State Nature Biosphere Reserve Research Articles

The content of chemical elements in <i>Trаpa nаtans</i> and <i>Nymphoides peltata</i> of the Volga Delta

Aim. To identify the specific features of the accumulation of heavy metals in Trаpa nаtans and Nymphoides peltata in the Volga delta. Materials and Methods. Plant sampling was carried out in the Astrakhan State Nature Biosphere Reserve. Determination of the concentration of chemical elements was carried out using atomic absorption spectrophotometry. Results. As a result of the research it was noted that the plant species studied had some similarities in the accumulation of chemical elements. In both types of plants iron was predominantly accumulated, manganese content being in second place in terms of metal concentration. Chromium and cadmium were found to be in the lowest concentrations. Nymphoides peltata is an iron accumulator compared to Trapa natans. The leaves of Trapa natans are manganese concentrators, while the stems are copper concentrators. Conclusions. Based on the specific features identified in the accumulation of chemical elements in plants, a proposal is put forward regarding the possibility of using the leaves and stems of Nymphoides peltata as a test object for monitoring iron and chromium concentrations in water and the leaves of Trapa natans for monitoring copper concentrations in water.

The confinedness of undergrowth Picea obovata and Abies sibirica (Pinaceae) to tree-related microhabitats and their development features at various phases of post-fire succession in green-moss dark coniferous forests in the Northern Pre-Urals

Forest ecology frequently explores the role of microsite mosaics in forest communities for the regeneration of forest-forming tree species. The present study aims to find out whether the ontogenetic structure and differentiation of Siberian spruce (Picea obovata) and Siberian fir (Abies sibirica) undergrowth plants by the plant vitality are associated with their occurrence on various microsites. The study has been carried out in the Pechora-Ilych State Nature Biosphere Reserve, Russia. In green-moss fir-spruce forests, 23 temporary sample plots were established, including 1) forest communities of the intermediate phase of post-fire succession (in areas where fires happened in 1850–1900) and 2) forest communities of the late phase (in areas where there were no fires, at least since the mid-XIX century). On the study plots, P. obovata and A. sibirica undergrowth individuals were recorded indicating ontogenetic state, vitality and microsite substrate for each plant. Using the Z-criterion, a comparison of the occurrence frequencies (%) of various undergrowth groups of P. obovata and A. sibirica on various microsites has been carried out, i.e. within each species and between the studied species, as well as at each phase of post-fire succession and between the phases. The analysis showed that, in communities of both succession phases in both species, undergrowth plants of ontogenetic state im2 occurred on deadwood logs less frequently than the undergrowth plants of the earlier ontogenetic state im1. At the same time, in both species on the flat ground surface an opposite occurrence trend for these ontogenetic states was revealed. In communities of the late succession phase, A. sibirica undergrowth plants of the ontogenetic state im2 and normal vitality occurred on a flat ground surface within inter-crown sites more frequently than plants of reduced and low vitality. A comparison between the species showed that in forest communities of both succession phases, A. sibirica undergrowth plants of im1 and im2 ontogenetic states more frequently occupy flat ground surface than deadwood logs, whereas P. obovata undergrowth plants more frequently grow on deadwood logs than on the flat ground surface. In addition, in communities of the intermediate succession phase, A. sibirica undergrowth is more likely than P. obovata to be found in the under-crown sites (especially on a flat ground surface). In communities of the late succession phase, A. sibirica undergrowth more often grows in under-crown sites on the near-trunk elevations of living trees. In both species, 40–50% of im2 plants of low vitality grow in inter-crown sites. To clarify the influence of the microsite mosaics on the regeneration processes in the studied forests, more detailed and large-scale studies are further needed, which will allow us obtaining more representative samples of undergrowth plants at various ontogenetic states.

