Middle Taiga Zone Research Articles

Carbon Accumulation and the Possibility of Carbon Losses by Vertical Movement of Dissolved Organic Carbon in Western Siberian Peatlands

We studied the peat stratigraphy of the Mukhrino peatland, which is a typical ombrotrophic bog for the Middle Taiga zone of Western Siberia, to gain insights into its history, hydrology, and carbon fluxes. For the first time in Western Siberia, seven cores were collected from locations that were chosen to represent the typical present-day vegetation types, and this was performed for the dating of the separated dissolved (DOC) and particulate organic carbon (POC) fractions, which were determined using the Accelerator Mass Spectrometer (AMS) radiocarbon (14C) method. The oldest peat was found at the bottoms of an underlying lake (10,053 cal. year BP) and an ancient riverbed (10,989 cal. year BP). For the whole history of the peatland, the average peat accumulation rate was estimated to be 0.067 ± 0.018 cm yr−1 (ranging from 0.013 to 0.332 cm yr−1), and the carbon accumulation rate was 38.56 ± 12.21 g m−2 yr−1 (ranging from 28.46 to 57.91 g m−2 yr−1). There were clear age differences between the separated samples of the DOC and POC. The DOC was older than the POC in the uppermost 150 cm of the peat deposit and younger in the deeper layers. The difference in age increased with depth, reaching 2000–3000 years at the bottom of the peat deposit (depth of 430–530 cm). Following the consideration of a range of factors that could potentially cause the dating discrepancy, we hypothesised that the DOC continuously moves down into the mineral sediment beneath the peat, as an additional carbon flux that results in the mixing of younger and older carbon. On this basis, we estimated the apparent rate of the DOC’s downward movement and the associated rate of carbon loss. The first estimate of the average rate of the DOC’s downward movement in Western Siberia was 0.047 ± 0.019 cm yr−1, causing carbon loss in the range of 28–404 mg m−2 yr−1.

Productive traits and biological features of young horses of Yakut breed in different areas of breeding

The Republic of Sakha (Yakutia) is one of the regions of Russia where drove breeding of horses has long been developed. In the modern realities of horse breeding, to further increase the number of drove breeding of horses and improve their productive, reproductive and adaptive traits, one of the most important techniques is to increase the genetic diversity of animals. The purpose of the research was livestock characteristics, the study of productive traits and biological characteristics of young horses of Yakut breed of the Arctic zone (Momsky ulus) in a comparative aspect with young horses of the Middle Taiga zone (Amginsky ulus). So, in terms of pre-slaughter weight and slaughter yield, the foals of the Momsky ulus had superiority. At the age of 6 months, they had a higher preslaughter weight by 9,3 kg (P ≥ 0,99), and a heavier carcass by 10,09 kg (P ≥ 0,99), compared with their herdmates of the Amginsky ulus. According to the slaughter yield, the foals of the Momsky ulus also had superiority. In the foals of the Momsky ulus at the age of 6 months the slaughter yield was 56,5 %, which was higher in comparison with the young animals of the Amginsky ulus by 2,5 abs.% (P ≥ 0,95). Probably, the higher pre-slaughter weight of foals in the Momsky ulus was due to more productive pasture lands with a higher nutritional value of plants. Chemical analysis of horse meat showed that the meat of foals of the Arctic zone (Momsky ulus) has a lower fat content. This allows you to get meat with a lower energy value, a suffi ciently high protein content and is a higher-quality product, which is probably due to the composition of the feed of this zone. Breeding of Yakut horses in the Arctic zone of Yakutia is more attractive from the point of view of the growth and development of young animals, obtaining better quality horse meat.

A New Method for Determining the Calendar Age of Plants of Heracleum sosnowskyi and Evaluation based on the Age Composition in Cenopopulations of the Species in the North

Studies have been carried out to determine the calendar age of plants of the invasive species Hogweed Sosnovsky (Heracleum sosnowskyi Manden.). The study of the root structure showed the presence of growth rings formed by increments of secondary xylem, which makes it possible to use the xylochronological approach to estimate the calendar age of H. sosnowskyi. The number of xylem rings on the transverse section of the root corresponds to the number of remnants of annual increments on the longitudinal section of the underground caudex. The method of accounting for annual increments on a longitudinal section of the caudex is simple and effective and allows you to determine the age of plants of H. sosnowskyi in the field, without resorting to tissue contrast and microscopy. Plants of H. sosnowskyi in natural cenopopulations of the middle taiga zone of the Komi Republic, started flowering in the third year of life, and their calendar age reached 7 full years.

