Swampy mesotrophic peatmoss spruce forests of European Russia and Urals

На основе выборки из 130 геоботанических описаний, сделанных авторами в 1995-2019 гг. или взятых из литературы, проведена доминантно-детерминантная классификация топких мезотрофных (Picea abies s.l.) ельников сфагновых, развивающихся при подтоплении либо периодическом затоплении в Европейской России и на Урале. Ценотическое разнообразие этих сообществ определяется спецификой названных процессов в сочетании с климатическими факторами, тогда как роль почвообразующих пород почти не выражена. Выделено 6 ассоциаций с 6 субассоциациями и 2 вариантами, всего 11 синтаксонов (табл. 1). В их числе подтопленные ельники вейниковые сфагновые с господством Calamagrostis purpurea s.l. и Equisetum sylvaticum в травяном ярусе (4 субассоциации в разных подзонах тайги либо долготных секторах), вздутоосоковые с Carex rostrata и C. vesicaria и вахтовые с Menyanthes trifoliata (2 субассоциации). Кроме того, выделены эндемичные для Южного Урала ельники малоцветковоосоковые с C. pauciflora и Rubus chamaemorus, развивающиеся на поверхностном дождевом стоке (2 варианта), приречные северотаежные водноосоковые с Carex aquatilis и затопленные южно- и подтаежные белокрыльниковые с Calla palustris. Для большинства синтаксонов характерны Swampy mesotrophic peatmoss spruce forests, dominated by Picea abies s.l. and originated due to inundation or periodical flooding, have been classified in European Russia and the Urals using the dominant-determinant approach to vegetation. The data set involves 130 relevés made by the authors in 1996-2019 or taken from the published sources. 11 syntaxa are totally recognized (see Table 1). Inundated reedgrass-peatmoss (with the dominance of Calamagrostis purpurea s.l. and Equisetum sylvaticum in the field layer; 4 subassociations in different subzones or longitudinal sectors), sedge-peatmoss (with Carex rostrata and C. vesicaria), and trefoil-peatmoss (with Menyanthes trifoliata; 2 subassociations) spruce forests are recognized. In addition, one can distinguish sedge-cloudberry-peatmoss spruce forests with Carex pauciflora и Rubus chamaemorus in the subalpine belt of the Southern Urals, developing due to surficial rain flow, also riverine northern-boreal sedge-peatmoss forests with Carex aquatilis and flooded southern- and hemiboreal calla-peatmoss spruce forests with Calla palustris. The observed syntaxonomic diversity is governed by inundation/flooding intensity and longevity together with latitudinal zonation and climate continentality, whereas the role of bedrock type influence is minimal. Multi-dominance and mutual replaceability are typical for peatmosses in most of the syntaxa.

Mongolian peatland documents 5000-year pollution history and a baseline of Pb and Tl in northeastern Asia

<p>Peat records of trace metals pollution history over thousands of years are not widely reported in northeastern Asia, although the mining/metallurgy have already started in the past 5000 years. Peat core was collected in September 2015, from the Nur Sphagnum bog, in Selenge province, in the NW part of the Kenthii Mountains, Mongolia. The Nur Sphagnum bog (49°39’N; 107°48’E; 1250 m.a.s.l.) is the largest wetland located in the mountain taiga forest of Mongolia in the northern part of the Hentei highlands. The mean January and July temperatures are -27.1°C and 18.3°C respectively, while mean annual precipitations are 288 mm. The peatland is composed of than 10 species of Sphagnum, while herb layer is dominated by Carex rostrata, and several species of Sphagnum. The dominant tree species are composed of Betulaplatyphylla, Pinussylvestris, Piceaobovata and Abiessibirica. As for the Nur bog, no research on elemental or isotopic geochemistry was undertaken currently. Our preliminary geochemical study established a baseline for typical heavy metal, Pb, 1.1 mg kg-1, which is reasonable to represent a pre-industrial background value in Mongolia, even in northeastern Asia. The average Pb content through the cores was 2.2 mg kg-1, which was significantly lower than the level in northeastern China and showed that the it was still typical area of pristine ecosystem in northern Mongolia. However, the elevation of Pb and Tl contents in the near surface layers was also observed, with an enrichment factor of 6, which suggested that the anthropogenic impact was approaching in this region and more attention should be paid to safeguard its nature heritage.</p>

