The common frame for research at the Palaeobotanical Section in Frankfurt includes aspects of both, sedimentology/facies and systematic (palaeo)botany and may therefore be summarized under the heading of “Terrestrial Palaeoecology”.
This is a direct expression of the interdisciplinary tradition of Senckenberg palaeobotany between geo- and biosciences. Therefore, most of the present research projects consequently are a continuation and further development of traditional research programs at Senckenberg in Frankfurt. The may be assigned to the following major fields.
Plant remains of Paleogene age and their sedimentological context, especially within Germany, are a major research focus of Palaeobotany at Frankfurt. Running projects mainly comprise sediments of Eocene age in terrestrial and marginal marine settings, such as the lacustrine deposits of Messel and Eckfeld and the lignite-bearing successions of the mining districts of Helmstedt and the Geiseltal. Projects include systematic work on individual taxa of pollen/spores, fruits/seeds, flowers, leaves and, sometimes, wood fom Messel and Eckfeld which is done in close cooperation with external and internal experts and specialists. There are milestone publications on pollen from Messel (Thiele-Pfeiffer 1987) and Eckfeld (Nickel 1996), leaves from Messel (Wilde 1989) and fruits/seeds from Messel (Collsinson, Manchester & Wilde 2012).
For Eckfeld, there is a long-term cooperation with the University of Mainz and the Natural History Museum Mainz/State Collections for Natural Sciences Rhineland-Palatinate (Herbert Frankenhäuser). Present work mainly includes Juglandaceae, conifers, ferns and some selected taxa of unknown affinity. The pollen which is preserved in-situ in flowers at Messel and Eckfeld is used in another project as a base for comparisons with dispersed pollen taxa and may help in refining their systematic assignment, especially by applying Scanning Electron Microscopy.
Systematic palynological studies at Messel and Eckfeld allowed for a reconstruction of climate and vegetation around the maar lakes and their surroundings (Thiele-Pfeiffer 1987 and Nickel 1996, respectively). Supported by a grant from the German Research Foundation (DFG) Olaf Klaus Lenz later started high-resolution studies on a research core from the Messel pit (“Messel 2001”) which led to a series of pioneering papers. They were designed to resolve changes in the vegetation with time by the help of modern statistical methods. In a first step reconstruction of the re-occupation of the area devastated by the eruption ca. 48 Millio years ago by the vegetation became possible. Analyzing quantitative changes in the composition of the pollen and spores as recovered from the oil shale of the Middle Messel Formation clearly revealed orbital and suborbital cyclicity as the driving force for changes in climate and vegetation. Furthermore, varve countings for the first time directly revealed ENSO-cyclicity for Eocene lacustrine sediments. Statistical analyses of plant biodiversity which were based on pollen and spores as proxies recently revealed fluctuations in the same ranges. Altogether this proves in high resolution that surprisingly similar mechanisms acted for climate change in greenhouse and icehouse systems of the Cenozoic.
Another famous lagerstätte for the terrestrial Middle Eocene in Germany is the former lignite mining district of the Geiseltal near Halle (Saale). Prior to final flooding of the mining area five field campaigns were conducted here between 2000 and 2003 in close cooperation with the Geiseltalmuseum in Halle. They mainly served for securing data and samples from remnant sections spanning much of the middle Eocene land mammal stage “Geiseltalian”. Most of the >1500 individual samples and a number of plant fossils have not yet been studied in detail and form a base for ongoing and future research. Inspired by previous work of Walter Riegel the opencast mine Schöningen-Southfield of the Helmstedt Lignite Mining District became an important research focus. Several thousand samples have been collected here in a great number of individual sections. Altogether they span more than 10 million years from the uppermost Paleocene to the middle Eocene and therefore include the critical episodes of the so-called Paleocene-Eocene Thermal Maximum (PETM) and succeeding climate excursions. Detailed palynological analyses of selected parts of the section are now studied with respect to vegetation, climate and palaeoecology. It is important here that the taxonomic resolution for the study is greatly enhanced by the combination of light microscopical techniques and scanning electron microscopy. Initial results are promising, but, a great number of samples and some more sections still remain to be studied. The German Research Foundation (DFG) recently provided the funds for a statistical study of plant (palyno) biodiversity throughout the whole section by Olaf-Klaus Lenz.