Scheuchzerio-Caricetea Nigrae Research Articles

Растительность осоково-гипновых и лесных болот богатого грунтового питания на северной границе их распространения в Западной Сибири

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.

Notes on distribution and habitat preferences of Sphagnum inexspectatum and S. mirum in Western Siberia

New records of two rare moss species, Sphagnum inexspectatum Flatberg (4) and S. mirum Flatberg & Thingsgaard (9) are reported from Western Siberia, and discuss them in context of their habitat preferences in region as well as general range. Their distribution in Russia is considered and re-assessed. Geobotanical relevés of plant communities with Sphagnum inexspectatum and S. mirum from Western Siberia are presented. It is shown that in the taiga zone S. inexspectatum occurence is closely related to communities of the alliance Stygio-Caricion limosae Nordhagen 1943, class Scheuchzerio-Caricetea nigrae Tx. 1937, and similar Sphagnum carpets in meso-oligotrophic mires, where it grows as single stems among other peat mosses in poor conditions on slightly acidic substrates. In forest tundra and southern tundra this species occurs only in communities of the alliance Caricion stantis Matveyeva 1994. More diverse communities with S. mirum are assigned mainly to the alliance Sphagno-Caricion canescentis Passarge (1964) 1978, which comprises sedge-Sphagnum vegetation located in fens and transitional bogs in a wide variety of habitats from moderately poor to moderately rich in mineral nutrients and with slightly acidic substrate. This species occurs both with low (as single stems) and high abundance (frequently being dominant) in moss layer.

Мелкоосоковые сообщества топей и мочажин болот севера Западной Сибири

The classification of West Siberian mire vegetation is more or less well developed in the southern part of the forest zone (Lapshina, 2010) while in the northern part of the West Siberian Plain it has received much less study. There are only a small number of publications containing descriptions of mire types and plant communities (Pyavchenko, 1955; Boch et al., 1971; Kirpotin et al., 1995; Smagin, 2003; Neshatayev et al., 2002). This paper presents the classification results for the low-sedge vegetation of waterlogged hollows and Sphagnum lawns, within flat palsa-bogs, ombrotrophic raised bogs and transitional mire complexes, which is assigned to two alliances — Stygio–Caricion limosae Nordhagen 1943 and Scheuchzerion palustris Nordhagen ex Tx. 1937 of the class Scheuchzerio–Caricetea nigrae Tx. 1937. The classification is based on 422 relevés performed in 2004–2019 at 22 plots located between 63° and 75° N in the northern taiga, forest tundra, and southern tundra subzones of West Siberia (Fig. 1). In the most recent summary “Vegetation of Europe…” (Mucina et. al., 2016), the alliance Stygio–Caricion limosae is assigned to the order Sphagno watnstorfii–Tomentypnetalia Lapshina 2010, however this does not seem conclusive. Communities of this order are closely associated with rich fens, often spring fens fed by ground water, which does not correspond to the real conditions in which communities of this alliance are developed. Ecologically, in the current structure of the class Scheuchzetio–Caricetea nigrae (Peterka et al, 2017), the alliance Stygio–Caricion limosae has taken the true place of the alliance Rhynchosporion albae Koch 1926 (ICPN, Art. 36), which was initially unambiguously associated with the order Caricetalia nigrae Koch 1926 based on the original relevés and diagnostic species (Rhynchspora alba, Agrostis canina, sphagnum