Soil organic matter in temperate forest-grassland systems: A case study from the Southern Cis-Ural, Russia

Understanding the dynamics of SOM in different land use types is critical for effective land management and climate mitigation strategies. In this study, we investigated the differences in soil organic matter (SOM) content between forest and grassland landscapes in the mountainous zone of Republic of Bashkortostan, Russia. We collected soil samples from multiple locations under both land use types and analysed them for SOM content using standard laboratory techniques. The results showed that the SOM content varied from 2.2 to 15.3% under forest landscape with an average of 6.7% and was characterized by high variability (51.8%). The SOM concentrations under grassland ranged from 2.1 to 6.5% with an average of 3.2%, while the coefficient of variation was 31.8%. According to the classification, the average SOM value in forest soils was classified as “high”, while in grassland soils it was classified as “low”. Overall, the variability in SOM content within forested landscapes can be influenced by a range of factors, including topography, erosion, and redeposition of soil. These factors contributed to the complex patterns of SOM accumulation and decomposition observed in forest soils, and should be considered when evaluating the potential impacts of land use change on SOM. Our study highlights the importance of understanding the factors that influence SOM content in soils, and the need for careful management of land use systems to maintain or enhance soil fertility and productivity

Soil organic matter in temperate forest-grassland systems: A case study from the Southern Cis-Ural, Russia

Understanding the dynamics of SOM in different land use types is critical for effective land management and climate mitigation strategies. In this study, we investigated the differences in soil organic matter (SOM) content between forest and grassland landscapes in the mountainous zone of Republic of Bashkortostan, Russia. We collected soil samples from multiple locations under both land use types and analysed them for SOM content using standard laboratory techniques. The results showed that the SOM content varied from 2.2 to 15.3% under forest landscape with an average of 6.7% and was characterized by high variability (51.8%). The SOM concentrations under grassland ranged from 2.1 to 6.5% with an average of 3.2%, while the coefficient of variation was 31.8%. According to the classification, the average SOM value in forest soils was classified as “high”, while in grassland soils it was classified as “low”. Overall, the variability in SOM content within forested landscapes can be influenced by a range of factors, including topography, erosion, and redeposition of soil. These factors contributed to the complex patterns of SOM accumulation and decomposition observed in forest soils, and should be considered when evaluating the potential impacts of land use change on SOM. Our study highlights the importance of understanding the factors that influence SOM content in soils, and the need for careful management of land use systems to maintain or enhance soil fertility and productivity

Influence of Bacteria of the Genus <i>Pseudomonas</i> on Leguminous Plants and Their Joint Application for Bioremediation of Oil Contaminated Soils

The modern approach to the creation of biological products to stimulate plant growth is based on the study of specific inter-bacterial interactions. This study describes the impact that the introduction of strains of the genus Pseudomonas has on annual and perennial leguminous plants and the ecosystem of the leguminous plant—the indigenous microbial community. The objects of research under the conditions of vegetation experiments were plants of field peas (Pisum sativum L.), white lupine (Lupinus albus L.), chickpea (Cicer arietinum L.), alfalfa (Medicago sativa subsp. varia (Martyn) Arcang.), and white sweet clover (Melilotus albus Medik.). For the treatment of plant seeds, a liquid culture of strains of growth-stimulating bacteria Pseudomonas koreensis IB-4, and P. laurentiana ANT 17 was used. The positive effect of the studied strains on the germination, growth and development of plants was established. There was no inhibitory effect of inoculants on rhizobia; on the contrary, an increase in nodule formation was observed. The possibility of recultivation of oil-contaminated soil using chickpea and alfalfa as phytomeliorants and growth-stimulating strains P. koreensis IB-4, P. laurentiana ANT 17 as inoculants was evaluated. It is proved that seed treatment improved the morphological parameters of plants, as well as the efficiency of oil destruction

Assessing and Mapping Changes in Forest Growing Stock Volume over Time in Bashkiriya Nature Reserve, Russia

