Multi-proxy environmental reconstruction of the Eemian and Early Vistulian – Before, during and after the life of the forest rhino Stephanorhinus kirchbergensis (Jäger, 1839) from Gorzów Wielkopolski (NW Poland)

Abstract

The natural environment of the Eemian Interglacial (MIS 5e) and Early Vistulian (MIS 5 d-a) in many areas in Central Europe is still insufficiently and fragmentarily known. Therefore, after the discovery of an almost complete skeleton of the Eemian Stephanorhinus kirchbergensis (Jäger, 1839) in outcrop of palaeolake sediments near Gorzów Wielkopolski (GW site, GS3 profile), a multi-proxy analysis was conducted for a precise recognition of the environmental and climate changes taking place before, during and after the life of this individual. Comprehensive palaeobotanical investigations of sediments of two palaeolakes lying above each other were performed palynological analysis including NPPs and algal analysis, plant macroremains studies (including wood fragments), as well as palaeozoological analyses of the Cladocera, Chironomidae and Coleoptera. The picture of changes in the environment and climate obtained thanks to the performed analyzes presented in a short way looks as follows. The end of the Wartanian Glaciation (MIS 6) was characterised by the dominance of herbaceous vegetation. Along with the gradually changing climatic conditions, the landscape of the Eemian Interglacial was dominated in sequence by birch, pine, oak (the so-called First Thermal Optimum), hazel forests with linden, hornbeam (Second Thermal Optimum) with a rarely recorded dry oscillation, then spruce with fir and again pine forests. The “older Eemian lake” during this time changed from deep, cold, oligotrophic and carbonate to shallower, cold waters with higher trophy, then deeper with lower trophy, again shallower with peats and dystrophic conditions and finally became terrestrial. The age of the post-Eemian part of the GS3 profile was reinterpreted, recognizing OSL dating as more reliable than radiocarbon dating, determining the age as Early Vistulian. Subsequent stages of this part of profile were characterised by significant cooling and intense development of heaths and peatbogs (MIS 5d), double return of pine and birch forests separated by intra-interstadial cooling (MIS 5c), recooling with dominant herbaceous plants (MIS 5b) and last warming with birch forests (MIS 5a). The “younger Early Vistulian lake” was formed with the rising of the water level. It was shallow, cold, low-trophic, with the water heating up in the summer, which caused trophic increases. Water levels fluctuated. With the progressing terrestrialization, oligotrophy appeared. Each of used proxies reconstructs a fragment of palaeoenvironmental changes on land and/or in the reservoir, registering climatic events on both regional and local scales. However, only the combination of all results allows for a full picture of natural changes.