10 million years of interaction between terrestrial plant biodiversity and climate in the early Paleogene of the Helmstedt Mining District

• Applicant: Privatdozent Dr. Olaf Lenz
• Subject Area: Geology
• Term: from 2017 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 394329649

The sedimentary succession of the Helmstedt Mining District (Lower Saxony, Germany) covers the entire Paleogene greenhouse phase and its gentle demise almost continuously from the latest Paleocene to the middle Eocene, including the Early Eocene Climatic Optimum (EECO) and its steady but slow decline, the transition to the Middle Eocene Climatic Optimum (MECO) and some short-term warming events such as, e.g., the Paleocene-Eocene Thermal Maximum (PETM). The more than 200 m thick section comprises 13 lignite seams and their interbeds which formed in an estuarine setting at the southern margin of the Proto-North Sea.An appropriate selection of samples from a large stock offers a unique chance for studying both, long- and short-term interaction between the composition of vegetation as well as plant diversity and climate by applying pollen and spores as proxies across the last natural greenhouse system. The identification of the thermal events will be done by analyses of carbon isotopes, since especially short-term events such as the PETM coincide with pertubations in the global carbon cycle, manifested in negative carbon isotope excursions. With the exact identification in the succession, it is possible to reconstruct the vegetation for times before, during and after specific thermal events. Therefore, a high amount of samples will be studied qualitatively and quantitatively with respect to the taxonomic composition of the microflora by conventional light microscopy supported by SEM studies in selected samples. Several multivariate statistical methods will be used for distinguishing associations of pollen taxa which are most probably representing distinct plant communities that can be traced in their development over time and throughout the thermal events. Special focus is on diversity changes in the vegetation using measures such as richness and evenness.

• DFG Programme: Research Grants
• International Connection: USA
• Co-Investigators: Professor Dr. Walter Riegel; Privatdozent Dr. Volker Wilde
• Cooperation Partner: Katharina Methner, Ph.D.