КСЕРОФИЛЬНЫЕ ЭНДЕМЫ ФЛОРЫ РОССИЙСКОГО КАВКАЗА И ИХ РОДСТВЕННЫЕ СВЯЗИ

Abstract

The article is devoted to the study of endemics of xerophilous flora of various regions of the Russian Caucasus, adjacent and remote territories (Western Mediterranean, Caucasus, Greater Caucasus, Transcaucasia. Asia Minor and Western Asia, Eastern Mediterranean, Pontic region, Palaearctic). The purpose of the study is to identify their species composition, genetic links between them, which are necessary for solving the problems of florogenesis. The article analyzes the results of many years of floristic research in different territories of the Caucasus, publications on the flora of these, adjacent and alienated territories. The study used methods of historical reconstruction, morphological-ecological-geographical analysis, including the method of evolutionary series, as well as the method of phlorogenetic analysis and synthesis. Information on the genetic and geographical relationships of the taxa under discussion was obtained by analyzing the position of the species in the genus system (in the case of monotypic genera, the position in the family system), which made it possible to identify the closest relatives, determine their geographic localization, and suggest the time and directions of migration flows of ancestral species. As a result of the analysis of the distribution of 52 species of endemics of the xerophilic flora of the studied regions of the Russian Caucasus, as well as the flora of adjacent and remote areas, possible genetic links between them were revealed. The closest relationships of endemic euxerophytes were noted within the territory of the Greater Caucasus (26.3%), they are significant with endemic species of the Western Mediterranean, Anterior and Asia Minor (9.6% each) and weaker - with species of the Eastern Mediterranean (5.1%), The Pontic region and the Palaearctic (1.3% each). Based on the analysis of the relationship of paleoand neoendemics, it was concluded that the process of formation of the endemic nucleus of the flora of euxerophytes took place at least in three stages: due to heterochronous waves of migration from distant western and eastern centers of formation of xerophilic flora of the Ancient Mediterranean, through the formation of secondary centers in Asia Minor and Western Asia, and then in the Western Mediterranean; the most recent most intensive speciation, which took place in the territories of Inland Dagestan, the Central Caucasus and Northwestern Transcaucasia, on a Caucasian genetic basis in Tertiary speciation centers, led to the loss of many types of distant family ties. The results obtained expand our understanding of migration processes and the history of the formation of the flora of the Caucasus.