Included here is the Gulf of Bothnia which represents the northern part of the Baltic Sea in Northern Europe.

Bothnian Seashore Meadows

These zonal communities in the Gulf of Bothnia are analogous to the saltmarshes of fully saline seawater but here were the salinity can be as low as 0.2% there is fewer halophytes (salt tolerant species).  Among the hydrophytic vegetation of the so-called hydrolittoral (wet littoral) zone halophytes are virtually absent, but because of the sub arid climate in this area during the growing season bare salt patches can develop in the geolittoral or dry littoral zones and as a result these usually support more halophytes. Several zones or meadow types occur in the geolittoral. These usually include a pioneer zone of Eleocharis uniglumis followed by a more extensive Juncus gerardii zone. The latter includes a curious mixture of glycophytes (non salt tolerant species), such as Parnassia palustria, and halophytes such as Glaux maritima, Salicornia europaea, Spergula salina and the endemic taxon Odontities vernum subsp. littoralis (Scrophulariaceae). Festuca rubra meadows often occur landward of the Juncus gerardii distinguished by a rich variety of glycophytic species. Other characteristic taxa include Calamagrostic neglecta, Carex glareosa, Leontodon autumnalis and the endemic or near endemic taxa Euphrasia bottnica (Scrophulariaceae) and Primula nutans subsp. finmarchica (Primulaceae). Other zones may be present especially at the sheltered ends of bays such as Limingan lahti and Kempeleen lahti. For example, an Eleocharis acicularis zone can form a wide and luxurious meadow near the deltas of rivers. Common associates such as Eleocharis palustris, Ranunculus trichophyllus var. eradicatus and Subularia aquatica may be present, but outstanding among this flora is Alisma gramineum subsp. wahlerbergii (Alismataceae), which is considered to be endemic to the Baltic Sea. Also at the head of bays are several Carex meadows. These may be dominated by Carex halophila (Cyperaceae) – a species confined to shores of Bothnian Bay. In coastal meadows along the White Sea and Arctic shores, Carex mackenziei, which has a circumpolar distribution, and or C. paleacea may be important components, whereas in the hydrolittoral species such as Equisetum fluviatile, Phragmites communis and Schoenoplectus tabernaemontani often predominate. Other important taxa associated with these coastal meadows include Baltic endemics such as Artemisia bottnica and A. maritima subsp. humifusa (Asteraceae), Agrostis stolonifera var. bottnica, Deschampsia bottnica and Hierochloë odoata subsp. baltica (Poaceae), Juncus articulatus var. hylandri (Juncaceae), Mentha arvensis var. litoralis (Lamiaceae) and the European endemics Angelica archangelica subsp. litoralis (Apiaceae), Agrostis gigantea var. glaucescens (Poaceae), Atriplex longipes subsp. praecox (Chenopodiaceae) and Myosotis palustris var. praecox (Boraginaceae).

References

Beeftink, W. G. 1977. The coastal saltmarshes of western and northern Europe: an ecological and phytosocialogical approach. In: Ecosystems of the World 1 - Wet Coastal Ecosystems. Ed. V. J. Chapman. Elsevier Scientific Publishing Company.

Dahl, E. 1998. The Phytogeography of Northern Europe. Cambridge University Press.

Erickson, L. & Wallentinus, H-G. 1979. Sea-shore vegetation around the Gulf of Bothnia. Wahlenbergia, 5: 1-219.

Polunin, O. & Walters, M. 1985. A guide to the vegetation of Britain and Europe. Oxford University Press.

Ratcliffe, D. 2005. Lapland: A Natural History. T & A D Poyser.

Siira, J. 1970. Studies in the ecology of the sea-shore meadows of the Bothnian Bay with special reference to the Liminka area. Aquilo Series Botanica, 9: 1-109.