Pollen based vegetation reconstruction

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  • ELSA-23-Pollen-Stack all pollen counts
  • ELSA-23-Pollen-Stack all pollen counts resampled
  • ELSA-23-Pollen-Stack all pollen counts smoothed
  • ELSA-23-Pollen-Stack all pollen counts smoothed resampled
  • ELSA-23-Pollen-Stack 20+ pollen counts
  • ELSA-23-Pollen-Stack 20+ pollen counts resampled
  • ELSA-23-Pollen-Stack 20+ pollen counts smoothed
  • ELSA-23-Pollen-Stack 20+ pollen counts smoothed resampled
  • ELSA-23-Pollen-Stack no pollen
  • ELSA-20-Pollen-Stack all pollen counts
  • ELSA-20-Pollen-Stack all pollen counts resampled
  • ELSA-20-Pollen-Stack all pollen counts smoothed
  • ELSA-20-Pollen-Stack all pollen counts smoothed resampled
  • ELSA-20-Pollen-Stack 20+ pollen counts
  • ELSA-20-Pollen-Stack 20+ pollen counts resampled
  • ELSA-20-Pollen-Stack 20+ pollen counts smoothed
  • ELSA-20-Pollen-Stack 20+ pollen counts smoothed resampled
  • ELSA-20-Pollen-Stack no pollen
  • ELSA-23-Pollen-Stack Graphics

Tree Pollen

Pollen, deposited in the lake sediments, are the most established tool for paleovegetation reconstruction. The signal can, however, be biased from long distance transport and erosion of fossil pollen from soils. The latter must be regarded indeed as a source for most of the ELSA cores, because most maar lakes receive a part of the sediment from fluvial inflow or local erosion gullies, but most of the pollen appear to be deposited directly from air. The main argument in this direction is the observation that the pollen from all MIS 3 cores have an almost identical pollen succession (Albert et al., in prep.)

However, single pollen grains, which does not fit the general picture, must be treated careful before interpretation. This is most problematic if pollen from temperate trees appear in stadial or glacial sections. We regard these single pollen as being reworked from older soils. The Eifel pollen pattern is established for the Holocene since long, but there are no existing information of the typical vegetation succession in the time from the last glacial maximum (MIS 2) back to MIS 4. This time has seen 15 warm interstadial of a duration from centuries to a few millennia. The first pollen profiles from Auel and Dehner Maar has documented for the first time a MIS 3 profile for the Eifel (Sirocko, 2009, Sirocko et al., 2016). The early MIS 3 is accordingly clearly dominated by a pronounced spruce (Picea) maximum (48,000 – 60,000 yr b2k), a finding now reproduced by 5 other records (Albert et al., in prep.). The presence of spruce continues during GI12 and GI11, and then disappears. Small amounts of spruce during GI3 could be reworked. A synthesis of all GI3 records with decadal resolution is under preparation.

Tree Pollen and Non-Tree Pollen

The interstadials of MIS 3 all reveal grass, birch and pine. Stadial sediments are often free of pollen. This could represent a landscape free of vegetation, e.g. during the Heinrich 4 event, or the pollen have been dissolved. This must have occurred for most of the time between 25,000 – 14,700 yr b2k. Pollen are extremely hard and cannot be dissolved by any acid, but they deteriorate as soon as they are exposed to oxygen. This must have been the case in the sediments of the LGM, when temperatures reached below 4°C even in the summer nights and cold, oxygen rich surface water sunk to the lake basin because of its high density. The glacial ELSA pollen and macroremain record (see below) suggest for the Last Glacial Maximum the continuous presence of grass and moss, and some birch during the warmer phases.  

Pollen stratigraphical marker points and tephra layers (red) in core HM1 from Holzmaar.
Pollen curves are smoothed with a 3 pt running mean.
The ELSA-23-Pollen-Stack, present to 60,000 yr b2k, >20 pollen grains counted per sample, pollen curves are smoothed
with a 10 pt running mean, colored dots show the unsmoothed data.
The ELSA-23-Pollen-Stack, 60,000 to 132,000 yr b2k, >20 pollen grains counted per sample, pollen curves are smoothed
with a 15 pt running mean, colored dots show the unsmoothed data.
The ELSA-23-Pollen-Stack, present to 132,000 yr b2k, >20 pollen grains counted per sample, pollen curves are smoothed
with a 15 pt running mean.