Spatial distribution of bryophyte species diversity in Eastern Europe

To assess the spatial distribution of bryophytes in Eastern Europe, more than 53,000 localities of 1296 species were analyzed in 397 squares of 100 x 100 km. The number of species within (or density) of one square varies from 591 (southwest of the Kola Peninsula to less than 50 (in arid steppe and semi-desert regions in the southern part of Eastern Europe and in some of arctic and north-taiga poorly studied territories). 8 centers of bryophytes species diversity have been identified in Eastern Europe: Kola Peninsula, South Karelian, Ural, Estonian, Smolensk-Moscow Upland, Carpathians, Black Sea, Caucasian, as well as 7 intermediate sub-centers: Arkhangelsky, Timansky, Narochansky, Volzhsko-Kamsky, South Ural, Belovezhsky, Kiev-Mozyrsky. Their characteristics and unique species for each centers are given. A structural model of the organization and interrelationships of bryofloras in Eastern Europe is proposed. The elevated mountain regions are the concentration of maximum diversity and refuge for many rare species of bryophytes in the region. The central connecting core of the system is the Smolensk-Moscow Upland. It is through this center, there is a connection between the western and eastern parts of the bryoflora of Eastern Europe. The most related element of the spatial structure of bryophytes in Eastern Europe is the Kyiv-Mozyr subcenter (5 ribs), through which the main migration of bryophytes from north to south and vice versa occurs. The Belovezhsky and Narochansky subcenters each have 4 ribs and also actively contribute to the migration process. Through the elevated areas of the Arkhangelsky and Timan subcenters, the Kola Peninsula and South Karelian regions are connected with the Urals. The most isolated in the region is the Caucasus, which maintains links with other centers through the Black Sea center.