Features of the mechanism of aerosol fractionation in solid hydrometeors

The object of the study is the dispersed fractions of an aerosol substance in the snow cover. At the sampling sites located in the middle taiga zone within the Mezen-Vychegoda Plain on a high terrace in the Sysola river valley, 3 km west of the city of Syktyvkar, fresh snow and surface frost were sampled. The analysis of the ratios in the surface hoarfrost of subdispersed fractions of the aerosol substance was carried out in conjunction with the granulometric analysis of freshly fallen snow. Studies using the method of dynamic light scattering of the granulometric composition of an aerosol substance in freshly fallen snow and surface hoarfrost formed between snowfalls showed that a bimodal distribution of particles is recorded in all snow samples. At the same time, the distribution of submicron aerosol particles in frost samples is already characterized by the presence of three modes. Also, with an increase in the duration of the period between snowfalls in hoarfrost samples, a redistribution of particles between fine and medium fractions is observed in the direction of a significant increase in particles in the fine fraction, but the volume concentration of particles of the large fraction changes slightly. It is assumed that the identified circumstance is associated with the action of capillary forces and the adhesion of dry precipitation during the crystal formation of hoarfrost (it is proposed to call this phenomenon "frosty condensation"). A similar effect was also observed in the West Siberian southern taiga and the coastal tundra of the Lower Pechora region.

Fire-Induced Alterations of Soil Properties in Albic Podzols Developed under Pine Forests (Middle Taiga, Krasnoyarsky Kray)

Fires are one of the most widespread factors of changes in the ecosystems of boreal forests. The paper presents the results of a study of the morphological and physicochemical properties and soil organic matter (SOM) of Albic Podzols under pine forests (Pinus sylvestris L.) of the middle taiga zone of Siberia (Krasnoyrsky kray) with various time passed after a surface fire (from 1 to 121 years ago). The influence of forest fires in the early years on the chemical properties of Albic Podzols includes a decrease in acidity, a decrease in the content of water-soluble compounds of carbon and nitrogen and an increase in the content of light polycyclic aromatic hydrocarbons (PAHs) in organic and upper mineral horizons. Podzols of pine forests that were affected by fires more than forty-five years ago are close to manure forest soils according to most physical and chemical properties. Significant correlations were found between the thickness (r = 0.75, p < 0.05), the moisture content (r = 0.90, p < 0.05) of organic horizons and the content of ∑PAHs in the organic horizon (r = −0.71, p < 0.05) with the time elapsed after the fire (i.e., from 1 to 121 years). The index of the age of pyrogenic activity (IPA) calculated as the ratio of ∑ PAHs content in the organic horizon to ∑ PAHs at the upper mineral horizon is significantly higher in forests affected by fires from 1 to 23 years than for plots with «older» fires (45–121 years). Thus, the article presents the conserved and most changing factors under the impact of fires in the boreal forests of Russia.

The carbon dioxide fluxes at the open-top chambers experiment on the ombrotrophic bog (Mukhrino field station)

The continuous measurement of CO2 fluxes at the open-top chamber experiment in the ombrotrophic peatland (located in the middle taiga zone, West Siberia, Russia) has been provided during the warm season of 2022 (beginning of June to beginning of October). The Reco, NEE and GPP were calculated for this period; abiotic factors related to CO2 emissions, such as PAR, air temperature, water table level and precipitation, were also measured. The monthly average values showed a negative NEE of -9.89 C g m-2 month-1 in July, a negative GPP of -34.19 C g m-2 month-1 in July, and a positive values Reco of 41.68 C g m-2 month-1 in August. In 2022, the studied peatland hollows were only a carbon stock in July, while in the remaining months they were a source of CO2, which could be caused by small precipitation amount.
 The monthly average diurnal variations of CO2 fluxes showed similar behaviour for both the OTC plot and control plot fluxes, which may be explained by the similarity in vegetation cover.