Volatile Organic Compound fluxes in a subarctic peatland and lake

<p>Arctic climate is warming twice as much as the global average, due to a number of climate system feedbacks, including albedo change due to retreating snow cover and sea ice, and the forest cover expansion across the open tundra. Northern ecosystems are known to emit trace gases (e.g., methane and volatile organic compounds, VOCs) to the atmosphere, from sources as diverse as soils, vegetation and lakes. These trace gas fluxes are likely to show a trend towards greater emissions with climate warming.</p><p>Here we report ecosystem-level VOC fluxes from Stordalen Mire, a subarctic peatland complex with a high fraction of open pond and lake surfaces, underlain by discontinuous permafrost and located in the Subarctic Sweden (68º20' N, 19º03' E).</p><p>In 2018, we deployed two online mass spectrometers (PTR-TOF-MS) to measure rapid fluctuations in VOC mixing ratios and to quantify ecosystem-level fluxes with the eddy covariance technique. One of the instruments obtained a growing-season-long dataset of biogenic emissions from palsa mire vegetation dominated by mosses (e.g., <em>Sphagnum</em> spp.), graminoids (such as <em>Eriophorum</em> spp. and <em>Carex</em> spp.), dwarf shrubs (e.g. Empetrum spp. and Betula nana) surrounding the ICOS Sweden Abisko-Stordalen long-term measurement station. The second instrument measured VOC fluxes during two contrasting periods (the peak and the end of the growing season) from a subarctic lake and its adjacent fen, permafrost-free, minerotrophic wetland with vegetation dominated by tall graminoids, mainly <em>Carex rostrata</em> and <em>Eriophorum angustifolium</em>.</p><p>At both sites, isoprene was the dominant VOC emitted by vegetation, showing clear diurnal patterns along the season and especially during the peak of the growing season in July. At the ICOS Sweden station, isoprene fluxes exceeded 2 nmol m<sup>-2</sup> s<sup>-1</sup> on several days in July, with a July monthly average midday emission of 1 nmol m<sup>-2</sup> s<sup>-1</sup>. The fen site showed average midday emissions of 2 nmol m<sup>-2</sup> s<sup>-1</sup> during the peak growing season. Other VOCs emitted by vegetation at both sites in July were, with decreasing magnitude, methanol, acetone, acetaldehyde and monoterpenes. In contrast, acetaldehyde and acetone were not emitted but mostly deposited to the fen at the end of the season. In contrast to the wetland, the lake was a sink for acetaldehyde and acetone during all measurement periods.</p><p>Thermal imaging and spectral analysis of vegetation will be used to assess relationships between VOC fluxes, vegetation surface temperatures and phenology under varying environmental conditions.</p>

Roots, Tissues, Cells and Fragments—How to Characterize Peat from Drained and Rewetted Fens

We present analyses of macroscopic and microscopic remains as a tool to characterise sedge fen peats. We use it to describe peat composition and stages of peat decomposition, to assess the success of rewetting of a formerly drained fen, and to understand the workings of these novel ecosystems. We studied two percolation fen sites, one drained and one drained and rewetted 20 years ago. Years of deep drainage have resulted in a layer of strongly decomposed peat which lacks recognizable macro-remains. We could associate micro-remains with macro-remains, and thus still characterise the peat and the plants that once formed it. We show that the strongly decomposed peat is of the same origin as the slightly decomposed peat below, and that is was ploughed. We present descriptions of eight types of the main constituent of sedge peat: plant roots, including Carex rostrata type, C. lasiocarpa/rostrata type, C. limosa type, C. acutiformis type, C. echinata type, Phragmites australis type, Cladium type, Equisetum type. We describe three new non-pollen palynomorph types (microscopic remains) and five new subtypes. The rewetted fen provides insights into plant succession after rewetting and the formation of peat that predominantly consists of roots. Results indicate that leaf sheaths may be a consistent component of the peat.

Dynamics of vegetation changes in oil and salt-contaminated oligotrophic ridge-hollow mire complexes after reclamation (Middle Pre-Ob region, Khanty-Mansi Autonomous Okrug – Yugra)

Oligotrophic ridge-hollow and ridge-hollow-pool complex mires are widely distributed in the central part of West Siberia, including many oil fields of the Middle Pre-Ob region. The article considers the dynamics of re-vegetation of oil and salt-contaminated areas of these mire types subjected to reclamation. Survey materials for 2–3 years and 15 years after reclamation allow to identify the main trends in vegetation restoration in the short and medium term. The reversible oligotrophication of ridges manifests in a relative decrease in the participation of the meso-eutrophic species on contaminated mire sites. In the hollows, however, the similar trend can be traced only in relation to oil-contaminated sites, whereas in the salt-contaminated hollows, the strong eutrophic conditions last. In the medium-term perspective, most typical oligotrophic hollow species, with the exception of Eriophorum russeolum and Oxycoccus palustris, were unable to recover. In the course of dynamic changes in the vegetation, the leading role in recovery successions gradually passes to mesotrophic and eutrophic species possessing massive root systems and aerenchyma – Eriophorum angustifolium, Phragmites australis, Carex rostrata, etc. Restoration of the moss layer is several years behind that of the grass layer, and due to the lack of competition, the participation of liverworts in it is of great importance, especially in salt spills. At the same time, among mosses as in the case of vascular species mesotrophic components are the main dominant ones15 years after reclamation.

