Bridging Morphological and Molecular Approaches in Soil Fauna Diversity Assessments at European level

Bridging Morphological and Molecular Approaches in Soil Fauna Diversity Assessments at European level

Köninger, J., Potapov, A., Ross, G., Tsiafouli, M., Seeber, J., Beule, L., Hedlund, K., Frouz, J., Blasbichler, H., Orgiazzi, A., Briones, M.J. I.

 

Recent advances in molecular approaches to identify multiple species from a mixed sample, have expanded our availability to perform large-scale analyses of soil biodiversity. However, methodological challenges remain, particularly when trying to reconcile molecular results with those derived from traditional morphological-based identifications. For example, previous studies have recorded unexpected higher diversities in the more intensively managed agricultural lands compared to woodlands and grasslands, which contrasts with earlier morphological analyses and highlights the need for methodological cross-validation.

Here, we address these challenges by comparing soil fauna diversity data derived from several international large-scale surveys. For example, the SOB4ES EU-funded project encompassing diverse European land uses and the Biodiversa+ project (accronym) focussing on woodlands both collected morphological as well as molecular data. Additionally, we compared the DNA metabarcoding results from LUCAS (2018 survey) with morphological data derived from the EcoFINDERS and SOILSERVICE projects. Our analyses reveal the existence of a significant variability in diversity metrics between ecosystem types, emphasizing the importance of contextualizing molecular results through complementary morphological analyses. Furthermore, our results also highlight the need to refine molecular methods (e.g. primer choice and removal of relict DNA) to ensure the robustness of the data interpretations for their potential use in policy-making and biodiversity indicator development.