Оценка продуктивности и адаптивности селекционных номеров ежи сборной в среднетаежной зоне Республики Коми

The aims of the present research were to study selection samples of cocksfoot in the conditions of the middle taiga zone of the Komi Republic with the ecological adaptability parameters, calculated on the basis of green mass yield, with a subsequent selection of the most promising forms for further breeding. The experimental part of the work was carried out in the breeding nurseries laid on the experimental fields of the A.V. Zhuravsky Institute of Agrobiotechnologies FRC Komi SC UB RAS (Syktyvkar) in 2019-2021. We studied 7 cross-pollinated lines from wild-growing populations from the Komi Republic (BN-184, BN-185, BN-186, BN-188), Norway (BN-1817) and Finland (BN-1816) which were given breeding numbers (BNs). Since there were no locally recognized varieties during the study period, BN-1810 was taken as a control. Agroclimatic conditions during the years of research varied. By the environmental conditions’ index, 2020 saw favorable growing conditions (Ij = +14.2) and 2019 – relatively unfavorable (Ij = -18.4). The average yield of green mass of cocksfoot ranged within 22.6-30.3 t/ha in 2019-2021. BN-188 demonstrated the highest result (30.3 t/ha). Almost any breeding number showed a high ecological adaptability: the plasticity coefficient varied within 0.91-1.09. BN-1810, BN-185, BN-184, BN-1816 turned out to be highly adaptive and flexible (bi=1.00-1.09, Si2=0.25-0.75). BN-188 (125.5 %) and BN-185 (115.2 %) were marked through the highest stability level of variety. These numbers also were first by the stability index (0.50 and 0.47, respectively). Four of the studied breeding numbers had the adaptability coefficient of 1.03-1.12 with the highest value of BN-188. The greatest genetic flexibility between genotype and environmental factors was noted for BN-188 (18.1), as well as for BN-185 (17.5), BN-1810 (17.5) and BN-1816 (17.6). BN-185 (Sc=6.9) and BN-188 (Sc=6.4) are classified as having the highest breeding value. In total, according to the set of adaptability parameters, the breeding numbers BN-188 and BN-185 were recognized as highly promising forms by the breeding value (Sc = 6.4 and 6.9, respectively), stable productivity, and homeostatic index (Hom. = 1.4).

Эколого-ценотическая активность видов среднетаежной флоры

The control of the main weeds of forestry objects has always played an important role in forestry. The development of evidence-based measures, primarily in the areas of forest nurseries, relies on identifying the features of formation, functioning and activity of segetal plant species. The research aims at developing and adapting evidence-based approaches to the weed control in forest nurseries of the middle taiga zone of the European North by analyzing the ecological status of species in a particular agrophytocenosis and by differentiating species according to the nature of ecological and cenotic relationships. Data on plants was obtained in forest nurseries of Northwestern Russia. The diversity of plant communities was studied by route method throughout the forest agrocenoses, carrying out geobotanical descriptions of the ground cover. The projective cover of vascular plants was observed when describing the vegetation. The results revealed the following regularities: segetal flora is dominated by a group of predominantly weed species, consisting of eurytopic and active weed species (42 %); stenotopic and hemistenotopic plant species, the so-called typical or faithful complex species, represent 34 %; facultative plant species complete the series (24 %). The systematization of a large amount of scientific data became the basis for the theoretical substantiation and implementation in practice of monitoring the most active plant species in agrophytocenoses of forest nurseries. A comprehensive analysis of plant communities of forest nurseries allowed the authors to propose their floristic classification of vegetation. The presented classification considers all the floristic and ecological differences between the studied communities and can be used in the weed control in the northern part of the Russian plain. For citation: Konovalova I.S., Konovalov D.Yu. Ecological and Cenotic Activity of Species of the Middle Taiga Flora. Lesnoy Zhurnal = Russian Forestry Journal, 2022, no. 6, pp. 94–106. (In Russ.). https://doi.org/10.37482/0536-1036-2022-6-94-106

Размерно-качественные характеристики круглых сортиментов, заготавливаемых с применением многооперационных лесных машин