There is growing recognition that forest ecosystems are a key component in the global carbon cycle, and there is a clear demand for their study. This research is a comparative analysis of forest growing stock volume (GSV) and determination of annual growth in Bashkiriya Nature Reserve (Russia) for 1979 and 2015 using 8395 and 8405 observation plots, respectively. Also, we evaluated the spatial distribution and produced digital maps of the species and their GSV for each year. The results showed that pine and birch were the dominant species (60.5 and 24.8% of the area in 2015, respectively) and there were no significant changes in the area of stands during the 36-year period. We found that the GSV in the reserve had increased by an average of 23.2% over the 36-year period. Specifically, the total forest GSV increased from 7,678,960 in 1979 to 10,003,890 m3 in 2015, representing an annual gain of 0–1.5 m3/ha. The increase in GSV was mainly associated with an increase in birch and pine trees. The annual growth of GSV was determined as 1.8–2.1 and 1.4 m3/ha per year for pine and birch forests, respectively. However, these types of trees belong to the age categories of mature and overmature stands, i.e., with reduced intensity of GSV gain. Digital maps produced as part of this study provide a visual representation of the changes in forest spatial patterns and GSV over time, highlighting areas of the reserve where the stock has increased or decreased. This study leveraged a substantial dataset, which provided valuable retrospective insights into the dynamics of pristine forest ecosystems, allowing for the assessment of changes over a 36-year period. Overall, this study highlights the importance of the ongoing monitoring and assessment of GSV levels, especially in the context of rapidly changing environments and climates

Assessment of Chemical Properties, Heavy Metals, and Metalloid Contamination in Floodplain Soils under the Influence of Copper Mining: A Case Study of Sibay, Southern Urals

The ecotoxicological condition of soils around mining areas is most often unsatisfactory, which affects entire ecosystems and human health. This research sought to analyze the morphological, agrochemical properties, and content of heavy metals (Cd, Cu, Zn) and metalloids (As) of soils located in a floodplain. The study was conducted within the city of Sibay (Republic of Bashkortostan, Russia). The soil samples were collected from the floodplains of the rivers Karagayly and Khudolaz. According to morphological studies, the soil cover was represented by the Lithic Leptosols, Stagnic Phaeozems, and Fluvisols. The results showed that the soils were characterized by high values of organic matter, potassium, and low levels of phosphorus. Soils that were located away from the city in the Karagayly River were not contaminated. However, the floodplain areas pertaining to the urban district and located near the quarries were characterized by severe anthropogenic soil pollution, disrupted integrity of the soil cover, decreased vegetation, and accumulating labile forms of heavy metals and metalloids. The highest degree of pollution was observed in the floodplain soil of the river Khudolaz where all elements exceeded the maximum permissible concentration (MPC) level. Soils in the floodplain of the Karagayly river were marked by an increased degree of contamination of Zn: exceeding MPC by 1.6 times. With the trend toward an arid climate, the ecotoxicological condition of floodplain soils is an important challenge

How Has the Hazard to Humans of Microorganisms Found in Atmospheric Aerosol in the South of Western Siberia Changed over 10 Years?

One of the most important components of atmospheric aerosols are microorganisms. Therefore, it is necessary to assess the hazard to humans, both from individual microorganisms which are present in atmospheric bioaerosols as well as from their pool. An approach for determining the hazard of bacteria and yeasts found in atmospheric bioaerosols for humans has previously been proposed. The purpose of this paper is to compare our results for 2006&ndash;2008 with the results of studies obtained in 2012&ndash;2016 to identify changes in the characteristics of bioaerosols occurring over a decade in the south of Western Siberia. Experimental data on the growth, morphological and biochemical properties of bacteria and yeasts were determined for each isolate found in bioaerosol samples. The integral indices of the hazards of bacteria and yeast for humans were constructed for each isolate based on experimentally determined isolate characteristics according to the approach developed by authors in 2008. Data analysis of two datasets showed that hazard to humans of culturable microorganisms in the atmospheric aerosol in the south of Western Siberia has not changed significantly for 10 years (trends are undistinguishable from zero with a confidence level of more than 95%) despite a noticeable decrease in the average annual number of culturable microorganisms per cubic meter (6&ndash;10 times for 10 years)

Influence of geological factors on uranium and thorium distribution in drinking water salt deposits (Republic of Bashkortostan)