mosses of sec. Subsecunda). Therefore, we also consider the alliance Stygio–Caricion limosae belonging to the order Caricetalia nigrae, where it fits better judging by its ecological and floristic features. The differential species combination of the alliance Stygio–Caricion limosae in the northern part of West Siberia includes Carex limosa, Drosera obovata, Juncus stygius, Gymnocolea inflata, Sphagnum perfoliatum, S. platyphyllum, S. subsecundum, Utricularia minor, U. ochroleuca, Warnstorfia exannulata, and W. fluitans. Within this alliance, two new associations with subassociations have been described: Utricularo ochroleucae–Caricetum limosae and Sphagno perfoliati–Caricetum rotundatae, of which the first one occurs in the northern taiga mires, while the second one in the forest tundra and southern tundra subzones. The order Scheuchzerietalia palustris Nordhagen ex Tx. 1937 comprises ombrotrophic vegetation of Sphagnum lawns and bog hollows (Mucina et al., 2016) and currently includes the only alliance Scheuchzerion palustris. Its typical boreal suballiance Scheuchzerienion palustris suball. nov. (nomenclature type — lectotypus hoc. loco: ass. Scheuchzerietum palustris Tüxen, 1937: 61) is represented by two associations: Eriophoro vaginati–Sphagnetum baltici and Carici limosae–Sphagnetum jenseni. Their distribution to the north is limited by the mire complexes of the northern taiga. Further north similar habitats are occupied mainly by communities of the predominantly subarctic suballiance Caricion rariflorae. Within this suballiance, two associations — Carici rotundatae–Sphagnetum baltici and Carici rotundatae–Sphagnetum lindbergii — are widely distributed over the entire gradient from the northern taiga to the southern tundra. The ass. Carici rariflorae–Sphagnetum baltici occurs only occasionally and is bound to the forest tundra and southern tundra. Statistical processing of the entire data set was performed to confirm the classification results and make a number of syntaxonomic decisions. The results of t-SNE ordination (t-distributed stochastic neighbor embedding method) (van der Maaten, Hinton, 2008) confirmed the validity and expediency of separating oligotrophic and mesooligotrophic low-sedge communities of hollows and fens not only at the alliance level, but also at the order level. Despite certain physiognomic and floristic similarities, the location points of the two alliances in multidimensional space are well differentiated and do not overlap with each other (Fig. 10). Calculation of the floristic similarity degree of relevés with regard to species abundance and visualization of the statistical processing results have clearly demonstrated that the entire relevé array of oligotrophic sphagnum lawns in the alliance Scheuchzerion palustris can be divided by the dominant sphagnum moss species into separate clusters, within which dominant grass layer clusters could also be distinguished. Given that, in the future, the formal statistical processing of large sets of geobotanical data will become an increasingly important tool to underpin syntaxonomic decisions, this fact cannot be ignored. In this connection, we propose to review the current practice of identifying associations of mire vegetation by the dominant species of vascular plants and sub-associations by the dominant moss species. The latters are of primary importance in the poor-species plant communities of waterlogged hollows and fens, because they are more sensitive to ecological conditions of habitats, which ultimately determine the entire floristic composition and community structure.

