A current, more detailed assessment of the bog and wetland areas in the Russian Federation (RF) and the carbon stock in their peat layers has been conducted. Compared to the previous assessment (Vompersky et al., 1994), the creation of the Wetlands of Russia geoinformation system (GIS) of the Institute of Forestry Science, Russian Academy of Sciences (Vompersky et al., 2005), has made it possible to include, in addition to the cartographic basis, replenishable layers of thematic content and determine the areas of peatlands and carbon stock in their peat layers not only for the whole country, but also for separate constituent entities of the RF country as a whole, but also for the constituent entities of the RF. It is important for the administration of each constituent territory to be aware of the peat stock volumes in order for sustainable nature management to be maintained. It is shown that the area of bogs and wetlands amounted to 328 million ha and the peat stock to 216.3 billion t (absolute dry mass). The stock of carbon associated with the peat was 108.7 billion t. Compared to previous estimates, the area decreased by 11

Natural peatlands represent a wide range of habitats that contribute to the conservation of biodiversity, including microbial biodiversity. Molecular biological methods make it possible to significantly increase the accounting of microbial diversity compared to the cultivation methods. The studies on microbial diversity in minerotrophic peatlands using molecular biological methods lag significantly behind such studies for ombrotrophic peatlands. In this work, we characterized the taxonomic composition and functional potential of the prokaryotic community of the minerotrophic pine swamp (fen) in the Tver region of northwestern Russia using high-throughput sequencing of 16S rRNA gene fragments. This study is unique, since it was carried out not in individual horizons but across the entire fen profile, taking into account the differentiation of the profile into the acrotelm and catotelm. The composition and dominants of bacterial and archaeal communities were determined not only at the level of phyla but also at the level of classes, families, and cultivated genera. The prokaryotic community of the studied fen was shown to have a high taxonomic diversity (28 bacterial and 10 archaeal phyla were identified). The profile differentiation of the taxonomic composition of prokaryotic communities is most clearly manifested in the analysis of the acrotelm and catotelm. In the bacterial communities of the acrotelm, the top three phyla included Acidobacteriota, Alphaproteobacteria, and Actinomycetota, in the catotelm—Betaproteobacteria, Bacteroidota, and Chloroflexota. In archaeal communities of the acrotelm, we discovered the monodominance of Nitrososphaerota, in the catotelm—the dominance of Bathyarchaeota and subdominance of Thermoplasmatota, Halobacterota, and Aenigmarchaeota. The hot spots of microbial diversity in the studied fen profile were found to be the 0–20 cm layer of the acrotelm and the 150–200 cm layer of the catotelm. In contrast to the taxonomic composition, the functional profiles of the prokaryotic communities of the acrotelm and catotelm were generally similar, except for methane metabolism, which was primarily carried out in the catotelm.

The article presents the results of studies of the pine catena’s stands structure, conducted in the Zapadnodvinsky forestry of the Tver region (Zapadnodvinsky forest-swamp station of the Institute of Forest Science of the RAS, IFS RAS), linking the biogeocenosis of the forest and swamp parts of the oligotrophic bog. The purpose of the research is to study the forestry characteristics, morphometric indices, origin, age structure, dynamic processes and volume indicators of pine stands during the transition of the forest part of the catena to the oligotrophic bog. The pine catena includes four sections with a total length of 110 m and a width of 40 m: the upper forest automorphous zone (PP 1), the slope transit zone (PP 2 and 3) and accumulative zone (PP 4) with forest types changing from cranberry-blueberry pine woods of II quality class to shrub-sphagnum meso-oligotrophic pine woods on 6 m of peat (V quality class), underlain by organic lake sediments. The age structure of stands varies from the conditional evenly-aged restorative dynamics in the forest part to the highly-unevenly-aged dynamics found closer to the climax phase of the meso-oligotrophic sphagnum swamp. The forest part is characterized by the better condition indicators’ values, while the oligotrophic bog’s stands have the worst ones. The pine biogeocenosis of an oligotrophic sphagnum bog is close in dynamic characteristics to sustainable climax forest communities with a maximum age of the first generations trees of approximately 240–280 years. The stands condition along the catena profile varies from healthy in the forest part to the weakened with the degradation development dynamics in the accumulative part of the sphagnum bog.

