We argue the presence in the delta of the Volga River of a new class of desert halophyte communities Climacopteretea crassae Akhani 2004 ex Świerszcz et al. 2021. This class was originally presented ...by H. Akhani (2004) as a syntaxon uniting plant communities with a predominance of annual succulent plants with C4 photosynthesis in Iran. The class was proposed previously, without specifying the nomenclature type.
In 2021, the class Climacopteretea crassae was validated (Świerszcz et al., 2021). S. Świerszcz and his co-authors gave the class a floristic and ecological characterization. The syntaxa of this class remind such of the class Therosalicornietea Tx in Tx. et Oberd. 1958 in terms of the high representation of annual species of the Chenopodiaceae family (although with the participation of perennial species). However, they cannot be called the pioneer communities that usually characterize communities of the class Therosalicornietea. Compared to communities Therosalicornietea they occupy drier habitats. In addition to the strong salinization of the soil, from the surface they can also be solonetzic. Typically, habitats of the class Climacopteretea crassae are significantly affected by grazing by farm animals. The order Psylliostachyetalia spicato-leptostachyae Świerszcz et al. 2021 and the alliance Climacopterion lanatae Berdyev et Golub in Golub 1995 were assigned to the class Climacopteretea crassae.
We proposed a new alliance Petrosimonion oppositifoliae all. nova in the order Psylliostachyetalia spicato-leptostachyae. The ass. Suaedo-Petrosimonietum Golub 1986 was placed in this alliance. This association was originally included in the class Glycyrrhizetea glabrae Golub et Mirkinin Golub 1995 (Golub and Mirkin, 1986; Golub, 1986), and later in Therosalicornietea R. Tx. in R. Tx. et Oberdorfer 1958 (Golub, 1995; Golub and Maltsev, 2013). Plant communities of this association are found in the delta of the Volga River in dry habitats, mainly located on the slopes of Baer hillocks and their foots with a deep level of groundwater. The soils are highly saline and solonetzic. Above the habitats occupied by ass. Suaedo-Petrosimonietum, along the slopes of Baer hills and on their tops, zonal communities of class Artemisietea lerchianae Golub 1994 occur. Various meadow and halophytic plant communities grow below this association. New alliance Petrosimonion oppositifoliae all. nova was suggested.
We suppose that further study of the desert halophytic vegetation of the Caspian Lowland will allow to establish other syntaxa of class Climacopteretea crassae on this territory. Thus, in our opinion, the non-ranking plant communities of Petrosimonia oppositifolia–Suaeda acuminata comm., Suaeda altissima–Suaedaa cuminata comm., Suaeda tragus–Suaeda acuminata comm., occurring in this lowland, including Russia are closely related to this class (Freitag et al., 2001). In addition, a new class of halophyte communities separate from Climacopteretea crassae should be established for this territory on automorphic and similar soils, the floristic composition of which differs significantly from the phytocenoses of hydromorphic soils, such as those belonging to class Therosalicornietea Tx. in Tx. et Oberd. 1958. But the consideration of this issue requires further study of the vegetation of the Caspian lowland and the territories adjacent to it.
The vegetation of sedge-hypnum and forest swamps rich in soil nutrition was studied in “Chistoe Boloto” (Open Mire), located in the low left-bank terrace of the Irtysh River valley in the environs of ...Tobolsk city (58.25°–58.09°N, 68.15°–68.34°E) near the northern limit of this mire type distribution in Western Siberia.
A total of 7 associations, 2 subassociations, 1 variant, and 1 community type are described, of which one association (Hamatocauli vernicosae–Caricetum lasiocarpae) and 2 subassociations (Telypterido palustris–Betuletum pubescentis inops and Thelypteridetum palustris brachythecietosum mildeanae) are introduced as new ones. Communities are assigned to 4 alliances of 3 orders and 2 classes.
The class Alnetea glutinosae Br.-Bl. et Tx. ex Weshoff et al. 1946 of coniferous and small-leaved forests of Eurasia includes the order Calamagrostio purpureae–Piceetalia obovatae Lapshina 2010 combining forest-like swamp communities with dark coniferous species in the tree layer, called “sogra” in Siberia, with two associations within 2 alliances in the study area.
Ass. Mnio stellari–Pinetum sibiricae Lapshina 2010 (Fig. 2) of the alliance Carici cespitosae–Piceion obovatae Lapshina 2010 includes communities of the dark coniferous sogra. Their considerable geographical remoteness from the main distribution area in the south of the forest zone of Western Siberia and noticeable differences in the species composition allowed to establish within it var. Viola epipsila.
Ass. Carici appropinquatae–Pinetum sylvestris Lapshina 2010 (Fig. 3) of the alliance Carici appropinquatae–Laricion sibiricae Lapshina 2010 combines birch–pine herb-tussock sedge communities, rich in soil nutrition, dominated by Carex apropinquata, Thelypteris palustris.
The class Scheuchzeria palustris–Caricetea nigrae Tx. 1937 is represented by the alliance Saxifrago-Tomentypnion Lapshina 2010 in the study area. Diverse communities of sedge-hypnum and Menyanthes-low sedge-hypnum fens, which are visually well distinguished in the vegetation cover by the dominance of different sedge species (Сarex diandra, C. dioica, C. limosa, C. rostrata) and Menyanthes, correspond well in their floristic composition to the diagnosis of the ass. Brachythecio mildeanae–Caricetum limosae Lapshina 2010 (Fig. 6) described on the hypnum fens in the southeast of Western Siberia.
