Decrease In Species Diversity Research Articles

Cascading impacts of nitrogen deposition on soil microbiome and herbivore communities in desert steppes

Human activities in the last century have intensified global nitrogen deposition, resulting in the degradation of ecosystem function and loss of biodiversity worldwide. Nitrogen addition is a crucial method for examining the effects of atmospheric nitrogen deposition on species composition and structure of soil microbiome and biotic community, as exogenous nitrogen inputs can trigger cascading effects on ecosystem functions. In a 6-year experiment, we evaluated the impact of nitrogen addition on soil microbial-plant-insect systems in desert steppes. Our results show that nitrogen addition significantly altered soil microbial composition and ecological function, leading to a decrease in nitrogen-fixing bacteria and an increase in saprophytic fungi. High levels of nitrogen addition increased total plant biomass while decreasing species diversity. Additionally, high nitrogen addition levels suppressed below-ground biomass of gramineae and legumes compared to low nitrogen addition. Nitrogen addition also increased herbivore abundance by altering insect community structure, particularly benefiting chewing pests over sucking pests, thus heightening the risk of biological disasters through trophic cascading effects. Consequently, excessive nitrogen addition may destabilize desert steppe ecosystems by disturbing soil microbial-plant-insect interactions, hindering the maintenance of biotic community diversity and steppe productivity.

Microhabitat coverage influences avian species composition more than habitat heterogeneity in Hong Kong urban parks

The relationship between habitat heterogeneity and diversity can underpin design of urban spaces for biodiversity conservation. The area-heterogeneity trade-off hypothesis predicts that higher habitat heterogeneity should result in an increase in species richness but only up to a point, beyond which habitat micro-fragmentation leads to decreases in species diversity. However, the strength of area-heterogeneity trade-offs at small spatial scales is not well studied. We studied the relationship between avian diversity and habitat heterogeneity in 16 small urban parks across Hong Kong during the winter dry season across 2016 and 2017 (ten repeated surveys in total for each park). Habitat heterogeneity was assessed by measuring the evenness of microhabitat coverage of seven habitats as well as vertical canopy cover. In total, 12,973 individuals of 73 bird species were recorded in the study. Habitat heterogeneity had a small but negligible effect on total bird species richness or abundance. However, water coverage was positively related to total, intermediately rare and habitat specialist bird species richness, and shrub coverage was positively related to total and common bird species richness. These results demonstrate that environmental heterogeneity had little effect on avian species richness in urban green spaces at small spatial scales. We also found that microhabitat coverage can affect avian diversity and abundance, and these effects are specific to certain groups of bird species. When managing urban green spaces for biodiversity conservation in densely urbanized cities, a decrease in management disturbance (e.g. tree topping or pesticide application) will likely benefit avian species. Together with the fact that some locally uncommon species were observed throughout the study, capacity exists for environmental enhancement of these small urban parks to contribute to local avian conservation.

Concurrent nitrogen and phosphorus enrichment increases ecosystem carbon use efficiency in an alpine grassland

Ecosystem carbon use efficiency (CUEe) is a crucial indicator for assessing the capacity of ecosystems to sequester atmospheric carbon (C). However, it remains unclear how nitrogen (N) and phosphorus (P) influence CUEe and how climatic factors regulate CUEe. Here, a four-year manipulative experiment was conducted in a semi-arid alpine grassland ecosystem to explore the response of CUEe to N and P additions with fluctuating interannual precipitation. Our study revealed that the N and P combination synergistically improved CUEe; the single additions of N or P did not affect CUEe. The variation in CUEe was correlated to a larger in net ecosystem CO2 exchange (NEE) relative to gross ecosystem productivity (GEP). Similarly, the combination of N and P significantly increased aboveground biomass, whereas addition alone did not. Under the combined addition of N and P, a significant decrease in species diversity led to decreases in CUEe. Moreover, precipitation indirectly increased CUEe by increasing NEE. Our findings underscore the co-limitation of N and P resources for CUEe in the alpine grassland ecosystem and identify community structure and climate factors as key drivers of CUEe variations following nutrient enrichment.

Responses in species diversity in the Hulunbuir grassland to phosphorus addition under nitrogen-limiting and non-limiting conditions.

