Current Research
Soil fauna interact in complex belowground food webs. My aim is to dissect multitrophic interactions of soil fauna and reveal the functional role of these interactions for carbon fluxes, nutrient mobilisation and plant performance. In particular, I am interested in how microfauna affect the functioning of plant symbionts for nutrient acquisition and carbon partitioning.
In order to obtain a mechanistic understanding of these multitrophic interactions, I have chosen to work with model species belonging to different functional affiliations, e.g. plant growth promoting rhizosphere bacteria, protozoa, mycorrhizal fungi, endophytes and collembola. My model plant species comprise typical grassland species e.g. Plantago lanceolata and Holcus lanatus and crop plants, e.g. Hordeum vulgare and Zea mays.
As a soil ecologist with background in zoology, plant physiology and microbiology, I am familiar with techniques from multiple disciplines, e.g. working with stable isotopes to quantify nutrient and carbon fluxes, phospholipid fatty acids to characterize microbial communities, measurement of soil respiration to quantify microbial biomass and growth limiting nutrients and cultivation of soil microbes, fungi and insects.
Scientific Career
08/2008 until present: Postdoc at the University of Cologne, Cologne Biocenter, Department of Terrestrial Ecology, Germany; Professor Michael Bonkowski
12/2007 – 04/2008: Postdoc at the Darmstadt University of Technology, Germany. Data analysis and coordination function of the RTN Marie Curie Network “BIORHIZ” (http://www.zi.ku.dk/biorhiz/); Professor Stefan Scheu
12/2005 – 12/2007: Binational PhD of the Institut Nationale Polytechnique de Lorraine, France (Dr. Christophe Robin) and Darmstadt University of Technology, Germany (Professor Stefan Scheu) in the framework of the RTN Marie Curie Network “BIORHIZ” (http://www.zi.ku.dk/biorhiz/). Title of PhD ‘Protozoa (Acanthamoeba castellanii) and arbuscular mycorrhiza (Glomus intraradices) in the rhizosphere mediate the acquisition and partitioning of carbon and nitrogen for the plant.”
05/2004 – 11/2004: Staff member of the Hessian forestry department (HESSEN FORST) and Federal Biological Research Centre for Agriculture and Forestry (BBA) Darmstadt; “Abatement of the forest cockchafer (Melolontha hippocastani) with products of the entomopathogenic fungus Beauveria brongniartii - Extention and continuation of previous experiments.”; Dr. Gisbert Zimmermann
04/2003 – 12/2004: Diploma thesis at the Federal Biological Research Centre for Agriculture and Forestry (BBA) Darmstadt, Technical University of Darmstadt and Free University of Berlin, Germany; title ‘Experiments to the appliance of the “Catch and Infect”- Technique with the entomopathogenic fungus Beauveria brongniartii for the biological control of the forest cockchafer (Melolontha hippocastani)’. Dr. Gisbert Zimmermann, Dr. Joachim Ruther & Prof. Stefan Scheu
04/2002 – 08/2002: University of Osnabrück, Germany. Practical training in Dideoxy- and Microsatellite-DNA techniques: Population biology studies of Andrena vaga PANZER (Hymenoptera, Andrenidae) and Colletes cunicularius L. (Hymenoptera, Colletidae). Professor Anselm Kratochwil & Dr. Axel Hochkirch
09/2000 – 07/2001: Université de Bordeaux I, France . Maîtrise “Biologie des populations et des écosystèmes, Option: Adaptation des végétaux à leur environnement” participation of the European student exchange program « ERASMUS
10/ 1997 – 04/ 2004:Study of biology at the Technical University Darmstadt, Germany
Majors: Ecology, Zoology and Animal physiology
Selected Publications
Ladygina, N., Henry, F., Kant, M.R., Koller, R., Reidinger, S., Rodriguez, A., Saj, S., Sonnemann, I., Witt, C., Wurst, S., 2010. Additive and interactive effects of functionally dissimilar soil organisms on a grassland plant community. Soil Biology & Biochemistry 42, 2266-2275.
Scherber, C., Eisenhauer, N., Weisser, W.W., Schmid, B., Voigt, W., Fischer, M., Schulze, E.-D., Roscher, C., Weigelt, A., Allan, E., Beszler, H., Bonkowski, M., Buchmann, N., Buscot, F., Clement, L.W., Ebeling, A., Engels, C., Halle, S., Kertscher, I., Klein, A.-M., Koller, R., Konig, S., Kowalski, E., Kummer, V., Kuu, A., Lange, M., Lauterbach, D., Middelhoff, C., Migunova, V.D., Milcu, A., Muller, R., Partsch, S., Petermann, J.S., Renker, C., Rottstock, T., Sabais, A., Scheu, S., Schumacher, J., Temperton, V.M., Tscharntke, T., 2010. Bottom-up effects of plant diversity on multitrophic interactions in a biodiversity experiment. Nature 468, 553-556.
Eisenhauer, N., Cesarz, S., Koller, R., Worm, K., Reich, P.B., 2012. Global change belowground: impacts of elevated CO2, nitrogen, and summer drought on soil food webs and biodiversity. Global Change Biology 18, 435-447.
Scharroba, A., Dibbern, D., Hünninghaus, M., Kramer, S., Moll, J., Butenschoen, O., Bonkowski, M., Buscot, F., Kandeler, E., Koller, R., Krüger, D., Lueders, T., Scheu, S., Ruess, L., 2012. Effects of resource availability and quality on the structure of the micro-food web of an arable soil across depth. Soil Biology & Biochemistry 50, 1-11.
Koller, R., Robin, C., Ruess, L., Bonkowski, M., Scheu, P.D.S., 2013. Litter quality as driving factor for plant nutrition via grazing of protozoa on soil microorganisms. FEMS Microbiology Ecology, DOI: 10.1111/1574-6941.12113
Koller, R., Rodriguez, A., Robin, C., Scheu, S., Bonkowski, M., 2013. Protozoa enhance foraging efficiency of arbuscular mycorrhizal fungi for mineral nitrogen from organic matter in soil to the benefit of host plants. New Phytologist, DOI: 10.1111/nph.12249
Koller, R., Scheu, S., Bonkowski, M., Robin, C., 2013. Protozoa stimulate N uptake and growth of arbuscular mycorrhizal plants. Soil Biology & Biochemistry (accepted)
Professional Memberships:
Gesellschaft für Ökologie
Deutsche Bodenkundliche Gesellschaft