Оценка окислительно–восстановительных реакций донных отложений пруда Угольчик методом автографии на фотобумаге

The article considers the analysis of bottom sediments selected on the territory of the Central Forest State Natural Biosphere Reserve of the Tver region, in the Ugolchik Pond for the assessment of redox reactions by autography on photo paper, which is an indicator of the state and number of anaerobic microorganisms at the bottom of the reservoir according to autography. Keywords: BOTTOM SEDIMENTS, AUTOGRAPH ON PHOTO PAPER, AQUATIC ECOSYSTEMS, ECOLOGICAL ASSESSMENT OF WATER BODIES

Nature reserves (zapovedniks) in the Volga catchment: protection, research and management

AbstractIn the Russian Federation, the protection category “Zapovednik” represents a strictly protected area, where the access is restricted and the aim is to keep the area “forever wild”. We provide an overview about the organization of these nature reserves and highlight their contribution to fundamental research. Aquatic ecosystems in zapovedniks provide pristine sites of great importance for long-term monitoring and research, which fosters process understanding regarding interannual variability and development of aquatic coenosis. We present a long term monitoring and research project about abiotic and biotic parameters in the Central Forest State Nature Biosphere Reserve. Examples from the Privolzhskaya Lesostep Nature Reserve include monitoring of invasive fish as well as analyses about the influence of beavers on fish. The Astrakhan Biosphere Nature Reserve in the Volga delta is a hotspot for fish biodiversity; thus, there the state nature reserve security service plays an important role to avoid poaching. Our case studies from the Volga Basin exemplify the structure and function of nature reserves and highlight their contribution to research, protection and management of aquatic ecosystems. Long-term datasets from the zapovedniks can (i) improve process understanding, (ii) ensure protection of aquatic systems and sustainable water management and (iii) support knowledge-based decisions.

THE FIRST FINDING OF MACROSACCUS ROBINIELLA (CLEMENS, 1859) AND OBOLODIPLOSIS ROBINIAE HALDEMAN, 1847 NEAR VORONEZH

The data about finding of Macrosaccus robiniella (Clemens, 1859) (Lepidoptera, Gracillariidae) and Obolodiplosis robiniae Haldeman, 1847 (Diptera, Cecidomyiidae) in Voronezhsky State Nature Biosphere reserve are given for the first time. Some features of the biology of the local population of M . robiniella are shown.

Интродукция кедра и лиственницы в условиях Кольского Заполярья

The purpose of this study was to investigate the history of growth of the introduced species Pinus sibirica Du Tour and Larix sibirica Ledeb. in the Murmansk region and their state in natural areas of preferential protection. The first finds of Siberian cedar in the Arctic region were recorded in 1911, and Siberian larch in 1925. In the 1930s and 1950s–1960s, these kinds of trees were extensively cultivated in the region. Many cedar and larch growth areas are protected as natural monuments of regional significance. Currently, there are eight natural monuments with Siberian cedar growing on the territory of the Murmansk region and seven natural monuments with Siberian larch. The condition of the trees in the territories under preferential protection and the Lapland State Natural Biosphere Reserve was studied in detail. The invasive species occupy a territory of about 70 ha. It was a complete or random enumeration of the trees and undergrowth with measurements of height and diameter. Siberian cedar ranged in height from 0.02 to 18.00 m, whereas Siberian larch was between 0.01 and 18.00 m. Cedar diameters varied from 0.3 to 31.7 cm, whereas larch diameters ranged from 0.4 to 38.3 cm. It is shown that coniferous introduced species are well acclimatized to the natural conditions of the Arctic, which increases the biodiversity of ecosystems and aesthetic perception. Pinus sibirica Du Tour and Larix sibirica Ledeb. fructify in the conditions of the Kola Arctic region that is a sign of a natural regeneration. It is recommended to monitor the conditions of the plantations on a regular basis in order to provide appropriate care. With the inclusion of plots with the growth of the studied species in natural areas of preferential protection, it is necessary to study their condition, location, accessibility, and targeted application. Evaluation of the effectiveness of existing forest management system will allow a more rational approach to the conservation of valuable cedar and larch tree species in the Arctic region. For citation: Isaeva L.G., Ershov V.V., Urbanavichus G.P., Borovichev E.A. Introduced Species of Cedar and Larch in the Climate Conditions of the Kola Arctic Region. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 4, pp. . 41–57. (In Russ.). https://doi.org/10.37482/0536-1036-2023-4-41-57

Features of biology and population dynamics of Cephalanthera rubra (Orchidaceae Juss.) in the Sochi Black Sea region

