On the Distribution of Pleurozium schreberi (Bryophyta, Hylocomiaceae) in the East European Plain and Eastern Fennoscandia

Pleurozium schreberi is one of the most common moss species in the forest area. It is dominant in the moss layer of blueberry and wood sorrel forests. It can occur in small quantities in almost all types of forests (even in bogs). It is also a typical component of the moss layer in tundra. The article considers the distribution of Pleurozium schreberi in the East European Plain and Eastern Fennoscandia. On the basis of literature sources on the occurrence of the species in different regions (according to point data), a model map of species distribution using the kriging-method has been created. The overlaying of the model map on the maps of spatial distribution of climatic parameters and vegetation zones in this area has revealed that the biogeographical preferences of the species. P. schreberi is characterized by its highest distribution in the forest zone. It often occurs here and represents a phytocenotically active species. The occurrence of Pleurozium schreberi dramatically decreases in the transition from the forest to the steppe zone, where it is a rather rare species, growing exclusively in pine and birch pegs. This species disappears in the open steppe. From the steppe zone to the south, the occurrence of Pleurozium schreberi gradually decreases with increase in summer temperatures and decrease in precipitation and with forest disappearance. In the north, where the species is highly active, its range abruptly ends on the coast of the Arctic Ocean. This pattern of distribution of Pleurozium schreberi is associated both with cenotic preferences and with climate: it becomes rare in regions with summer temperatures higher than +23°C and annual precipitation of less than 400 mm.