With the distance from the Tobolsk slope and gradual reduction of the groundwater influence, the domination in Menyanthes-low sedge-hypnum communities gradually flows from the ass. Brachythecio mildeanae–Caricetum limosae to Carex lasiocarpa — ass. Hamatocauli vernicosae–Caricetum lasiocarpae ass. Nov (Fig. 7).
A characteristic feature of the studied mire is the wide distribution of sedge-fern and fern communities among low sedge-hypnum fens dominated by Carex lasiocarpa and Thelypteris palustris, which are assigned to associations Thelypterido–Caricetum lasiocarpae Lapshina 2010 (Fig. 8) and Thelypteridetum palustris Lapshina et al. 2018 (Fig. 9). The latter is established as subass. brachythecietosum mildeanae subass. nov.
Comparison of the of mire habitats is made based on L. G. Ramenskiy ecological scales (Ramensky et al., 1956). Ecological indices (grades) of water supply and nutrient condition for each relevé are calculated. The ecological ordination of mire habitats (Fig. 10) shows values for mineral nutrition (Y-axis), and for water supply (wetness) (X-axis). According to the scale of mineral nutrition, the t communities exist in a narrow ecological range corresponding to mesotrophic conditions (6.5–9.0 grades). This is due to the fact that at high values of electrical conductivity and a medium close to neutral (EC=180–430; pH=6.5–7.5), peat soils rich in ground nutrition are poor in nitrogen and phosphorus (Wassen et al., 2005).
According to the humidity scale, the studied vegetation may be divided into 3 groups: communities of hydromesophilic (77–88 degrees), subhydrophilic (89–94 degrees), and aerohydrophilic (95–103 degrees) habitats corresponding to the main classes of mire vegetation.
The first group includes syntaxa of two alliances of wooded swamps of the class Alnetea glutinosae, which occur in moderately humid habitats. The low birch swamps communities of the class Alnetea glutinosae are common in higher water saturated habitats. Syntaxa of low sedge-hypnum, fern, and sedge-fern fens of the class Scheuchzerio–Caricetea nigrae are common to the most wet fen habitats, often associated with high level of water horizons buried in peat deposits.
The classification results and ordination of syntaxa are confirmed by the t-SNE method, which allows displaying multidimensional hyperspaces on the plane. The right side of the ordination diagram (Fig. 11) shows well-differentiated low sedge-hypnum fens communities of the class Scheuchzerio–Caricetea. The rare sedge-hypnum communities with the Paludella squarrosa dominance are located somewhat apart, bonded to the exits of springs. The opposite part of the diagram shows well-differentiated communities of wooded swamps within the class Alnetea glutinosae. They are adjoined by communities of the ass. Thelypterido palustris–Betuletum pubescentis, within of the class Alnetea glutinosae.
The most difficult challenging was to determine the position of Carex lasiocarpa-dominated fern, sedge-fern and sedge-hypnum communities within the higher units of classification. They occur in ecologically similar habitats as low sedge-hypnum communities of the alliance Saxifrago-Tomentypnion with well-represented diagnostic species in these.
Due to that and the presence of hypnum moss layer, we assigned these communities to the alliance Saxifrago-Tomentypnion of the class Scheuchzeria-Caricetea.
The vegetation of frozen peat mounds and polygons of palsa bogs as well as tundra-mire complexes, according to the Braun-Blanquet classification, is assigned to Oxycocco-Sphagnetea class Br.-Bl. et ...Tx. ex Westhoff et al. 1946 (Koroleva, 2006; Lavrinenko and Lavrinenko, 2015; Telyatnikov et al., 2021; Jiroušek et al., 2021) and considered within two alliances – Oxycocco microcarpi–Empetrion hermaphroditi Nordhagen ex Du Rietz 1954 and Rubo chamaemori–Dicranion elongati Lavrinenko et Lavrinenko 2015. However, the data on the phytocoenotic diversity of these mire types are very scarce.
Our research was conducted between 2004 and 2019 in the northern part of the Khanty-Mansi and the southern part of the Yamal-Nenets Autonomous Areas of the Tyumen Region at 20 study sites (Fig. 1) located between 63° and 75° N in the northern taiga, forest tundra and southern tundra of West Siberia. Additionally, we used relevés obtained in 2021 at 3 study sites at the northern boundary of the larch woodland sub-zone and in the southern tundra of the Taimyr Peninsula in the middle reaches of the Dudypta River (70.5°–71.5°N and 90.5°–95.0°E).
Seven associations, 9 subassociations and 9 variants (Tables 1–6) have been identified in the class Oxycocco-Sphagnetea on the base of 376 vegetation relevés of palsa bogs and tundra-mire complexes. Furthermore, 567 previously published relevés of ecologically similar syntaxa from the adjacent regions (Koroleva, 2006; Lavrinenko and Lavrinenko, 2015; Telyatnikov et al., 2021; Lavrinenko et al, 2022) were used for statistical processing and comparative analysis.
A comparison of all identified and previously described syntaxa in similar habitats of the Russian Subarctic were made (Table 7). Statistical processing and t-SNE ordination (t-distributed stochastic neighbor embedding method) (van der Maaten, Hinton, 2008) of the entire data set was performed to confirm the classification results (Fig. 11).
Cluster analysis (Fig. 12) showed a significant difference between the 4 groups of syntaxa at a high hierarchical level.
Two clusters, I and IV (Fig. 12) are assigned to the earlier described alliances Rubo chamaemori–Dicranion elongati and Oxycocco microcarpi–Empetrion hermaphroditi.