Cephalanthera rubra (L.) Rich. is sporadically distributed in the Sochi Black Sea region. It occurs in the forests of the low-mountain and mid-mountain belts of the southern macroslope of the Main Caucasian Range. The number of individual populations is from two-three to a dozen individuals, usually populations are distant from each other over long distances. C. rubra can be attributed to hemiephemeroids, having spring-early summer green shoots with a period of summer-autumn-winter dormancy. The growing season lasts 3 months. Morphometric indicators of individuals of different ontogenetic states are given. The dynamics of the ontogenetic structure of the population from the area of the hornbeam forest in the vicinity of the village Illarionovka for 8 years is shown. In the ontogenetic spectra of the studied large population, the predominance of generative individuals is constant. The population is full-membered, normal type, stable. The species is self-compatible, autogamy was not revealed. The model species for pollinators seems to be Lathyrus laxiflorus (Desf.) Kuntze, which is absent from the studied population. Fruit formation in different locations does not always occur; it is absent in the studied population. Seeds of Limodorum-type, linear or fusiform, about 1.3 mm long. The species is protected in the Sochi National Park and in the Khosta Department of the Caucasian State Natural Biosphere Reserve.

MATERIALS ON THE FAUNA OF EPHEMEROPTERA, PLECOPTERA AND TRICHOPTERA OF THE KRONOTSKY NATURE RESERVE AND OTHER REGIONS OF KAMCHATKA

As a result of collection in 2014–2021, additional information was obtained on the fauna and distribution of three orders of amphibiotic insects Ephemeroptera, Plecoptera and Trichoptera of the Kronotsky State Natural Biosphere Reserve and other regions of the Kamchatka Peninsula. The general list of the three orders the studied territory includes 56 species: 8 species of mayfl ies, 17 – stonefl ies, and 31 – caddisfl ies. For the territory of Kronotsky Nature Reserve are noted 50 species: 8 – mayfl ies, 11 – stonefl ies, and 31 – caddisfl ies; the presence of 48 previously known species is confi rmed. Stonefl y Capnia nigra (Pictet, 1833) and caddisfl y Hydropsyche kozhantschikovi are fi rst fi nds for the reserve. Plecopterans Plumiperla diversa (Frison, 1935) is discovered for Geyser Valley streams for the fi rst time, and Isocapnia orientalis Zhiltzova, 1975 is a new fi nding for the Kamchatka Peninsula.

The Influence of Eurasian Beaver (Castor fiber L.) Activity on the Transformation and Functioning of Riparian Phytocoenoses in the Southern Boreal Zone (European Russia)

The reintroduction of Eurasian beaver (Castor fiber L.) results in significant changes in ecosystems. The purpose of this study is to assess the impact of the environment-forming activity of C. fiber on the riparian phytocoenoses of the Raifa forest sector of the Volga-Kama State Nature Biosphere Reserve (Middle Volga region, European Russia) after the reintroduction. Phytoindication methods of ecological–coenotic groups and indicator values were used to assess changes in environmental conditions under the influence of beaver activity. The influence of the beaver reintroduction factor on the increase in the moisture regime (by three points according to the Tsyganov indicator values) and the illumination of habitats, the richness of soils in nitrogen, and the acidity and salt regime of soils (by one point) was revealed. Under the conditions of fodder and construction activities of the beaver, an increase in the proportion of aquatic and wetland groups from 10.2% to 28.2% and boreal plant species from 15.0% to 27.6% was detected. An expansive nature of the change in the degree of landscape occupancy with wetland plants was noted. A decrease in the degree of landscape occupancy (3 to 2 points) of the distribution of ruderal species in the riparian zones of the waterbodies of the reserve due to the activity of the beaver was revealed. Based on phytoindication and ecological–coenotic analyses, it was shown that the reintroduction of C. fiber into the waterbodies of the Raifa forest sector of the reserve is responsible for maintaining the necessary microclimatic conditions for the preservation of natural southern boreal communities. The results obtained can be used for predictive assessment of the influence of the beaver on riparian (small rivers and lakes) plant communities of forest ecosystems in the Middle Volga region of European Russia and other regions of the planet with similar environmental conditions.

