Current projects
Evolution of competitive ability in phytoplankton (ChlamEE)
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Competition is an important ecological force structuring phytoplankton communities. As photo-autotrophs, most phytoplankton require some essential resources including light, nitrogen, and phosphorus. How competitive abilities for these resources evolve is unknown. We aim to understand how competitive abilities of phytoplankton evolve. We use chemostat experiments and lab microcosms experiments as well as genomics, proteomics and single-cell mass spectrometry to try to answer some of the following questions. Do they respond to selection under nutrient limitation? Are there constraints or trade-offs in species' ability to respond to selection? What cellular traits correspond with resource-use efficiency or fast population level growth? Can we identify genomic elements or molecular phenotypes associated with strong competitive abilities for different inorganic resources.
This project is supported by funding from the Swiss National Science Foundation and Eawag. |
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Ecological and evolutionary drivers of ecosystem stability
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In an outdoor pond experiment, we are trying to understand the relative contributions of ecological species turnover and evolutionary adaptation in phytoplankton communities to changes in ecosystem functioning in response to eutrophication and the presence or absence of two keystone species. It has been shown that phytoplankton can evolve rapidly, and that evolutionary adaptation can fundamentally alter their ecological interactions. My group is quantifying the relative contributions of ecological and evolutionary change in the phytoplankton community to to total changes in algal biomass and stability.
This collaborative project is supported by Eawag. |
What is the structure of intraspecific thermal performance?
Many aspects of the environment shape an organism's growth. Temperature is among the most important determinants of organismal metabolic and population-level growth rates. This can shape rates of species interactions and resultant community- and ecosystem-level processes. In a project led by Joey Bernhardt (NEREUS Postdoctoral Fellow), we are testing how genetic variation in thermal performance is structured within a species. Do we see generalist-specialist trade-offs? How is genetic variation in thermal performance related to competitive ability? Are these traits correlated or is variation in these traits unstructured, suggesting that thermal performance is free to evolve in response to selection?
Searching for change in aquatic systems from space
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We are using satellite images to understand changes in phytoplankton communities (abundance and composition) in lakes in Switzerland and around the world. What is the influence of environmental change and perturbation? Will we be able to detect human influence on lakes?
This project is a collaboration with Eawag postdoc, Luis Gilarranz, Daniel Odermatt and Vasilis Dakos. |
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Understanding global biodiversity change
Land-use change is one of the major causes of biodiversity change. Using satellite hyper-spectral imagery one can study the transitions between land cover classes. We are comparing species occurrence records from biodiversity databases with processed remote sensing imagery to determine the extent to which biodiversity change is predictable based on land-use conversion. We aim to provide an answer to the hotly debated question: "Is local biodiversity increasing or decreasing?" but on a global scale.
This project is a collaboration with Eawag postdoc, Luis Gilarranz and Tobias Frey.
This project is a collaboration with Eawag postdoc, Luis Gilarranz and Tobias Frey.