Syntaxonomy of peatland vegetation: case study of the central zone of Lake Baikal eastern coast

Peatland vegetation is dominant among azonal vegetation types within the central zone of Lake Baikal eastern coast. In order to classify the phytosociological diversity of peatland vegetation, the supervised k-means clustering method was applied. According to the main concept of the method, the unidentified dataset from this study was subjected to the classification among identified units (a priori groups) from the north-eastern area of Lake Baikal. The unidentified dataset is composed of 55 relevés, which were collected in the central zone of the Lake Baikal eastern coast. The identified a priori groups comprise 12 associations distinguished according to the Braun-Blanquet approach. Those associations are based on classification of 138 relevés, which were taken in the course of studies of the north-eastern part of Lake Baikal, such as Svyatoi Nos Peninsula and Barguzinskiy mountain range. As a result, we obtained the assignment of unidentified relevés among those a priori groups. The supervised k-means clustering performed well in assignment of unidentified relevés to a priori groups and proved to be a useful tool for the classification and syntaxonomical positioning of unidentified peatland vegetation. The peatland vegetation was classified into classes: Oxycocco-Sphagnetea and Scheuchzerio-Caricetea nigrae.

Fen grassland vegetation under different land uses (Biebrza National Park, Poland)

The majority of European fen grasslands are seminatural and require appropriate management to maintain their high natural value. The research area was located in the middle basin of the Biebrza River Valley, where fen grasslands vegetation was i) grazed by Konik horses, ii) mowed once every 2–4 years, or iii) abandoned for 16 years. The question was as follows: How do different land use types affect the floristic composition and restoration of abandoned fen grasslands? In the examined sites we measured floristic composition and soil physicochemical parameters. The observed changes in the floristic composition resulting from the introduction of the new type of land use were significant and they occurred in a relatively short period of time. With the cessation of mowing for 16 years, the intermittently wet Molinia meadows were replaced by trees and shrubs of alder woodlands (Alnetea glutinosae class), and the plant species diversity significantly decreased. The mowing of the Molinion meadows once every 2–4 years proved to be sufficient to prevent the encroachment of trees, but it was not enough to stop the expansion of Molinia caerulea. In the site grazed with Konik horses for 13 years, the primary fen grassland vegetation (Scheuchzerio-Caricetea nigrae) was replaced by species of low, trampled swards and intermittently wet meadows (Molinio-Arrhenatheretea class). The soils under all of the sites differing in the land use type were classified as Eutric Rheic Hemic Histosols. They were typical peatland soils, slightly acidic to neutral. The results of the soil analyses indicate the high natural states of the studied areas and that their extensive use only slightly affected their physicochemical properties. Greater soil bulk density was noticed under the pasture than under the abandoned and mowed sites, but the extensive grazing of Konik horses caused only a slight increase in volumetric density to 0.19 g cm−3. Our results show that on both the mowed and the grazed sites, the content of soil organic matter and soil organic carbon was higher than that on the abandoned site. In the mowed part as well as in the grazed part, long-lasting monitoring of the effects of the management strategies used on vegetation and soil properties is still needed.

Effect of different land-use on occurrence and morphological traits of Carex buxbaumii (study from Biebrza National Park, Poland)

Carex buxbaumii is rare sedge of moist to wet meadows, marshes and fens. The population trends and detailed habitat requirements of this species remain unknown. In Poland, C. buxbaumii belongs to EN category of IUCN, while is even more endangered in other European countries. The knowledge on this species is limited, but probably it needs active protection for its maintenance. It is also known that plants respond morphologically to changes in the site conditions which may help to determine the ways of effective method of their conservation. Therefore, we examined the frequency and morphology of Carex buxbaumii growing in a sward of fen-grasslands i) abandoned for 15 years, ii) mowed, or iii) grazed by Konik horses. The description of the occurrence and of the morphological reaction to the differentiation in land–use type of C. buxbaumii is presented against the background of changes in vegetation cover that occurred in 2010–2016 in the examined fen-grassland.There was stated that C. buxbaumii grew on peat soils, of high content of organic matter and Ca+2. The type of land-use significantly differentiated both the frequency and morphology of C. buxbaumii. In the mowed site C. buxbaumii grew as an element of the Molinion vegetation and appeared there with 100% frequency. The individuals growing in the mowed site had the longest shoots, the longest inflorescence brackets, and the longest terminal spikes. In the site grazed by Koniks, C. buxbaumii was a component of Scheuchzerio–Caricetea nigrae vegetation, while its frequency of C. buxbaumii was 87%. The shoots there were the shortest, and in general, the morphology was the most differentiated. In the abandoned site C. buxbaumii abundance amounted 46%, and the individuals were smaller than those under the mowing regime but larger than those grazed by Koniks. In that site, the previous vegetation with high proportion of the Molinion and Phragmitetea species was replaced by Alnetea glutionosae vegetation, represented mainly by trees and shrubs. We have shown that the best conditions for the development of the C. buxbaumii population in the examined fen-grasslands are created under an extensive mowing regime.

Ecological and biological aspekt new locality of Drosera anglica Huds. near Końskich

<p>The work concerns the occurrence conditions <em>Drosera anglica.</em> (EN) within the site located 10 km from the village of au nord Końskie near the Czarna River. The species is very dispersed but in a few places the density was 5-10 of specimens per 1m<sup>2</sup>. This species grows within a patch which is poor in terms of its flora. No significant expansion of trees or shrubs has been noted. This is related to quite a high level of water. Such conditions are favourable to the development of another species under threat of extinction, <em>Rhynchospora alba. </em>Plant-based patches with participation of sundew are heterogeneous in terms of syntaxonomy. Presence of species has been observed, e.g. from the classes of <em>Phragmitetea </em>and <em>Scheuchzerio-Caricetea nigrae</em>. Soil analyses indicate that the soils under observation are not very acidic, with average content of CaO and ash content which is optimal for this species with the ratio of C:N which indicates a temporary mire. The content of heavy metals is in norm and poses no threat to the surroundings (Pb 64-65 ppm, Cd 2.7-2.9 ppm). Wide ranges in the analysed samples refer to chromium. They do not have an adverse effect on the development of <em>Drosera anglica</em>. A very crucial threat is the consequence of succession, competition and hydrological conditions.</p>

