Taxon-specific primary production of phytoplankton by bio-optical modeling under different conditions of nutrient supply

• Applicant: Professor Dr. Christian Wilhelm
• Subject Area: Plant Physiology
• Term: from 2006 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 20498336

The aim of this work is the analysis of the phytoplankton primary production by biooptical modeling and by a new method to estimate the absolute biomass formation by FT-IR spectroscopy under different nutrient conditions. The validity of the bio-optical models and the usability of FT-IR based biomass quantifications will be tested under laboratory conditions using nitrogen and phosphorus limitation to modulate the physiological activity of the cells. IR-spectroscopy will be used not only to measure the incorporation of the carbon and nitrogen into the newly formed biomass but also to follow changes in the macromolecular composition of the cells in response to nutrient stress. After successful application of the new methodologies to laboratorygrown cultures, it will be tested in natural phytoplankton communities analyzing the daily and seasonal changes in primary production in an eutrophic lake.

• DFG Programme: Research Grants