Erhard Schulz
University of Würzburg
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Featured researches published by Erhard Schulz.
Historical Biology | 1994
Erhard Schulz
Holocene records from the southern Sahara in Niger allow a reconstruction of the vegetation history and inform us about the former extension of the Mediterranean. Both pollen and charcoal analyses evidenced the direct contact of Sudanian and Saharan savannas during the middle Holocene at about 19°N, whereas at 20°N the transition from the Saharan savanna to the desert was found. In southwestern Libya (26°N) a combination of a Saharan desert vegetation and a semi‐desert Artemisia shrub on the plateaus demonstrated the contact with Mediterranean influenced formations. Regular ash and charcoal layers in middle‐Holocene sediments of the northern Niger prove an early interference of man with the vegetation development. One has to imagine that, in combination with the cattle‐keeping and the later metal production, man could have changed the former northern Sudanian vegetation into the present Sahelian savanna system from the middle Holocene on.
Journal of African Earth Sciences | 2002
Erhard Schulz; Abdelhakim Abichou; Tarek Hachicha; Simon Pomel; Ulrich Salzmann; Kamel Zouari
Sebkhas are temporary lacustrine systems depending on the number and extension of floodings. They may create laminated sediments which can be exploited as ecological archives. Contrary to those of meromictic lakes they are seasonal but not annual. After each flooding a detritus layer and a plasmo-condensed layer of bacteria and algae are formed in the water body or film and during the subsequent dessication a third subaeric layer of evaporites is build up. These laminae show a quasi-textile fabric and they can trap and conserve any dust and fine grained material. A high resolution pollendiagram covering the last two millennia as well as geochemical analysis from a southeastern Tunisian sebkha demonstrate the potentials of these ecological archives.
Archive | 2004
Roland Baumhauer; Erhard Schulz; Simon Pomel
The change from a fresh water lake to a sebkha during the middle Holocene was investigated in the Segedim depression/North-eastern Niger using continuous thin sections for micropetrography, palynology and for diatoms. This record is clearly divided into several units showing sequences of laminated anoxic to oxic clays, the stage of a sebkha with an inflow of loess, fine broken quartz grains and salts which are covered by dune sands made of rounded and clay covered quartz. The mineral assemblages of the three principal units are defined by the illite/kaolinitecalcite/aragonite-pyrite association (oxic lake), a kaolinite-calcite-halite-anhydrite (anoxic lake) and a montmorillonite-celestine-sodium carbonate-gypsum association connected to the sebkha. The composition of the sediments indicates a remarkable influence of sedimentation (ashes, phytoliths, charcoals, carbonates).
Zentralblatt für Geologie und Paläontologie, Teil I | 2014
Erhard Schulz; Tarek Hachicha; Laurent Marquer; Simon Pomel; Ulrich Salzmann; Abdelhakim Abichou
A record of laminated sediments of Sebkha Mehabeul in Southeast Tunisia provided a high-resolution environmental archive for the last two millennia. It allowed a detailed reconstruction of the sedimentological evolution, of the mineral environment and hydrological history as well as the vegetation and landscape evolution and of climatic development. The impluvium character of the sebkha allowed it to establish a palaeopluviometric record, as well as the reconstruction of drought and flood periods. A pollen diagram revealed the persistent semi desert environment in the context of a cultural landscape. Despite the resilience of the semi desert ecosystems and periods of favourable climatic episodes the human impact was always strong enough to impede a change to more demanding ecosystems like steppe or woodlands.
Quaternary Research | 2008
Laurent Marquer; Simon Pomel; Abdelhakim Abichou; Erhard Schulz; David Kaniewski; E. Van Campo
Vegetation History and Archaeobotany | 2002
Manfred Rösch; Otto Ehrmann; Ludger Herrmann; Erhard Schulz; Arno Bogenrieder; Johann Peter Goldammer; Matthias Hall; Hans Page; Wolfram Schier
Universitätsforschungen zur prähistorischen Archäologie | 2013
Manfred Rösch; Wolfram Schier; Otto Ehrmann; Arno Bogenrieder; Mathias Hall; Ludger Herrmann; Erhard Schulz
Vegetation History and Archaeobotany | 2014
Erhard Schulz; Ulrich Vannina; Mathias Hall
Archive | 1995
Ulrich Salzmann; Erhard Schulz
Land | 2017
Manfred Rösch; Harald Biester; Arno Bogenrieder; Eileen Eckmeier; Otto Ehrmann; Renate Gerlach; Mathias Hall; Christoph Hartkopf-Fröder; Ludger Herrmann; Birgit Kury; Jutta Lechterbeck; Wolfram Schier; Erhard Schulz