The Jena Grassland Experiment (Jena Experiment) aims at understanding the importance of biodiversity for processes on an ecosystem level. The main experiment has been running since 2002. As part of the experiment, the composition of plant communities of one to 60 species and one to four functional groups is manipulated. Matter fluxes are measured and interactions between organisms are investigated and compared. A second experiment, the Trait Based Experiment, deals with so-called biodiversity effects that are determined by the characteristics (traits) of the species involved.

The sub-project led by the research group in Oldenburg analyses the relationship between plant biodiversity and ecological stoichiometry of multiple ecosystem processes and trophic interactions. We investigate the composition of elements within the soil, plants and consumers along a gradient in species number and composition. We test, whether (i) plant diversity enhances the incorporation of multiple elements in high concentration in plant material and whether (ii) a variable stoichiometry of plants affects the feeding of herbivore insects and the function of other animal groups such as pollinators or decomposers.