Insight into Invertebrate Community in Solonchak Soil Type Using EDNA Metabarcoding – A Pilot Study

Summary Solonchaks are soils characterized by high concentrations of soluble salts. These soils form unique ecosystems that provide habitats for organisms adapted to such extreme conditions. Invertebrates are one of the groups of organisms that inhabit these soils and play a significant role in ecosystem resilience contributing to soil health and fertility. However, the diversity of invertebrates inhabiting the solonchaks remains underexplored. The development of eDNA metabarcoding method has facilitated the detection of soil invertebrates, overcoming the limitations of conventional labor-intensive and time-consuming methods. eDNA metabarcoding made it possible to study/monitor changes in soil invertebrate diversity. This pilot study employed eDNA metabarcoding to detect soil invertebrates in solonchak soils at two agricultural fields in Vojvodina, Serbia. Furthermore, we compared two analytical methods of eDNA metabarcoding data – clustering and denoising sequences. eDNА metabarcoding method proved to be effective in detection of invertebrates. Using BOLD database, 0.21% OTUs and 0.11% ESVs were successfully assigned to expected Invertebrate phyla (Arthropoda, Annelida and Nematoda), with two specific species identified: Aporrectodea jassyensis and Sminthurinus elegans. Comparison of the two analytical approaches, denoising and clustering, revealed that these approaches identified the same taxonomic categories. However, given the limited sample size, further studies should compare these two approaches using a more extensive dataset to better estimate their usefulness.