Landscape Invariants–Order Parmeters of a Dynamic System

The article considers theoretical and methodological substantiation of identifying invariants problem in nonlinear dynamic systems. Invariance in context of stable spatio-temporal structures in a landscape was proposed by V.B. Sochava in 1961. The accumulation of long-term series of landscape observations by means of multispectral imaging made it possible to identify invariants in practice. An analysis of Landsat multispectral measurements from 1987 to 2022 for the southern taiga landscape (Central Forest State Nature Biosphere Reserve) shows that invariants identified as order parameters primarily determine total aboveground vegetation biomass, the water content in vegetation and soils, and the intensity of photosynthesis, i.e. bioproduction process. The proposed scheme for analyzing time series of remote sensing data makes it possible to assess landscape cover at the time of survey with respect to invariants and to identify the main control parameters that determine changes in environmental conditions and self-development of geosystems. The assessment of vegetation and relief contribution to formation of invariants structure was made to reveal invariants physical meaning. The results showed that relief has little effect on order parameters, and vegetation cover make the greatest contribution to invariant structure formation. Since invariants make it possible to identify the most stationary states, they can be used to solve applied problems in agriculture and forestry, as well as in the assessment of various ecosystem services.

Высокогорный природный парк «Ак Чолушпа» как территория экотуристского интереса

Высокогорный природный парк «Ак Чолушпа» как территория экотуристского интереса

CAREX BOHEMICA (CYPERACEAE) В ВОЛОГОДСКОЙ ОБЛАСТИ

Data on the distribution, biomorphology, ecological and phytocenotic features, and protection of Carex bohemica Schreb. in the Vologda Region are presented. The choice of the object of study is associated with the rarity of the species in the region and its poor knowledge base. Bohemian sedge was registered in the region for the first time only 45 years ago and is currently known from 11 localities situated in two administrative districts (Vytegorsky and Cherepovetsky). All records are concentrated only in the western part of the region, where the species is found in the coastal areas of two reservoirs of the Volga-Baltic waterway and two disappearing lakes. Findings of the species fall within the boundaries of 6 squares of grid mapping adopted in Atlas Florae Europaeae. The life form of the species is defined as a loose turf-forming perennial polycarpic herbaceous plant with self-orthotropic non-succulent assimilate shoots. C. bohemica is found along the banks and shallows of karst lakes, flood zones of reservoirs, and floating peatlands. The species prefers sandy, sandy-stony or silty soils, and a changeable-level hydrological regime. In localities known in the region (as well as in other parts of the range), the species may not occur for some time but later appear copiously, showing a short burst of abundance. The species is included in the Red Data Book of the Vologda Region with the 2/VU/II conservation status. C. bohemica was recorded within the boundaries of three protected areas (Darvinskiy State Natural Biosphere Reserve, hydrological natural reserves (zakaznik’s) “Kushtozersky” and “Shimozersky”). The necessary protection measures for the species include control and monitoring of the state of the populations identified in the region and targeted surveys for new places of its growth, as well as further studies of its ecology and, if necessary, introduction measures.

Ancient Deep Sea Bottom in Modern Mountains: New Aspects of Geoheritage from Guzeripl in Southwestern Russia

Geoheritage studies have different perspectives, among which treatment of geological features in relation to particular areas and settlements seems to be promising for better local planning and tourism organization. The small town of Guzeripl in the Western Caucasus (southwestern Russia) experiences tourism-triggered development. Five localities, which are parts of two earlier established geosites, are found directly in this settlement and in its vicinity. They show representative siliciclastic deposits dominated by shales, which accumulated on the deep bottom of the Caucasian Sea in the Early Middle Jurassic. New field investigations allowed for the collection of information regarding the improvement of the geological knowledge of this study area and the reconsideration of its geoheritage in relation to the settlement’s needs. Particularly, the tentative approach for the functional assessment of the localities was proposed and applied. It is established that the localities represent not only deep-marine siliciclastic deposits, trace fossils, and specific palaeoenvironment, but also the structural elements (anticline, syncline, and fault) of the complex deformed domain. They differ by functional value, with two of the most valuable localities directly in Guzeripl, and all of them can be employed for the settlements’ needs. Geoscientists, guided student groups, and geotourists can choose Guzeripl to collect new data, train, and for new impressions. Importantly, geotourism based on the considered localities can diversify the experience of visitors, and it can be combined with and facilitated by ecotourist activities already offered by the Caucasus State Nature Biosphere Reserve, which is famous for its natural heritage. The study area focuses on the spatial distribution of geoheritage relatively to the touristic patterns.