Актуальность исследования обусловлена необходимостью выявления источников поступления естественных радиоактивных элементов в питьевую воду, а также возможностью использования солевых отложений питьевых вод (накипи) в геохимических и экологических исследованиях. Наличие на территории Башкортостана различных геологических структур (горная область, предгорный прогиб, платформа), а также большое разнообразие горных пород различного возраста и состава (вулканогенные, интрузивные, осадочные, метаморфические) благоприятствует данным исследованиям и обуславливает большое разнообразие микроэлементного профиля местности. Цель: оценка содержания и пространственного распределения радиоактивных элементов в солевых отложениях питьевых вод (накипи) на территории Республики Башкортостан. Объекты. Проанализированы данные по содержанию U и Th в 467 пробах солевых отложений питьевых вод (накипи) из 267 населенных пунктов Республики Башкортостан. Пробы отобраны из различной посуды (эмалированные и электрические чайники, кастрюли, котлы, самовары), которая используется для кипячения воды из централизованных и индивидуальных (скважины, колодцы, ручьи) источников водоснабжения. Методы. Для анализа содержания U и Th использовался метод инструментального нейтронно-активационного анализа на базе исследовательского ядерного реактора ИРТ-Т ТПУ. Обработка данных проводилась с использованием программных пакетов Statistica 8.0 и Microsoft Excel 2013. Построение карт пространственного распределения естественных радиоактивных элементов в солевых отложениях питьевых вод проведено с помощью программы ArcGIS 10.2 в модуле Geostatistical Analyst методом обратных расстояний. Результаты. Полученные данные позволяют говорить о неравномерном распределении естественных радиоактивных элементов (U, Th) в солевых отложениях на территории Республики Башкортостан. Региональный фон концентрации U и Th отличается пониженными значениями. Вариации их содержания определяются воздействием как природных, так и антропогенных факторов. Закономерности распределения U в пробах накипи хорошо согласуются с особенностями геологического строения территории. В пределах платформенной части распределение U является более равномерным по площади, чем в горной части республики, что отражает сравнительную однородность геологических и тектонических условий. По результатам картирования выделено четыре зоны повышенного содержания U в образцах солевых отложений: зауральская, уральская, западная и южная. В пространственном распределении Th не выявлено четкой корреляционной связи с особенностями геологического строения и металлогении территории. Выделены три зоны: северная, центральная и юго-восточная. Отмечены отрицательные аномалии содержания Th, территориально совпадающие с крупными горнодобывающими центрами. Показатель Th/U отношения характеризуется низким значением для всей территории Башкортостана - 0,002. При этом положительные аномалии данного показателя зафиксированы в северной и юго-восточной частях республики, где они обусловлены, преимущественно, геологической составляющей.The relevance of the research is caused by the need to study the sources of natural radioactive elements entering drinking water and their areal distribution, as well as the possibility of using carbonate sediments of drinking water (scale) in geochemical and environmental studies. In the Republic of Bashkortostan (Russia), these studies are favoured by different geological structures within the area (mountainous area, foredeep and platform) and variety of rocks of different age and composition (volcanic, igneous, sedimentary, metamorphic), which determines the diversity of the microelement profile of the area. The aim of the research is to assess the radioactive elements content and spatial distribution in anthropogenic carbonate sediments (drinking water scale). Object of the research. The data on U and Th content in 467 samples of carbonate deposits (scale) from 267 settlements of the Republic of Bashkortostan was analysed. Samples were taken from various utensils (enamelled and electric kettles, pots, boilers), which is used for boiling water from centralized and individual (wells, streams) water sources. Methods. The method of instrumental neutron activation analysis based on the research nuclear reactor IRT-T TPU was used to analyse the uranium and thorium content. Data processing was carried out using software packages Statistica 8.0 and Microsoft Excel. The spatial distribution of natural radioactive elements was mapped using ArcGIS 10.2 in the Geostatistical Analyst module using the inverse distance method. Result. The data obtained allow speaking about uneven distribution of natural radioactive elements (U, Th) in anthropogenic carbonate deposits on the territory of the Republic of Bashkortostan. The average level of the studied chemical elements is characterized by low values of both uranium and thorium. Variations of their content in the studied formations are determined by the combined impact of natural and anthropogenic factors. The regularities of U distribution in scale samples correspond to the geological structure of the territory. Within the platform part, uranium distribution is more uniform than in the mountainous part of the Republic, which reflects the comparative homogeneity of geological and tectonic conditions. According to the results of mapping, four zones of high uranium content in samples of anthropogenic carbonate deposits were identified: Trans-Uralian, Uralian, Western and Southern. In Th spatial distribution there was no clear correlation with the features of the geological structure and metallogeny of the territory. There are three zones: Northern, Central and South-Eastern. Negative anomalies of Th content geographically coinciding with large mining centers are noted. Th/U ratio is characterized by a low value for the whole territory of Bashkortostan - 0,002. At the same time, positive anomalies of this indicator were recorded in the Northern and South-Eastern parts of the Republic, where they are mainly determined by geological component

Influence of geological factors on uranium and thorium distribution in drinking water salt deposits (Republic of Bashkortostan)

