Untersuchungen zur Pollen- und Sporenflora des Bitterfelder Bernsteins - Erste Ergebnisse

Vorgestellt werden erste Ergebnisse palynologischer Untersuchungen an Bitterfelder Bernstein. Anhand von mindestens 18 Pollen- und Sporentypen „Höherer Pflanzen“ wird eine Rekonstruktion der Umweltbedingungen im Bernsteinwald vorgenommen. Erstmals konnte Nyssa (Tupelobaum) für den Bitterfelder Bernsteinwald nachgewiesen werden. Unter Berücksichtigung der stratigraphischen Reichweite einzelner Pollen- und Sporentypen wird versucht, das Bildungsalter der Bernsteine abzuleiten. Vermutlich datieren sie in das Bartonium bis Priabonium (SPP 17 bis SPP 18, ca. 41,3-33,9 Ma).First results of palynological investigations on Bitterfeld amber are presented. A reconstruction of the environmental conditions in the amber forest is carried out on the basis of at least 18 types of pollen and spores of "Higher plants". For the first time, Nyssa (Tupelo) could be detected as a species of Bitterfeld amber forest. Taking into account the stratigraphic range of individual pollen and spore types, an attempt is made to derive the age at which amber was formed. Bitterfeld amber presumably date from Bartonian to Priabonian (SPP 17 to SPP 18, ca. 41,3-33,9 Ma)

Table 1 : AMS-14C data used for the reconstruction of the Wismar Bay shoreline displacement curve

The Baltic coast of Mecklenburg-Vorpommern is located in the transition Zone between the region of Fennoscandian Uplift and the Central European Depression. In relation to the eustatic sea-level rise, the northeast coast shows a slower inundation, while for the southwestern area a faster transgression is indicated, which can be attributed to crustal movements. To determine the spatial and temporal differences since the onset of the Littorina Transgression, three relative sea-level curves have been established along a transect parallel to the gradient of upliftlsubsidence. The Wismar Bay area is one endpoint of the transect demonstrating today 10 Abb., 2 Tab. a relative sea-level rise of 1.4 mm/a. To determine the relative sea-level curve for the Wismar Bay, two sites were investigated on Rustwerder Spit (Poel) and Redentin. They provided reliable depth-age data, while the stratigraphy was additionally supported by lithological/geochemical, pollen, diatom and macrofossil data. Additional evidence was provided by archaeological submarine surveys and excavations. Comparing the new relative sea-level curve with a curve from the Vorpommern coast, it can be shown that for the period from 4000 cal BC until present, the differences between the two curves are caused by a constant neotectonic movement, while for the older periods an increasing isostatic component must be taken into account

Quantitative reconstructions of changes in regional openess in north-central Europe reveal new insights into old questions

International audienc

Testing the Effect of Relative Pollen Productivity on the REVEALS Model: A Validated Reconstruction of Europe-Wide Holocene Vegetation

International audienceReliable quantitative vegetation reconstructions for Europe during the Holocene are crucial to improving our understanding of landscape dynamics, making it possible to assess the past effects of environmental variables and land-use change on ecosystems and biodiversity, and mitigating their effects in the future. We present here the most spatially extensive and temporally continuous pollen-based reconstructions of plant cover in Europe (at a spatial resolution of 1° × 1°) over the Holocene (last 11.7 ka BP) using the ‘Regional Estimates of VEgetation Abundance from Large Sites’ (REVEALS) model. This study has three main aims. First, to present the most accurate and reliable generation of REVEALS reconstructions across Europe so far. This has been achieved by including a larger number of pollen records compared to former analyses, in particular from the Mediterranean area. Second, to discuss methodological issues in the quantification of past land cover by using alternative datasets of relative pollen productivities (RPPs), one of the key input parameters of REVEALS, to test model sensitivity. Finally, to validate our reconstructions with the global forest change dataset. The results suggest that the RPPs.st1 (31 taxa) dataset is best suited to producing regional vegetation cover estimates for Europe. These reconstructions offer a long-term perspective providing unique possibilities to explore spatial-temporal changes in past land cover and biodiversity