This paper presents discussion on the results of subfossil Cladocera analyses from five lakes in Poland (Przedni Staw Lake, Perespilno Lake, Gościąż Lake, Imiołki- fossil lake and Ostrowite Lake). The Cladocera are represented in sediments by remains of planktonic (Bosminidae, Daphnidae) and littoral (Chydoridae) forms. Cladoceran assemblage phases ("ecostratigraphy") were determined on the basis of changes in dominance of indicator species and past ecological conditions were reconstructed. The results are being discussed from the viewpoint of climate change and anthropogenic activity and their role in the lake evolution. Moreover, an attempt to use the cladoceran phases for stratigraphic division of the Late Glacial and Holocene was made. During the Bolling/Allerod interstadial, distinguished on the basis of Pollen analysis, Cladocera indicated short phase of bad condition (dry or cold?), probably as the Old Dryas climate results. The beginning of Holocene are characterized, in mountain and lowland lakes, by high increase in the number of species and specimens of Cladocera. This described clear warming and marked the boundary Late Glacial/Holocene. It was indicated that the "ecostratigraphy" based on Cladocera can be useful for climatostratigraphy, if climate was the major factor controlling the development of freshwater lakes.

The Reserve Dury, Tuchola Pinewoods, Poland, includes five depressions with no outflow filled up with biogenie sediments. They undergo terrestrialization processes to a high degree. In four of the basins there are still some open water areas surrounded by floating mire with raised and transitional bog plants. For the needs of protection service officers some palynological and geological research were carried out. All the geological cores were described in detail following the Troels-Smith system. The deepest core Dury I was selected for pollen analysis. Ten Local Pollen Assemblage Zones (L PAZ) show the history ofregional and local plant communities. On the basis of two air photographs, modem dynamics of floating mire in four basins were evaluated. The results allow us to correlate the geological layers, to describe the Late Glacial and Holocene succession of plant cover at Dury I site, and to show the stages of filling-in of basins with lacustrine sediments and peat.