Blanchet, Claire

Combination of pollen and lacustrine DNA markers to develop reconstructions of the trajectories of mountain socio-ecosystems
WP4 PhD Student

My training

During my degree, I wanted to specialize in the study of the history of vegetation dynamics. Thus, I did a Master's degree in Biodiversity, Ecology & Evolution with a specialization in ChronoEnvironment and Paleoecology at the University of Montpellier. I was thus able to learn the different tools and methods used for the reconstruction of paleoenvironments, such as palynology. This exploration was for me a personal as well as a professional discovery. It was therefore only natural that I wanted to continue working in this field.

The project

Pollen and environmental DNA stored in lake sediments allow us to trace the history of current and past vegetation and that of various past agricultural activities (cereal growing, or indirectly pastoral activities). Unlike environmental DNA, palynological studies provide a regional picture of vegetation cover. Indeed, pollen grains have different aerodynamic properties depending on the taxa, which affects the transport distance between the pollen source and the deposition area. In addition, many herbaceous plants cannot be recognized. Environmental DNA allows this limit to be exceeded by providing better taxonomic resolution for some of these species.

These methods will be used on modern lake sediment sequences to assess their respective capacities to reflect the current landscape. Then, they will be applied to two sequences of lake sediments covering several thousand years in order to have very detailed reconstructions of paleovegetation and paleo-system services.

Published on March 6, 2019