Structural indicators (abundance and diversity) of the fungal and actinomycete complexes of eutrophic peat soils in the zone of active organic detritus decomposition, namely, litter (L and F layers) and eutrophic peat horizon (TE), were analyzed. Samples were e taken in swamped forests (black alder, pine, birch, and mixed forest stands) of the Tver and Tomsk oblasts (Russia) in summer of 2021. The abundance of mycelial organisms was measured by fluorescence microscopy and plate method. Species of culturable representatives were identified by their phenotypic traits. The fungal mycelium in the litter is two–tenfold longer as compared with the TE horizons; the abundance of culturable fungi is bigger by two‒three orders of magnitude; and that of actinomycetes, by one‒two orders of magnitude. The litter fermentative layer (F) displays the maximum carbon content of the mycelial component (3‒10 mg C/g). The stocks of actinomycete biomass in the zone of active organic detritus decomposition varies from 23 to 60 kg/ha and of fungal biomass, from 1593 to 3718 kg/ha. The share of litter in the total stock of mycelial biomass across the profile is larger in deciduous forests. In total, 70 species of culturable fungi belonging to 43 genera and 42 actinomycetes species of 12 series and 4 sections were isolated from the zone of active organic detritus decomposition. Representatives of Penicillium, Talaromyces, and Trichoderma genera are prevalent in the fungal complex and of Streptomyces, in the actinomycete complex. The litter does not yield to the TE horizon in terms of species diversity of both fungi and actinomycetes. The species similarity of fungal complexes of the litter and TE horizon is 0.68 and that of actinomycetes, 0.27.

In 1995–1998 and 2013–2016, we measured methane fluxes (1Q-median-3Q, mgC m−2 h−1) in the Petushikha black alder swamp of the boreo-nemoral zone of European Russia. At microelevations (EL sites), flat surfaces (FL), microdepressions (DEP), and water surfaces of streams and channels (STR) sites, the fluxes comprised 0.01–0.03–0.09, 0.02–0.06–0.19, 0.04–0.14–0.43, and 0.10–0.21–0.44, respectively. The biggest uncertainty of methane fluxes was caused by seasonal variability (the level of relative variability of fluxes is a nonparametric analogue of the coefficient of variation) which comprised 144%, then by spatial variability—105%, and the smallest by interannual variability—75%. Both spatial and temporal variability of methane fluxes at different elements of the microrelief is heterogeneous: the most variable are communities that are “unstable” in terms of hydrological conditions, such as FL and DEP, and the least variable are the most drained EL and the most moistened STR (“stable” in terms of hydrological conditions). The obtained data on the fluxes and their spatial and temporal variability are consistent with the literature data and can be used to optimize the process of planning studies of the methane budget of “sporadic methane sources”, such as waterlogged forests. This is especially relevant for an adequate assessment of the role of methane fluxes in the formation of the waterlogged forests carbon budget and a changing climate.

The comprehensive study of mycobiota in full profiles of eutrophic peatlands based on abundance and diversity rates has been carried out in order to broaden the knowledge on microorganisms’ biodiversity in wetland ecosystems and get a detailed understanding of their functioning. Thick eutrophic peatlands of forest and floodplain origin in Tver and Tomsk oblasts, Russia, were the objects of research. The abundance of fungi has been assessed by luminescent microscopic and plate methods. Culturable fungi were identified basing on their phenotypic features. All the numbers and rates acquired were analyzed considering that the peatland profile could be divided into acrotelm and catotelm layers. Samples were taken from the peatlands layer-by-layer with regard to botanical composition of peat in September 2019. The length of fungal mycelium varied in the studied peatlands from 195 m to 2.3 km per gram, the number of spores varied from 8 to 45 million spores per gram of dry peat. The fungal mycelium biomass differed (2–24 times) from peatland to peatland, whereas the fungal spore biomass was similar at all studied sites. Fungal biomass supplies in the studied peatlands, calculated for the whole profile, varied from 2 to 18.7 t/ha. Alder peatland (Alnusglutinosa) of forest origin was especially rich in fungal biomass. The proportion of fungal biomass in the acrotelm varied from 52 to 72% of total fungal biomass throughout all the peat profile. Culturable fungi were represented by 52 species of 32 genera. In the samples of analyzed fungi the representatives of genera: Mortierella, Cladosporium, Penicillium, and Trichoderma were the most widespread. The list of fungi species and the frequency of their occurrence are presented in the study. The Shannon’s biodiversity index varied from 1.8 to 2.5. The taxonomic similarity of the fungal complexes in the studied peatland in accordance with the Sørensen-Dice Index did not exceed 0.65.

