CHANGES IN THE FLORA AND VEGETATION OF PLAIN UKRAINE DURING THE LATE MIOCENE

Abstract

This paper presents the results of the analysis and synthesis of a large array of palynological data characterising the Upper Miocene deposits of the plain Ukraine, represented by the marine strata of the Upper Sarmatian, Maeotian and Pontian, as well as their continental analogues – fossil soils of the Yefremivka, Ivankiv and Lubymivka climatolites and clays of the Belbek, Salgyr and Oskil climatolites. The degree of characterisation of each Upper Miocene stratum is analysed. Attention is drawn to the insufficient palynological study of the transitional deposits of the Upper Maeotian and Lower Pontian, a certain inconsistency in the stratigraphic basis of the palynologically characterised Pontian deposits of the Odessa region, and the incomplete palynological study of the Portafer and Bosphor beds of the Pontian, as well as the problematic issues, existing at the current stage of research, regarding the correlation of multifacial Pontian deposits, which do not yet allow for a detailed understanding of the dynamics of changes in plant communities throughout the Pontian period. The necessity of conducting additional palynological studies of the Maeotian and Pontian deposits of Ukraine, as well as their continental analogues, is substantiated with the aim of their stratification and the refinement of palaeofloristic reconstructions. The stages of vegetation development during the Late Miocene have been traced, and the characteristic features and distinctive traits of each of the identified stages have been determined. The main patterns of flora and vegetation development in the plain Ukraine at the end of the Miocene have been determined. It has been established that the restructuring of the flora and vegetation, which began in the late Middle Sarmatian period, was most clearly evident during the Late Sarmatian period. The proportion of tree species within the vegetation decreased, mainly at the expense of conifers, whilst the area covered by herbaceous communities within the vegetation increased. The vegetation of the Pontian period, in terms of the generic and specific composition of tree species, was richer and more diverse compared to that of the Maeotian, particularly the Late Maeotian. A trend of gradual cooling and aridisation of the climate from the Middle to the Late Miocene has been traced, a trend also characteristic of the Miocene period in other European countries.