Stella Angela Berger

Stilling: forsker

Telefon: 55 58 44 00

E-post: Stella.Berger@bio.uib.no

Besøksadresse: Thormøhlensgt. 53 A/B

I’m interested in population dynamics and seasonal succession of aquatic plankton organisms. Growth and loss rates of phytoplankton, micro- and mesozooplankton are strongly dependent on environmental factors such as nutrients, stratification depth, light, temperature, CO2, and stoichiometry - factors that vary within and between years and might even change with global warming. Disentangling direct and indirect effects on different components of the planktonic microbial food web and their interaction is a major challenge in aquatic research and needs experimental approaches within the lab and the field e.g. using mesocosms.

In August 2009 I started as Researcher in Aquatic Mesocosm Studies at University of Bergen (UiB, Department of Biology) at the EU FP7 project MESOAQUA – a network of leading MESOcosm facilities to advance the studies of future AQUAtic ecosystems from the Arctic to the Mediterranean coordinated by Jens C. Nejstgaard in cooperation with leading mesocosm facilities in Europe (including Ny Ålesund, Umeå, Kiel, Montpellier and Heraklion). I think this position at UiB in the work group of “Marine Micobiology” is an excellent opportunity to work in a leading scientific environment with ample chances to promote, design and conduct frontline mesocosm studies and assist applicants at the Bergen mesocosm facility in Espegrend. Another important part of this job is to build an international network between leading aquatic scientists and new users to the filed, especially supported by the development of the MESOAQUA webpage.

My career in aquatic biology has been focused on relationships between biotic variables and environmental drivers in freshwater conducting lab, mesocosm and lake studies from 1997 until my PhD thesis in 2005 at the Ludwig-Maximilians-University of Munich, Germany in the group of Sebastian Diehl. Since 2005 I have worked as a Post-Doc in the German Research Foundation priority program AQUASHIFT – The impact of climate variability on aquatic ecosystems: Match and mismatch resulting from shifts in seasonality and distribution coordinated by Ulrich Sommer, IFM-GEOMAR, Kiel, Germany. Within this project I led large-scale and long-lasting freshwater mesocosm experiments both using water enclosures in lakes and in land-based systems investigating the influence of environmental factors (stratification depth, nutrients, temperature, organism composition) on different plankton organisms in the pelagic zone. The end of 2010 will terminate the AQUASHIFT project and I am now working up the last of the data, while various results have been presented on several national and international meetings. I currently prepare the material for scientific publications.

marine and freshwater plankton ecology, mesocosm experiments

Publikasjoner i Cristin

Hillebrand H., M.E. S. Bracken, S.A. Berger, B.K. Eriksson, L. Gamfeldt, D.S. Gruner, B. Matthiessen, S. Moorthi, U. Sommer. Declining richness and shifting dominance with global warming across ecosystems. (in revision)

Berger S.A., I. Peeken, S. Diehl. Phytoplankton taxonomic composition in relation to environmental variables: A comparative lake study using pigment analysis. (in revision)

Schalau K., S.A. Berger, K. Rinke, D. Straile and F. Peeters. Modelling natural Daphnia populations with a physiological structured model: application to conditions in mesocosm experiments. (in preparation)

Berger S.A., S. Diehl, H. Stibor, G. Trommer, and M. Ruhenstroth. 2010. Water temperature and stratification depth independently shift cardinal events during plankton spring succession. Global Change Biology (doi: 10.1111/j.1365-2486.2009.02134.x)
Supporting Information here

Berger S.A., S. Diehl, H. Stibor, G. Trommer, M. Ruhenstroth, A. Wild, A. Weigert, C.G. Jäger, M. Striebel. 2007. Water temperature and mixing depth affect timing and magnitude of events during spring succession of the plankton. Oecologia 150:643-654. (DOI 10.1007/s00442-006-0550-9)

Berger S.A., S. Diehl, T.J. Kunz, D. Albrecht, A.M. Oucible and S. Ritzer. 2006. Light supply, plankton biomass, and seston stoichiometry in a gradient of lake mixing depths. Limnology and Oceanography 51: (4) 1898-1905.

Diehl, S., S.A. Berger, and R. Wöhrl. 2005. Flexible nutrient stoichiometry mediates environmental influences on phytoplankton and its abiotic resources. Ecology 86: 2931-2945.

Ptacnik R., S. Diehl, S.A. Berger. 2003. Performance of sinking and nonsinking phytoplankton taxa in a gradient of mixing depths. Limnology and Oceanography 48: 1903-1912

Diehl S., S.A. Berger, R. Ptacnik, A. Wild. 2002. Phytoplankton, light and nutrients in a gradient of mixing depths: field experiments. Ecology 83: 399-411.

Theses

Berger S.A. 2005. Environmental variables and plankton communities in the pelagic of lakes: enclosure experiment and comparative lake survey. PhD thesis. Ludwig-Maximilians-Universität, München, Germany.

Berger S.A. 1998. Influence of epilimnion depth on experimental phytoplankton communities. Diploma thesis (in German). Ludwig-Maximilians-Universität München, Germany.

 

 

MESOAQUA – a network of leading MESOcosm facilities to advance the studies of future AQUAtic ecosystems from the Arctic to the Mediterranean (EU FP7 project 2009-2012, coordinated by Jens Nejstgaard, University of Bergen, Norway)

AQUASHIFT – The impact of climate variability on aquatic ecosystems: Match and mismatch resulting from shifts in seasonality and distribution (DFG priority program 2005-2010, coordinated by Ulrich Sommer, IFM-GEOMAR, Kiel, Germany)