Oligotrophic peatlands traditionally have a high profile in microbiological research. Eutrophic peatlands are studied by residual principle and their research is generally focused on the active layer, acrotelm. The purpose of our study was to assess microbial biomass, its structure and activity in the full profiles of peatlands of various geneses. We investigated eutrophic peatlands of lacustrine, forest, and floodplain origins in Tver and Tomsk regions. Luminescent microscopy was used to analyze the microbial biomass. Microbial respiration was examined by gas chromatography. Microbial biomass stocks calculated for a three-meter layer of the studied peatlands varied from 7 to 13 t/ha. Eukaryotic biomass stocks reached 3–9 t/ha, and prokaryotic biomass stocks were about 3–4 t/ha. Eukaryotes predominated in the microbial biomass of the acrotelm, while prokaryotes predominated in the microbial biomass of the catotelm. Bacteria dominated in the structure of prokaryotic biomass all over the profiles of the studied peatlands. The fraction of actinomycetic mycelium did not exceed 15%. It was found that prokaryotic biomass depends on the botanical composition of peat in the eutrophic peatlands. This dependence becomes stronger from the woody peat to the herbaceous peat. The comparison of eutrophic peatlands of different geneses demonstrated their microbial specificity. Thus, the peatland of forest bogging had the maximum microbial pool among all peatlands. The peatland of lacustrine origin was characterized by the saturation of the acrotelm with microbial biomass. The peatland of floodplain origin was maximally enriched in bacterial biomass. In many layers of studied peatlands, the potential respiration level was 2–5 times higher than the actual one. Microbial respiration reached its maximum intensity in the peatland of floodplain origin.

Swamp forests have been insufficiently studied yet in comparison with thoroughly examined carbon pools and greenhouse gas fluxes of peat bogs. This is primarily since the GHGs in swamp forests have huge spatial (due to the developed microrelief) and temporal variations (due to strong fluctuations in the groundwater level (GWL)). This significantly complicates their study, producing ambiguous results, especially in short-term field research. From June to October 2013–2016, we measured soil respiration (Rsoil) in an alder swamp using the static chamber method at five microsites: depression (DEP), flat surface (FL), elevations (EL), tussocks (TUS), and near-stem tussocks (STUS). We carried out a computer simulation of the total Rsoil for the season based on Rsoil measurements, monitoring of GWL, and soil temperature. In 2013–2016, the average Rsoil values (mgC m−2 h−1 ± σ) on DEP, FL, EL, TUS and STUS comprised 54 ± 50, 94 ± 72, 146 ± 89, 193 ± 96, and 326 ± 183, respectively, whereas the total Rsoil values for the season (tC ha−1 season−1 ± σ) comprised 2.0 ± 0.5, 3.5 ± 0.5, 5.3 ± 1.6, 5.4 ± 2.7, and 12.6 ± 3.2. According to the results of observations, GWL was at the level of several cm below the soil surface for most of the season. In 2014 and 2015, there were extra dry periods that led to a drop in GWL to a mark of 30–40 cm below the soil surface. Despite their short duration (2–3 weeks), these dry periods can lead to an increase in the total Rsoil for the season from 9 to 45% in the TUS–EL–STUS–FL–DEP sequence.

Regressive development is widespread in peatlands of the northern hemisphere; a new type of peatlands—regressive bogs—should be introduced in addition to the traditional peatland types, such as eutrophic, mesotrophic, and oligotrophic peatlands. Diagnostic features and classification of soils typical of regressive bogs have already been discussed in relevant scientific literature. However, there are virtually no data on the microbiological analysis of soils of the aforementioned bog types. The aim of this study is to identify structural and functional organization of the microbial communities in soils of a regressive noncryogenic bog (sampling area in Tver oblast of the West Dvina Forest-Bog Station of the Institute of Forest Science, Russian Academy of Sciences). Numerous black bare peat spots without sphagnum mats, from 0.05 to 1 m 2 in area demonstrate a high degree of regressive process at the studied bog. Data on the number and biomass of microorganisms were obtained by direct method of fluorescence microscopy. The taxonomic composition of bacterial and fungal communities was determined by plate method, while direct microscopy was used for algal communities. The CO 2 and CH 4 emissions were analyzed using chamber method. It was found that the total microbial biomass in the soils under regressive spots is higher than in the soils without any features of regressive process; the regressive peat mat had its own biomass reaching 50% of the total biomass in the active layer. Algae predominate in the biomass of regressive peat mats. Bacteria and fungi constitute 13–26% of the total biomass of regressive peat mats. Regressive mats are characterized by a high number of algae and bacteria. It should be noted that all algae genera found in the regressive peat mats represent the species characteristic of oligotrophic peatlands. Fungi of regressive peat mats were represented by mycelium and spores. During the wet period, the length of fungal mycelium rapidly increased by one–two orders of magnitude and reached 2 – 4 km/g. The domination of Penicillium miczynskii and Umbelopsis vinacea species, which typically predominate in eutrophic peatlands, can be considered a specific feature of the micromycetal complex of the regressive peat mat. Regressive peat mats are characterized by higher rates of plant residues mineralization because of the accumulation of nitrogen. This leads to an increase in the carbon dioxide emission, on the one hand, and to an inhibition of methanogenesis, on the other hand.

