On the Flora of the Onezhskoye Pomorye National Park (Arkhangelsk Region)

During a survey in 2020 of the western part of the Onezhskoye Pomorye National Park in the area from Lake Parusnoe in the south to Cape Letny Orlovsky in the north, 353 taxa of vascular plants were recorded, including 341 native and 11 alien. Species were listed for 9 geographical points. Occurrence of each species was determined on a 4-point scale: 1 - very rare, 2 - rare, rather rare, 3 - quite often (sporadically), 4 - common, at each point. The calculated average occurrence gives a fairly satisfactory information on each species distribution in the western part of the national park. Species with an average occurrence of 3.0 - common. The floras composition of geographic locations and species occurrence are largely related to the features of the coastline. To the south of Cape Chesmensky, the coasts are practically devoid of indentations, the littoral is silty-sandy, the exposition of the coasts is southwestern, the coasts are largely protected from the northern winds by end moraine ridges and hills. On Cape Chesmensky and to the north of it, the littoral is sandy and bouldery, which led to the formation of boulder capes and numerous bays of various sizes, the coast at first has a northwestern, and to the east of Cape Letny Orlovsky, a northern exposure, without protection from the northern (and eastern) winds. An analysis of the species distribution south of Cape Chesmensky, as well as on the cape itself and north of it, showed rather significant differences in the occurrence of many coastal species (the influence of the littoral and supralittoral composition), more thermophilic forest species of predominantly southern distribution, and cold-resistant species of predominantly northern distribution (influence of exposure). Four species listed in the Red Data Book of the Arkhangelsk Region were found in the surveyed area: Pseudathyrium alpestre, Botrychium boreale, Blysmopsis rufa, Rhodiola rosea, as well as 10 species included in the list recommended for biosurveillance: Dryopteris filix-mas, Sparganium hyperboreum, Ruppia maritima, Catabrosa aquatica, Puccinellia coarctata, Carexlivida, Hammarbya paludosa, Cakile arctica, Thymus serpyllum subsp. tanaënsis, and Crepis nigrescens. The information obtained can become the basis for floristic monitoring.