Environmental traits determining plant species distribution in selected midforest bogs

The investigations were carried out in six small mid-forest peat bogs with active peat-forming processes, all situated in the Lublin region (Eastern Poland). The bogs represented two floristically different types of peatland: raised bogs and transitional mires species composition analysis and specific chemistry analysis (pH, Eh, carbon content, N, P, Mg, Na, Ca, Mn, Fe, dehydrogenase activity and water level) were performed. The plant assotiations/communities of the peat bogs represented three phytosociological classes: Scheuchzerio-Caricetea nigrae, Oxycocco-Sphagnetea, and Vaccinio-Piceetea. The analysis of redox potential measured in the different communities revealed differences in the Eh values between these phytocoenoses (p < 0.001). Assotiations representing Vaccinio uliginosi-Pinetum were found in areas characterised by the highest redox potential. Redox potential values in these communities were significantly higher than the values recorded in bog communities and mosaic associations. Seasonal variability of the redox potential was noted as well. The current research indicates that soil chemical parameters: pH, Eh are closely related with water table level and plant distributions.

Сообщества класса Scheuchzerio–Caricetea nigrae (Nordh. 1936) Tx. 1937 в восточноевропейских тундрах

There are few publications on the classification of vegetation of Scheuchzerio–Caricetea nigrae class in the Arctic (Daniёls, 1982; Matveyeva, 1994; Zanokha, 2003). In Russia classification of mires is more or less well designed for the taiga zone of the European North and the West Siberia. Communities of sedge-hypnum mires and sedge-sphagnum hollows of flat palsa-bogs in the East European tundra are described in the dominant classification traditions (Andreev, 1932; Bogdanovskaya-Gienef, 1938; Dedov, 2006). N. Yа. Katz (1936) briefly described the vegetation of the Arctic mineral sedge mires on the Vaygach Island. In present paper the results of the mires classification carried out upon the basis of 148 relevés made in 1998–2014 in 26 sites in the East European tundra along the latitudinal gradient from typical tundra to northern forest-tundra.

Nutrients availability and hydrological conditions of selected wetland ecosystems in the Biebrza river valley

Abstract: Nutrients availability and hydrological conditions of selected wetland ecosystems in the Biebrza river valley. Paper presents results of investigation of hydrological conditions and nutrients limitation and availability for wetland vegetation in selected sites within Biebrza river valley. Analysed sites were overgrown by tall sedge Magnocaricion vegetation (Caricetum gracilis and Caricetum elatae), wet meadow Molinio-Arrhenatheretea vegetation (Molinietum caeruleae), and sedge-moss Scheuchzerio-Caricetea nigrae vegetation (Caricetum lasiocarpae). There were noted a close relationship between vegetation types, hydrological regimes and kind of nutrient limitation. Low productive Molinio-Arrhenatheretea and Scheuchzerio-Caricetea nigrae vegetations fed mainly by groundwater were limited by phosphorus, while highly productive Magnocaricion vegetation, fed by river water, was subjected to nitrogen limitation. We have found big diversification of groundwater and surface water levels within habitats of different vegetation types along the Biebrza river valley. Magnocaricion vegetation present on flooded areas is characterized by significant water level fluctuations and long-lasting inundations. On areas covered by Molinio-Arrhenatheretea vegetation we noted majority of water levels not exceeding the level of the ground surface. Whereas Scheuchzerio-Caricetea nigrae vegetation, fed by groundwater, is characterized by low variation of groundwater levels.

