RUDN Journal of Ecology and Life Safety

Rapid urban expansion is reshaping landscapes across Sub-Saharan Africa, but its effects on vegetation structure remain underexplored. This study examines vegetation responses to urban growth in Makurdi, Nigeria, from 2000-2025, using land-use/land-cover analysis and landscape metrics. Urban intensity zones were delineated to account for spatial variability of anthropogenic impact, and vegetation structure was assessed at class and landscape levels with FRAGSTATS. The results show extensive growth in development accompanied by vegetation decline and fragmentation. Low-intensity zones retained cohesion, while moderateintensity zones experienced the greatest fragmentation and loss of dominance, indicating their high vulnerability. High-intensity zones remained degraded, with small, isolated remnants. The landscape metrics further reveal increasing fragmentation, edge complexity, and heterogeneity, alongside declining cohesion. These findings highlight scale-dependent vegetation responses and demonstrate the value of configuration-based metrics for ecological insight. The multiscale framework provides a robust basis for urban planning aimed at conserving vegetation integrity in rapidly growing African cities.

The aim of this study is to assess the mechanisms of trifluralin’s effect on Paramecium caudatum . The problem of herbicide pollution in aquatic ecosystems is highly relevant today, as these substances enter water bodies from agricultural lands via groundwater and surface runoff. Trifluralin is a widely used herbicide that can enter aquatic ecosystems and pose a threat to aquatic organisms. During the experiment, the effect of trifluralin at concentrations of 1,0; 2,5; 5,0; 10,0 and 25,0 mg/L on the survival and reproduction rate of ciliates was studied over 5 days. It was found that trifluralin exerts a statistically significant dose-dependent toxic effect on P. caudatum , starting from a concentration of 2,5 mg/L. At high concentrations (10,0 and 25,0 mg/L), acute toxicity effects (mortality and reduced motility) were observed, and on days 3-5, inhibition of reproductive function (a cytostatic effect) was noted. The concentration of 1,0 mg/L was considered non-effective, as it did not cause statistically significant differences compared to the control group. The results indicate that the mechanism of trifluralin’s toxic action on ciliates may be associated with the inhibition of cell division. Given the low solubility and potential persistence of trifluralin in water, its entry into water bodies may pose a long-term hazard to aquatic ecosystems. The obtained results can be used to predict the impact of trifluralin on the structure of aquatic ecosystems, where protozoa occupy a key position in the microbial loop and serve as a food source for many aquatic organisms.

The development of regenerative tourism has been proposed as a response to the limitations of conventional sustainable tourism, particularly its restricted capacity to address long-term socioecological challenges. However, empirical evidence supporting regenerative tourism remains limited, especially at territorial and public policy scales in biodiverse countries. This study aims to analyze birdwatching tourism as a regenerative-oriented tourism practice in Brazil, based on national public policy evidence. The research adopts analytical and conceptual design grounded in secondary data analysis. The primary source is the National Diagnosis of Public Policies for Birdwatching Tourism in Brazil published by the Ministry of Tourism in 2025, complemented by institutional reports and peer-reviewed scientific literature on bird conservation, citizen science, and regenerative tourism. The data were reinterpreted using an analytical framework focused on key regenerative dimensions, including conservation financing, biodiversity monitoring, participatory governance, and territorial planning. The results indicate that birdwatching tourism in Brazil operates predominantly within areas of high conservation priority and is supported by measurable mechanisms relevant to regeneration. These mechanisms include the generation of economic resources associated with conservation activities, large-scale biodiversity monitoring through citizen science platforms, and institutionalized governance arrangements aligned with biodiversity conservation policies. Although the concept of regenerative tourism is not explicitly employed in Brazilian tourism policy, birdwatching tourism demonstrates functional characteristics consistent with regenerative principles. The study concludes that birdwatching tourism in Brazil can be understood as a regenerative-oriented practice when regeneration is interpreted as a long-term, systemic, and policy-mediated process. The findings contribute to strengthening the empirical basis of regenerative tourism research and highlight the relevance of public policy analysis for assessing regenerative dynamics in megadiverse contexts.

The research paper examines the analysis of factors involved and the improvement of water purification technology for the production of powdered fortified mixture based on soybean and milk protein. A series of laboratory tests of coagulation release of contaminants from solution to sediment was carried out. An innovative solution has been developed for the physico-chemical treatment of wastewater using technical soda and sea salt. The temperature factor of flocculation has been determined experimentally, and it has been established that at temperatures above 46°C, a casein clot is formed, which complicates the operation of the flotation plant. Based on the results of the research, the authors of the article have developed measures and technological solutions for the design of workshop sewage treatment plants, including an individual design average that provides a temperature coagulation factor, a reagent flotation device and a flotation foam and sludge treatment unit. The developed physico-chemical purification method is an optimal and economically feasible technological solution for local facilities, providing the necessary degree of pollution extraction prior to discharge into the urban sewer network with dramatically changing wastewater parameters during the work shift, and the proteins isolated from the solution do not contain aluminum or iron salts and can be used in soil preparation. for landscaping after disinfection.

The physicochemical and toxicological properties of cellulose-containing fiber, which is a by-product of animal feed production, have been investigated and a consortium of microorganisms has been established, which is developing at the facility under study. The chemical composition of cellulose-containing fiber is as follows: moisture - 47.00%; ash - 1.16%; organic matter - 51.84% (including: starch - 25.10%; fats - 4.40%). The nitrogen and phosphorus content in the test sample is 2.43 and 1.90%. The dependence of changes in pH and humidity on the time of natural fermentation of the sample studied is investigated. The ash of the studied by-product was analyzed, in which oxides predominate: silicon SiO2 - up to 51.30%; phosphorus P2O5 - up to 17.63%; aluminum Al2O3 - up to 10.25%. Microbiocenosis of aqueous extracts from cellulose-containing fiber has been established when seeded on solid agarized media; microorganisms belonging to the genera Penicillium , Cladosporium , Bacillus , Saccharomyces , Schizosaccharomyces and Escherichia are predominant. The multiplicity of dilution of aqueous extract from the studied object, in which there is no harmful effect on aquatic organisms, is equal to 100, which corresponds to low-hazard waste in terms of the degree of negative impact on the environment.

Mountain cities are characterized by high spatial heterogeneity, limited territories suitable for development, and increased vulnerability to anthropogenic impact. The research presents an approach to assessing the spatial structure and environmental sustainability of mountain cities based on an integral index of structural and planning indicators, tested on the example of Vladivostok. The index is formed using indicators characterizing the structure of the city’s water-green framework. The structural elements of the green infrastructure were identified by the method of morphological spatial analysis (MSPA), the weights of the indicators were determined by the CRITIC method, taking into account their variability and mutual correlation. The obtained index made it possible to identify a pronounced spatial differentiation of the ecological stability of the territory of Vladivostok, related to the features of the relief, planning structure and functional zoning. The results of the study demonstrate the possibilities of using the proposed approach to identify vulnerable and reserve territories and its application in the zoning of landscaping priorities, the establishment of environmental protection regimes and spatial planning of mountain towns.