The flora of open coasts and the estuaries of rivers is an important element of the Arctic flora and represents the littoral halophytic floristic complex. The salt marsh flora includes 113 species of vascular plants (12% of the total amount of Arctic flora), belonging to 62 families. Due to geographical conditions, the partial floras of coastal wetlands of the Russian Arctic have similar taxonomic and typological structure. In the geographical structure of flora-coenotic complex, the Arctic circumpolar species dominate. The Arctic coastlines are subjected to frequent disturbances associated with frost action, storms and ice pressure ridges that affect species richness and the ability of human populations to exploit coastal resources successfully. The dynamic changes of salt-marsh plant communities are site-specific: 1) in the initial stages, vegetation development mostly depends on the physical-chemical substrate properties and tidal action, 2) the spatial-temporal processes of successional change over a long time result in the environment development and changes in edaphic conditions. The time scale of these changes brought about by disturbances is biologically important as there must be sufficient time to allow genetic adaptation in plant and animal populations.

Ecological plasticity in the tidal zone, specifically the effects of daily and seasonal dynamics of environmental factors on the dominant species of vascular plants and epilithic lichens has been studied. The investigations were conducted on the Pomorian coast of the White Sea (Republic of Karelia) during two growing seasons (2012-2013). The studies of the morphological and anatomical characteristics of dominant individuals in the plant and lichen cover types have been made along the model transect through different substrate types. Determination of plasticity of plants and lichens was made by the method of Cornelissen exploiting coefficient of variation (CV). The obtained data showed that the investigated groups of vascular plants and lichens on the tidal zone on all measured morphological and anatomical parameters have a high level of plasticity

No abstract

No abstract

Coastal ecosystems (coastal wetlands) of Arctic seas are tracts of the Earth's surface showing a maximum diversity of living organisms due to a high heterogeneity of the area given that they are in oscillatory conditions. The greatest diversity of coastal ecosystems can be observed on open, shallow mud shores and in river mouths of northern tidal seas with salinized marine alluvium. Coasts of this type are widespread at the all seas of the North Ice Ocean basin. Coastal wetlands are unique transitional zones between the sea and the coastal tundra and the. communities built on permafrost. Massifs of maritime marshes support an important canal of the carbon extraction from the atmosphere and its burial and thus have the potential to lessen the greenhouse effect.