Exploratorien zur funktionellen Biodiversitätsforschung

Scientific investigators:

Prof. Dr. Wolfgang  Wilcke

Martin Schwarz
(University Bern)

Daniela Pallischeck

Dr. Jan Siemens

Lisa Krüger
(University Bonn)

Prof. Dr. Beate Michalzik

Sebastian Bischoff
(University Jena)

Sustainable forest and grassland management is characterized by closed element cycles.

We test two hypotheses:

(1) Nutrient inputs and their (re)cycling at the ecosystem level are related to land-use intensity.

(2) Nutrient and carbon leaching decreases along a gradient of increasing naturalness of forests and grasslands associated with an increasing plant diversity from monocultures to near-native plant communities.

Introduction and Aims

Element and nutrient budgets of ecosystems are divided into input (atmospheric deposition, manuring), internal turnover and transfer (mineralization, weathering, uptake into biomass, accumulation, translocation) and output (leaching, gaseous emission, harvest). Transport of elements and nutrients from/to external compartments as well as inside of natural ecosystems mainly occurs dissolved in water. For both, distribution and retention of elements and nutrients, processes in soil and canopy are important and therefore attract special interest. Many of these processes are mediated biologically and it is assumed that synergies evolve from higher biodiversity levels which enhance element recycling and decrease nutrient losses. Therefore, we will determine water fluxes and nutrient turnover of three differently biodiverse management systems in forests and grasslands at each of the three exploratories (altogether 54 experimental plots).

Methods

We will install rainfall, throughfall and stemflow samplers to determine atmospheric inputs and turnover processes in the canopy. Rates of weathering and element cycling in soils will be assessed with zero-tension lysimeters and suction cups,  elemental turnover and element sources will be studied by stable isotope techniques (?13C, ?15N, ?18O).

The results of this research are prerequisites to disentangle effects of land-use and biodiversity and to evaluate effects on element cycling.