VALIDATING ENVIRONMENTAL DNA (EDNA) APPROACHES TO ASSESSING SOIL MICROEUKARYOTIC BIODIVERSITY**

Authors

Alejandro Coronado*, Kennesaw State University, Kennesaw, GA 30144Follow
Juliana Hayhome*, Kennesaw State University, Kennesaw, GA 30144Follow
Jasmine On*, Kennesaw State University, Kennesaw, GA 30144Follow
Rosalyn Standford*, Kennesaw State University, Kennesaw, GA 30144Follow
Kaylee Thomas*, Kennesaw State University, Kennesaw, GA 30144Follow
Tiago Pereira, Kennesaw State University, Kennesaw, GA 30144Follow

Abstract

Microeukaryotic organisms, particularly nematodes, are highly abundant and diverse in soil ecosystems, where they fulfill critical ecological roles. Their spatial distribution is influenced by various environmental factors, including soil texture, nutrient levels, and vegetation. Despite their ubiquity, there is limited understanding of microeukaryotic biodiversity in natural soil habitats. Environmental DNA (eDNA) metabarcoding is a promising method to enhance our knowledge of soil microeukaryotic communities. Compared to traditional morphology-based taxonomy, eDNA metabarcoding can be more cost-effective, faster, and may provide greater resolution, including the detection of rare species. In this study, we used eDNA metabarcoding (18S rRNA) to characterize microeukaryotic and nematode communities across various soil habitats, distinguished by vegetation and soil density in the Shipley-Skinner Reserve, Southern CA, USA. We also compared diversity patterns using two sampling methods: raw soil and Baermann funnels, the latter is specifically designed to recover higher nematode abundance and diversity. Our analyses reveal that soil microeukaryotic diversity patterns are method-dependent. The raw soil dataset exhibits higher alpha-diversity across all metrics , which is expected from a larger data set. When solely focusing on nematodes, the Baermann funnel dataset displayed the highest diversity. Despite differences in alpha diversity and community composition, significant differences between soil types and among soil habitats were detected by beta-diversity analysis (nMDS and PERMANOVA) in both datasets, thus supporting their effects in structuring soil communities. As expected, nematodes were more abundant in the Baermann funnel samples, while fungi dominated the raw soil DNA sequences. Furthermore, our analysis revealed that nematode community composition varied considerably between sampling methods, with cephalobids and dorylaimids more abundant in the Baermann funnel and soil datasets, respectively. These findings underscore the importance of understanding the nuances of different eDNA metabarcoding methods to accurately assess patterns of soil biodiversity.

Acknowledgements

KSU Dept. of Ecology, Evolution, and Organismal Biology

Recommended Citation

Coronado*, Alejandro; Hayhome*, Juliana; On*, Jasmine; Standford*, Rosalyn; Thomas*, Kaylee; and Pereira, Tiago (2026) "VALIDATING ENVIRONMENTAL DNA (EDNA) APPROACHES TO ASSESSING SOIL MICROEUKARYOTIC BIODIVERSITY**," Georgia Journal of Science, Vol. 84, No. 1, Article 45.
Available at: https://digitalcommons.gaacademy.org/gjs/vol84/iss1/45