EVOLutionary adaptation of Antarctic PHytoplankton in a fluctuating Environment (EVOLPHE)

• Applicant: Dr. Christoph Plum
• Subject Area: Oceanography
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 542002778

The Southern Ocean (SO) experiences major alterations in environmental conditions associated with decreasing sea-ice duration and extend, changes in seasonality, increasing temperature variability with increasing sea-surface temperature (SST), freshening of coastal areas, and changes in the availability of essential nutrients such as iron, nitrogen and phosphorus. Phytoplankton can display a range of adaptive strategies to changes in environmental conditions, including phenotypic plasticity and adaptive evolution. This project investigates the underlying mechanisms of evolutionary adaptation in Antarctic phytoplankton to projected changes in multiple environmental drivers considering environmental variability. To understand the underlying mechanisms, complex laboratory experiments will be conducted investigating phytoplankton responses (in growth, photosynthesis, biomass and particulate stoichiometry) to factorial manipulations of temperature, light (increase of mean and variability) and nutrient availability. The variation of these parameters translates into environmental heterogeneity that strongly affects phytoplankton phenotypic plasticity and adaptation. Therefore, the second major aim is to understand the mechanisms of long-term evolutionary response in SO phytoplankton traits (growth, photosynthesis) to gradually increasing temperature under constant and fluctuating conditions and the plastic response to projected multifactorial scenarios as well as the tolerance to thermal extremes after long-term adaptation. The originality of the project lies in the combination of evolutionary ecology and global change biology to assess the adaptive capacity of different functional groups of marine microorganisms in response to interactive effects of changing environmental properties and alterations in environmental variability. Overall, the project will improve our mechanistic understanding of evolutionary adaptation in Southern Ocean phytoplankton and how future changes in environmental conditions will alter the functioning of plankton communities. This understanding is crucial for predicting how SO organisms and the Antarctic food web will respond to climate change scenarios composed of a multitude of changing factors.

• DFG Programme: Infrastructure Priority Programmes
• Subproject of: SPP 1158: Infrastructure area - Antarctic Research with Comparative Investigations in Arctic Sea Ice Areas
• International Connection: Uruguay
• Cooperation Partner: Dr. Miriam Gerhard