Twenty-one year dynamics of vegetation from long-term plots in East European tundra

The results of vegetation monitoring from 1999 to 2020 on 12 plots laid out in different types communities Cape Bolvansky Nos the northwest Bolshezemelskaya tundra are presented (Fig. 1). area is located border between southern and typical subzones.
 On five long-term with clay-loam patches bare ground sparse shrubby willowsedge-dwarf shrub-moss were formed. They belong zonal ass. Dryado octopetalaeHylocomietum splendentis Andreev 1932 subass.caricetosum capillaris Lavrinenko et 2018 (Table 1) class Carici arctisibiricaeHylocomietea alaskani Matveyeva 2021 prov., order Caricetalia arctisibiricae-lugentis prov. alliance octopetalaeCaricion arctisibiricae Koroleva Kulyugina Chytr al. 2015. Plot M6 has a 2-element horizontal structure: large loam (3.04.5 m long, 1.01.5 cm wide) elongated along slope alternate flat areas turf them, dominated by dwarf shrubs Dryas octopetala subsp. subincisa Salix reticulata mosses Aulacomnium turgidum, Hylocomium splendens, Tomentypnum nitens; rims absent. lanata grows groups shallow depressions mosses. Plots M5, M9, M11 M12 occupy lower parts hill slopes deluvial plumes; 3-element structure rounded or oval (1.5-3.0 (up 5.0) diameter) surrounded rims, such ring structures separated troughswith hygrophilous (Aulacomnium palustre, Ptilidium ciliare, Sphagnum spp.), where shrub willows (mainly glauca) grow. well formed usually covered (Arctous alpina, subincisa, Empetrum hermaphroditum, reticulata), sedge Carex bigelowii arctisibirica Dicranum elongatum, Rhytidium rugosum).
 Three occupied shrub-lichen rare layer elfin Betula nana, which affiliated Loiseleurio procumbentisVaccinietea Eggler ex Schubert 1960, Deschampsio flexuosaeVaccinietalia myrtilli Dahl 1957, Loiseleurio-Arctostaphylion Kalliola Nordhagen 1943 2). M3 M4, light loamy soils slightly convex tops hills conditions good drainage, birch belonging ass.Loiseleurio-Diapensietum (Fries 1913) subass. salicetosum nummulariae 2006 plot M2, part gentle under snow cover winter, community an almost continuous lichen chionophilic Сladonia was Cladonietum rangiferino-arbusculae 2020.
 M1 M7, relief peat-gley soil, belongs Oxycocco-Sphagnetea Br.-Bl. Tx. Westhoff 1946 Oxycocco microcarpiEmpetrion hermaphroditi Du Rietz 1954. cotton grass tussocks (Eriophorum vaginatum) shrub-cloudberry-lichen-moss Pleurozio schreberiEriophoretum vaginati subass.sphagnetosum lenenses 2022 3).
 M8 M10 represented complexes polygonal peatlands. polygons both plots, shrub-cloudberry-lichen ass.Rubo chamaemoriDicranetum elongati Dedov 2015 assigned Rubo chamaemoriDicranion formed.
 21-year period made it possible set some trends changing composition plant syntaxa.
 main species found all survey years (1999, 2014, 2017 2020). most floristically rich communitis, total 160 identified, 22 (14%) once. three four boggy communities, 7 (8%) 90 10 (11%) 95 species, respectively, also identified Within each plot, change number over range 724%. It important understand that variability due identifying (appearance) / missing (disappearance) single mainly lichens (including crustaceous ones).
 many there general increase herbaceousness (due sedge, grasses, grass, cloudberries) particularly noticeable activity Equisetum arvense, began create green aspect.
 greatest structural transformations took place 2- structure. finding disappearance spongy nanorelief result frost boiling) their gradual overgrowth cryptogamic crusts, small flowering plants, shrubs. In tundras, clear module patchrimtrough disappearas overgrowing partial subsidence (in places merged overgrown look like turf). subass.salicetosum nummulariae, completely lichens, mosses, shrubs, surface leveled difference height turf. New formation not been anywhere, but 20 fresh outpourings detected within old spots M4 at top hill.
 glauca S. lanata, predominantly 1015 cm, increased 1.52.5 times plots.
 A decrease cottongrass tussock ass.Pleurozio further replacing (and later sphagnum) revealed.
 Our generally agree transformation influence climatic factors, established American sector Arctic [Gould al., 2009; Elmendorf 2012; Jorgenson 2015; Harris 2021]. Noting heterogeneity responses climate change, authors report projective coverage ecosystems, as abundance evergreen deciduous when reducing lichens.