Bacterial communities of the six Ericaceae bog plants were studied. The total number of bacteria on the vegetative organs of the Ericaceae plants was high and comparable to the one on Sphagnum mosses. Members of bacterial taxa colonizing both heather plants and Sphagnum mosses were identified. According to their 16S rRNA gene sequences, predominant bacteria of the epiphytic-saprotrophic complex were identified as Pseudomonas, Stenotrophomonas, Serratia, and Chryseobacterium species. The physiological diversity of the hydrolytic bacterial complex was significantly higher in the Ericaceae plants than in the Sphagnum mosses. Analysis of the taxonomic position and functions of identified bacteria indicated that the studied bacteria were capable of stimulating the growth of plants inhabiting ombotrophic bogs.

оСоБеННоСТИ СоСТоЯНИЯ ЛеСНЫХ ЭКоСИСТеМ В РаЗНЫХ ПРИРоДНЫХ ЗоНаХ еВРоПеЙСКоЙ ТеРРИТоРИИ РоССИИ В УСЛоВИЯХ ИХ НеУПРаВЛЯеМоГо ИСПоЛЬЗоВаНИЯ

We studied the consequences of a fire that affected 29 ha of a drained forested raised bog in Tver oblast, Central European Russia. The drainage network consisted of open 1-m-deep ditches with 60 to 160 m ditch spacing. The groundwater level (GWL) varied within the studied drained bog. We used the method of assessing the loss of soil carbon (C) based on the difference between the ash concentration in the burnt peat of the upper layer and underlying unburnt layers. The carbon loss was higher near the drainage ditches than in the sites remote from ditches. The sample median values of carbon loss (kg C/m 2 ) were estimated at 0.37 near the drainage ditches and at 0.22 for the remote sites with a distance of 160 m between ditches. They increased to 2.23 and 0.79 near and far from the drainage ditches for 106 m ditch spacing, and ranged from 1.13 to 2.10 near the drainage ditches and were equal to 0.45 at the remote sites for 60 m ditch spacing. The maximum loss of C was at the bog margin with the 70-cm-deep GWL; the sample median was equal to 2.97 kg C/m 2 . The results obtained for C loss from the wildfire on the raised bog agree with the estimates obtained by other authors (1.45–4.90 kg C/m 2 ) and confirm the importance of taking such loss into account in the estimates of the carbon budget of peat soils (Histosols).

The results of stationary studies of swampy southern taiga forests in Yaroslavl oblast are presented. Estimates of changes in the thickness of peat horizon in peat podzolic gley soils (Folic Albeluvisols) of forests subjected to clearcutting and further intensive forest management in the past 30 years are given. The mean annual precipitation in these three decades has been 116 mm higher than that during the preceding three decades, which has led to a progressive swamping of spruce stands on heavy loamy soils within virtually flat (with slopes up to 0.0035) surfaces and an increase in the organic matter storage in the peat soil horizon with the mean annual rate of 22–68 g/m 2 . On more pronounced slopes (0.0050), no swamping of spruce and pine stands growing on sandy soils has taken place. Surface drainage of swampy forests through the network of shallow ditches has led to an increase in the productivity of forests; in most cases, the pool of organic matter in the peat horizon has been decreasing with the mean annual rate of 32–46 g/m 2 . This attests to the reversible character of swamping in dependence on climatic fluctuations and forestry measures. Changes in the carbon pool of swampy soils during short (several years) excessively wet or excessively dry periods may be significantly higher than the average values for 30 years in different types of forests. This allows us to consider swampy forests as the source of significant errors in the estimates of the current contribution of biota to the carbon cycle, because their role (as well as the role of other forests) is assessed without taking into account considerable short-term fluctuations in the carbon pool of their soils.

Люминесцентно-микроскопическим методом с помощью флуоресцентного двухкомпонентного красителя L7012 LIVE/DEAD определена жизнеспособность бактерий в толще верховых и низинных торфяников. Живые клетки бактерий обнаружены по всему профилю. Их доля была максимальной в верхних слоях – 60% и не превышала 25% в нижней толще. На долю мертвых клеток бактерий приходилось от 3 до 19%, а на долю покоящихся клеток – от 25 до 95%. Количество последних увеличивалось вниз по профилю независимо от типа торфяника. Доля наноформ не превышала 5% от общей численности бактерий. Клетки наноформ в отличие от бактерий обычных размеров характеризовались высокой жизнеспособностью (93–98%).