Due to the need to achieve the principles of sustainable development and to understand the processes of formation of phytocenoses in areas that were adversely affected by the industrial impact, this study assessed the condition of the Grachevsky uranium mine (Kazakhstan), which underwent conservation procedures about 25 years ago. The purpose is to determine the level of water quality and phytocenosis of the shores of the reservoir accumulating natural effluents from reclaimed dumps and anthropogenic sites of a uranium mine, as well as quality indicators and toxicology. The assessment included a qualitative research method (analysis of documents) to determine agro-climatic conditions and empirical methods of collecting information. The authors studied the intensity of ionizing radiation of the gamma background of the water surface of the reservoir (and sections of the shoreline and territories adjacent to the reservoir), and hydrochemical parameters of the waters of the reservoir, and performed a description of the botanical diversity. The vegetation cover of the sections of the reservoir shore is at different stages of syngenesis and is represented by pioneer groupings, group thicket communities, and diffuse communities. Favorable ecological conditions for the settlement and development of plants develop within the shores of the reservoir. The intensity levels of ionizing radiation do not exceed the maximum permissible levels and practically do not affect the formation of phytocenoses. An anthropogenically modified dry meadow with the participation of plants typical of the steppe zone has been formed on the floodplain terrace. Concerning the indicators of quality and toxicology of this reservoir, the water can be used for household and drinking purposes under the condition of prior water treatment. It can be concluded that a high level of natural purification of the reservoir waters occurred within twenty years after the reclamation of the uranium mine.

In urban ecosystems to the west of the Elektrostal Heavy Machinery Plant, six years after the radiation incident, local sites with a total area of 0.2 km2 with an increased equivalent dose rate of γ radiation of 0.15–0.40 μSv/h and a high specific activity of 137Cs reaching 8328–8740 Bq/kg in the upper soil horizons were identified. Statistically significant direct correlations were noted between the specific activity of 137Cs in the layer of 0–10 cm of soil and the equivalent dose rate of γ radiation at the surface and height of one meter. The types of vertical distribution of 137Cs in soils of polluted urban ecosystems, including those on which earth decontamination works were carried out, have been determined. The calculated 137Cs transfer coefficients increase in the series of trees Salix alba < Sórbus aucupária < Ácer platanoídes < Malus domestica < Alnus incana < Ácer negúndo; and grassy vegetation Týpha angustifólia < Artemísia vulgáris < Tussilágo fárfara < Cirsium arvense < Urtíca dióica.

The article deals with issues related to the development of radioecology as an independent scientific discipline. The achievements of past years and the studies that are currently being carried out, as well as promising areas of development in this area are analyzed. A corrected periodization of the stages of development of radioecology is proposed, taking into account the experience accumulated to date in the field of this discipline. At the initial stage (1895–1929), empirical material was collected; at the first stage (1930–1960), the theoretical foundation was laid and radioecology was formed as an independent discipline; at the second stage (1961–1990), intensive development of radioecology was noted; and, at the third stage (1991–2010), there was progressive development of radioecology; the fourth—modern—stage of the development of radioecology is in the beginning of the 21st century (2011–present). For each stage, the main scientific achievements and evolution of ideas in the field of radioecology are considered. It is postulated that, at present, the development of this discipline is associated with the further improvement of world nuclear technologies, the elimination of the consequences of a number of radiation incidents (the accident at the Fukushima nuclear power plant in 2011), the revision of the concept of radiation protection of the environment and a number of other provisions. Particular attention is paid to forest radioecology, one of the most important main areas of this science.

The purpose of this study was to assess the processes of plant community formation on recultivated dumps of spent uranium-containing industrial waste from uranium deposit mines, as well as to identify the degree of impact of agro-climatic factors, agrochemical indicators of soils of recultivated dumps, and the level of residual ionizing radiation on the productivity of the emerging vegetation cover. Studies of plant colonization of recultivated Grachevsky and Shantobinsky uranium mine dumps located in Northern Kazakhstan were carried out. The mining and technical stage of reclamation consisted of planning a dump with slopes of 15° and covering it with a 1 m layer of chestnut soil. In total, 30-35 plant species are present in the dumps, the projective coverage is approximately the same (56.6-70.0%), and the herbage density is 15-16.6 plants/100 m2. As a result of the measures taken to recultivate the dumps, the intensity of the background ionizing radiation at the Grachevsky mine dump was in the range of 25-35 µR/hr and at the Shantobinsky mine dump 10-25 µR/hr, which indicates compliance with safety standards. The plant species which can be used for artificial plant colonization of uranium-containing waste dumps, were identified.