The alliance Rubo chamaemori–Dicranion elongati comprises shrub-moss (Dicranum elongatum, Polytrichum strictum)-lichen communities on dry frozen peat mounds of oligotrophic palsa bogs and polygonal mires in the forest tundra and tundra zone of European Russia. It includes 4 associations (Fig. 11, 12) Tephroserido–Politrichetum stricti, Rubo chamaemori–Dicranetum elongati, Pleurozio schreberi–Caricetum globularis, Rubo chamaemori–Caricetum rariflorae, previously described on the east coast of the Kola Peninsula and in the East European tundra (Koroleva, 2006; Lavrinenko, Lavrinenko, 2015; Lavrinenko et al., 2022).
The alliance Oxycocco–Empetrion hermaphroditi includes open and forested dwarf shrub-Sphagnum communities of relatively dry hummocks and ridges dominated by Sphagnum fuscum on ombrotrophic raised bogs in the boreal and forest-tundra zones of Eurasia. The alliance is represented by a single ass. Ledo palustris–Sphagnetum fusci occurred on frozen bogs in the north of Western Siberia. We consider this association in the narrow sense (sensu Du Rietz, 1921), including only non-forested dwarf shrub-Sphagnum (S. fuscum) communities of subarctic subcontinental regions of Europe and Western Siberia.
Two new alliances, along with the previously described ones are proposed (Fig. 12, clusters II and III) – Rubo chamaemori–Cladonion stygiae all. nov.and Sphagnion lenenses all. nov. (Table 8). They combine dwarf shrub-lichen communities of palsa bogs of the northern forest taiga zone in Western Siberia and oligotrophic dwarf shrub-cotton grass-lichen-Sphagnum communities with S. lenense and S. balticum in raised bogs of Asian part of the Subarctic, respectively.
The alliance Sphagnion lenenses is represented by the recently described ass. Ledo decumbentis–Eriophoretum vaginati (Lavrinenko et al., 2022). Based on additional data from the southern tundra zone of Western Siberia and the Taimyr Peninsula, two new subassociations are described within the association L. d.–E. v. sphagnetosum lenenses and cladonietosum amaurocraeae.
The alliance Rubo chamaemori–Cladonion stygiae includes 3 associations, replacing each other from south to north: ass. Ledo palustris–Cladonietum stygiae ass. nov. with 2 subass. L. p.–C. s. typicum, and sphagnetosum fusci, differing by the ratio of mosses and lichens in the ground cover (northern taiga) → ass. Cladonio stygiae–Caricetum globularis with 2 subass. C. s.–E. v. typicum and salicetosum pulchrae (forest tundra) → ass. Sphagno lenenses–Cladonietum stygiae (southern tundra). We also assigned conventionally the Ledum palustre–Polytrichum communities (ass. Ledo palustris–Polytrichetum stricti) to the same alliance. They represent the long-term successional stage in the post-fire restoration of the dwarf shrub (Ledum palustre)-lichen vegetation of frozen peat palsas.
Despite a relatively small number and wide ecological amplitude of the majority of dominant and constant species in raised bog communities of Oxycocco-Sphagnetea, the species constancy and abundance (phytocoenotic activity) in communities of various alliances differ clearly, which makes it possible to identify the differential species combinations (Table 8).
Two alliances described here and previously known all. Rubo chamaemori–Dicranion elongati are assigned to the new order Rubo chamaemori–Cladonietalia arbusculae ord. nov.
Differential species combination of the alliance Rubo chamaemori–Dicranion elongati (having a central position in the order), is common to all communities of the class Oxycocco-Sphagnetea in the Subarctic. These species are proposed as diagnostic species of the new order: Betula nana, Cladonia arbuscula, C. amaurocraea, C. rangiferina, C. stygia, Dicranum elongatum, Empetrum nigrum s. l., Flavocetraria cucullata, Polytrichum strictum, Rubus chamaemorus, Vaccinium vitis-idaea subsp. minus.
The order Sphagnetalia medii Kästner et Flössner 1933 is represented in the north of Western Siberia by only one alliance — Oxycocco microcarpi–Empetrion hermaphroditi, common mainly in the boreal forest zone.
The new structure of the class Oxycocco-Sphagnetea shows the major zonal and sectoral-geographical categories of mire vegetation in Northern Eurasia.
The involvement of the entire volume of relevés data set and the expansion of the survey to the boreal zone and eastern regions of Russia will allow the hierarchical structure and differences of higher units in the class Oxycocco-Sphagnetea to be more clearly demonstrated.
Brief information is provided on the Mire field seminar with international participation held on September 8–9, 2022 on the basis of the Polistovsky State Nature Reserve (Pskov Region, Russia). The ...two-day seminar included a plenary session and a field trip to the territory of the Reserve with a visit to the “Plavnitsa mire” ecotrail. Ten reports were presented as well modern methods of studying mire ecosystems were demonstrated.
An increase in the dominant species participation in plant cover (increase in their projective cover, biomass, share in the total grass stand biomass) leads to change in the occurrence of many ...associated species, which may effect on the degree of difference (similarity) in the species composition of communities located in various habitats, and, accordingly, on the results of their classification. We considered this issue using the example of non-forest communities with high and low participation of certain dominants.
