Koroleva N., Kopeina E. Grasslands in the lower flow of Varzuga River (Murmansk Province) as a value habitat types

Polar-Alpine Botanical Garden-Institute, Kola Science Center of Russian Academy of Sciences, 184250, Kirovsk, Russia. E-mail: flora012011@yandex.ru; kopeina-e@yandex.ru
Humid floodplain grasslands in the low flow of Varzuga River (Murmansk region) represent European floodplain grasslands on the northernmost limit of distribution. The composition and structure of these plant communities are still poorly known. We studied grasslands in the river valley and on river islands from Varsuga to Ust’-Varzuga in 2013–2015; and then used GRAPHS hierarchical clustering (Novakovsky, 2004) of grasslands dataset. This clustering was based on 187 vegetation plots selected to represent the variety of grassland vegetation. It resulted in 6 plant community types, namely: Low-floodplain Grassland, High-floodplain Grassland, Open Grassland on Young Alluvia, Deschampsia Tussock Grassland, Moist Grasslands and Seashore Grassland. Syntaxonomy of grasslands is still unclear. Flora of grasslands includes character species of the Order Epilobio lactiflori–Geranietalia sylvatici Michl, Dengler & Huck 2010: Cirsium heterophyllum, Trollius europaeus, Geranium sylvaticum, Ranunculus acris, Filipendula ulmaria (Class Mulgedio-Aconitetea Hadač & Klika in Klika & Hadač 1944), and Molinietalia Koch 1926: Lysimahia vulgaris, Mentha arvensis, Poa palustris, Potentilla anserina, Sanguisorba officinalis, Thalictrum flavum, Veronica longifolia (Class Molinio-Arrhenatheretea Tx. 1937), and specific arctic species with euro-Siberian and euro-Asiatic distribution: Astragalus subpolaris, Dianthus superbus, Hedysarum arcticum, Oxytropis sordida, Veratrum lobelianum etc. Coenoflora of vascular plants of grasslands is very rich and counts 236 species, 6 of which were included in the Red Data Book of Murmansk Region (2014) – Armeria scabra Pall. ex Schult (3) NT, Hedysarum arcticum B. Fedtsch. (2) EN, Ligularia sibirica (L.) Cass. (3) NT, Ribes nigrum L. (3) NT, Thymus subarcticus Klok. et Shost. (3) NT, Zannichellia repens Boenn. (3) NT.