Habitat and phytocenosis conditions of the occurrence of Ostericum palustre in the Natura 2000 „Lisi Kąt” site

Ostericum palustre Besser is a species protected by the domestic and EU laws. In Poland it occurs in about 150 sites one of which is located in the area covered by Natura 2000 Lisi Kąt. The population existing there, estimated as 35,000 individuals, covers the acreage of 342 ha. The species persists there mostly in over-dried and transformed-by-meadow-management reed beds with the share of Carex acutiformis and C. gracilis, in phytocenoses of Scheuchzerio-Caricetea nigrae with a large share of mosses, in overgrowing patches of the alliances of Molinion as well as sporadically within reed beds with Carex pseudocyperus. Its share in similar phytocenoses coincides with the reports in literature in the region of the Notec Valley. In most cases those are heavily disturbed systems, transitional in nature, which must have been the reason for a relatively high level of species variation. The habitat preferences of Ostericum palustre, determined with Ellenberg's indicator values (L, T), correspond to the values optimal for the species. Soil, on the other hand, can be referred to as slightly acid, average fertile and mostly moist.

Habitat conditions and diversity of flora based on transitional peat bog in Bledow on the Silesian Upland

Presented research focused on determining the characteristics of soils, waters and vegetation covering a transitional peat bog in Bledow and potential hazards which might cause its degradation. Four soil pits were made for this purpose and piezometers were installed in their immediate vicinity. It allowed investigation of physical and chemical properties of this habitat waters. Diversity of the peat bog vegetation was determined on the basis of 17 phytosociological releves made by Braun-Blanquet’s method. The results demonstrated that the analysed peat bog is at the accumulation phase and the main factor shaping the habitat conditions in the peat bog itself and on its edge was high groundwater level. On the other hand, the feeding water and its level affected chemical and physical properties of the analysed peat bog soils. Low value of the studied peat bog water mineralisation and low share of calcium and magnesium ions in the mineralisation influenced low pH values and low degree of base cation saturation, which has been reflected in the floristic composition of the peat bog. In conditions of high moisture content, a process of organic matter accumulation was taking place in the surface horizons, whereas on the peat bog and on its edge an apparent soil and vegetation zonation was visible. On the edge of the peat bog trees encroaching into Sphagno recurvi-Eriophoretum angustifolii peat bog patches was observed on semi-hydrogenic soils and disappearance of species of the Scheuchzerio-Caricetea nigrae class. It was found that disturbance of natural water relationships poses the most serious potential hazard to the analysed peat bog.

Spring fen Scheuchzerio-Caricetea nigrae in the Polish Western Carpathians – vegetation diversity in relation to soil and feeding waters

&lt;p&gt;The species composition of vegetation associated with the Carpathian fens primarily depends on the type of water present and the hydrological feeding of the soils that occur there. These, in turn, shape the fertility of the fens. Those with typically formed &lt;em&gt;Carici-Agrostietum caninae&lt;/em&gt; and &lt;em&gt;Valeriano-Caricetum flavae&lt;/em&gt; fundamentally differ in the properties of their soils and feeding waters. These include differences in mineral content, pH, CaCO&lt;sub&gt;3&lt;/sub&gt; levels, degree of peat decomposition, electrical conductivity and oxygenation of the waters that feed the fens. &lt;em&gt;Carici-Agrostietum caninae&lt;/em&gt; is a homogenous plant association adapted to extreme habitat conditions. It is characterized by a very narrow range of essential soil and feeding water parameters. &lt;em&gt;Valeriano-Caricetum flavae&lt;/em&gt; is a highly diverse association. Considerable diversity both in terms of plant species and vegetation structure reflects very wide ranges in the properties of soil and feeding water. Vegetation patches of transitory character were also identified. These contained plant species characteristic of both associations. The character of the vegetation depends mainly on fen soil pH and the degree of mineralization of the feeding waters. It is only these parameters that allow intermediate patches to be clearly distinguished. The degree of peat decomposition, mineral content and water oxygenation all differ for &lt;em&gt;Carici-Agrostietum caninae&lt;/em&gt; and &lt;em&gt;Valeriano-Caricetum flavae&lt;/em&gt;, whereas the values for intermediate patches display a range of parameters typical of both investigated associations. Consequently, vegetation present in these patches reflects to a greater or lesser extent one of the two analyzed plant associations.&lt;/p&gt;

Mire Vegetation Database of Latvia

The TURBOVEG database Mire Vegetation Database of Latvia (GIVD ID EU-LV-002) comprises 1927 releves described in mires of Latvia by the author since 1995 and is annually updated. The plot size is 1 4 m. Percentage cover of Vascular plants and bryophytes were evaluated for each sample plot. It also includes 156 releves on vegetation changes in pine forests after selective cutting and heath mowing in Erica tetralix habitats. This is a private database. The data are mainly used for preparation of mire vegetation classification system of Latvia. So far the database covers two classes Phragmito-Magnocaricetea and ScheuchzerioCaricetea nigrae. When Vegetation Database of Latvia at Laboratory of Geobotany of Institute of Biology will be created it will be part of national vegetation database.

