Palynology & Paleoenvironmental Dynamics
The primary objective of our group’s research is to contribute to a better understanding of the climatic, environmental and biological evolution of the Earth system. We aim to achieve this goal by analyzing the fossil record of primary producers both on land and in the oceans.
The biological evolution of primary producers is closely linked with changes in climatic and environmental conditions. At the same time, the fossilized remains of primary producers (such as pollen and spores of vascular plants in the terrestrial realm and dinoflagellate cysts in the marine realm) are sensitive proxies for environmental changes. These so-called palynomorphs occur in high abundances in terrestrial and marine sediments, thus yielding signals of evolutionary and environmental change with high temporal resolution.
A further advantage of this palynological approach lies in its potential for a direct land/sea correlation: The analysis of terrestrial palynomorphs recovered from marine sediments facilitates the reconstruction of paleoclimatic and paleoenvironmental change on the continents within a marine-based age frame. Moreover, through the integration of terrestrial palynomorph datasets with marine proxy data, leads and lags between climatic and environmental signals from the continents and the oceans can be determined.
The palynological results are integrated with geochemical (notably biomarker) and sedimentological data. This approach necessitates interdisciplinary research projects including biological and geological sciences. It allows us to analyse the role of primary producers as responders, drivers and moderators of climatic and environmental change.
Because primary producers have played a prominent role in climatic and environmental change ever since their appearance early in Earth’s history, our group’s research activities encompass time intervals from the Silurian to the Holocene. Our current research activities focus on climatic and environmental change under icehouse conditions during the Oligocene and Quaternary, and under greenhouse conditions during the Triassic, Jurassic, Cretaceous, and Paleogene. Within these time intervals, our research concentrates on deciphering climatic and environmental dynamics both in terrestrial ecosystems and marine ecosystems.
Terrestrial ecosystems: Vegetation response to climatic and environmental change
Terrestrial ecosystems represent the immediate environment in which humans live. Hence, decoding the response of terrestrial ecosystems to intrinsic (e.g., competition) and extrinsic (e.g., climate change) stress factors is especially important for understanding our past, present and future.
Our group studies the reaction of terrestrial vegetation to climatic forcing on different timescales and under different boundary conditions during Earth’s history. In all these studies, we aim to interpret our results in close conjunction with coeval developments in the marine realm in order to obtain a better mechanistic understanding of the underlying climate processes.
Marine ecosystems: Organic-walled phytoplankton response to climatic and environmental change
Earth’s oceans play a pivotal role in the origin and evolution of life. Moreover, the productivity of marine primary producers, which accounts for more than 50 % of the total primary productivity within Earth’s biosphere, plays a central role in the global carbon cycle. Through the export of atmospheric CO2 into organic carbon reservoirs, the productivity of marine primary producers exerts strong control on the concentration of greenhouse gases in Earth’s atmosphere. The resulting organic-carbon-rich sediments, often termed „black shales“, form hydrocarbon source rocks and have therefore developed into a cornerstone of today’s world economy.
As marine palynological proxy, our group mainly utilises the organic-walled cysts of dinoflagellates (commonly termed „dinocysts“). Dinoflagellates have been one of the most prominent groups of marine primary producers in Earth’s oceans since the Late Triassic. They also form symbiotic partnerships with many marine invertebrates in the ocean today.