The 226Ra, 238U, and 232Th fractions have been studied in the virgin gray soil under the forest and in the agro-gray soil of the Tula forest entanglements (Tula Zaseki). Radionuclides have been fractionated by Pavlotskaya’s sequential extraction method. The 238U and 232Th concentrations have been determined with an inductively coupled plasma quadrupole mass spectrometer. The 226Ra activity has been measured using an alpha-radiometer, taking into account the decay of radium isotopes and the accumulation of their daughter decay-related products. Long-term (decades) and systematic use of phosphorus fertilizers leads to an increase in 226Ra, 238U, and 232Th reserves in the ploughed layer (0–25 cm) of the agro-gray soil to levels of 15.1, 15.4, and 16.2 kBq/m2, respectively, which is 1.7, 1.4, and 1.1 times higher than in the virgin gray soil under the forest. Alongside with that, a considerable amount of radionuclides (21.9

Examining the overgrowth of dumps, techno-soils, and areas containing waste products of uranium mines is vital for understanding the dynamic features of vegetation cover in technogenic landscapes. The main aim of this study was to investigate variations in the plant species composition and their productivity in dumps and technological areas and the intensity of soil ionizing radiations under varying environmental conditions based on the Shantobe Uranium Deposit, Kazakhstan. The vegetation at the waste dumps and technogenic sites is in the early stages of syngenesis and is representative of pioneer and group-thicket communities. Adverse ecological conditions associated with intense sulfate salinization formation thrive at the technological sites. However, the floristic composition is illustrative of highly resistant species (Calamagrostis epigejos and Phragmites australis) and secondary species. Typically the formation of steppe zone plant communities of Kazakhstan does not occur in these sites. The productivity of the recultivated dump and banks of the former uranium mine is quite high at 120–150 g/m2, which matches the meadow-ruderal communities of Northern Kazakhstan. However, the lowest productivity of 30–37 g/m2 emerged in the non-recultivated and partially processed sulfuric acid heap leaching stacks containing uranium ore, which create exceedingly unfavorable conditions for the establishment of crop plants. Several plant species identified as self-seeding live in partially processed piles of sulfuric acid heap-leaching uranium ores with a sufficient level of resistance to survive in soil with high levels of sulfate-containing salts and ionizing radiation of 1200–1400 μR/hr. These facts can authenticate to consider the possibility of growing these plant species in the artificial grassing of uranium-containing dumps to create herbage.

В данной статье рассматриваются данные, полученные в ходе исследования продуктивности поливидовых агрофитоценозов в условиях Северного Казахстана. Описаны методика проведения и результаты полевых опытов по использованию злаково-бобовых травосмесей, подобранных согласно почвенно-климатическим условиям данного региона, для повышения продуктивности пастбищ. Приводятся метеорологические условия в данном регионе за 2021 год. В результате проведенных исследований были проведены агрохимические оценки почвы, учет густоты многолетних трав; высота злаково-бобовых травосмеси; определена продуктивность злаково-бобовых травосмеси путем скашивания и взвешивания с разбором по видовому составу травосмеси и высушивание снопов до воздушно-сухого состояния. Определены фотосинтетическая деятельность растений путем измерения содержания хлорофилла в растениях экспресс-методом: прибор N-tester SPAD 502 Plus Chlorophyll Meter, предназначенный для определения уровня азотного питания растений по содержанию хлорофилла в листьях в полевых условиях.

An algorithm has been developed for the simulation model of carbon behavior in herbaceous communities of various types, both autonomous and as a part of complex phytocenoses. The influence of external factors is taken into account, such as solar radiation, precipitation, air temperature, clouds, and wind speed. The dynamics of soil moisture level and temperature are reproduced. The algorithm can be modified, depending on the discreteness of consideration of the simulated processes. The algorithm is tested in modeling the dynamics of the phytomass of a community of ground elder ( Aegopodium podagraria L.) that is dominant in the herbaceous cover of the ground elder oak grove on dark-gray forest soil. The EcoGrass model is used to conduct numerical experiments to study the impact of the potential global climate change and consumption of phytomass by animals on the productivity of this community. Threshold values of influence factors have been determined upon reaching which the normal functioning of the community is disrupted.

