We study plankton communities and food webs in field studies, laboratory experiments, and modelling studies to contribute to ecological theory building and to the solution of urgent ecological problems such as the consequences of biodiversity loss.
The core areas of my research are:
Due to their high diversity, plankton communities can adapt their functional properties to fluctuating environmental conditions. This influences their biomass dynamics and the maintenance of their functional biodiversity. In addition, interesting feedback loops arise between the dynamics in the biomasses and the functional properties of the individual populations.
Plankton ecology contributes significantly to ecological theory building, because plankton communities are relatively easily manipulated in the laboratory, have short generation times and have a relatively clear spectrum of functional properties. This makes plankton communities an ideal experimental model system that can be used to study both general and specific ecological research questions.
We combine different process-oriented mathematical modelling approaches with the analysis of field data from Lake Constance and chemostat experiments. The latter are mainly carried out by our cooperation partners within the DFG (German Science Foundation) Priority Programme DynaTrait(SPP 1704), which I lead. If we consider variability in functional properties within populations and communities not as noise but as their inherent property, we can better understand the biodiversity and dynamics observed in natural and experimental systems.
I also have a broad interest in quantitative food webs and other processes that affect the dynamics of species-rich communities, relying on extensive field measurements and experiments.
In the research area Interplay between trait diversity and ecological dynamics using plankton communities as model systems, we currently work on five sub-projects within the DFG Priority Programme DynaTrait:
Relationships between behaviour, eco-physiology and spatio-temporal distribution of C. acidophila in an acidic lake (Mark Clegg, Antje Gerloff-Elias, Bertram Boehrer/UFZ Magdeburg, Ursula Gaedke, Elly Spijkerman)
Trophic structure, energy flows, dynamics and stability in the microbial food web of an extremely acidic lake (pH 2.6) (Ursula Gaedke, Norbert Kamjunke)
Synchronisation of age-structured phytoplankton populations (Thomas M. Massie, Bernd Blasius (Institute of Physics, University of Potsdam), Ursula Gaedke, Guntram Weithoff, Gregor F. Fussmann (Department of Biology, McGill University, Montreal))
Dynamic behaviour of phytoplankton populations far away from equilibrium (Thomas M. Massie, Bernd Blasius (Institute of Physics, University of Potsdam), Ursula Gaedke, Guntram Weithoff, Gregor F. Fussmann (Department of Biology, McGill University, Montreal))
Foodweb-interactions and long-term development in the plankton community of Lake Constance (Katrin Tirok,)
Modelling climate-induced changes in the saisonal plankton development (Katrin Tirok, Ursula Gaedke)
Mixotrophic flagellates during re-oligotrophication (Norbert Kamjunke, Tanja Henrichs, Ursula Gaedke)
The effects of diversity on single populations: niche differentiation of phytoplankton (1) and individual fitness of terrestrial plants (2) (Andrea Schmidtke, Guntram Weithoff, Ursula Gaedke, Markus Fischer)
Influence of productivity and diversity on invasibility of phytoplankton communities (Erik Sperfeld, Ursula Gaedke, Guntram Weithoff)
Differential edibility by copepods and cladocerans determines the saisonal patterns in variability of cilaites and phytoplankton in Lake Constance (Veronika Huber, Ursula Gaedke)
Saisonal change between coherent and compensatory dynamics in phytoplankton (David Vasseur (McGill University, Montreal, Canada), Ursula Gaedke und Kevin McCann (University of Guelph, Guelph, Canada))
Variability at population level and the degree of synchronization of plankton populations influences the variability at community level stronger than diversity (Ursula Gaedke)
Patterns in the temporal variability of plankton in Lake Constance: spectral analysis to investigate frequency-dependent compensatory dynamics and portfolio-effect (David Vasseur (Calgary University, Kanada), Ursula Gaedke)
Patterns in variability of plankton biomass and production (Ursula Gaedke, David Vasseur (University of Calgary, Canada), Guntram Weithoff)
Selected key publications:
Ruiter, P. C. de, and U. Gaedke (2017) Emergent facilitation promotes biological diversity in pelagic food webs. Food Webs (in press).
Coutinho, R., T. Klauschies, and U. Gaedke (2016) Bimodal trait distributions with large variances question the reliability of trait-based aggregate models. Theoretical Ecology, 6: 4141-4159 DOI 10.1007/s12080-016-0297-9.
Klauschies, T., D. A. Vasseur, and U. Gaedke (2016) Trait adaptation promotes species coexistence in diverse predator and prey communities. Ecology and Evolution, 9: 389-408 DOI: 10.1002/ece3.2172.
Boit, A., N.D. Martinez, R. J. Williams, U. Gaedke (2012) Mechanistic theory and modeling of complex food web dynamics in Lake Constance. Ecol. Lett., 15:594-602
Massie, T. M., B. Blasius, G. Weithoff, U. Gaedke, and G. Fussmann (2010) Cycles, phase synchronization and entrainment in single-species phytoplankton populations. Proc. Nat. Acad. Sci. (PNAS) 107: 4236-4241
Tittel, J., V. Bissinger, B. Zippel, U. Gaedke, E. M. Bell, A. Lorke & N. Kamjunke (2003) Mixotrophs combine resource use to out-compete specialists: implications for aquatic food webs. Proc. Nat. Acad. Sci. (PNAS) 100: 12776-12781
Gaedke, U., S. Hochstädter, and D. Straile (2002) Interplay between energy limitation and nutritional deficiency: Empirical data and food web models. Ecological Monographs 72: 251-270
Hairston, N. G., Jr, W. Lampert, C. E. Cáceres, C. L. Holtmeier, L. J. Weider, U. Gaedke, J. M. Fischer, J. A. Fox & D. M. Post (1999) Lake ecosystems: Rapid evolution revealed by dormant eggs. Nature 401: 446
A full list of publications of all members of my working group and the members of the Priority Programme DynaTrait funded by the German Science Foundation (DFG) can be found here:
I'm happy to send single PDFs on email request.