The phenomenon of nitrogen deposition resulting in species loss in terrestrial ecosystems has been demonstrated in several experiments. Nitrogen (N) and phosphorus (P), as major nutrients required for plant growth, exhibit ecological stoichiometric coupling in many ecosystems. The increased availability of nitrogen can exacerbate the ecological effects of phosphorus. To reveal the ecological effects of phosphorus under nitrogen-limiting and non-limiting conditions, we conducted a controlled N-P interaction experiment over 5 years in the Hulunbuir meadow steppe, where two nitrogen addition levels were implemented: 0g N·m-2·a-1 (nitrogen-limiting condition) and 10g N·m-2·a-1 (nitrogen-non-limiting condition), together with six levels of phosphorus addition (0, 2, 4, 6, 8, and 10g P·m-2·a-1). The results showed that nitrogen addition (under nitrogen-non-limiting conditions) significantly decreased species diversity in the steppe community, which was exacerbated under phosphorus addition. Under nitrogen-limiting conditions, phosphorus addition had no marked impact on species diversity compared to the control; however, there were substantial differences between different levels of phosphorus addition, exhibiting a unimodal change. Under both experimental nitrogen conditions, the addition of 6g P·m-2·a-1 was the threshold for affecting the community species diversity. Nitrogen addition reduced the relative biomass of legumes, bunch grasses, and forbs, but substantially increased the relative biomass of rhizomatous grasses. In contrast, phosphorus addition only markedly affected the relative biomass of forbs and rhizomatous grasses, with the former showing a unimodal pattern of first increasing and then decreasing with increasing phosphorus addition level, and the latter exhibiting the opposite pattern. The different responses of rhizomatous grasses and other functional groups to nitrogen and phosphorus addition were observed to have a regulatory effect on the changes in grassland community structure. Phosphorus addition may increase the risk of nitrogen deposition-induced species loss. Both nitrogen and phosphorus addition lead to soil acidification and an increase in the dominance of the already-dominant species, and the consequent species loss in the forb functional group represents the main mechanism for the reduction in community species diversity.

Bubbling trouble: Effects of supersaturated water on benthic macroinvertebrates

AbstractThe saturation of total dissolved gases (TDG) in water remains around 100%. Certain circumstances can lead to TDG values exceeding 100%, resulting in TDG supersaturation (TDGS). TDGS above about 110% can be toxic to animals that rely on water for gas exchange. However, saturation beyond 200% can occur in freshwater downstream of dams and hydroelectric power plants. Despite its impact, TDGS is often overlooked as a hazard to aquatic life, particularly for benthic macroinvertebrates. This study aimed to examine the effects of TDGS on nine species of benthic macroinvertebrates. We used replicated tank studies to manipulate TDGS levels from 100% to 120% and investigated the overall survival and species‐specific effects on survival and buoyancy. We also present a summary on the effects of TDGS on invertebrate species previously tested. The results indicate that seven of nine species exhibited increased buoyancy when exposed to TDGS, causing them to float on the water surface. Additionally, a Cox Proportional Hazards model revealed a significant effect of TDGS on the survival of the macroinvertebrates. The sensitivity towards TDGS varied greatly among species of benthic macroinvertebrates, and significant species‐specific effects were only observed for Isoperla grammatica, Baetis rhodani and Asellus aquaticus. Among these, the two latter species showed clear dose‐related effects caused by TDGS, enabling the assessment of LT50 (time required to kill half of the tested population). B. rhodani was most sensitive with a LT50 of 3.7 days at 119% TDGS. Both species had visible air bubbles under the exoskeleton. Our findings highlight that direct and indirect effects on benthic macroinvertebrates can occur even at low to moderate levels of gas supersaturation, likely causing reduced density, decreased species diversity and altered species composition. The emerging evidence strongly supports the implementation of regulations on TDGS in freshwaters.

Faecal egg count reduction tests and nemabiome analysis reveal high frequency of multi-resistant parasites on sheep farms in north-east Germany involving multiple strongyle parasite species

Anthelmintic resistance in sheep parasitic gastrointestinal nematodes is widespread and a severe health and economic issue but prevalence of resistance and involved parasite species are unknown in Germany. Here, the faecal egg count reduction test (FECRT) was performed on eight farms using fenbendazole, ivermectin and moxidectin and on four farms using only moxidectin. A questionnaire was used to obtain data on management practices to potentially identify risk factors for presence of resistance. All requirements of the recently revised WAAVP guideline for diagnosing anthelmintic resistance using the FECRT were applied. Nematode species composition in pre- and post-treatment samples was analysed with the nemabiome approach. Using the eggCounts statistic package, resistance against fenbendazole, ivermectin and moxidectin was found on 7/8, 8/8 and 8/12 farms, respectively. No formal risk factor analysis was conducted since resistance was present on most farms. Comparison with the bayescount R package results revealed substantial agreement between methods (Cohen's κ = 0.774). In contrast, interpretation of data comparing revised and original WAAVP guidelines resulted in moderate agreement (Cohen's κ = 0.444). The FECR for moxidectin was significantly higher than for ivermectin and fenbendazole. Nemabiome data identified 4 to 12 species in pre-treatment samples and treatments caused a small but significant decrease in species diversity (inverse Simpson index). Non-metric multidimensional scaling and k-means clustering were used to identify common patterns in pre- and post-treatment samples. However, post-treatment samples were scattered among the pre-treatment samples. Resistant parasite species differed between farms. In conclusion, the revised FECRT guideline allows robust detection of anthelmintic resistance. Resistance was widespread and involved multiple parasite species. Resistance against both drug classes on the same farm was common. Further studies including additional drugs (levamisole, monepantel, closantel) should combine sensitive FECRTs with nemabiome data to comprehensively characterise the anthelmintic susceptibility status of sheep nematodes in Germany.