It is necessary to carry out a statistical assessment of the harvested wood parameters in order to increase the yield of round timber and the overall productivity of logging operations while operating multi-operational forest machines. Modern forestry harvesters are equipped with a variety of CAN control sensors to monitor operation and have onboard software that can collect and store input data on various file types to ensure continuous correct operation. One of the main file types is STM (trunk files). These files are presented in two forms: some contain information for each individual tree trunk in different files, and others store all the data for all trunks in one. The second type of STM files is the most relevant when analyzing the operations carried out at the logging site. However, it is inconvenient to use STM files every time to get information, so there is a need to convert the initial data into a table for easy transfer and decision-making at risk and uncertainty. The article proposes a method for transferring such data to a CSV table using Python pandas, numpy, seaborn, matplotlib programming language libraries, which help to process large data arrays quickly and efficiently and display them graphically. The data obtained by two operators using a medium-class Ponsse Ergo 8W machine in the typical natural and production conditions of the Mondi Syktyvkar JSC (Komi Republic, middle taiga zone) were used for the transfer. The efficiency of the operators’ work was assessed. We obtained functions for determining the volume of a tree trunk on the basis of the reported data from the forest machines. The analysis of structured data on the operation of multi-operational forest machines helps to improve decision-making during subsequent felling of trees with the selection of species, which provides the largest volume of round timber output. Moreover, it is possible to adjust assortment tables (APT-matrices) for shortand medium-term planning of assortment harvesting volumes.

Regulation of land-destructive load on water catchment areas of small rivers

In the paper, the issues of provision the sustainable functioning of the ecosystems (natural-engineering systems) of the catchment area of small rivers were considered. It was distinguished, that one of the most widespread kinds of impact is land-destructive load, associated with direct expropriation and transformation of lands, occupied by natural ecosystems. The authors present the criteria for regulation of the land-destructive load, based on the assessment of the diversity of natural and anthropogenic-modified ecosystems in the catchment area of a small river. It was found, that a part of anthropogenic-modified ecosystems should not exceed 35–40 % of the total catchment area (for the middle and southern taiga zone).

Contacts Between the Populations of Chirkovskya and Asbestos-Tempered Palayguba Ceramics

In the end of the last quarter of the III millennium BC populations producing the Chirkovskaya (Fatyanovo-like) pottery combining the late Volosovo and Fatyanovo-Balanovo features migrated from the Upper and Middle Volga to the middle and northern taiga zone of Eastern Europe. On the southern and south-eastern coasts of Lake Onega migrating groups contacted with the aboriginal populations producing the Asbestos-tempered pottery of the Palayguba type. Contacts of the local and incoming groups, according to the results of the study, were restricted only to marriage and can be traced by the changes in the ceramic production. Differences in the spread of decoration motives, characteristic for local varieties of the Chirkovskaya pottery allow the author to suggest two main directions of the influence of migrating groups onto the aboriginal culture with the Palayguba ceramics. The frst vector of contacts starts in the Middle Volga region, continues to the Sukhona River basin and, through Lacha and Vozhe lakes, proceeds to the south-eastern coast of Onega Lake. The southern vector which is connected to the Upper Volga region, proceeds from the Beloye lake basin to the southern coast of Onega Lake.

Особенности мужского мейоза на примере четырех сортов овса посевного (Avena sativa L.), возделываемых в условиях Центральной Якутии

