Greenhouse conditions in Lower Eocene coastal wetlands? - Lessons from Schöningen, Northern Germany

Published: April 24, 2020, 8:07 p.m.

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.04.24.059345v1?rss=1 Authors: Lenz, O. K., Riegel, W., Wilde, V. Abstract: The Paleogene succession of the Helmstedt Lignite Mining District in Northern Germany includes coastal peat mire records from the latest Paleocene to the middle Eocene at the southern edge of the Proto-North Sea. Therefore, it covers the different long- and short-term climate perturbations of the Paleogene greenhouse. 56 samples from three individual sections of a Lower Eocene seam in the record capture the typical succession of the vegetation in a coastal wetland during a period that was not affected by climate perturbation. This allows to distinguish facies-dependent vegetational changes from those that were climate induced. Cluster analyses and NMDS of well-preserved palynomorph assemblages reveal four successional stages in the vegetation during peat accumulation: (1) a near-coastal vegetation, (2) a lowland mire, (3) a transitional mire, and (4) a terminal mire. Biodiversity measures show that plant diversity decreased significantly in the successive stages. The highly diverse vegetation at the coast and in the adjacent lowland mire was replaced by low diversity communities adapted to wet acidic environments and nutrient deficiency. The palynomorph assemblages are dominated by elements such as Alnus or Sphagnum. Typical tropical elements which are characteristic for the Middle Eocene part of the succession are missing. This indicates that a more temperate climate prevailed in northwestern Germany during the early Lower Eocene. Copy rights belong to original authors. Visit the link for more info