The levels of specific activity of 137Cs and the contents of mobile forms (1 M ammonium acetate extraction) of heavy metals (Zn, Cu, Ni, Co, Cr, Pb) and petroleum products were studied in the upper soil horizon of urban landscapes of the city of Elektrostal under conditions of local radioactive and chemical contamination were studied. In the soils within a short radius (0–100 m) around the heavy engineering plant, the specific activity of 137Cs and the contents of mobile forms of Pb, Cu, and Zn were increased. The lognormal distribution law of 137Cs was found in the upper (0–10 cm) soil layer; five years after the radiation accident, the specific activity of 137Cs varied from 6 to 4238 Bq/kg. The coefficients of variation increased with an increase in the degree of soil contamination in the following sequence: Co < Ni < petroleum products < Cr < 137Cs < Zn < Pb < Cu ranging from 50 to 435%. Statistically significant direct correlation was found between the specific activity of 137Cs and the contents of mobile forms of Pb, Cu, and Zn in the upper horizon of urban soils, and this fact indicated the spatial conjugacy of local spots of radioactive and polymetallic contamination in the studied area. It was shown that the specific activity of 137Cs, as well as the content of heavy metals and petroleum products in the upper layer (0–10 cm) of the soils disturbed in the course of decontamination, earthwork and reclamation is reduced.

In the present work, the fractionation of heavy natural radionuclides was investigated in Albic Retisol in the Moscow region of Russia. Fractionation was performed using the Pavlotskaya method. 238U and 232Тh were measured via inductively coupled plasma mass spectrometry and 226Ra was measured using an alpha-radiometer that considered the decay of Ra isotopes and accumulation of the resulting decay-related products. Results showed that the potential mobility of radionuclides during migration to adjacent environments and biological availability to plants follows the order 226Ra > 238U > 232Тh. The depletion of 226Ra in the humus horizon A was manifested as a decrease in the 226Ra/238U activity ratio to below 1 in fraction F4.1 (associated with organic matter) and fraction F4.2 (acid-soluble compounds). The profile distribution of 226Ra and 238U in the residual fraction revealed the genetic relationship between these radionuclides. Mobile compounds of 238U and 232Th leached into the lower part of the profile where they became fixed, mainly as the components of fractions associated with organic matter and crystallized iron oxides. A similar profile distribution was found for 238U, 232Тh, and Fe in the acid-soluble fraction associated with crystallized iron oxides. The results obtained herein can form the basis for regulating the mobility and bioavailability of radionuclides to ameliorate their adverse effects on plants and soil ecosystems.

The simulation model of seasonal dynamics of 137Cs in the components of the oak forest ecosystem EcoradOak_CS_FW has been further developed, which now includes first- and second-order consumers. The radiocesium redistribution is modeled in a full-scale food web of a forest ecosystem of the soil–vegetation–herbivores–predator type. The algorithm used in the model allows us to take into account the effects of the soil, meteorological, phenological, and physiological factors on the behavior of radionuclide in the food web and predict radiological situations under various conditions of radioactive fallout. Data obtained with the model on the contamination of animals with radiocesium are used to calculate the dynamics of the internal dose. The results of modeling can be used in the rationing of forest products of deciduous forests. The model is also applicable to the study of potassium redistribution in the trophic chain of a deciduous forest ecosystem.

Some aspects of the application of simulation modeling of radionuclide behavior in food chains of land ecosystems are discussed. A model of behavior of 137Cs in the soil–vegetation–herbivores–predators system is described. The results of modeling, including the calculation of the dynamics of the dose load on animals, are presented. It is shown that according to the simplified Chernobyl scenario of the radiological situation, dose loads on herbivores are significantly lower than on predators. In general, the main contribution to the dose load in animals during the first ten years is made by external irradiation. Then, the external and internal dose loads become approximately equal.

The content and profile distribution of 137Cs in iron-illuvial dwarf and shallow-podzolic podzols (Albic Podzols) under bilberry-lichen and green-lichen-bilberry pine forests in the located near the Kola Nuclear Power Plant have been analyzed. The pollution density (reserve) of 137Cs in the root-inhabited layer (0–30 cm) in the studied soils was significantly lower than the established control level of 37 000 Bq/m2 and amounts to 530–2459 Bq/m2. A significant part of 137Cs (60 to 90%) was concentrated in mineral horizons. It has been shown that the pollution density of 137Cs in the observation zone of a nuclear power plant was mainly due to global fallout. The greatest influence on 137Cs accumulation in the studied soils was exerted by the organic matter reserve.

Статья знакомит читателя с основами использования имитационного моделирования в радиоэкологии. Приведено несколько примеров имитационных радиоэкологических моделей разного уровня, иллюстрирующих возможности метода. Модели позволяют исследовать процессы поведения радионуклидов в экосистемах, прогнозировать развитие радиоэкологической ситуации при различных сценариях выпадений, осуществлять реконструкцию радиоэкологических процессов, недостаточно изученных входе радиационных инцидентов прошлого, рассчитывать динамику дозовой нагрузки на компоненты экосистем и человека. Обсуждаются некоторые проблемы применения имитационного моделирования в радиоэкологии.