Anatomical and Morphological Features of Scots Pine Heartwood Formation in Two Forest Types in the Middle Taiga Subzone

Currently, there is no consensus on how growing conditions affect the heartwood formation in Scots pine. Comparing the results obtained by different authors is difficult due to methodology differences and poor descriptions of the objects used. We selected two sample plots in (1) a blueberry pine forest on nutrient-rich and moist soil and (2) a lichen pine forest on nutrient-poor and dry soil and performed their detailed characterization. The sample plots were located 22 km apart in the middle taiga subzone (Karelia Republic, northwest Russia). In each sample plot, we selected five dominant trees (model trees), from which we took cores at different trunk heights (0.3, 1.5, 4.5, 7.5 and 10.5 m). The cores were treated with 2,6-dichlorophenolindophenol to identify the heartwood zone. Additionally, samples were taken to study the structural features of the transition zone between sapwood and heartwood. In both forest types, the number of heartwood rings depended on the cambium age, and the patterns of parenchyma cell death did not differ in the transition zone. These facts point to a predominantly internal regulation of the heartwood formation in Scots pine. The heartwood radius and its proportion on the cross-sections were significantly higher in the blueberry pine forest than in the lichen pine forest, despite the relative values of the annual ring width. Further research is needed to develop successful Scots pine heartwood width models under a wide range of conditions.

The Impact of Agricultural Use of Retisols on the Molecular Structure of Humic Substances

Agricultural soil use does not only affect the amount of soil organic matter, but also the molecular composition of humic (HAs) and fulvic acids (FAs). Changed hydrothermal conditions and composition of the incoming plant residues are reflected in the rate of humification and its products. The objective of this study was to compare the molecular composition of HAs and FAs isolated from Eutric Albic Stagnic Histic Retisol (Loamic), two Eutric Albic Retisols (Loamic)—mature and arable. Plots of mature Retisols are located at a middle taiga (Komi Republic, Russia) in a bilberry-green-moss birch-spruce forest. The plot of Retisols arable is located in the fields of the Syktyvkar state farm, which is 3.3 km northeast of mature Retisol plots. The development period is about 40 years, it is sowed with a pea-oat mixture. The results obtained indicate that soil reclamation essentially increases the proportion of aromatic components and decreases the content of carboxyl and ester groups in the humic substance (HS) structure. An increased extent of hydromorphism of Retisols leads to the enrichment of HS with aliphatic fragments.

Productivity of natural phytocenoses of the Namsky agrolandscape in Yakutia under organic and mineral nutrition regimes

The results of the study of the productivity potential of natural phytocenoses of different species composition in the Namsky agrolandscape of the middle taiga subzone of the Republic of Sakha (Yakutia) are presented. The research was conducted in 2009-2016. The soils of the experimental plot are permafrost soils with a thin humus layer. The effect of mineral and organic fertilizers on the productivity of steppe meadows was studied. On herb-grass, wheatgrass, steppificated phytocenoses the following practices of organo-mineral nutrition of plants were used: control (no fertilizer); humus 20 t/ha; humus 20 t/ha once every 4 years + N60P60K60 annually; N30P30K30 annually; humus 20 t/ha annually. The optimum rates of organic and mineral nutrients to improve the productivity potential of natural steppe meadows have been established. The highest productivity potential in the Namsky agrolandscape was obtained with the combined application of organic and mineral fertilizers (humus 20 t/ha once every 4 years + N60P60K60 annually). On herb-grass and wheatgrass phytocenoses hay yield reached 23.0-24.1 c/ha. Yield per 1 ha of metabolizable energy was 27.0-22.4 GJ, fodder units 1472-1663, crude protein 336-371 kg. The content of digestible protein in 1 fodder unit in herb-grass was 92 g, in wheatgrass - 102 g. The annual application of mineral fertilizers at a dose of 60 kg/ha of the active substance provided a 2-fold increase in the productivity of natural phytocenoses, depending on agroclimatic conditions of the growing season. The influence of mineral fertilizers and their joint application with organic fertilizers on the yield of natural phytocenoses is statistically reliable, which indicates the possibility of regulating the productivity of steppificated phytocenoses.

Atmospheric Methane Consumption and Methanotroph Communities in West Siberian Boreal Upland Forest Ecosystems

Upland forest ecosystems are recognized as net sinks for atmospheric methane (CH4), one of the most impactful greenhouse gases. Biological methane uptake in these ecosystems occurs due to the activity of aerobic methanotrophic bacteria. Russia hosts one-fifth of the global forest area, with the most extensive forest landscapes located in West Siberia. Here, we report seasonal CH4 flux measurements conducted in 2018 in three types of stands in West Siberian middle taiga–Siberian pine, Aspen, and mixed forests. High rates of methane uptake of up to −0.184 mg CH4 m−2 h−1 were measured by a static chamber method, with an estimated total growing season consumption of 4.5 ± 0.5 kg CH4 ha−1. Forest type had little to no effect on methane fluxes within each season. Soil methane oxidation rate ranged from 0 to 8.1 ng CH4 gDW−1 h−1 and was negatively related to water-filled pore space. The microbial soil communities were dominated by the Alpha- and Gammaproteobacteria, Acidobacteriota and Actinobacteriota. The major group of 16S rRNA gene reads from methanotrophs belonged to uncultivated Beijerinckiaceae bacteria. Molecular identification of methanotrophs based on retrieval of the pmoA gene confirmed that Upland Soil Cluster Alpha was the major bacterial group responsible for CH4 oxidation.