Phytosociological and ecological study of springs in Trentino (south-eastern Alps, Italy)

A phytosociological survey of the crenic vegetation was made in Trentino (south-eastern Alps), combining the field method of the Braun-Blanquet approach with a numerical syntaxonomical analysis. A set of 139 phytosociological releves, including vascular plants and bryophytes, were classified using cluster analysis. The vegetation types were assigned to 7 different phytosociological classes: Platyhypnidio-Fontinalietea antipyreticae, Montio-Cardaminetea, Adiantetea, Scheuchzerio-Caricetea nigrae, Molinio- Arrhenatheretea, Galio-Urticetea, Mulgedio-Aconitetea. The classes Platyhypnidio-Fontinalietea antipyreticae and Montio- Cardaminetea represent the core of crenic vegetation, including permanently or intermittently submerged plant communities, mostly made up of bryophytes, or non-submerged communities dominated by bryophytes or vascular plants. The other classes include chasmophytic bryophyte-rich communities and hygrophilous or tall herb communities lying around the periphery of the springs. 23 vegetation types were identified and, whenever possible, classified at the association level, or as phytocoena. The environmental parameters showed different ranges among vegetation types. A number of environmental variables were recorded during the vegetation survey, including altitude, shading, discharge, flow velocity, with exhaustive hydrochemical sampling. Conductivity, alkalinity and pH showed similar distribution patterns, clearly separating the vegetation types into two distinct groups, differing in the nature of the substratum. The altitudinal range was very broad and shading was also very variable. Nitrate and phosphate levels showed that the majority of vegetation types were irrigated by oligotrophic crenic waters. Finally, the bryophyte-dominated vegetation types belonging to the class Platyhypnidio-Fontinalietea antipyreticae occurred in springs with the highest discharge values and variation. Discriminant analysis confirmed that the environmental descriptors that best accounted for the among-group variation were pH and alkalinity (first variate); the second variate reflected a gradient of altitude and discharge.

Distribution patterns, history, and dynamics of peatland vascular plants in Pomerania (NW Poland)

Distribution patterns, history, and dynamics of peatland vascular plants in Pomerania (NW Poland) Pomerania is rich in various peatlands (fens, transitional bogs, raised bogs, spring-water mires, etc.), which support many rare and threatened plant species. This study was aimed: (1) to determine the phytogeographic diversity of Pomeranian peatland vascular plants associated with the classes Oxycocco-Sphagnetea and Scheuchzerio-Caricetea nigrae; (2) to attempt a reconstruction of the history of their postglacial migrations; and (3) to assess the dynamic trends of selected species. A database of records of 83 Pomeranian peatland plants was created, and cartograms of their distribution in Pomerania were made. Each taxon was briefly described, considering its distribution, phytocoenotic spectrum, and biological properties (e.g. pollination mode, diaspores dispersal). The phytogeographic analysis took into account geographic and directional elements, as well as mountain species found in Pomeranian peatlands. The plants' potential for colonization of new sites was assessed on the basis of Raunkiaer's life forms, modes of pollination and seed dispersal, and types of life strategies. As a result of numerical analysis and visual comparison of cartograms, 5 regional distributional types were distinguished: western, northern, eastern, all-Pomeranian, and disjunct. Within the eastern and all-Pomeranian types, which showed internal variation, several subtypes were distinguished. Most of the considered climatic variables (growing season length, temperature, and precipitation variables) were found to affect significantly the floristic variation of Pomeranian peatlands. The available palaeobotanical, palaeoclimatic, palaeoecological, and phytogeographic data, as well as original field research on the distribution of the taxa, allowed the formulation of hypotheses on the time and directions of their migration into Pomerania. Moreover, dynamic trends of selected species are analysed, and the decline of many peatland plant species in Pomerania is discussed.