Oribatid Mites for Monitoring Arctic Ecosystems: Comparing Morphological Analysis and COI Metabarcoding Along a Disturbance Gradient

Oribatid mites are highly sensitive bioindicators and are among the most promising groups of soil microarthropods for ecosystem monitoring. However, their taxonomic identification using morphological methods is labor-intensive and time-consuming. We tested COI metabarcoding as an alternative to the traditional approach and assessed whether it could complement morphological assessment of oribatid mites in monitoring Arctic ecosystems. In northwest Russia, Oribatida were found to be effective bioindicators. All the Oribatida indicators studied (population density, relative abundance in the soil microarthropod community, number and occurrence of species/OTUs, Shannon (H) and Simpson (1–D) indices, and dominance structure) appeared to be sensitive to anthropogenic impact and strongly related to the degree of human disturbance. Morphological analysis and DNA metabarcoding generally revealed concordant spatial patterns in oribatid community indicators, although the absolute values of some indicators differed. Combining DNA metabarcoding to characterize oribatid mite diversity and dominance structure with morphological methods to estimate population density and relative abundance within soil microarthropod communities may provide complementary information for assessing ecosystem disturbance and improve the accuracy of assessments of the degree of negative anthropogenic impact.