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.

Spitsbergen is the largest island in the Svalbard Archipelago (Norway) that has been permanently populated. The harsh Arctic climate prevents development of large vascular plants such as trees. A two-year aerobiological survey was conducted within the framework of two consecutive polar expeditions (2014 and 2015) in Spitsbergen (Calypsobyen, Bellsund). The air quality was measured continuously from June/July to August using a 7-day volumetric air sampler, Tauber trap and moss specimens. Collected air samples and gravimetric pollen deposits were processed following transfer to sterile laboratory conditions and analyzed with the aid of light microscopy. Days when pine pollen grains were detected in the air were selected for further analysis. Clusters of back-trajectories, computed using the Hybrid Single Particle Lagrangian Integrated Trajectory model in combination with ArcGIS software as well as the Flextra trajectory model, showed the movement of air masses to the sampling location at Hornsund, and thus indicated the likely origin of pollen grains. The GlobCover 2009 and CORINE Land Cover 2012 datasets were employed to establish the distribution of coniferous forests in the areas of interest. Conclusions were drawn based on the analyses of the circulation of air masses, using visualization of global weather conditions forecast to supercomputers. For the first time we have demonstrated that pine pollen grains occurring in pine-free Spitsbergen, could originate from numerous locations, including Scandinavia, Iceland, Siberia and northern Canada. Pollen grains were transported via air masses for distances exceeding ~2000 km. Both air samples and gravimetric pollen deposits revealed the same pattern of Pinus pollen distribution.