Geographical conditions and evolution of vegetation cover of Middle Volga Region in the pliocene

The development of flora on the territory of the Middle Volga region during the Pliocene is discussed. An attempt to reconstruct geographic conditions and vegetation cover is taken. A short description of the natural environment and landscape, of the vegetation cover of the Middle Volga and adjacent territories is done. The comparative scheme of the total and the regional scales of Pliocene is added. In the given paper one assumes the upper boundary of the Pliocene to be the upper boundary of the Gelasian Stage. The Pliocene is rather turbulent geological period during there was a relatively quick change of warm and cold phases, each of which is characterized by landscape and climate change. Landscape transformations took place against a background of progressive climate cooling with an increase in the contrast of summer and winter temperatures. Main geomorphological structures of the Middle Volga region, such as the Volga Upland, Samara Bend, Zhiguli Mountains, Obshhij Syrt, river network, appeared prior or during this period. Main plant formations in their broadest sense (taiga, broad-leaved and small-leaved forests, steppes) had already been formed by the beginning of the Pliocene. During the Pliocene period the depletion of those plant formations took place. It occurred due to the gradual extinction of thermophilic species and bringing in their composition to modern formations. Most of the species had taken modern form by the end of the Pliocene.