The study area included the vicinity of the city of Maikop, the foothills and mountain ranges of the Western Caucasus (the basins of the Belaya and Bolshaya Laba rivers, 200–2500 m a. s. l.), as well as coastal areas of the Black Sea shelf and shallow areas of the Taman Bay of the Azov Sea (depths from 0.1 to 5 m). The objects of study were communities with varying degrees of participation of certain species, located in natural (semi-natural) and anthropogenic habitats of different types: 7 communities with the dominance of brown algae Ericaria bosphorica and Gongolaria barbata (Cystoseira sensu lato) (macrophytobenthos of the Black Sea), 6 — aquatic plants Zostera noltei and Z. marina (macrophytobenthos of the Azov Sea) and Solidago сanadensis (synanthropic communities), 5 each dominated by Calamagrostis arundinacea (subalpine meadows), Calamagrostis epigejos, Botriochloa ischaemum (low mountain meadows, synanthropic communities), Rubus caesius (edges and old fields) and Medicago falcata (synanthropic communities).
Within each community 25–30 plots (0.5×0.5 m) were established. A sample of aboveground biomass was taken in each plot. For each of them were determined: 1) the weight of the wet biomass in general (W), the biomass of dominating (Wd) and associated species (Ws); 2) the degree of dominance (D = Wd / W), 3) the number and composition of associated species. For marine bottom communities, the Wd reflected the joint biomass of Ericaria bosphorica and Gongolaria barbata as well as Zostera noltei and Z. marina, respectively. In addition, since macrophytobenthos dominants may effect both negativly (competition) and positivly (protection, substrate) on other species, their participation in communities was assessed through absolute (Wd) biomass.
From each series 10 samples with both the lowest (LD) and the highest (HD) dominant participation were selected. Data on species constancy in groups of LD biomass samples taken from 5 to 7 communities dominated by certain species were combined into one Table (infracenotic system, ICS), as well as data on species constancy in groups of samples with HD. The degree of differentiation of ICS with LD and with HD was assessed in two ways: 1) through the number of species considered as diagnostic for certain communities (the higher the number of such species, the higher the degree of differentiation of the ICS); 2) by visual comparison of the results of PCA-ordination of biomass samples with LD and with HD.
The results show that an increase in the participation of dominants in non-forest terrestrial and marine bottom plant communities leads to a decrease in the constancy of associated species. As a result, some species lose their diagnostic status, while others become diagnostic ones. The number of the first in most cases is much higher than the second. Therefore, groups of samples with HD are characterized by a smaller number of diagnostic species than groups of samples with LD, and, accordingly, less differentiation. To a greater extent, this is expressed in communities with the dominance of Rubus caesius, Calamagrostis arundinacea, C. epigejos and Medicago falcata, and to a lesser extent, in communities with the dominance of Solidago сanadensis, as well as in macrophytobenthos. In addition only about 40 % of the species identified as diagnostic in groups of samples with HD are diagnostic for groups of samples with LD, taken from the same communities. Including, in communities with the dominance of Solidago canadensis — only 20 %, Zostera noltei and Z. marina — 25 %, Rubus caesius — 33 %. The PCA-ordination of groups of samples with low and high dominance of Calamagrostis arundinacea, Rubus caesius, Medicago falcata and Cystoseira s. l. shows slightly higher differentiation of the former (with LD) than the latter (with HD). In communities with low and high participation of other dominants, the differences in this regard are not pronounced.
Thus, our results showed that groups of biomass samples with low and high participation of dominants, taken from the same communities, are characterized mainly by different numbers and composition of diagnostic species. This means that the results of the plant communities classification based on the ecological-floristic approach may depend, among other things, on the degree of species dominance in the sample plots. However, there is a circumstance that limits the significance of our results for the practice of syntaxonomic studies of terrestrial vegetation. It is associated with a significantly different size of sample plots that we used for biomass sampling (0.25 m2) and which are usually used for terrestrial communities (16–100 m2). In particular, if the influence of dominants on other species is indiscriminate, then it should be expected that its consequences for the community species richness, and, accordingly, the occurrence of species, will be clearly felt only in relatively small sites (Powell et al., 2011, 2013; Akatov et al., 2021, 2022; Afanasyev et al., 2022). The relevés of macrophytobenthos (sampling of biomass) are usually made on much smaller sample plots (0.1–0.25 m2). Therefore, for the practice of hydrobotanical research, our results may be more useful.
Open sands in the Western Transbaikalia occupy large areas. Syntaxonomy of psammophytic vegetation has been developed for many regions of Baikal Siberia: the Selenga basin (Dulepova, Korolyuk, 2015), ...the Baikal coast (Brzeg, Wika, 2001; Chytrý et al., 1993; Dulepova, 2016), the Barguzin basin (Dulepova, Korolyuk, 2021), Verkhnecharskaya depression (Dulepova, Korolyuk, 2013). However, the sand vegetation in the Khudan River valley still was not studied. This area is interesting because it is remote and isolated from regions with wide distribution of sand dune vegetation. The objective of the study is to identify the diversity of psammophytic communities of the Khudan River valley and determine their syntaxonomical position.
The dataset includes 45 relevés of psammophytic communities performed by the author between Innokentievka and Mogsokhon villages, Kizhinginsky district of the Republic of Buryatia (Fig. 1). Data analysis was carried out using IBIS 7.2 (Zverev, 2007), Statsoft Statistica v.8.0 (Hill, Lewicki, 2007), and PAST 3.0 (Hammer et al., 2001). As a result of cluster analysis (Ward method, Sokal & Sneath similarity measure No. 1) the syntaxa of lowest ranks were identified (Fig. 3).
