence but still belongs to the fungal feeders/secondary
 decomposers group. (2) Of the 292 species studied 43.7% were classified as
 fungal feeders/secondary decomposers, 27.0% as primary decomposers and
 15.7% as predators/scavengers, only few species include CaCO3 into their
 skeleton (6.1%), feed on lichens (4.9%), mosses (2.1%) or marine algae
 (0.7%). (3) In about one-third of the species studied the trophic niche
 was constant or varied little between sites or habitats, but in two-thirds
 of the species, their trophic niche varied between habitats, with some
 species even shifting trophic levels, indicating trophic plasticity. (4)
 When aggregated at higher taxonomic level oribatid mite species clustered
 in only three instead of six trophic groups. This indicates that species
 within the same high-level taxon often belong to different trophic groups,
 for example, because feeding habits evolved convergently. Therefore, to
 accurately reflect the trophic ecology of oribatid mites their stable
 isotope signatures need to be analysed at the species level. However,
 stable isotope analyses also have limitations, e.g. feeding on bacteria
 and fungi cannot be separated, and the same is true for feeding on
 ectomycorrhizal and arbuscular mycorrhizal fungi. Other methods such as
 fatty acid, amino acid and molecular gut content analyses as well as
 microbiome analyses may complement stable isotope studies and resolve
 oribatid mite trophic niche differentiation at a higher resolution. This
 will contribute to a better understanding of the local coexistence of
 large numbers of species in soil. Finally, we provide perspectives on how
 to integrate microarthropods into soil food webs using stable isotope and
 other methods allowing deeper insight into theirtrophic structure.
description: In this study, we reviewed the state of the art of the trophic
 ecology of a highly abundant and diverse soil animal taxon, oribatid mites
 (Oribatida), investigated by stable isotope analyses. The review is based
 on 25 papers reporting stable isotope data of 292 oribatid mite taxa from
 30 different sites.
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