Habitats’ characteristics and population structure of Triglochin maritima L. (Juncaginaceae) found in the intertidal zone of the White Sea littoral

Populations of the dominant halophyte circumboreal-polar species Triglochin maritima L. found on the western coast of the White Sea, in the estuaries of the rivers (Kolezhma, Keret’) were studied. Three experimental plots located along the transect line of the coast, which differ by the type of substrate and vegetation were assessed. Different eco-coenotic conditions of the species habitat, including geomorphic shore types, wave actions, mechanical and chemical composition of the substrate, and the types of drainage were observed. The increase in some biometric and population parameters of the T. maritima plants located in the tidal zone of the open coast, on the bay coasts, on muddy-silty and sand-gravel substrates within allocated areas was revealed. These structural features allow T. maritima to adapt dynamically to the unstable conditions of existence in the tidal zone of White Sea.