The Review of Sarmatian Flora and Vegetation on the Territory of Eastern Georgia

Abstract

The Sarmatian deposits (Volhynian, Bessarabian and Khersonian regiosubstages) of Eastern Georgia were studied by pollen analysis. In the composition of flora 165 components were determined. Among them are 44 cryptogams, 33 gymnosperms, and 88 angiosperms. The palynological complexes were interpreted by landscapephytocoenological method and in the development of vegetation six stages were established, which reflect the changes in composition of vegetation. The I and II stages correspond to the lower part of Volhynian. The II stage was the initial moment of increasing of grass cover on territory of Eastern Georgia. The III stage, which embraced the most part of Bessarabian, was the climatic optimum, simultaneous in both regions of Georgia. The widening of open stands was reduced in the IV stage and stopped in the V stage (end of Bessarabian and beginning of Khersonian). On territory of Eastern Georgia, the upper part of Khersonian (VI stage) was the time of more broad distribution of open landscapes. As a result, during the Sarmatian stage, the climate in Eastern Georgia was unstable, and humidity levels dropped permanently. The sharper character this phenomenon received in the end of Khersonian stage, after which on territory of Eastern Georgia the open landscapes widely expanded.