Plant macrofossils and malacocoenoses of Quaternary mineral-organic sediments at Starunia palaeontological site and vicinity (Carpathian region, Ukraine)

The unique nature of the Starunia palaeontological site, where near-perfectly preserved large mammals were discovered at the beginning of the 20th century, and incomplete knowledge on the development of palaeoenvironment in the Velyky Lukavets River valley in the Late Pleistocene and Holocene were the reasons for undertaking new comprehensive palaeobotanical and malacological studies. Starunia is also one of the sites bearing Pleistocene fossil flora, rare in this part of Europe. The results of plant macrofossil analysis show that in the Weichselian Middle Pleniglacial the landscape was dominated by steppe and tundra plant communities, being represented mostly by various grass and sedge species. Areas of higher humidity were covered with shrub tundra with Betula nana. The temperature requirements of taxa which are cool climate indicators show that the minimum July temperature amounted to at least 10°C. The record of Late Weichselian malacofauna confirms the dominance of an open landscape, mostly with steppe and steppe-tundra communities, as well as the presence of a dry, continental climate. At the beginning of the Holocene, an improvement of climatic and humidity conditions led to a fast local expansion of plant communities of the low and transition peat bog type, in the surroundings of shallow, periodically drying-up water pools. From the Middle Pleniglacial up to the present day, the area has been characterized by the presence of species tolerating an increased amount of salt in the environment. Their presence should be associated with natural brine effluences derived from Miocene strata in the bedrock.