Table 7. Duration of sedimentation, sedimentation rates, and pollen concentration of sediment core Schmiecher See

The pollen concentrations were determined as described by Stockmarr (1971) using Lycopodium spores as markers. If in addition to the pollen concentration also the yearly pollen input is known the number of years needed to deposit sediment of a certain thickness can be calculated. Table 7 shows the results of an estimate based on an assumed yearly input of 255 pollen grains per 1 cm**2. The chosen value lies in the lower range of values stated for the treeless Canadian tundra where 5 to 762.5 pollen grains fall every year on each cm**2 of surface (Ritchie & Lichti-Federovich 1967). The calculated results must be regarded rather rough and highly speculative as in addition to the arbitrarily chosen value of the yearly input interruptions of sedimentation or loss of sediment by erosion have not been considered.