Актуальность исследования обусловлена необходимостью выявления источников поступления естественных радиоактивных элементов в питьевую воду, а также возможностью использования солевых отложений питьевых вод (накипи) в геохимических и экологических исследованиях. Наличие на территории Башкортостана различных геологических структур (горная область, предгорный прогиб, платформа), а также большое разнообразие горных пород различного возраста и состава (вулканогенные, интрузивные, осадочные, метаморфические) благоприятствует данным исследованиям и обуславливает большое разнообразие микроэлементного профиля местности. Цель: оценка содержания и пространственного распределения радиоактивных элементов в солевых отложениях питьевых вод (накипи) на территории Республики Башкортостан. Объекты. Проанализированы данные по содержанию U и Th в 467 пробах солевых отложений питьевых вод (накипи) из 267 населенных пунктов Республики Башкортостан. Пробы отобраны из различной посуды (эмалированные и электрические чайники, кастрюли, котлы, самовары), которая используется для кипячения воды из централизованных и индивидуальных (скважины, колодцы, ручьи) источников водоснабжения. Методы. Для анализа содержания U и Th использовался метод инструментального нейтронно-активационного анализа на базе исследовательского ядерного реактора ИРТ-Т ТПУ. Обработка данных проводилась с использованием программных пакетов Statistica 8.0 и Microsoft Excel 2013. Построение карт пространственного распределения естественных радиоактивных элементов в солевых отложениях питьевых вод проведено с помощью программы ArcGIS 10.2 в модуле Geostatistical Analyst методом обратных расстояний. Результаты. Полученные данные позволяют говорить о неравномерном распределении естественных радиоактивных элементов (U, Th) в солевых отложениях на территории Республики Башкортостан. Региональный фон концентрации U и Th отличается пониженными значениями. Вариации их содержания определяются воздействием как природных, так и антропогенных факторов. Закономерности распределения U в пробах накипи хорошо согласуются с особенностями геологического строения территории. В пределах платформенной части распределение U является более равномерным по площади, чем в горной части республики, что отражает сравнительную однородность геологических и тектонических условий. По результатам картирования выделено четыре зоны повышенного содержания U в образцах солевых отложений: зауральская, уральская, западная и южная. В пространственном распределении Th не выявлено четкой корреляционной связи с особенностями геологического строения и металлогении территории. Выделены три зоны: северная, центральная и юго-восточная. Отмечены отрицательные аномалии содержания Th, территориально совпадающие с крупными горнодобывающими центрами. Показатель Th/U отношения характеризуется низким значением для всей территории Башкортостана - 0,002. При этом положительные аномалии данного показателя зафиксированы в северной и юго-восточной частях республики, где они обусловлены, преимущественно, геологической составляющей.The relevance of the research is caused by the need to study the sources of natural radioactive elements entering drinking water and their areal distribution, as well as the possibility of using carbonate sediments of drinking water (scale) in geochemical and environmental studies. In the Republic of Bashkortostan (Russia), these studies are favoured by different geological structures within the area (mountainous area, foredeep and platform) and variety of rocks of different age and composition (volcanic, igneous, sedimentary, metamorphic), which determines the diversity of the microelement profile of the area. The aim of the research is to assess the radioactive elements content and spatial distribution in anthropogenic carbonate sediments (drinking water scale). Object of the research. The data on U and Th content in 467 samples of carbonate deposits (scale) from 267 settlements of the Republic of Bashkortostan was analysed. Samples were taken from various utensils (enamelled and electric kettles, pots, boilers), which is used for boiling water from centralized and individual (wells, streams) water sources. Methods. The method of instrumental neutron activation analysis based on the research nuclear reactor IRT-T TPU was used to analyse the uranium and thorium content. Data processing was carried out using software packages Statistica 8.0 and Microsoft Excel. The spatial distribution of natural radioactive elements was mapped using ArcGIS 10.2 in the Geostatistical Analyst module using the inverse distance method. Result. The data obtained allow speaking about uneven distribution of natural radioactive elements (U, Th) in anthropogenic carbonate deposits on the territory of the Republic of Bashkortostan. The average level of the studied chemical elements is characterized by low values of both uranium and thorium. Variations of their content in the studied formations are determined by the combined impact of natural and anthropogenic factors. The regularities of U distribution in scale samples correspond to the geological structure of the territory. Within the platform part, uranium distribution is more uniform than in the mountainous part of the Republic, which reflects the comparative homogeneity of geological and tectonic conditions. According to the results of mapping, four zones of high uranium content in samples of anthropogenic carbonate deposits were identified: Trans-Uralian, Uralian, Western and Southern. In Th spatial distribution there was no clear correlation with the features of the geological structure and metallogeny of the territory. There are three zones: Northern, Central and South-Eastern. Negative anomalies of Th content geographically coinciding with large mining centers are noted. Th/U ratio is characterized by a low value for the whole territory of Bashkortostan - 0,002. At the same time, positive anomalies of this indicator were recorded in the Northern and South-Eastern parts of the Republic, where they are mainly determined by geological component