Pollen evidence for Late Pliocene - Early Pleistocene vegetation and climate change in the North Caucasus, North-Western Caspian Region

Pollen and spores have been analysed in deposits of the Akchagylian-Apsheronian in the north-western Caspian Sea region, providing a picture of past vegetation and climate change for the late Pliocene to early Pleistocene. On the basis of pollen assemblages in sediment cores and outcrops from the North Caucasus (the Caucasus Mineral'nyye Vody region, the Tersko-Sunzhensky area and the foothills of Dagestan), climatic fluctuations, and related changes in vegetation can be recognized for the time from 3.6 to 0.8 Ma. The lower Akchagylian is characterized at first by an open landscape dominated by steppe vegetation. In the middle of the lower Akchagylian, the transgression of the palaeo-Caspian spread, and the treeless landscapes of the earliest Akchagylian were replaced by forests with thermophilic relicts. During the middle-upper Akchagylian and Apsheronian periods, the vegetation cover of the North Caucasus gradually changed: forests were replaced with steppe and semi-desert vegetation in response to episodes of aridification, and changes were evident in the structure of the dendroflora. The vegetation of the North Caucasus shows changes consistent with climatic warming at around 3.2 Ma which coincides with a period of warming in the Mediterranean and probable represents the "Mid Pliocene Warm Period".