Development of a subarctic peatland linked to slope dynamics at Lac Wiyâshâkimî (Nunavik, Canada)

A palaeoecological study of a subarctic minerotrophic peatland was undertaken to reconstruct the formation of the site as an archive of slope geomorphological processes. The study peatland is located about 400 m from Caribou slope (unofficial name) on Lepage Island, Lac Wiyâshâkimî, Nunavik (northern Québec, Canada). The site is close to the lakeshore and receives runoff directly from Caribou slope and its catchment. Gravity processes have been active on Caribou slope since the deglaciation of the region at approximately 6000 cal. yr BP. These processes may be differentiated in terms of Holocene stages of intensity. The objective of our study was to detect evidence of gravity processes in the peatland and to note their frequency since its establishment using loss-on-ignition testing, macrofossil analysis and radiocarbon dating. Our results indicate that peat began to accumulate over the sandy-gravelly sediments at around 4900 cal. yr BP. Larix Laricina, Carex aquatilis and Carex rostrata were present at this time until 4660 cal. yr BP, at which point these taxa were replaced by aquatic taxa such as Hippuris vulgaris and Daphnia (aquatic invertebrates). The percentage of mineral sediments (sand) remained high during this period, which could be linked to slope activity. After 4660 cal. yr BP, sandy sediments diminished while episodes of aquatic conditions and sand inflow occurred on at least three occasions (at 4660, 3905 and 3130 cal. yr BP). The increase in water flow and the introduction of more medium to fine sand into the peatland could be linked to slope movements and the long-distance runout of debris flow that we observed in the field. Given these factors, conditions at the study site remained wet from the earliest phases until the present. Unlike the subarctic permafrost peatlands in northern Québec, permafrost did not become established at the study site.

Знахідка Drosera rotundifolia L. біля озера Святого (Хмельницька область)

У статті повідомляється про знахідку Drosera rotundifolia L. у межах заболочених берегів території гідрологічної пам’ятки природи загальнодержавного значення – озера Святе, що увійшла в НПП «Мале Полісся» Хмельницької області. Наведено результати геоботанічних, фітоценотичних досліджень, екології місцезростання виду. Рослинність представлено формаціями Sphagneta magellanicum, Sphagnetа cuspidatum, які утворюють асоціації Sphagnum magellanicum + Carex rostrata + Sphagnum cuspidatum + Ledum palustre + Calla palustris + Drosera rotundifolia. Висвітлено дані про чисельність особин у ценопопуляції на моніторинговій території. Отримані дані засвідчують сприятливі умови для подальшого розвитку та самопідтримання популяцій у ценозі. Також виявлено зростання Scheuchzerіa palustris L., яка занесена до Червоної книги України.

The nomenclature of two hybrid taxa in Carex sect. Vesicariae (Cyperaceae) currently assigned as Carex rostrata var. borealis and Carex stenolepis

In a recent study of Carex sect. Vesicariae in northern Europe, two hybrid species were identified using microsatellite markers. Whereas both taxa already have names associated with them, we find that these names are not appropriate for use. In this study, the taxon previously described as C. rostrata var. borealis is raised to species level as the hybrid taxon Carex ×saamica (from C. rostrata × C. rotundata). We furthermore show that the name C. stenolepis, after designation of a lectotype, becomes a synonym of C. rostrata, and hence accept C. ×grahamii as the priority name for the hybrid taxon (from C. saxatilis × C. vesicaria) previously denoted as C. stenolepis. Arguments for these choices are given. Four other species names that have been assigned to the two hybrid taxa are discussed. Types are identified or designated for the names C. rostrata var. borealis, C. stenolepis, and C. ×grahamii. A key to the hybrid taxa and their parents is given.

Radiocarbon and lead-210 age-depth model and trace elements concentration in the Wolbrom fen (S Poland)

A one-meter long peat core was taken from the peatland in Wolbrom (Silesian-Cracovian Upland, southern Poland). The analysis of the botanical composition showed that Wolbrom is a fen. Vegetation species such as Carex rostrata and Phragmites australis have been found. An age-depth model was constructed using 12 conventional radiocarbon dates and 13 lead-210 dates from the upper part of the deposit. In this work, the results of radiocarbon dating are presented. According to the model, we can estimate the age of the fen. The oldest part comes from a depth of 1.05 meter and its conventional age is 5940 ± 95 BP (modelled date 5000–4790 BC, 68.2% probability interval). The accumulation rate varies between approximately 0.53 mm·yr-1 and 6.48 mm·yr− 1. The core has been also tested for the presence of trace elements (Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn) using ICP-OES. There are considerable variations in the concentrations of the tested metals – in many cases the concentration starts to rise at about 40 cm and may be connected with the human activity. This depth corresponds to the modelled age intervals 355–300 BC (17.4%) and 205–45 BC (50.7%).