Reconstruction of the trophic development of Lake Krakower Obersee (Mecklenburg, Germany) by means of sediment- diatom- and pollen-analysis

Changes in composition of diatom (Bacillariophyceae) communities and pollen content were analyzed in two cores from the lake Krakower See, Mecklenburg-Vorpommern, Northern Germany. Based on the pollen stratigraphy, a time-depth-curve was built that allowed an estimate of the rate of sedimentation. The pollen curves, especially those of settlement indicators, showed the human influence in the surrounding area. Diatom assemblages clearly indicated that human activities had influenced not only the terrestrial vegetation but also the water body of the lake and it’s trophic conditions. From a natural oligo- to mesotrophic lake that had small oscillations in prehistoric times it switched rela-tively fast into an eutrophic one around 700 years ago. This radical change in the trophic status was an effect of both damming up for mills in the 13th century and increasing settlement activities around the lake. Key words: paleolimnology, diatom and pollen stratigraphy, TP reconstructio