Comparative assessment of the environmental status of the Luga River locations
T.V. Kuznetsova, A.B. Manvelova, L.L. Kapranova
Section: Monitoring of natural and anthropogenically disturbed areas
We have conducted a comprehensive assessment of the ecological status of the Luga River locations. The analysis was based on aquatic environment quality indicators, and data on heavy metal content in bottom sediments and tissues of indigenous bivalve mollusks Unio pictorum L. (Mollusca, Bivalvia), as well as on the mollusks’ physiological status (Condition Index – CI) in 7 locations of the Luga River. Differences in the physicochemical characteristics of surface water quality and heavy metal content and bioaccumulation were revealed. The maximum heavy metal concentrations in bottom sediments were typical for Zn and Pb, lower – for Cu and Cd, regardless of the sampling site. The heavy metal’s bioaccumulation coefficient in mollusk soft tissues was maximum for Zn, to a lesser extent for Cu and Cd, and minimum for Pb. The minimum CI values were obtained for the sampling site below Tolmachevo, the maximum – for the sampling site below confluence of the Solka and the Luga rivers. A small population of mollusks has been identified within the city of Luga. This may be due to the low dissolved oxygen content in the water in addition to environmental pollution. The CI (general health status) was calculated using various morphometric and mass parameters of mollusks sampled in different locations. A comparative analysis of the CI showed the effectiveness of this approach in assessing the ecological status of the studied aquatic ecosystems based on the status of the local biota.
Keywords: comprehensive assessment of the ecological status, physicochemical indicators of water quality, heavy metals, sediments, tissues of mollusks, condition (general health status) indexes of bivalves
Article published in number 3 for 2025 DOI: 10.25750/1995-4301-2025-3-065-073
Views: 15
Climatic and post-agrarian vectors of transformation of forested areas in old-developed regions of European Russia
The article analyses changes in the vegetation cover in several districts of the Kostroma Volga region within 1985–2023 using multi-temporal Landsat and MODIS satellite data. Two thematic maps of vegetation cover and land surface (M 1 : 100 000) were prepared based on Landsat images (for 08.08.1985 and 10.08.2018). The maps were used to identify changes in dominant classes of the region. Case study in some districts show that the share of coniferous forest communities increased from 32.6 to 43.8%. The share of deciduous communities remained unchanged (39.7–39.9%). The proportion of ‘indigenous’ forests (classified as one class in 1985 and 2018) was 25.9% for coniferous forests and 26.2% for deciduous forests. Comparison of detailed resolution images of Corona KH-2 (19.08.1973) and ESRI Imagery (29.04.2023) shows that areas of changes are associated with overgrowing fallow lands and agricultural territories. The most active overgrowth can be observed at the edges of plots bordering with forest phytocenoses. The canopy density indices calculated from Landsat winter and early spring images reflect changes in the forest communities most fully. After a conflagration in 1972 forest communities with a canopy density of up to 80–90% were restored by 2015. Undisturbed coniferous native forests are characterized by a gradual decrease (about 0.2% per year) in canopy density values; this fact can be used as an indicator of intact forests. Analysis of changes in the spectral EVI (Enhanced Vegetation Index) shows that most of the forest community classes remain stable. However, the considerable length of the observation period (24 years) leveled out the calculated linear trend for many sites, even with large changes.