Биологическая активность буроземов в молодых «окнах» полога леса Кавказского биосферного заповедника

The ecological features and biological activity of Cambisols of acidic low mountains in the upper reaches of the Belaya River in the Western Caucasus have been carried out. The studies were carried out on the territory of the Caucasian State Natural Biosphere Reserve in the primary beech -fir forests and “windows” of fallouts formed at the site of the death of old trees. The investigated “windows” aged 2-6 years are characterized by increased insolation and a special microclimate, they quickly overgrow with undergrowth and grassy vegetation. This leads to a change in the physical, chemical and biological properties of Cambisols. The moisture content of soils, the degree of saturation of soils with bases increase significantly, the content of humus and active carbon increases. A change in edaphic properties leads to an increase in the number of microorganisms and microbial biomass. The enzyme activity of Cambisols from different area s varies considerably and does not have an unambiguous behavior. Despite the differences in the values of individual indicators of biological activity, the integral assessment showed practically equal values for the Cambisols of primary forests and young “windows” of fallouts.

INVENTORY AND ANALYSIS OF THE FLORA OF THE VISIMSKIY RESERVE

The vascular plant flora of the Visimskiy State Natural Biosphere Reserve was studied. It comprises 530 species, 238 genera and 69 families of vascular plants. 510 species were classified as native plants and 20 species as alien plants (4% of the species composition). The top families in terms of the number of species are Asteraceae, Rosaceae, Poaceae, Ranunculaceae. The top genera in terms of the number of species are Alchemilla, Ranunculus, Carex, Poa, Hieracium. The geographical analysis revealed the dominance of Holarctic, Eurasian, boreal and boreal-nemoral species. The analyzed flora also contains the species associated with highlands and lower mountain belts. 10 endemic and subendemic species of the Urals, 24 species listed in the Red Data Book of the Sverdlovsk Oblast, and 2 species included in the Red Data Book of the Russian Federation occur on the territory of the Visimskiy Nature Reserve. The list of the flora of the Visimskiy Reserve is available in the GBIF repository.

Age structure and growth of Bufo verrucosissimus (Amphibia, Anura, Bufonidae) in the Caucasian State Nature Biosphere Reserve (Russia) at the end of the XX century

Bufo verrucosissimus is an endangered species in the Russian Federation. One of the largest protected areas where B. verrucosissimus is preserved is the Caucasian State Nature Biosphere Reserve. The paper presents data on age structure and growth of B. verrucosissimus collected in the Caucasian State Nature Biosphere Reserve in 1987–1990 and stored in the collection of Sochi National Park. The age of 16 females and 51 males was determined using the method of skeletochronology. The age of adult females was 6–10 years (on average 7.9 years), and males 2–9 years (on average 5.8 years). Females were statistically significantly superior to males in average age. In terms of body length, significant differences between males and females where noted in groups of seven- and ten-year-old animals. The body length of studied animals (60.8–116.4 mm for females and 61.2–86.3 mm for males) corresponds to the size of adult toads from other localities in the North Caucasus. Females grow evenly throughout their lives, while the growth of males slows down significantly after reaching puberty. Males were able to reach the maximum body length faster than females (the growth coefficient was 0.722 for males and 0.163 for females). According to the von Bertalanffy equation, the maximum possible body length was 130.9 mm for females and 74.6 mm for males.

ВИДОВОЕ БОГАТСТВО ИНФУЗОРИЙ МАЛОГО ЗАБОЛАЧИВАЮЩЕГОСЯ ВОДОЕМА: ОБЩИЕ ПРОБЛЕМЫ СОХРАНЕНИЯ ИХ БИОРАЗНООБРАЗИЯ

This article presents the results of the fi rst study of the species composition of ciliates from the polyhumous lake Mohovoye, located in the Volga-Kama State Natural Biosphere Reserve; discusses the general issues of the need to organize the conservation and protection of protozoa and their habitats; provides a brief overview of the experience accumulated in the world on this issue. The aim of the work was to identify new and rare species of ciliates, to describe their autecological and distributional features as a descriptive basis for further identifi cation of potential diversity. 53 species have been recorded in the deep-water part of the lake, while there are species that have not even been identifi ed to the genus level. Lacrymaria cf. sapropeliсa Kahl, 1927, Trichospira inversa (Claparède & Lachmann, 1858), two species from the family Spathidiidae, as well as the main dominant Pseudoblepharisma tenue var. viride (Kahl, 1926) have not previously been recorded in this region. Their detection is more likely due to the low level of study of such undisturbed habitats than to the endemism of these species. The uniqueness of the lake and the whole complex of ciliates species lies in the signifi cant magnitude of the maximum abundance – 753.7 million cells/m3 ; 53-75% of the abundance was formed by P. tenue var. viride (Kahl, 1926), which is a rare species in other waterbodies. In general, mainly mixotrophic ciliares form a very narrow and high, like a “bacterial plate” abundance maximum. The problem of the conservation of the ciliates biodiversity lies in the underestimation of their importance, due to their inconspicuousness and cosmopolitanism; the low attractiveness of small reservoirs as “pockets of diversity” for limnologists and the lack of well-trained specialists in the systematics of ciliates who can be able to competently combine morphological and molecular genetic research methods.

