Home – Home – Jornals – Contemporary Problems of Ecology 2022 number 5

The dynamics of forest biomass in boreal forests have a significant impact on global carbon cycles. Biomass assessments contribute to understanding the carbon balance of forest vegetation in Siberia. This paper discusses methods for estimating above-ground forest biomass based on radar remote sensing data used in modern research (2010-2021). Methodologies used for biomass assessments are described, including stages of field research, data pre-processing, and modelling of the relationship of remote sensing (RS) data with biomass. Radar sensing has limited capabilities for assessing forest biomass related to characteristics of the survey equipment and parameters of stands. In modern research, a combination of optical and radar data of RS is carried out, which allows to obtain more accurate assessment of biomass using regression models, machine learning, and special techniques (BIOMASAR, SWCM, MaxEnt). The use of data on the optical depth of vegetation cover, estimated from microwave survey data, makes it possible to solve the saturation problem when estimating large amounts of biomass. Comparison of the accuracy of biomass estimation methods is difficult due to the lack of uniform approaches to conducting experiments and calculating errors. Biomass assessment errors based on optical and radar data vary considerably, averaging ~25 %. The assessment of the biomass of boreal forests of Siberia is difficult due to the small amount of supporting field materials. Nowadays, to assess the biomass of boreal forests with a high spatial resolution, it is promising to develop methods based on machine learning algorithms for radar remote sensing data from the Sentinel-1 and ALOS-PALSAR satellites.

Based on the landscape differentiation of the territory, an assessment of the hydrological role of the forest communities dominating in the Podkamennaya Tunguska basin in terms of their contribution to the total evaporation in the watershed was made. Evapotranspiration indicators, obtained from the Earth remote sensing data from the MODIS Global Evapotranspiration Project (MOD16 ET), which take into account the climatic characteristics of the study area, the types of terrestrial surface, and the diversity of vegetation cover were used. Studies have shown that the evapotranspiration of the identified classes of forest vegetation is characterized by significant variability both in space and in time. The variability of evapotranspiration over the years is primarily related to the variability of meteorological elements and the value of the leaf area index. In the spatial aspect, the variability of evaporation is determined by the general climatic characteristics of the study area and the forest species composition. As a result of data analysis, a reduction trend in annual evapotranspiration in the Podkamennaya Tunguska basin from 2000 to 2014 was revealed. A comparative analysis of evapotranspiration trends with temperature and precipitation trends confirms that the reduction trend in evapotranspiration is due to Climate change in region. It was found that the landscape structure of watersheds can be used to indicate the processes that form evapotranspiration as an important component of the water balance, and to determine the hydrologically significative boundaries of landscapes. An estimation of land surface evaporation from Earth remote sensing data (MOD16 ET product) can be used in water balance calculations in watersheds of various scales, especially in the absence of a runoff database.

A comparative study of the haptoral morphology of three species of diplozoon (Monogenea: Diplozoidae) from the gills of fish from polluted water bodies (the Obʼ River, Rybinsk Reservoir, Russia) and unpolluted Lake Tana (Africa) has been made. An examination of the haptors of Paradiplozoon megan (Bychowsky et Nagibina, 1959) from ide and Diplozoon paradoxum von Nordmann, 1832 from bream caught in the Obʼ River and Rybinsk reservoir has revealed a large number of abnormalities of the attachment clamps. Various abnormalities of the attachment clamps were also found in Paradiplozoon spp. from the barbel from the Lake Tana, which does not experience industrial pollution. According to the literature data, abnormalities in the structure of the attachment haptor in diplosoids were also found in relatively clean water bodies. Only in unpolluted water bodies such type of abnormalities as the formation of rudiments of the fifth and sixth clamps was recorded. It is hypothesized that pollution of water is not the main reason for the formation of anomalies in the structure of clamps, there is a native (“genetic background”) frequency of occurrence of abnormalities in Diplozoidae.