Keywords: forest stands, satellite research methods, global transformations of boreal ecosystems
Article published in number 3 for 2025 DOI: 10.25750/1995-4301-2025-3-188-194
Views: 13
Phyto- and zooplankton community of Usinskiy Bay and adjacent waters of the Kuibyshev Reservoir during the blooms starting
O.V. Mukhortova, N.G. Tarasova, V.S. Zhikharev
Section: Monitoring of natural and anthropogenically disturbed areas
The article presents the results of studies the plankton community (phyto- and zooplankton) of the Usinskiy Bay (UB) and the adjacent water area of the Priplotinnyy (near-dam) reach (PR) during the blooms starting. We found that favorable conditions for the blooms development were formed in the UB and PR water areas – sufficiently high temperature and a slightly alkaline environment. The UB plankton community has greater species richness than the PR one. Phytoplankton abundance and biomass varied widely: 2.31–149.52 million cells/L and 0.53–13.15 mg/L, respectively. Depending on the plankton community structure the studied area can be divided into three zones: reservoir (including the river estuary), transitional, and the bay. During the studies period Cryptophyta prevailed in the PR phytoplankton, and Cyanobacteria were predominant in the UB. The blooms phenomenon with a level from “moderate” to “intense” was recorded only at two sampling stations, remote from the Kuibyshev reservoir. Zooplankton abundance and biomass varied widely: 78–579 thousand specimens/m3 and 0.61–2.33 g/m3, respectively. The nauplial and copepodite stages of Heterocope caspia Sars, 1897 (Copepoda) dominated in zooplankton of the reservoir, while its adults prevailed in the UB. At farthest from the Usa River estuary sampling stations, there was a change in the share of the main zooplankton taxa: an increase of the rotifers share and a decrease in branched crayfish share.
The object of the study is the distillary stillage storage located within the boundaries of the federal protected area “Samarskaya Luka”, near the village of Rozhdestveno in the Samara region. Testing of the technology for utilizing long-term storage distillery waste (stored in the environment for more than 3 years) through aerobic composting at an industrial site has been conducted. During the three-week composting cycle, measurements of temperature and the chemical composition analysis of the composting mass were conducted. The volumetric fractions in the initial compostable mixture, including long-stored dis-
tillery stillage, immature (recycled) compost, and sawdust, were 30–35% for each of the components. In the selected samples, the following parameters were monitored: moisture, pH, and the content of organic matter, as well as nitrate (N-NO3-), nitrite (N-NO2-), and ammonium nitrogen (N-NH4+). Aldehydes, ketones, esters, higher alcohols, organic acids (including aromatic)content was also determined. Only acetic and butanoic acids with a slight difference of 0.91 mg/kg were detected when assessing the concentration of organic components in samples taken after the second and third week of composting. There wasa significant decrease in the N-NH4+ and N-NO2- content as well as an increase in N-NO3- content after two weeks of composting. As a result of composting, the proportion of organic matter decreased, and the pH stabilized to values above 6.0 units. The results of the experiment demonstrated the effectiveness of aerobic composting as a method for the disposal of distillery stillage. The addition of recycled compost and sawdust contributed to reducing the duration of composting from 21 to 14 days.
Article published in number 3 for 2025 DOI: 10.25750/1995-4301-2025-3-162-170
Views: 8
Dye wastewater treatment using lignin from durian rind (Durio zibethinus Rumph. ex Murray)
Tran Y Doan Trang, Lai Hong Dzung, Do Thi Cam Van, Ta Thi Huong, Nguyen Quang Tung, Thi-Dung Ha, Do Thi Hanh, Vu Phuong Lan
Section: Chemistry of natural environments and objects
The agricultural sector is generating increasing amounts of solid waste, leading to a growing trend of reusing or recycling these waste materials into valuable resources. This study evaluated the potential of lignin extracted from durian rind (DR) to remove methylene blue (MB) dye from wastewater. Lignin samples were characterized using Fourier transform infrared spectroscopy, optical microscopy, scanning electron microscopy, and thermal analysis. The impact of different factors, including pH, initial MB concentration, adsorbent dosage, and contact time, was evaluated in the batch adsorption experiments. The data showed that the maximum adsorption capacity of the lignin from DR occurred at pH of 5, with an adsorbent dosage of 10 g·L-1 and a contact time of 60 minutes. Kinetic studies showed that the adsorption process was well described by a pseudo-second-order kinetic model with a high adsorption capacity of 40.16 mg·g-1. Additionally, the adsorption isotherm results aligned well with the Langmuir equation, indicating monolayer adsorption on a homogeneous surface. The physical adsorption mechanism was proposed to involve electrostatic interactions, π interactions, and hydrogen bonding between the adsorbate and the adsorbent. In conclusion, this study highlights the potential for agricultural waste, such as durian rind, to be repurposed into effective adsorbent materials for treating dye contamination in water environments.