Extreme environmental factors decrease seed setting and form unseeded or thinning panicles. Since meiosis underlies formation of gametes, it largely determines further processes associated with pollination, fertilization and development of a full-fledged seed. In this regard, studies meant to identify the peculiarities of male meiosis for plants cultivated in the severe natural and climatic conditions of Central Yakutia are relevant and of particular interest. The goal of this study was to identify the characteristics of male meiosis in oat (Avena sativa L.) varieties adapted to local conditions. We should emphasize that no studies of meiosis in common oats under the conditions of Central Yakutia have been performed earlier. We used four varieties of common oats (Pokrovsky, Vilensky, Pokrovsky 9, and Khibiny 2) as study material. All the varieties under analysis were hexaploids (2n = 6x = 42). The studies were conducted in 2020 at the Pokrovsky Department of Yakut Research Institute of Agriculture, in Khangalassky ulus of the Republic of Sakha (Yakutia) located in the middle taiga zone. The weather and climatic conditions during the growing season were characterized by an insufficient provision of soil with productive moisture at the early phases of grain and forage crop growth and development. To analyze meiosis, we used oat spikelets sampled when they were emerging into the tube. The spikelets were fixed on June 25-27, 2020 in duplicate using Carnoy’s solution. We analyzed microsporogenesis and pollen fertility on the temporary squashed preparations of meiocytes using the generally accepted method with 4% acetocarmine staining. The results were statistically processed using Statistica 7.0 (StatSoft. Inc., USA). The samples were compared through one-way ANOVA. The general cytological picture of meiosis in the oat varieties under study mostly corresponded to the conservative scenario typical of monocotyledonous plants. However, all the oat varieties showed some deviations from the general meiosis pattern. One of such deviations was cytomixis - chromatin migration as part of nuclei between microsporocytes through one or several cytomictic channels (Fig. 1, 2). As a rule, the phenomenon of cytomixis in microsporocytes was observed at middle prophase 1 at the pachytene stage (Fig. 1). Nuclei migration was also observed at late prophase 1, for example, at the diplotene stage. Chromatin movement between two adjacent microsporocytes clearly correlated with the formation of micronuclei and cytoplasts. Quite often, this process was also accompanied by nuclei pycnosis (Fig. 2). We should note that rarely we observed massive destructive cytomixis in microsporocytes and tapetum cells. When studying common oat cultivars, we also found microsporocytes with separately lying bivalents that were not included in the metaphase plate (Fig. 2), as well as chromosomal bridges (Fig. 2) at the anaphase-telophase 1 stage. The proportion of microsporocytes with meiotic deviations in all the four cultivars was small (Fig. 3) and varied from 2.99 to 3.23% (Table 1). We found no consequences of the revealed deviations at the tetrad stage. Probably, either most deviations were compensated for by intracellular mechanisms or defective microsporocytes were excluded from the microsporogenesis and eliminated. Besides, these deviations of meiosis did not significantly decrease pollen fertility (Table 1). The results indicate that the observed deviations of meiosis do not significantly contribute to seed formation in such an important grain fodder crop as common oats in the climatic conditions of Central Yakutia. The article contains 3 Figures, 2 Tables, 27References. The Authors declare no conflict of interest.

The State of Soil Macrofauna in Pine and Spruce Forests of the Middle Taiga Zone during Reduction of Pulp and Paper Industry Emissions (Komi Republic)

The State of Soil Macrofauna in Pine and Spruce Forests of the Middle Taiga Zone during Reduction of Pulp and Paper Industry Emissions (Komi Republic)

Meadows and pastures in the agricultural landscapes of the Karelian province of the Middle Taiga zone of the North-West of Russia

In order to take into account the territorial differences of natural and economic conditions, to identify biological and ecological patterns, the agro-landscape and ecological zoning of natural forage lands (NFL) of the North-Western natural and economic region of the Russian Federation has been developed. The Karelian province occupies 23% of the area in the north of the Leningrad region, bordering Karelia and Finland. The Karelian province is located in the western part of the Middle Taiga zone, which is characterized by Eastern European Middle Taiga plains. Most of the area of the province (65%) is covered by forests. Agricultural land occupies only 4% of the total area of the province. Including arable land – 2%, hayfields and pastures – 1% each. The territory of the province is significantly moistened and swampy. Swamps occupy 11% of the area, under water – about 11%. Shrubs occupy 3% of the area of the province, other land – about 6%. The structure of NFL is dominated (53%) by normally moistened dry-grass grasslands on sod-podzolic soils. Fine-grained sweet-scented and finegrained grasslands with a large participation of various grasses are common. The yield of hay is 9–13 c/ha, feed is 70 c/ha. Grass-mixed grass and grass-sedge-mixed grass lowland and swampy meadows on swamp-podzolic soils occupy 44%. Grass stands with the dominance of the sod pike are common. Swampy depressions are occupied by large-seeded grass stands. The yield of hay is 10–15 c/ha, feed is 9–11 c/ha. The ecological state of the province’s landscapes is satisfactory-tense.