The class Brometea korotkiji Hilbig et Korolyuk 2000 unites the vegetation of open sands in East Siberian–Central Asian sector of the Palearctic (Lavrenko et al., 1988). Three species from its diagnostic combination were found in the Khudan valley: Bromopsis korotkiji, Carex sabulosa, Corispermum sibiricum. The order Oxytropidetalia lanatae Brzeg et Wika 2001 represents the psammophytic communities of Baikal Siberia. In the study area it is diagnosed by Oxytropis lanata and Chamaerhodos grandiflora. The range of the alliance Festucion dahuricae Dulepova et Korolyuk 2015 covers the Barguzin and the Selenga basins. In the analyzed relevés, Aconogonon sericeum, Agropyron michnoi, Artemisia xanthochroa, A. xylorhiza, Leymus littoralis, Festuca dahurica represent the diagnostic species of the alliance.
Communities of the ass. Corispermetum sibirici Gogoleva in Kononov ex Taran 1995 (Table, rel. 1, 2) form small patches along the gentle tops of dunes and ridges, more rarely on steep slopes and in deflation depressions (Fig. 4). Communities of the ass. Leymetum littoralis Dulepova et Korolyuk 2015 (Table, rel. 3, 4) occur in actively eroded habitats. The ass. Oxytropido lanatae–Caricetum sabulosae Dulepova et Korolyuk 2021 (Table, rel. 5) was found only once on flat sandy ridge (Fig. 5). Communities of the ass. Corispermo sibirici–Oxytropidetum lanatae Dulepova et Korolyuk 2015 are widespread on not fixed sands (Table, rel. 6–14). They occupy slopes, flat ridges and deflation depressions. The var. typica is characterized by domination of Oxytropis lanata and high abundance of Corispermum sibiricum. The var. festuca dahurica represents fescue sandy steppe with co-domination of Oxytropis lanata.
Association Aconogonetum sericei ass. nov. (Table, rel. 15–35). Holotypus – relevé 15 in Table (field no. 12-0720), Republic of Buryatia, Kizhinginsky district, south of the Ulzyte village, top of the sandy ridge, 16.08.2012, Korolyuk A. Yu.
Diagnostic species: Aconogonon sericeum, Bromopsis korotkiji.
Association represents the most widespread psammophytic communities in the Khudan valley (Fig. 6). The projective cover varies from 15 to 30 %, species richness — from 4 to 16 species per relevé. These features depend on anthropogenic pressure and wind erosion. The main dominant is Aconogonon sericeum. Some species occasionally demonstrate high abundance: Leymus littoralis, Artemisia xylorhiza, Oxytropis lanata, Bromopsis korotkiji.
Class Cleistogenetea squarrosae Mirk. et al. 1985 includes the steppe communities of the East Siberian-Central Asian type. The order Stipetalia krylovii Kononov et al. 1985 and the alliance Stipion krylovii Kononov et al. 1985 represent typical steppes. The diagnostic combinations of these syntaxa are represented by some species occurring in the studied psammophytic communities: Agropyron cristatum, Artemisia frigida, Carex duriuscula, C. korshinskyi, Chamaerhodos erecta, Dontostemon integrifolius, Heteropappus altaicus, Koeleria cristata, Poa botryoides, Potentilla bifurca, P. tanacetifolia, Pulsatilla turczaninovii, Serratula centauroides.
The community Thymus baicalensis (Table, rel. 39–44) was described on leveled sandy habitats between open sands and steppes or shrubs. Thymus baicalensis is the main dominant, occasionally Leymus littoralis and Aconogonon sericeum co-dominate.
The psammophytic vegetation of the Khudan valley is characterized by high diversity. An anthropogenic pressure contribute significantly to the exodynamic successions. Increased grazing results in the dominant life forms changes as following: shrubs and trees → bunchgrasses → taproot perennial grasses and semi-shrubs → rhizomatous plants → annual plants (Dulepova, 2012). The NMDS-ordination shows strong relation between species composition and community’ structure, succession state and coverage of different life forms (Fig. 7). The first axis on the scatter plot is related to the ratio of annuals and perennials. The second axis reflects the ratio of mobile (rhizomatous perennials) and immobile (taproot perennials, bunchgrasses, semi-shrubs) species.
The studied communities represent a part of a psammophytic complex of the Selenga basin as a whole. This is reflected in the unity of the flora and the existence of associations found both in the Selenga and Khudan valleys. The only ass. Aconogonetum sericei ass. nov. is confined to the Kizhinginsky district. In terms of phytocenotic diversity, the psammophytic vegetation of the Khudan River valley is poorer in comparison with the middle part of the Selenga basin.
Ladoga is the largest lake in Europe (with 17 870 km2 area, 838 km3 water volume, and 47/230 m average/maximum depths), it lies around connection of two large geological structures: the Baltic ...crystal Shield and Russian Platform (Isachenko, Reznikov 1996).
The climate is characterized by frequent fronts of the Baltic, White and Barents seas, and prevalence of intensive cyclonic activity the whole year around. The Ladoga lake influences on the adjacent territories making climate smoother near its shores; the Karelian coast is characterized by soft winter, and longer vegetative and unfrosted periods (Ladoga…, 2000). In conformity to L. E. Nazarova (Nazarova, 2006), the annual atmosphere temperature has increased on 1.1–1.3 °С within 50 years (1951–2000) in this region.
The study territory of North-Western Ladoga region is located in the southern area of the Baltic Crystaline Shield granite rock outcrops. The field researches were carry out on a key-site (35 km2) with the aim compile a large-scale vegetation map (M. 1 : 25 000). Landscape is heterogenic with rocks (granite and granodiarite, limnetic clay, pet) and complex relief (tops, slopes and foots of selgas, limnetic terraces and narrow selga depressions). The most easily reached sites of terraces and bogs were actively used as agricultural lands (up to 1940th by Finns, later on by Russians).
