Based on geochemical and biological investigations of a 6-m-long sediment core, a reconstruction of the environmental conditions in Charzykowskie Lake (northern Poland) is presented. The analyzed sediments consist of fine calcareous detritus gyttja interbedded by lake marl. The results of palynological analysis document the vegetation development around and in the studied lake and confirm the middle and late Holocene age of the sedimentation of the deposits. The identification of 22 taxa of subfossil Cladocera shows the biodiversity of the fauna and reflects the changes in the trophic and water level. The concentrations of various chemical elements suggest the origin of the sediments. Geochemical, including isotope, and biological data, made it possible to reconstruct the environmental conditions, as well as traces of human influence over the last ca. 6,200 years. Four stages of human impact have been documented by the pollen data. The first traces of human groups in the vicinity of Charzykowskie Lake are preserved in sediments from about 4,000 years ago. The human activity is poorly recorded in the Cladocera and in the geochemical compositions of the lake sediments, probably due to the size and depth of the lake and its isolation.

The aim of this study was to reconstruct the evolution of the Eemian palaeolake in the Żabieniec site (Garwolin Plain, Central Poland); it identifies changes in the water level and the trophic status of the lake resulting from panregional factors, including climate changes occurring during individual phases of the last interglacial, and local geologic-geomorphological factors shaping the palaeoenvironment using multi-proxy methods (palaeobotanical analyses, subfossil Cladocera and diatoms analyses as well as determinations of the stable isotopes). A record was obtained of all seven Regional Pollen Assemblage Zones (RPAZs) according to Mamakowa’s description of the Eemian pollen succession (1989), and of the changes in microfossil assemblages and isotopes in palaeolake sediments associated with lake evolution. Special attention was paid to the Middle Eemian RPAZ 4 (i.e. hazel phase) of the climatic optimum; all proxies associate this with the highest water level and a warm humid climate. During the E5/E6 RPAZs, the eutrophic lake transformed very quickly, and a transitional peatbog was formed. The higher humidity of the late Eemian resulted in another increase in water level. The multi-proxy record of the Żabieniec palaeolake which we obtained was compared to those of other Eemian water bodies in the Garwolin Plain and in Central Poland that exhibit sedimentation gaps especially during the younger part of the E5 RPAZ.