The Multiscale Monitoring of Peatland Ecosystem Carbon Cycling in the Middle Taiga Zone of Western Siberia: The Mukhrino Bog Case Study

The peatlands of the West Siberian Lowlands, comprising the largest pristine peatland area of the world, have not previously been covered by continuous measurement and monitoring programs. The response of peatlands to climate change occurs over several decades. This paper summarizes the results of peatland carbon balance studies collected over ten years at the Mukhrino field station (Mukhrino FS, MFS) operating in the Middle Taiga Zone of Western Siberia. A multiscale approach was applied for the investigations of peatland carbon cycling. Carbon dioxide fluxes at the local scale studied using the chamber method showed net accumulation with rates from 110, to 57.8 gC m−2 at the Sphagnum hollow site. Net CO2 fluxes at the pine-dwarf shrubs-Sphagnum ridge varied from negative (−32.1 gC m−2 in 2019) to positive (13.4 gC m−2 in 2017). The cumulative May-August net ecosystem exchange (NEE) from eddy-covariance (EC) measurements at the ecosystem scale was −202 gC m−2 in 2015, due to the impact of photosynthesis of pine trees which was not registered by the chamber method. The net annual accumulation of carbon in the live part of mosses was estimated at 24–190 gC m−2 depending on the Sphagnum moss species. Long-term carbon accumulation rates obtained by radiocarbon analysis ranged from 28.5 to 57.2 gC m−2 yr−1, with local extremes of up to 176.2 gC m−2 yr−1. The obtained estimates of various carbon fluxes using EC and chamber methods, the accounting for Sphagnum growth and decomposition, and long-term peat accumulation provided information about the functioning of the peatland ecosystems at different spatial and temporal scales. Multiscale carbon flux monitoring reveals useful new information for forecasting the response of northern peatland carbon cycles to climatic changes.

Key periods of peatland development and environmental changes in the middle taiga zone of Western Siberia during the Holocene.

The response of peatlands to climate change can be highly variable. Through understanding past changes we can better predict the response of peatlands to future climate change. We use a multi-proxy approach to reconstruct the surface wetness and carbon accumulation of the Mukhrino mire (Western Siberia), describing the development of the mire since peat formation in the early Holocene, around 9360cal. year BP. The mire started as a rich fen which initiated after paludification of a spruce forest (probably in response to a wetter climate), while the Mukhrino mire progressed to ombrotrophic bog conditions (8760cal. year BP). This transition coincided with the intensive development of mires in Western Siberia and was associated with active carbon accumulation (31gm-2 year-1). The ecosystem underwent a change to a tree-covered state around 5860cal. year BP, likely in response to warming and possible droughts and this accompanied low carbon accumulation (12gm2 year-1). If the future climate will be warmer and wetter, then regional mires are likely to remain a carbon sink, alternatively, a reversion to the wooded state with reduced carbon sink strength is possible.

Mineralization of Organic Matter in Oil-Polluted and Remediated Oil-Polluted Soils in the Middle Taiga Zone of West Siberia under Laboratory Conditions

Mineralization of Organic Matter in Oil-Polluted and Remediated Oil-Polluted Soils in the Middle Taiga Zone of West Siberia under Laboratory Conditions

A multi-proxy reconstruction of peatland development and regional vegetation changes in subarctic NE Fennoscandia (the Republic of Karelia, Russia) during the Holocene

A better understanding of past long-term environmental changes in the subarctic region is crucial for mitigation of the possible negative effects of climate warming in this vulnerable region. This study provides a new multi-proxy reconstruction of regional vegetation changes and peatland development for north-eastern Fennoscandia (Russia) during most of the Holocene. To that purpose, we performed plant macrofossil, pollen, testate amoebae, peat humification, loss on ignition and radiocarbon analyses of the peat deposits from a mire around Vodoprovodnoe Lake (the Kindo Peninsula, the Republic of Karelia). Our data indicate that the peat deposits started accumulating before 9147 ± 182 cal. yr. BP. The vegetation cover in the area was mainly typical for the northern taiga zone, except for the period ~7800–5600 cal. yr. BP, when it generally resembled the middle taiga zone. The vegetation cover and peatland were greatly affected by reoccurring fires, which can be partly related to human activity. These events were associated with an increased proportion of birch in the vegetation cover (as a pioneer species) and/or water level decreases. By 600 cal. yr. BP, the peatland and the surrounding vegetation reached its current state and only minor changes had been recorded since that time. Overall, our results suggest a considerable and unexpected role of fires in the postglacial dynamics of subarctic peatlands.

The state of soil macrofauna in pine and spruce forests of middle taiga zone during reduction of pulp and paper industry emissions (Komi Republic)

The state of soil macrofauna in pine and spruce forests of middle taiga zone during reduction of pulp and paper industry emissions (Komi Republic)

Новый подход к оценке площади поверхности хвои пихты сибирской

Новый подход к оценке площади поверхности хвои пихты сибирской