Speaker
Description
Protists are the most abundant predators in soils. Despite their abundance, they have only recently gained more attention in soil ecological studies. Understanding their biotic interactions and how they shape microbial communities is particularly important given the increasing anthropogenic pressure on ecosystems. Long-term fertilization (LTF), one of the most pervasive human impacts on soils, is known to affect fungal and bacterial communities. However, the impact of LTF on protist communities and predator-prey interactions in soils remains poorly understood. In this study, we investigate the impact of LTF on protist diversity and predator-prey dynamics in agricultural soils. We hypothesize that shifts in bacterial communities drive corresponding changes in protist communities. To test this hypothesis, we analysed 60 plots of the Zurich Organic Fertilization Experiment (ZOFE). Using metabarcoding of the small subunit ribosomal RNA genes, we analysed the bacterial, eukaryotic and, using specific primers, the Cercozoan communities. Cercozoa are often the most abundant predatory protists found in metabarcoding studies of soils. Additionally, we measured abiotic soil parameters and performed qPCR of 16S rRNA genes. Our preliminary analysis indicates that LTF does not affect the richness of the investigated microbial groups, but drives changes in their community composition. We detected a significant increase of the parasitic protist taxon Phytomyxea in the compost treatment. Mantel correlation analysis shows that changes in bacterial communities are positively correlated with changes in Cercozoan communities, even after correcting for abiotic effects. We will functionally classify the eukaryotic sequences using the EukFUNC database, and extend it with data on the morphology and locomotion of protists. This trait-based approach will allow us to link shifts in the protist community to potential changes in protist functions, predator-prey dynamics and nutrient cycling.
| Status Group | Doctoral Researcher |
|---|---|
| FOR TALKS: Poster Presentation Option | Yes, I’m willing to present as a poster. |