BMBF - BIOLOG / Diva

The BMBF-funded project 'The relationship between Biodiversity and Ecosystem Functioning in Grassland Ecosystems' is a collaborative research effort of the Friedrich-Schiller- University and the Max-Planck-Institute for Biogeochemistry both in Jena, with the Center for Environmental Research in Halle and the University of Leipzig. Using grasslands in Thuringia as model ecosystems, the project is designed to investigate the relationship between genetic/phenotypic diversity and ecosystem processes such as carbon and nitrogen fluxes. Seven research groups in the areas of plant physiology, biogeochemistry, entomology, mathematical modelling, plant taxonomy, mycorrhizal biology, and landscape modelling will use experimental and theoretical approaches to investigate the importance of biodiversity for the stability and functioning of ecosystems.

General Approach of the Project

On a world wide level anthropogenic influences are responsible for a steady decline of biological diversity. An unknown number of species got still extinct in recent times. Other species were at least reduced in their genetic diversity. This loss of biological diversity inevitably leads two the question about the importance of biodiversity for the functioning of ecosystems. First experiments, addressing this question, showed that a reduction of biodiversity might lead to a decrease in ecosystem functions.
Our joined project analyses the interactions between biodiversity, ecosystem processes and disturbances. The stability of well established grassland ecosystems is one of the main focuses. Applying experimental disturbances, stability of grasslands with low plant diversity compared to grasslands with high plant diversity is studied.

Goals of the Project

  • Quantification of carbon and nitrogen dynamics in grassland ecosystems subject to plant species diversity and composition.
  • Determination of phenotypical and genetical diversity of communities in grassland ecosystems.
  • Reaction of grassland ecosystem towards stimulated drought resulting in an increasing competition for water.
  • Reaction of grassland ecosystems towards a reduction in insect herbivory.
  • Development of an indicator system for ecosystem functions in grassland ecosystems based on taxonomical and structural plant biodiversity.
Biolog

19 sites of differently farmed mountain meadows in the 'Thüringer Schiefergebirge' (Thuringia, Germany) were selected for this project.
Explicit goal of the MYKO project performed by the Department of Terrestrial Ecology of the University of Leipzig was to study the diversity of arbuscular mycorrhizal fungi (AMF) at intensively and extensively farmed meadows respectively characterized by a lower and a higher plant biodiversity.
A nearly identical number of AMF species was found at both types of field sites. However, the species composition of their arbuscular mycorrhiza largely differed.

Differently farmed mountain meadows in the Thüringer Schiefergebirge (Thuringia, Germany). While the site on the left exhibited 27 plant species, the site on the right had 43. Nevertheless biomass production on the less diverse site was nearly twice as high than the one of the more diverse meadow.

Focus of our subproject STOFF-MYKO is quantification of the four nodal points input, transformation, accumulation, and loss of carbon in and from soils and understanding biological mechanisms behind in relation to plant diversity and land use intensity in different grassland ecosystems. Concerning carbon input into soils, we will especially analyse mycorrhizal symbioses between soil fungi and plant roots as they directly channel important amounts of photo-assimilates into soils. These readily available matter and energy resources promote microbial activity in the rhizosphere and the bulk soil and have a high impact on the balance between litter mineralization and humification. These two processes cause a dynamic equilibrium between accumulation of more or less stable /stabilised fractions of organic carbon and their mineralization with corresponding carbon dioxide output from soils. The different nodes (mycorrhizza, microbial biomass, carbon accumulation and carbon dioxide output) are closely related to plant diversity but up to now mechanisms and interactions behind remain to disentangle.

For further questions, please contact:
elke.schulz@ufz.de, marc.breulmann@ufz.de, stefan.hempel@ufz.de, francois.buscot@ufz.de