Long-term ecological research

Susann Wilhelm, Carola Wagner, Veronika Huber, Rita Adrian

Long-term records of various limnological variables over several decades allow us to analyse and predict short-term versus long-term effects such as variability in climatic conditions on lake ecosystems. We aim to identify possible phase lags in trophic interactions (mismatches) induced by variability in meteorology and climate. By considering responses within planktonic food webs, we anticipate to separate direct responses (temperature driven responses), from indirect responses (e.g. through the presence or absence of ice, changes in thermal stratification pattern, and species interaction driven responses). Our prime site is the Müggelsee, a shallow, polymictic, eutrophic lake, located at the south-eastern boundaries of Berlin, Germany. Our automatic monitoring station provides high resolution records of meteorological and physical parameters (at 5 minutes intervals) of the Müggelsee and may be visited at:
http://www.igb-berlin.de/abt2/ms/ms_dat.shtml

Cooperations:

CLIME
AQUASHIFT
Thorten Blenckner, Erken Laboratory, Department of Limnology, Uppsala University, Sweden
Dieter Gerten, Dept. Global Change and Natural Systems Potsdam-Institute for Climate Impact Research, Potsdam, Germany
David M. Livingstone, EAWAG, Dübendorf, Switzerland

Trophic interactions- The food quality of protozoans

Iola Gonçalves Boëchat, Rita Adrian

Planktonic prey vary in their potential to support growth and reproduction of their zooplankton predators, as they differ in such aspects as cell morphology, mobility, and the ability to synthesise and metabolise essential compounds. Among the factors that determine the food quality of planktonic organisms the cellular amount of highly unsaturated fatty acids, essential sterols, amino acids, and the elemental composition (C, N, P), have received considerable attention. We are interested in the questions of (1) how the chemical profile (fatty acids, essential amino acids, sterols, carbon, nitrogen, phosphorus) of protozoans, which differ in their trophic mode (algivorous versus bacterivorous protozoan species), reflect that of their prey and (2) whether the chemical composition of algivorous versus bacterivorous protozoans determines the food quality for zooplankton predators.