To the syntaxonomy of pounikkos mire complexes in the forest-tundra and tundra in the northern part of the Kola Peninsula
Authors: Koroleva N. E. 
Published: February 2020

Mires of the Kola Peninsula were investigated mainly in its southern part (Botch, 1989; Payanskaya-Gvozdeva, 1990; Smagin, 1999а, 1999b). The published relevés of tundra mires of the Peninsula are poor (Kalliola, 1939; Koroleva, 2001, 2006), and this paper surveys pounikkos mire complexes in its northern part, represents their classification according to the Braun-Blanquet approach accompanied by syntaxonomical tables. The investigated area is situated in the north of the Kola Peninsula within the forest tundra and in southern arctic tundra, with the mean annual air temperature between –0.5 °C and –2.0 °C and annual precipitation 600–700 mm. The geological basis is Archean and Proterozoic crystalline rocks, covered by coarse gravelly moraine and sandy fluvial-glacial deposits, and peat deposits in wetlands. Plant cover represents the combination of subarctic birch forests, tundra and mires. The mire complexes occur in river valleys, in lake and between moraine hill depressions, alternating with shrub and dwarf-shrub lichen tundra and forest-tundra on hill tops and slopes. Peat hummock (pounikkos) height is 0.3–0.5 (up to 1.0) м, their diameter is 0.3–0.7 (up to 1.5) м. In July the ice core is kept at 20–30 cm below the surface. Water-logged narrow ditches separate hummocks from each other. Inundated sedges- and water-cotton-dominated lawns, willow thickets along the water currents and small lakes are common within the mire complex. In the 2012 field season mounds and hummocks were densely inhabited by rodents, in particular by Lemmus lemmus. Oligotrophic and ombrogenous mosses lichens dwarf-shrub dominated communities of mounds, small turf hummocks (pounus, pounikkos) and on the margin of mire massifs belong to the alliance Oxycocco−Empetrion hermaphroditi Nordh. 1936 ex Neuhäusl 1969 (diagnostic taxa (DT): Eriophorum vaginatum, Oxycoccus microcarpus, Rubus chamaemorus, Mylia anomala, Sphagnum fuscum) with the ass. Empetro−Sphagnetum fusci subass. typicum Dierssen (1982) 1996 (DT Ledum palustre and Orthocaulis kunzeanus) and Empetro−Sphagnetum fusci subass. dicranetosum elongati (Regel 1923) stat. nov. (DT Dicranum elongatum). Species poor sedges- and cottongrass dominated oligo-, oligomesotrophic fens of flark and lawns belong to the alliance Caricion rotundatae (Kalliola 1939) stat. nov. (DT Carex concolor, C. rariflora, C. rotundata, Baeothryon cespitosum, Eriophorum polystachion, Sphagnum lindbergii, S. compactum, Warnstorfia exannulata, Sarmentypnum sarmentosum, Calliergon stramineum) with three associations: ass. Gymnocoleo inflatae−Caricetum rariflorae ass. nov. (DT Nardus stricta, Sphagnum compactum, Gymnocolea inflata, Anthelia juratzkana), ass. Warnstorfio sarmentosi−Caricetum concoloris ass. nov. (DT the same as for the alliance), ass. Eriophoro polystachii−Sphagnetum lindbergii (Kalliola 1939) stat. nov. (DT Sphagnum lindbergii). Low willows and sedges dominated communities along mire springs or in percolated areas are described as ass. Salici lapponi−Caricetum concoloris ass. nov. (DT Betula nana, Salix lapponum, S. phylicifolia, Calamagrostis strictа, Carex rostrata, Comarum palustre, Molinia caerulea, Viola palustris, Lophozia longiflora) with no affiliation to any alliance. Proposed new alliance Caricion rotundatae occurs in tundra and forest-tundra zone to the north of main areal of alliances Rhynchosporion albae Koch 1926 and Caricion lasiocarpae Vanden Berghen ap. Lebrun et al. 1949, which comprise oligotrophic and mesotrophic flark communities of boreal mires. Among diagnostic taxa of Caricion rotundatae are low sedges and brown mosses and in opposite to the alliance Rhynchosporion albae it doesn’t include the character species of Rhynchosporion albae (Carex livida, Scheuchzeria palustris, Rhynchospora alba). The studied mire complexes are very characteristic for the entire subarctic Fennoscandia, being located in the north of the Kola Peninsula close to the east-northern border of their European distribution area. They are considered to include more fast-growing permafrost hummocks comparing with palsa mires (Grab, 2003). Based upon their high alpha diversity and important ecological and scientific role, the discussed pounus mire massifs are perspective to be examined as possible value natural habitats.