The productivity - stoichiometry - diversity concept in grasslands: disentangling intra- and interspecific variance in resource use

• Applicant: Professor Dr. Helmut Hillebrand
• Subject Area: Ecology and Biodiversity of Plants and Ecosystems
• Term: from 2010 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 163658437

This subproject will analyze the relationship between plant diversity and the ecological stoichiometry of multiple ecosystem processes and trophic interactions. Ecological stoichiometry is a theoretical framework allowing the prediction of competitive and trophic interactions based on the balance between resource supply and resource needs of interacting species. The balance of multiple elements (C, N, P, and K) in the soil, plants and their consumers will be investigated across the gradient of plant diversity and species composition in the JenaExperiment. In the main experiment, we will track the stoichiometry of plant and insect chemical composition along the experimental gradients of species richness and functional diversity. We will test (i) whether plant diversity enhances the uptake and thus content of multiple elements on the community level, and (ii) whether differential stoichiometry will change consumption patterns by insect herbivores. In the trait-based experiment, we will address stoichiometry of elements on a species-specific basis, asking whether plant diversity alters the resource content and ratios of plant species depending on their traits and the traits of their co-occurring species. We will test whether (iii) higher coverage of the resource use traits increases resource use efficiency for multiple elements, and (iv) whether plant stoichiometry responds plastically to the competitive environment. Thereby we will address the question how species diversity affects ecosystem multifunctionality, i.e., whether more species are required to maintain the processing of different elements. Moreover, we will analyze whether functional turnover occurs, i.e., whether different species carry function in resource use efficiency and trophic transfer across time.

• DFG Programme: Research Units
• Subproject of: FOR 1451: Exploring Mechanisms Underlying the Relationship between Biodiversity and Ecosystem Functioning
• International Connection: Austria
• Participating Person: Professor Dr. Robert Ptacnik