In the course of adaptation of birds to living in urban areas, separate urban populations are formed, which are distinct by many biological and ecological characteristics from birds of the same species that inhabit natural environments. The Woodpigeon is one of the most common representatives of synurbic bird species that successfully managed to spread to cities in most of Europe. This article explores the history of formation of synurbic Woodpigeon groups in Belarus and looks at the differences in the breeding biology of forest and urban birds based on research in 2000-2021. During this period, we collected information about 109 Woodpigeon nests in forest areas and 368 nests in urban areas. In the course of our research, we found out that the synurbic Woodpigeon continues spreading to the north and east parts of Belarus. By now, urban birds live in around 70 % of the entire territory of the country. Our analysis of the Woodpigeon breeding biology showed that there are differences between forest and urban birds that stem from the fact that the latter live in urban areas. Despite the absence of clear differences in the phenology of the arrival of the Woodpigeon in cities and natural landscapes, the nesting period of urban birds starts earlier and lasts much longer. In addition, the share of birds that breeding more than one time a season is larger than in forest birds. The peculiarities of nesting sites observed in urban birds as opposed to wild birds result from the peculiarities of urban green spaces and the effect of predation. We discovered that in spring (April - May) the share of nest failures peaks. The breeding success of the Woodpigeon in urban areas amounts to 52 % of all nesting cases.

For the first time, the differentiation by microsites of the population of dung beetles of the inhabitants of horse droppings in South Sikhote-Alin, Primorsky Territory was studied. The heterogeneity of the substrate has a significant effect on the distribution of beetles among microstations. The key factor affecting the seasonal dynamics of the species composition, abundance and biomass of beetles in different parts of the droppings are the temperature and humidity regime. It is shown that the confinement of certain species of dung beetles to areas of horse manure can serve as a way of dividing their ecological niches and a way of avoiding competition within one functional group.

According to the results of soil collections of earthworms in the Omsk Region for 9 years, in the period from 2009 to 2018, their population was analyzed in order to identify the main environmental factors associated with the territorial heterogeneity of species richness and group density. Five types of Lumbricidae populations have been identified, two of which are divided into two subtypes each, where of 10 species and 2 subspecies of earthworms were found. It has been established that the greatest influence on the distribution of worms is exerted by such environmental factors as zonality and subzonality, the depth of the soil layer, and, to a lesser extent, the topography characteristics: 9, 7 and 0.7 % of the considered variance of the density similarity matrix, respectively. In general, all environmental factors and their combinations (modes) explain 38 % of the considered variance, the multiple correlation coefficient is 0.62. Invading species of European origin Dendrobaena octaedra (7-52 %) and Aporrectodea caliginosa (15-74 %) and native Eisenia n. nordenskioldi (6-28 %), as well as of Asian origin: Eisenia ventripapillata (42 %) and E. nana (16 %), for the territories of the southern forest-steppe and steppe, became the leaders in terms of the share of the population density in most taxa of the classification. Such changes in earthworm populations, namely the replacement of native species of the Eisenia nordenskioldi complex with invasive species, can significantly affect soil characteristics and ecosystem services determined by earthworms.

Regulation of river flow due to the construction of hydroelectric power plants and dams leads to a significant transformation of floodplain ecosystems and their components downstream. One of the ways to assess the ecological state of natural landscapes is to determine the enzymatic activity. At the same time, there is undeservedly little data in the world literature on the activity of enzymes in floodplain landscapes, not only disturbed but also natural. This fact is associated with difficulties in the study of floodplain areas, highly dynamic natural objects with a strong variation of properties and parameters in space and time. With this work, we partially fill this gap by showing whether the activity of enzymes can be used to assess the ecological state of floodplain soils with long-term regulation of river flow. As an example, the Zeya River has been regulated by the Zeya hydroelectric power station since 1975. We determined the activity of enzymes (phosphatases, ureases, catalases, polyphenol oxidases and peroxidases) in five types of floodplain landscapes: meadow on the riverine floodplain; meadow, arable land and forest on the central floodplain; swamp in the near-red depression. High activity of phosphatase (max. up to 10 mg/g), and low activity of urease (max. up to 0.55 mg/g) and catalase (max. up to 0.55 g/cm³) were found. The activity of polyphenol oxidase (max. up to 85 mg/100 g) and peroxidase (max. up to 290 mg/100 g) expressed through the humus accumulation coefficient (max. 41 %) indicates the average level of soil fertility of the floodplain. The diversity of enzymes was evaluated using the Pielow index and geometric mean. It was determined that under conditions of long-term regulation, the best indicators of enzymatic activity are characteristic of soils under floodplain forest, the minimum - for arable soils. A single soil parameter that would reliably affect all enzymes has not been identified. Phosphatase, urease and catalase exhibit significant positive relationships with H & Al. Strong positive relationships of catalase with organic matter and negative with pH. The data obtained allow us to state that long-term regulation of river flow leads to a decrease in the activity and diversity of enzymes.

