1. Louis Bolk Institute, Bunnik, The Netherlands
2. Department of Experimental Plant Ecology, Institute for Water and Wetland Research, Radboud University Nijmegen, Nijmegen, The Netherlands
3. Soil Biology Group, Wageningen University, Wageningen, The Netherlands
4. Wageningen Environmental Research, Wageningen, The Netherlands
5. Faculty of Science, Earth and Climate, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands