Hintergrundbild mit Feldern
 

sp3 Nutrient Cycling



Nitrogen (N) and Phosphorus (P) are the nutrients limiting productivity in most terrestrial ecosystems. Their availability in soils is therefore a major driver of ecosystem functioning. Soil nutrient availability has been generally shown to be in turn influenced by above-ground biodiversity in previous phases of the Jena Experiment, but it is still uncertain how these relationships may change over the long term.
Soil nutrient dynamics usually have a seasonal pattern, which may be changed by plant biodiversity, for example through changes in seasonal plant uptake. These changes in the seasonality of nutrient availability can best be studied using long-term data sets of high temporal resolution. Such data sets are now available in the Jena Experiment, where N and P in ecosystem solutions have been determined regularly from 2003 to the present day. Long-term data sets are also necessary to separate seasonal variation from long-term trends in nutrient concentrations and fluxes. Identifying long-term trends is especially important as the grassland in the Jena Experiment has been established on agriculturally used (and therefore fertilised) soils which are now in transition towards natural grassland states. This implies that nutrient cycles are drifting to a new steady-state. The magnitude of the change in nutrient concentrations and fluxes in this transition towards the new state might again be driven by the composition of the plant community, particularly by species richness as has already been reported for soil carbon concentrations in the closely cooperating SP4.
Further, these long-term data sets allow us to find potential differential responses in soil N and P of more or less diverse ecosystems to climate patterns and events (such as drought, heavy rain, heat, etc.). Findings from these data will help us assess whether the nutrient cycles of diverse ecosystems are more resilient to extreme events than those of less diverse ecosystems, which may have important implications for the function of the whole ecosystem.

Principal Investigator:


Prof. Dr. Yvonne Oelmann
University of Tübingen
Email / Web
Tel.: +49.7071.29.72398

Prof. Dr. Wolfgang Wilcke
KIT
Email / Web
Tel.: +49.7216.08.41621

Postdoc:

Dr. Eva Koller-France
KIT co University of Tübingen
Email / Web