The composition and content of phenolic compounds in leaves of Dasiphora fruticosa plants growing in the Far East, Southern and Eastern Siberia in the range of geographical coordinates 43°13′-62°52ʹ N was studied. The composition of the phenolic complex of D. fruticosa is represented by 16-22 components and remains constant, its variation occurs mainly due to minor components. Seven flavonolglycosides - hyperoside, isoquercitrin, rutin, avicularin, quercitrin, astragalin, kaempferol rutinoside, two aglycones - quercetin and kaempferol, and ellagic acid and its glycoside were determined using HPLC and UV spectrometry. The total content of phenolic compounds in plant leaves ranged from 13.5 to 28.3 mg/g, that of quercetin glycosides from 4.8 mg/g to 17.3 mg/g, and that of kaempferol glycosides from 0.1 to 1.3 mg/g. The total content of ellagic tannins in leaves varied from 6.9 mg/g to 12.9. mg/g. It was found that as D. fruticosa moved from south to north, increased insolation on the background of low-temperature stress, drought, content of all individual components increased, except for avicularin, the content of which, on the contrary, decreased. It was shown that the content of phenolic compounds (in total and in groups) is 53-75 % determined by temperature, of flavonols by 50-91 % by drought and by 50-54 % by solar radiation. Accumulation of ellagic compounds in leaves of D. fruticosa is 60 % determined by temperature, the other factors are of low importance. The factors making a significant contribution to the accumulation of phenolic compounds in D. fruticosa are air temperature, drought and UV radiation

The article presents an analysis of the influence of technogenic pollution on the content of biologically active substances and the antioxidant activity of the fruits of Rosa corymbifera Borkh. In the technogenic environment (on the example of the Donetsk region) were revealed an increase in the concentration of anthocyanins, tannins and oxycinnamic acids and a decrease in the level of flavonoids, ascorbic acid and polysaccharides. In the conditions of anthropogenic pressure, the content of flavonoids changes most significantly. A significant (2 times) increase in antioxidant activity under conditions of technogenic load was revealed. The interrelation of the content of heavy metals (lead, cadmium, mercury) in the soil (mobile forms) and fruits was evaluated. The conformity of the fruits of plants R. corymbifera, growing in the Donetsk region, to the requirements of the regulatory documents was evaluated.

The present work was carried out to study the reaction of plants Darlingtonia californica Torr. on the effect of Cu, Co and Mg ions in in vitro culture. For this, the following concentrations of mineral salts were tested: 0.1 (control), 10, 25, 50, 75 and 100 μM CuSO₄∙5H₂O (which corresponds to 0.006, 0.6, 1.6, 3.2, 4.8 and 6.4 mg/l of water-soluble Cu ions); 0.1 (control), 10, 25, 50, 75 and 100 μM CoCl₂∙6H₂O (corresponding to 0.006, 0.6, 1.5, 3.0, 4.4 and 5.9 mg/l of water-soluble Co ions) and 1500 (control), 4500, 7500, 10500, 15000 μM MgSO₄∙7H₂O (corresponding to 36, 108, 181, 253, and 362 mg/l of water-soluble Mg ions). The results showed a direct significant correlation between the accumulation of Cu, Co, and Mg ions in D. californica plants depending on their content in nutrient solutions. The maximum accumulation of ions was noted after 45 days of cultivation, Cu - 138.24 mg/kg of dry matter, Co - 249.92 mg/kg and 4722.26 mg/kg Mg. It was shown that the concentrations used did not significantly affect the parameters of plant growth and development in in vitro culture. The morpho-anatomical studies confirm the high level of ecological adaptation of this species to extreme conditions. In addition, the plants did not require specific cultural conditions, they are able to grow on nutrient media rich in mineral composition at a temperature of 24±1 °C and do not require low positive temperatures for the root system. The results show that D. californica plants are able to accumulate Cu, Co, and Mg ions and tolerate high concentrations of these elements in nutrient media under in vitro conditions; however, they are not characterized by an increased need for these elements for normal growth and development.