Article published in number 3 for 2025 DOI: 10.25750/1995-4301-2025-3-119-133
Views: 10
Study of pathogenicity factors of the genus Enterococcus bacteria isolated from the aquatic environment
S.S. Uskova, A.V. Martynova
Section: Monitoring of natural and anthropogenically disturbed areas
The genus Enterococcus is ubiquitous and included in many ecosystems. To date, the assessment of the role of these microorganisms in ecosystems with and without anthropogenic load remains controversial. Being widespread, these microorganisms have even been considered as sanitary indicators, and at the same time they can be one of the main causes of hospital diseases. This cannot but be absolutely due to changes in the microbiological properties of these bacteria, which are identified by the expression of pathogenicity factors that determines the microecological characteristics of enterococcal strains both within the genus and within the species. In this regard, it is relevant to study the species composition of the genus Enterococcus strains in combination with the characteristics of their pathogenicity factors using the example of strains isolated from the environment, in particular water bodies. The aim was to study the species composition and pathogenicity factors of the genus Enterococcus bacteria isolated from the aquatic environment. A study of 61 strains of the genus Enterococcus isolated in water samples from the Vtoraya Rechka River obtained in the city of Vladivostok was carried out from March 10, 2018, to September 24, 2020. The species composition of microorganisms of the genus Enterococcus isolated in the Vtoraya Rechka River is represented in most cases by such species as Enterococcus faecalis and E. faecium. The rarer species E. durans and E. casseliflavus were also found. In the Vtoraya Rechka River γ-hemolytic activity was most common – 85.24% of strains; and only 14.75% of strains had β-hemolytic activity. We found that 8.19% of the studied strains synthesized DNase, and 1.62% synthesized collagenase. The most common strains were those that were not capable to liquefy gelatin – 85.24%. The genus Enterococcus strains capable to synthesize various pathogenicity factors were found as a result of the studied water samples from the Vtoraya Rechka River exposed to anthropogenic impact. Hemolytic activity complex and the ability to synthesize gelatinase were their specific attributes. This suggests that Enterococcus strains isolated in an aquatic ecosystem may pose a serious threat to human health.
Section: Monitoring of natural and anthropogenically disturbed areas
Data on microbiological properties of podzolic soils (Retisols) in the first three years after logging that were exposed to heavy wheeled logging equipment are presented. The study was conducted on different technogenic logging plots: apiary plot (A) and trails (3P – three passes of logging equipment, 10P – ten passes, 10R – ten passes by leveling). Microbial biomass carbon (Cmic=MB) and microbial CO2 production rate (basal respiration, BR) were determined by the substrate-induced respiration method (SIR). MB content in the initial forest ranged from 24 to 815 µgC/g soil, and BR values ranged from 0.3 to 32.5 µg C-CO2/g/h. The apiary plot shows a gradual increase in MB content up to 2–14 times higher than the original forest over three years. In mineral horizons its values are maximum in the first year (80 µgC/g soil), then they decrease by eight times. There is a significant decrease in microbial carbon up to seven times in the first two years, followed by a sharp increase in the third year after logging in skidding trails. The share of Сmiс in the soil organic carbon of the studied soils ranged from 0.01 to 2.57%. The highest values of this parameter were detected in the mineral horizons of soils of the skidding trails. The share of Сmiс to water-soluble organic soil carbon is greater than that to the total carbon. It can be stated that in the modified soils of young clearcuts there is intensive accumulation of microbial carbon especially in carbon of water-soluble compounds in the third year after logging.
Regional soil monitoring of natural ecosystems with multicomponent heavy metals contamination requires both geochemical studies and express-methods for soils’ mutagenicity assessment using reliable test systems. We studied the mutagenic potential of arable soils in Armenian agricultural landscapes using Tradescantia clone 02 in the soil–plant system. Biotesting was carried out using two main bioassays: Tradescantia stamen hairs mutations test (Trad-SHM) and Tradescantia micronucleus test (Trad-MN). According to Trad-SHM bioassay, the level of recessive mutations (pink cells – PC) in the studied soil samples significantly increased the conditional background. The maximum PC and genetically undefined mutation (colorless cells – CC) manifestation was in a soil sample from the Hrazdan region, 600 m away from the industrial zone, where the values of the studied parameters exceeded the background level by 28 and 3.4 times, respectively (p<0.001). In terms of stunted stamen hairs the highest value was in the soil variant Martuni-2 and exceeded the control level by 3.7 times. According to Trad-MN, a significant increase in the frequency of both test criteria was also observed in soil samples from the Hrazdan region, located 400 m, 600 m and 800 m away from the industrial zone, as well as in samples from the Gavar region by 1.8–2 times (p<0.05). A correlation analysis of the dependence of the level of genetic effects on the chemical element (V, Cr, Mn, Fe, Co, Ni, Cu, Zn) content in the studied soil samples was carried out. To determine the level of soil pollution based on the concentration coefficient, the total pollution coefficient (Zc) and the sanitary-hygienic series were calculated.