The region is situated in taiga belt. Spruce, pine and small-leaved forests prevail in the study area, while meadows and bogs are less common. The most widespread are forests and woodlands with dominant Pinus sylvestris.
The vegetation was described by methods according to principles of ecological-phytocoenotic classification (Gribova, Isachenko, 1972; Neshataev, 1987; Vasilevich, 1995; Methods ..., 2002). 93 relevés were performed on sample plots of 400 m2 or within the community boundaries. The following characteristics were taken into account: density, height and diameter of trees, composition and grass-shrub and moss-lichen layer cover (in percents). In pine forest shares of Pinus sylvestris (the number of trunks) are >5 units (in 10-point scale); sparse low-tree pine communities on rocks with tree density of less then 0.3 were classified as woodlands. Associations are distinguished according the species dominance in the herb layer and the combination of ecological-phytocoenotic groups.
There are 5 groups of associations (Pineta cladinosa, Pineta hylocomiosa, Pineta nemoriherbosa, Pineta paludosa, Pineta sphagnosa), 12 associations and 11 variants established according to ecological-phytocoenotic classification.
Forest and woodland assosiations of Pinus sylvestris of the NW Ladoga region: Pinetum cladinosum saxatilis (Table 1; Table 7, syntaxa 1–3; Fig. 2); Pinetum fruticulosum saxatilis (Table 2, relevés 1–9; Table 7, syntaxon 4); Pinetum vacciniosum (Table 2, relevés 10–12; Table 7, syntaxon 5; Fig. 4); Pinetum myrtillosum (Table 3, relevés 1–19; Table 7, syntaxa 6–8; Fig. 5а, б); Pinetum myrtilloso–calamagrostidosum (Table 4, relevés 1–14; Table 7, syntaxa 9, 10); Pinetum calamagrostidoso–herbosum (Table 4, relevés 15–19; Table 7, syntaxon 11); Pinetum myrtilloso-oxalidosum (Table 5, relevés 1–7; Table 7, syntaxa 12–14); Pinetum oxalidosо–equisetosum (Table 5, relevés 8–12; Table 7, syntaxon 15; Fig. 6а, б); Pinetum nemoriherbosum (Table 5, relevés 13–16; Table 7, syntaxon 16; Fig. 7а, б); Pinetum filipendulosum (Table 5, relevés 17–18; Table 7, syntaxon 17), Pinetum fruticuloso–hylocomioso–sphagnosum (Table 6, relevés 1–3; Table 7, syntaxon 18; Fig. 8); Pinetum myrtilloso–sphagnosum (Table 6, relevés 4–5; Table 7, syntaxon 19).
Tops of the granite hills (selgas) are rocky coverd by frost resistent communities on primitive litogenic soils, where snow cover is blown off in winter. Common are communities of the ass. Pinetum cladinosum saxatilis with sparse and undersized Pinus sylvestris, unclosed lichen and greenmoss cover (Arctoparmelia centrifuga, Umbilicaria sp., Cladonia arbuscula, C. rangiferina, C. stellaris, C. uncialis s. str., Dicranum polysetum, D. scoparium, Pohlia nutans, Polytrichum juniperinum, Pleurozium schreberi) and woodlands of the ass. Pinetum cladinosum saxatilis var. callunosum (Calluna vulgaris, species of genera Cladonia, Dicranum polysetum, Pleurozium schreberi, Polytrichum juniperinum). Primitive litogenic soils are formed at gently tops and near-top slopes with forests of the ass. Pinetum fruticulosum saxatilis with some lichen.
Mid parts of selga slopes are occupied by different types on the “podbur” soil (similar to thin mountain taiga soil). The selga slopes are usually covered by forests of the ass. Pinetum myrtilloso–calamagrostidosum (Calamagrostis arundinacea, Vaccinium myrtillus) and ass. Pinetum myrtilloso–oxalidosum (Oxalis acetosella, Vaccinium myrtillus) with an admixture of small-leaved trees. The gentle slopes and bottom parts of selga slopes are occupied phytocenoses of the ass. Pinetum calamagrostidoso–herbosum with heliophilous subnemoral herbal species (Convallaria majalis, Fragaria vesca, Hepatica nobilis, Geranium sylvaticum, Rubus saxatilis, Pteridium aquilinum, Veronica chamaedrys, Viola canina) and mosses (Pleurozium schreberi, Dicranum polysetum, Hylocomium splendens, Rhytidiadelphus triquetrus).
The selga depressions are occupied by phytocenoses of the associations Pinetum fruticuloso–hylocomioso–sphagnosum and Pinetum myrtilloso–sphagnosum.
The lake terraces were used by Finns (up to 1944) as agricultural grounds (meadows, pastures, arable lands). After the end of cultivation the young grey alder groves with mesophytes (Aegopodium podagraria, Geum rivale) and hygromesophytes (Filipendula ulmaria, Lysimachia vulgaris, Scirpus sylvaticus) have became the most typical element of postagricultural lands where shade-requiring boreal and nemoral species gradualy were being replaced by heliophilous meadow plants (Veremeeva, 2004). The next succession stage is the appearance and growth of coniferous trees. Pine forests from the Pineta nemoriherbosa and Pineta paludosa groups on cultivated lake terraces are rather young (40–70 years). According to classification of G. A. Isachenko (Isachenko, 1996), such forests belong to the final (4th) succession stage of agricultural land with tree species before the restoration of coniferous forests. Also, ecotope conditions (soil richness, sufficient humidifying) promote increase the cover of nemoral (Aegopodium podagraria, Hepatica nobilis, Pulmonaria obscura, Milium effusum), hygromesophylous and hygrophylous herbs (Filipendula ulmaria, Athyrium filix-femina, Equisetum sylvaticum, Geum rivale, Oxalis acetosella, Deschampsia cespitosa). The presence of spruce in the tree stand, the abundance of Oxalis acetosella, nemoral and hygrophytic herbs shows that these forests of the associations Pinetum oxalidosо–еquisetosum, Pinetum nemoriherbosum and Pinetum filipendulosum when they are not affected by anthropogenic impacts may be restored to forests of the associations Piceetum oxalidosо–еquisetosum, Piceetum nemoriherbosum and Piceetum filipendulosum.
