Viral diversity and distribution across above- and belowground food webs: the project concept

Viruses are present in any cellular organism and are numerous in the environment. Though they influence nutrient cycles, interactions and energy flows in food webs, viral diversity distribution and assembly in ecosystems are still understudied [1].

In our project “Viral hotspots and fluxes across above- and belowground food webs (ViralWeb)” we aim to clarify mechanisms of distribution of viruses and their diversity forming across above- and belowground ecosystem compartments and food webs. We focus on plants, fungi, and invertebrate animals as model potential hosts. We also concentrate on RNA viruses, as they dominate eukaryotic viromes [2].

We hypothesize that the diversity and distribution of viruses in ecosystems depend on the diversity of hosts and flows of matter and biomass among ecosystem compartments and food-web nodes. We have three specific hypotheses:

1) the RNA viral diversity of the ecosystem is positively correlated with the diversity of potential viral hosts in this ecosystem;

2) there are local hotspots of viral diversity in systems, such as “cumulative” substrates (e.g., leaf litter) and hosts (top predators);

3) patterns of viral distribution in food webs are correlated with flows of matter and energy among food-web nodes and ecosystem compartments. We expect to detect a positive correlation between the similarity of viral community and connectedness of two nodes in a food web.

We plan to conduct our investigation based on biodiversity manipulation experiments in central Germany (the Jena Experiment and MyDiv). Our sampling design is based on plots with different diversity levels of hosts (plants, fungi, and invertebrates).

Green parts of plants, fungi, litter, soil, and invertebrate consumers by ecological groups [3] will be sampled. The diversity of hosts will be accessed using DNA analysis and morphological identification. The presence of viruses and replication evidences will be detected via high-throughput sequencing and strand-specific RT-PCR [4].

For both study sites food webs will be reconstructed and energy fluxes across above- and belowground compartments will be calculated [5]. Invertebrate hosts’ classification and body size measurement will be facilitated using image analysis approach [6]. Based on obtained average consumer sizes the biomass of food web nodes will be calculated [7]. Energy fluxes will be estimated from metabolic rates of invertebrates accounting for temperature and assimilation efficiency [8].

We expect the results of ViralWeb project to help us better understand the mechanisms of spread of viruses and clarify and predict the roles of viruses in ecosystems.

The project was supported by the Flexpool funding mechanism of the German Centre for Integrative Biodiversity Research (iDiv).

 

Refernces

[1] Williamson KE et al. (2017). Annual review of virology, 4:201-219. https://doi.org/10.1146/annurev-virology-101416-041639

[2] Wolf YI et al. (2018). MBio, 9(6):10-1128. https://doi.org/10.1128/mbio.02329-18

[3] Potapov AM et al. (2022). Biological Reviews 97:1057–1117. doi:https://doi.org/10.1111/brv.12832

[4] Baty JW et al. (2020). Myrmecol. News 30:213-228. https://doi.org/10.25849/myrmecol.news_030:213

[5] Potapov AM et al. (2024). Nature, 1-7. https://doi.org/10.1038/s41586-024-07083-y

[6] Sys S et al. (2022). Methods in Ecology and Evolution 2041–210X.14001. doi:10.1111/2041-210X.14001

[7] Sohlström EH et al. (2018). Ecology and Evolution 8:12737–12749. doi:10.1002/ece3.4702

[8] Potapov AM (2022). Biological Reviews, 97(4):1691-1711. https://doi.org/10.1111/brv.12857