Macrophyte diversity in rivers and streams of the Vologda Region and several other regions of Russia

The data paper contains the authors’ materials on the diversity of macrophytes, macroscopic plants regardless of their taxonomic position, in rivers and streams of East European Russia and Western Siberia. These data, collected on 247 rivers and 32 streams in 13 administrative regions of the Russian Federation, were provided as an occurrence dataset presented in the form of GBIF-mediated data. The main portion of the data was obtained in water objects of the Vologda Region (5201 occurrences). In addition, occurrences from the Arkhangelsk Region (347 occurrences), Khanty-Mansi Autonomous Okrug (159), Yaroslavl Region (132), Novgorod Region (97), Kostroma Region (41), Republic of Karelia (31), Sverdlovsk Region (29), Komi Republic (28), Orenburg Region (26), Chelyabinsk Region (22), Voronezh Region (22) and Tyumen Region (18) were given. The studies were carried out mainly in the southern and middle taiga and, to a lesser extent, in the northern taiga and the forest-steppe. The analysed watercourses belong to five drainage basins: the Azov Sea, the Baltic Sea, the White Sea, the Caspian Sea and the Kara Sea. The dataset contains materials on the diversity of Plantae (6094 occurrences) and Chromista (59 occurrences). This paper, in a standardised form, summarises mostly unpublished materials on the biodiversity of lotic ecosystems. The paper summarises the data obtained in long-term studies of phytodiversity in a range of rivers and streams of East European Russia and, fragmentarily, Western Siberia. A total of 6153 occurrences were included in the dataset. According to the GBIF taxonomic backbone, the dataset comprises 292 taxa, including 280 lower-rank taxa (species, subspecies, varieties) and 12 taxa identified to the genus level. All the occurrences are published openly through the Global Biodiversity Information Facility (GBIF) for the first time. Most of the data were stored in field diaries and, thus, by adding the data in GBIF, we believe that other researchers could benefit from it.

Cryosols from Tundra and Taiga Zones of Yakutia: Properties, Clay Mineralogy, and Problems of Classification

Abstract— Data on major properties and clay mineralogy in the profiles of slightly differentiated Cryosols forming in cold ultracontinental climate of Yakutia are discussed. The particular objects are represented by the cryozems of tundra, forest-tundra, and northern taiga of the Anabar and Alazeya plateaus and by the palevaya (pale) soil of middle taiga in Central Yakutia. The differentiation of clay minerals in the vertical soil profiles is poorly pronounced because of the strong homogenizing impact of cryoturbation processes. The profile of pale soil displays minor differences in clay mineralogy despite the strong difference in acid–base conditions of the upper and lower horizons. However, the obtained data suggest that mineral weathering in pale soils of Central Yakutia is more advanced than it was concluded in the 1970s on the basis of data on the absence of pronounced trends in the vertical distribution of clay minerals in their profiles. This is in good agreement with the presence of a sufficiently thick upper humus horizon in these soils, which is typical of the soils of more humid regions. It is suggested that pale soils of Central Yakutia should be classified as soddy pale soils.

Typological diversity and ecological-geographical characteristics of the forest cover of southern part of the Evenki region

The article presents the results of preliminary comprehensive ecological and geographical studies of the forest cover of the middle taiga subzone of Central Siberia. The higher syntaxa of forests were identified using the ecological-floristic classification of vegetation (Braun-Blanquet approach). All forest communities in the region are classified as Vaccinio – Piceetea Br.-Bl. in Br.-Bl. et al. 1939 and are represented by the following orders: Ledo palustris – Laricetalia gmelinii Ermakov in Ermakov et Alsynbayev 2004 – coniferous (mainly larch) forests of Northern Eurasia on permafrost soils characterized by stagnant moisture and low heat supply; Piceo obovatae – Pinetalia sibiricae Ermakov 2013 – typical Siberian dark coniferous forests; Lathyro humilis – Laricetalia gmelinii Ermakov et al. 2002 – boreal forests with the participation of xeromesophilic moderately thermophilic species, widespread in the ultracontinental climate of East, South Siberia and Mongolia. The features of their ecology and geographic regularities and the participation of order communities in the formation of forest cover in different parts of the studied region were considered.

Decomposition of Sphagnum mosses in Western Siberia bog ecosystems (on the example of Sphagnum fuscum)

On the base of experiments there were recorded the greatest mass losses of Sphagnum fuscum samples flat palsa mires in the first year of experiment, in the following years decay rate decreased significantly (from 24 % to 16 %). On middle taiga bogs there was observed decay rate increasing over the third year while on southern taiga bogs Sphagnum fuscum was decomposed almost evenly over three years. On ridges of ridge-hollow complex of middle taiga and southern taiga mass losses under destruction were greater than those in ryams. The most dynamic decomposition was recorded for forest-steppe ryam with decay mass losses over three years of 56% average.