Long-term evolution of phytoplankton communities and their resilience in response to environmental and anthropogenic pressures
Faced with the global alteration of coastal ecosystems under anthropogenic and climatic pressures, it is essential to assess the health status of marine environments. To facilitate ecosystem monitoring, scientists and managers frequently rely on synthetic biodiversity metrics and indices. Despite their widespread use, no single diversity index can capture all dimensions of biodiversity, and a combined approach using several indices is often recommended. Moreover, the choice and relevance of these indices may vary depending on the ecosystem and compartment studied, the temporal and spatial resolution of monitoring, and the methodological treatment applied to time series. In addition, these indicators mostly reflect community composition and structure rather than ecological functioning. Historically, abiotic factors have been considered the most important drivers of plankton community structuring and their responses to different pressures. In recent years, however, numerous studies have highlighted the major but underestimated role of biotic interactions.
The aim of my PhD is to determine how the resilience of phytoplankton communities to environmental pressures can be assessed using time series data, by integrating both biodiversity dynamics and biotic interactions.
This central question raises several scientific challenges:
The selection and relevance of biodiversity indicators in an ecological monitoring context.
The integration of functional and interactional dimensions beyond classical metrics
The assessment of ecological resilience through innovative approaches, notably association networks and their response to disturbances.
My PhD takes place within the framework of the INDIBIO project “Indicators and Bioregionalization – Methodological developments in support of the MSFD for pelagic habitats”, funded by the OFB.