Article published in number 3 for 2025 DOI: 10.25750/1995-4301-2025-3-171-177
Views: 8
Distribution of the Arceuthobium oxycedri (DC.) M. Bieb. semiparasite and attack rate of Juniperus oblonga M. Bieb. plants in Dagestan
G.A. Sadykova, Z.M. Asadulaev, M.M. Mallaliev
Section: Population ecology
The distribution of the Arceuthobium oxycedri (DC.) M. Bieb. semi-parasite in Dagestan was studied. It is one of 42 species of the Arceuthobium genus, which has the widest distribution and a wide range of hosts. We found that semiparasite is sporadically distributed in the studied area and has a narrower range compared to the range of the main host. A high level of Juniperus oblonga M. Bieb. plants infection was noted in most of the studied localities. Juniperus polycarpos C. Koch individuals (the Red Data Book species) were singly parasitized. The altitudinal distribution range of A. oxycedri on juniper bushes has been established. The range limitation of A. oxycedri for a number of J. oblonga populations (Talginskoe gorge, juniper grove of the Sosnovka natural boundary in the north of Lowland Dagestan, Southern Dagestan populations) is associated with limiting climatic factors. A detailed analysis of the A. oxycedri effect on J. oblonga bushes was carried out in a degrading population on the southern macroslope of the Nukatlinsky Range, opposite the Charoda Village, where the parasitized individuals’ proportion was 45%. We assessed the A. oxycedri effect on J. oblonga individuals depending on sex, age and growing conditions. The predominance of biometric indicators of parasitized bushes, the semiparasite presence both on mature and late generative stages bushes, and on immature ones, the predominance of the number of affected individuals among female bushes with the previously established higher vitality of female individuals, suggests that the A. oxycedri semiparasite inhabites healthy juniper bushes with high vitality regardless of their age.
Article published in number 3 for 2025 DOI: 10.25750/1995-4301-2025-3-178-187
Views: 1
The microbial communities’ development on the surface of crop residues
M.A. Alyoshin, T.V. Poludova, A.I. Botin, A.A. Zavalin
Section: Agroecology
As part of a laboratory model experiment, microbial communities were found on the surface of grain straw. As polymicrobial biofilms they formed during the initial period of the straw decomposition in sod-podzolic medium loamy soil (Eutric Albic Retisols (Abruptic, Loamic, Cutanic)). The metabolic activity of microorganisms on the surface of pea straw (Pisum sativum L.) was higher than on wheat straw (Triticum aestivum L.). The following dynamics was recorded. On day 1, an exponential growth phase was determined, within which an increase in metabolic activity and a significant increase in bacterial biomass were observed. From 2nd to 15th day there was the phase of stationary growth. From day 15, the phase of microorganism growth was replaced by the phase of death. A comparative analysis of the metabolic activity of microorganism dynamics on the surface of sterilized by autoclaving and non-sterile straw didn’t reveal the effect of the initial saprotrophic pool in the organization of microbial community on the surface of straw during its further decomposition. In scrapings from straw incubated in the soil for 5 or more days, a significant predominance of microbes on pea straw was observed. The microbiota was represented by small gram-negative and gram-positive rods, bacillus spores and micromycetes were also present. When straw is introduced into the soil, the gradient of the microbiome density distribution is determined. The study showed that bacteria immobilized on straw have increased viability, higher metabolic activity and contribute to more efficient decomposition of plant substrate. Adding straw to the upper soil layers helps restore and strengthen the soil microbiome.
ISSN 1995-4301
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