Relationships between the seasonal dynamics of soil fungi biomass and environmental factors in predominating forest types in the Bryansk woodlands (European Russia)

Being the crucial part of the forest soil's microbial pool, soil fungi in general and mycorrhizal fungi in particular are an important study object when it comes to forest ecosystems sustainability and preservation. Thus, the study of ectomycorrhizal fungi has been carried out in the Bryanskiy Les State Nature Biosphere Reserve, located in the south-eastern part of the Bryansk woodlands (European Russia). Forest types featured in the study are the local predominating types, namely green-moss-fructiculose pine forests and polydominant deciduous broadleaved nemoral-herbaceous forests with spruce. This study was aimed to assess seasonal dynamics of soil fungi' biomass overall and ectomycorrhizal fungi in particular over the course of the 2017 vegetation period (May – November) and its dependence on biotic and abiotic environmental factors, such as soil water content, temperature and vegetation. The vegetation period was divided into three periods of observation, namely an early (May – July), middle (July – September) and late (September – November) one. The method used to assess the fungal biomass was direct microscopic observation using the fluorescein diacetate staining. In order to estimate the ectomycorrhizal fungi biomass separately, trenching and in-growth mesh bags were employed. The obtained results suggest that the soil fungi biomass steadily increases over the vegetation period in both studied forest types. This is mostly affected by the forest type, available water amount and seasonal changes, while the temperature's impact is less pronounced. On average, the soil fungi biomass was higher in broadleaved forests than in pine forests (2.288 mg C × g-1 soil vs. 1.672 mg C × g-1 soil, respectively), with non-ectomycorrhizal component having comparable biomass. The dynamics of biomass differed in the two forest types. However, noticeable differences (p < 0.1) between the two forest types have only been recorded during the July – September period. The biomass of ectomycorrhizal fungi is smaller than the biomass of non-mycorrhizal fungi, but at the same time it is less affected by changes in moisture. Besides that, the study has shown that the forest litter characteristics can greatly affect the dynamics of the fungal biomass.

Microscopic fungi in the soils of forest ecosystems of the Voronezh State Natural Biosphere Reserve

Microscopic fungi in the soils of forest ecosystems of the Voronezh State Natural Biosphere Reserve

Estimating brown bear population density and abundance using camera traps in the Central Forest State Nature Reserve (west of European Russia)

This paper presents the results of estimating the population density and abundance of Ursus arctos (hereinafter – brown bear) in the Southern Forestry of the Central Forest State Nature Biosphere Reserve (CFNR), West of European Russia, in 2021 based on the Random Encounter Model (REM) based upon data obtained from camera traps. Methods for obtaining parameters necessary for building a model are demonstrated. A total of 7970 camera trap nights were worked out at 46 stations, and 502 independent trap events were obtained. The average relative abundance index (RAI) was 6.28 ± 1.59. The total average brown bear population density was 0.086 ± 0.034 individuals per 1 km2. The approximate estimated abundance was 18.98 ± 7.54 individuals. The coefficient of variation was 38%. Population density estimates had a pronounced seasonal dynamics. The minimum value was recorded for the period from 24 June to 23 July (individuals feeding on meadows and ants outside the CFNR core area), and the maximum for the period from 24 July to 22 August (brown bears feeding by berries in the CFNR core area). We found a strong significant correlation between brown bear population density and its relative abundance index (r = 0.81, p < 0.05). It was found that with an increase in the sampling period duration, the estimate of the population density noticeably decreases (r = -0.53, p < 0.05). Parameters of the average travel speed and activity level are a subject to the greatest variability, which determines the significant variability of the day range. In general, the method of population density estimation using REM is highly promising to carry out the brown bear population size estimation in forests and mountain forests, where visual estimations are difficult or impossible.