Brief information is provided about the Fourth All-Russian Conference “Biodiversity of the Far North’s Ecosystems: Inventory, Monitoring, and Conservation” held on June 5–9, 2023 in Syktyvkar on the ...base of the Institute of Biology Komi Scientific Centre Ural Branch of RAS.
The five-day conference included a plenary session, six thematic sections and a field excursion to the Ethno Park “Yyb”. More than 120 reports were presented and several modern methods of studying Arctic and Subarctic ecosystems were demonstrated.
This paper presents a characterization of the syntaxa of zonal dark coniferous forests dominated by Abies nephrolepis, A. sachalinensis, Picea jezoensis, P. glehnii, and P. obovata of the class ...Vaccinio-Piceetea Br.-Bl. in Br.-Bl. et al. 1939 and the order Abieti veitchii–Piceetalia jezoensis Miyawaki, Ohba, Okuda, Nakayama et Fujiwara 1968. The order Pinetalia pumilae Suzuki 1964, which unites thickets of Siberian dwarf pine (Pinus pumila), is also included. Each syntaxon is presented with its diagnostic taxa list, distribution, and habitat conditions. Furthermore, we validate the names of one alliance, two associations, and two subassociations of dark coniferous forests, because these syntaxa were described invalidly earlier (Vegetation…, 1988; Krestov, Nakamura 2002).
Ass. Piceetum glehnii Nakamura ex Korznikov et Krestov ass. nov.
Diagnostic species: Picea glehnii, Menziesia pentandra, Pogonatum japonicum (Krestov, Nakamura, 2002).
Synonyms: Piceetum glehnii Suzuki ex Nakamura in Miyawaki 1988 nom. inval. (3o, 5a); Piceetum glehnii Suzuki ex Krestov et Nakamura 2002 nom. inval. (3o, 5a).
Subass. Piceetum glehnii typicum Korznikov et Krestov subass. nov.
Diagnostic species: Arachniodes mutica, Rhododendron brachycarpum, Scapania sp. (Krestov, Nakamura, 2002).
Synonyms: Piceetum glehnii subass. von Rhododendron brachycarpum Nakamura in Miyawaki 1988 (orig. name) nom. inval. (3e, 3o, 5); Piceetum glehnii rhododendretosum brachycarpi Nakamura ex Krestov et Nakamura 2002 nom. inval. (3o, 4a, 5)
Subass. Piceetum glehnii sasetosum kurilense Krestov et Nakamura ex Korznikov et Krestov subass. nov.
Diagnostic species: Sasa kurilensis (Krestov, Nakamura, 2002).
Synonyms: Piceetum glehnii sasetosum kurilense Krestov et Nakamura 2002 nom. inval. (4a).
Ass. Piceo jezoensis–Abietetum sachalinensis Ohba ex Korznikov et Krestov ass. nov.
Diagnostic species: Acer mono subsp. mayrii, Galium kamtschaticum, Hydrangea petiolaris, Kalopanax septemlobus, Toxicodendron orientale, Trillium smallii, Prunus ssiori, Quercus mongolica (Krestov, Nakamura, 2002).
Synonyms: Piceo jezoensis–Abietetum sachalinensis Ohba 1967 nom. inval. (2b); Piceo jezoensis–Abietetum sachalinensis Ohba ex Nakamura in Miyawaki 1988 nom. inval (3o, 5a); Piceo jezoensis–Abietetum sachalinensis Ohba ex Krestov et Nakamura 2002 nom. inval. (3f, 3o, 5a, 16).
All. Pino pumilae–Piceion jezoensis Krestov et Nakamura ex Korznikov et Krestov all. nov.
Diagnostic species: Allium ochotense, Betula pendula subsp. mandshurica, Equisetum sylvaticum, Lonicera chamissoi, Pinus pumila, Pyrola asarifolia subsp. asarifolia, Sorbus aucuparia subsp. glabrata, Sorbus sambucifolia, Spiraea betulifolia var. aemiliana (Krestov, Nakamura, 2002).
Synonyms: Pino pumilae–Piceion jezoensis Krestov et Nakamura 2002 nom. inval. (3o, 5a).
Two alliances and two suballiances of larch forests, which belong to the class Vaccinio-Piceetea, are also validated in this paper. These names were previously published invalidly (Krestov et al., 2009; Sinelnikova, 2016).
All. Rhododendro aurei–Laricion cajanderi Krestov, Ermakov, Osipov et Nakamura ex Korznikov et Krestov all. nov. hoc loco
Diagnostic species: Pinus pumila, Spiraea betulifolia var. aemiliana, Rhododendron aureum (Krestov et al., 2009).
Synonyms: Rhododendro aurei–Laricion cajanderi Krestov, Ermakov, Osipov, Nakamura 2009
nom. inval. (3f).
