Currently I am working as a Postdoc at the department in the research group of Prof. Dr. Kees van Gestel on the effects of microplastics on soil fauna communities. Instead of following a more traditional ecotoxicological approach of applying a concentration range to a single species, we adopted a more ecology-based approach. We do this by exposing intact soil cores, with the native communities of soil fauna present, to microplastics which are applied through addition of sewage sludge. This way, the obtained results can be more easily linked to real-world situations where sewage sludge with microplastics is applied to natural fields.
Besides this Postdoc position, I am valorizing an experimental setup which I developed during my PhD by bringing the setup to market. With this setup, named CLIMECS (CLImatic Manipulation of ECosystem Samples; www.climecs.com), researchers can easily create different climatic scenarios by programming temperature profiles and precipitation patterns simultaneously. This setup therefore allows for testing of multiple stressor effects, and includes the option to create condition which mimic extreme climatic events. We have 40 individually programmable units at the VU, in which intact soil cores from the field can be exposed to maintain natural realism in the experiments. CLIMECS can now be bought by other interested parties, such as other universities, research institutes and R&D departments of (agritech) companies.
Before starting the positions above, I finished my PhD at this department on the effects of extreme climatic events on soil fauna communities with my thesis: “Feeling the heat: Effects of extreme climatic events on species performance, interactions and community composition”. To investigate this, I applied a variety of techniques ranging from field-monitoring and field- & laboratory-manipulations to modelling experiments.
Franken O., Huizinga M., Ellers J., Berg M.P. (2018). Heated communities: Large inter- and intraspecific variation in heat tolerance across trophic levels of a soil arthropod community. Oecologia, 186: 311-322. doi: 10.1007/s00442-017-4032-z.
• Awarded the Hanski Prize from Oecologia.
Franken O., Ferreira S.S.D, Jesse W.A.M., Berg M.P., Ellers J. (2018). A common yardstick to measure the effects of different extreme climatic events on soil arthropod community composition using time-series data. Frontiers in Ecology and Evolution, 6: 195. doi: 10.3389/fevo.2018.00195.
Franken O., Ooms A. (Eds) (2016) Themanummer bodemfauna. Entomologische Berichten, 76(2).
[Guest editor on a special issue about soil fauna]
González J.B, Petipas R.H, Franken O., Kiers E.T., Veblen K.E., Brody A.K. (2018). Herbivore removal reduces influence of arbuscular mycorrhizal fungi on plant growth and tolerance in an East African savanna. Oecologia, 187: 123-133. doi: 10.1007/s00442-018-4124-4.
Kiers E.T., Duhamel M., Beesetty Y., Mensah J.A., Franken O., Verbruggen E., Fellbaum C.R., Kowalchuk G.A., Hart M.M., Bago A., Palmer T.M., West S.A., Vandenkoornhuyse Ph., Jansa J., Bücking H. (2011). Reciprocal rewards stabilize cooperation in the mycorrhizal symbiosis. Science, 333: 880-882. doi: 10.1126/science.1208473.