Suball. Junipero sibiricae–Laricenion cajanderi Krestov, Ermakov, Osipov et Nakamura ex Korznikov et Krestov suball. nov.
Diagnostic species: Carex pallida, Chamaenerion angustifolium, Equisetum pratense, Juniperus sibirica, Lathyrus pilosus, Pyrola incarnata, Solidago decurrens (Krestov et al., 2009).
Synonyms:Junipero sibiricae–Laricenion cajanderi Krestov, Ermakov, Osipov et Nakamura 2009 nom. inv. (4a, 5a, 17).
All. Roso acicularis–Laricion cajanderi Sinelnikova ex Korznikov et Krestov all. nov.
Diagnostic species: Betula platyphylla, Calamagrostis langsdorffii, Chamaenerion angustifolium, Equisetum pratense, Galium boreale, Larix cajanderi, Ribes triste, Rosa acicularis, Rubus arcticus (Sinelnikova, 2016).
Synonyms: Roso acicularis–Laricion cajanderi Sinelnikova 2016 nom. inval. (3o, 5a).
The current phytosociological diversity of dark coniferous forests in the region includes one order, three alliances, and 17 associations. In further development of the Vaccinio-Piceetea classification system, we propose dividing the azonal subalpine forests from the temperate zone and the zonal boreal forests into two orders: the order Abieti veitchii–Piceetalia jezoensis s. str. for the temperate zone in Japan and Korea, and a new order for the boreal zone. The order Vaccinio–Pinetalia pumilae Suzuki 1964, which includes the alliance Vaccinio–Pinion pumilae Suzuki 1964 and two associations, Vaccinio–Pinetum pumilae Maeda and Shimazaki ex Suzuki 1966, and Ledo–Pinetum pumilae Kobayashi 1967, unites communities dominated by Pinus pumila. The syntaxonomical concept of the order Vaccinio–Pinetalia pumilae was established based on vegetation data from Japan (Kobayashi, 1967; 1971) and should be updated with vegetation relevés from the Russian Far East.
International Symposium “Mires of Northern Eurasia: Biosphere functions, diversity and management”, held on September 25–28, 2023 in Petrozavodsk, continued the traditions of the previous symposums ...organized by Karelian specialists in 2005 and 2015. Totally 101 participants from 21 regions of Russia and Belarus attended the Symposium. They represented 42 organizations: Universities and Research Institutes of the Russian Academy of Sciences, environmental organizations, Nature reserves and industrial enterprises. 86 scientists arrived to Petrozavodsk, 9 specialists presented online reports.
During the two days of the Symposium, 6 plenary and 56 sectional oral presentations and 28 posters were presented. Six plenary presentations were devoted to the history of mire research in different regions, the diversity of types of mires and mire vegetation, the history of climate and vegetation dynamics in the Holocene, the importance of mires in the exchange of greenhouse gases and the development of modern methodological approaches to the study of mire dynamics.
The most extensive section called “Diversity, structure, dynamics and functioning of mire ecosystems” contained 32 oral presentations. The issues of the typology of mire massifs of different regions of Russia, diversity and originality of mire plant communities, their dynamics, geographical distribution of mires, and conservation value of mire communities were highlighted. Such classical studies continue the traditions of the Russian and Soviet geobotanical school and provide a new level of insight into mire ecosystems and form the basis for solving such current problems as assessment of climate change, carbon balance, protection of rare species.
The traditional part of the mire conferences are the presentations devoted to paleoecology, based on the results of analysis of the peat deposit structure, were. Within the section “Mires and climate in the Holocene, Paleoecology” 15 oral presentations were devoted to the impact of climate change to the Holocene vegetation, the frequency of natural fires that have left traces in the peat sediments, reconstruction of vegetation successions on mires and their connections with archaeological research of the Middle Ages. Separately, a wide range of methods used by paleo ecologists was noted. Along them together with traditional spore-pollen analysis and analysis of plant macrofossils, some modern methods of analyzing arthropods and mollusks and testate amoebas were used.
At the section entitled “Research methods, management of mire ecosystems and their restoration” nine reports were presented, covering such topics as the influence of cranberry pickers’ on the mire vegetation, remote sensing methods used for monitoring plant successions and typology of mire ecosystems, the growth of sphagnum mosses as an indicator of activity of ultraviolet, and thermal analysis of organic matter of peat soils.
Twenty eight posters were exhibited at the poster session, their topics mostly repeated such of sectional presentations, but were more specific. The works of young scientists and students were presented there. The youngest participant of the session and the entire Symposium was a student of the Lomonosov Lyceum from Arkhangelsk, who presented a poster on the features of cranberries cultivated in the White Sea region.
An important part of the symposium were field trips. During two days participants were able to visit two remarkable sites in the southern part of Karelia. Small eutrophic fens near the village of Kolatselga (150 km west of Petrozavodsk) had a specific floristic composition. In 1942–43, two Finnish botanists have described these mires. Their publication provided an excellent comparative data for the further researchers. The participants of the Symposium visited four of these fens and assessed their current state. Another object of excursion were the mires of the Kivach Nature Reserve situated 80 km north from Petrozavodsk. The Reserve is a popular tourist attraction for visiting the Kivach Waterfall on the Suna River. However, the local nature is quite rich, diverse and picturesque, so the reserve serves as a traditional place for environmental research in Karelia. Local mires are also well studied; the participants of the Symposium visited some of them.
Video broadcasts of the symposium sessions are available on Youtube channel of the Karelian Scientific Center of the Russian Academy of Sciences, a collection of abstracts has been published (Mires…, 2023).