The resilience of Tethyan planktonic and benthic calcifying algae to Early Cretaceous perturbations: comparison between the Valanginian Weissert Event and the Early Aptian Oceanic Anoxic Event 1a

Abstract During the Cretaceous, the Berriasian–Aptian interval witnessed a transition from a relatively cool climate with intermittent polar ice to a greenhouse state that persisted throughout the Late Cretaceous. These palaeoclimatic changes were associated with the construction of large igneous provinces (LIPs), which significantly perturbed the ocean–atmosphere system by introducing large amounts of CO 2 , trace metals and micronutrients, thereby impacting the biosphere. Our study focused on the Tethyan Ocean during the Early Cretaceous, examining the resilience of planktonic and shallow-water benthic calcifying algae to environmental changes. We observed their adaptation, recovery dynamics and the influence of palaeoCO 2 levels on their resilience. Calcification patterns of calcareous nannoplankton served as a proxy for ecological and engineering resilience. While calcareous nannoplankton as a whole showed high resistance, individual taxa exhibited varying levels of resilience. Nannoconids, particularly narrow-canal ones, were highly sensitive and had low resistance. In contrast, Watznaueria barnesiae showed the least sensitivity and highest resistance, likely due to its adaptive strategies and long lifespan. Nannoplankton calcification recovery (engineering resilience) from the Weissert Event took c. 3 million years. After the Early Aptian Oceanic Anoxic Event 1a (OAE1a), instead, nannoplankton did not return to pre-perturbation conditions. In shallow-water platforms, Dasycladales, aragonitic benthic calcifiers, exhibited lower resilience compared to nannofossils. They experienced a decline in species diversity across both the Weissert Event and the OAE 1a, which could indicate higher sensitivity to reduced carbonate saturation under high atmospheric p CO 2 conditions. After the Valanginian Weissert Event, Dasycladales were able to recover, albeit they show a much lower engineering resilience compared to nannoconids, as it took nearly 10 million years to revert to pre-disturbance diversity. The OAE 1a represented a more intense perturbation: the decrease of species diversity was much more drastic and permanent, and Dasycladales were unable to recover, losing their dominant role as carbonate platform biocalcifiers for the remainder of the Cretaceous. Our study provides an assessment of the resilience of Tethyan phytoplanktonic and shallow-water benthic calcifying algae to disturbances during the Early Cretaceous, with implications for tipping points associated with palaeoCO 2 levels. The differential responses in terms of timing and magnitude and the recovery dynamics contribute to the understanding of the potential impacts of current and future global changes on the resilience of marine ecosystems and the thresholds that may lead to ecological crises.

Hydrothermal and eco-environmental evolution on the southeastern Chinese Loess Plateau since the last deglaciation: evidence from terrestrial mollusk records

The ongoing global warming is altering hydrothermal patterns and eco-environments. However, it is unclear how they would respond under a natural warming scenario. Terrestrial mollusks in loess-paleosol sequences could serve as natural biological archives to explore this issue. In this study, terrestrial mollusk records from two loess-paleosol profiles on the southeastern Chinese Loess Plateau (CLP) were analyzed. Our results show that the cold-aridiphilous species decreased and the overall biodiversity increased gradually during the last deglaciation (∼19.0–11.5 ka BP), which was accompanied with the shift from cold-dry to warm-humid climate. Moreover, the mollusk communities reacted to Heinrich event 1 (H1) cooling. In the early-middle Holocene (∼11.5–5.5 ka BP), mollusk communities were dominated by the thermo-humidiphilous species, characterized by stable community composition, increased species richness and evenness with warm-humid climate. Thereafter, there was a noticeable decrease in species diversity and increase in the cold-aridiphilous species in the mid-late Holocene (∼5.5–0 ka BP), associated with a gradual shift towards a cold-dry climate. On the whole, it is noteworthy that the count of thermo-humidiphilous species increased remarkably at ∼16 ka BP, which is synchronous with a significant increase in the Northern Hemisphere summer insolation. Interestingly, this change of terrestrial mollusks preceded the formation of the Holocene paleosol at ∼8 ka as indicated by the pronounced increase in magnetic susceptibility and decrease of mean grain size. This suggests that the substantial East Asian summer monsoon (EASM) precipitation lagged the onset of deglacial warming on the southeastern CLP. Furthermore, this delay may be attributed to the negative feedback of North Atlantic meltwater, which caused a decline in the intensity of Atlantic Meridional Overturning Circulation (AMOC) and inhibited the rapid enhancement of EASM precipitation during the last deglaciation. Altogether, this provides crucial geological background evidence for exploring the potential regional hydrothermal and biodiversity responses to global warming in the near future.

Ecological and agricultural assessment of the state of forage lands of boreal river floodplains in the oil-producing region (case study in the floodplain of the Kolva River, Usinsky district, Komi Republic)

Floodplain forage lands of the Pechora basin (Usinsky district of the Komi Republic) are experiencing a complex anthropogenic impact associated with both agricultural activity and pollution with petroleum products coming with flood waters. An ecological and agricultural assessment of the soil-vegetation cover of the Kolva floodplain used as hayfield (right-bank part) and pasture (left-bank part) was carried out. Soil combinations of the main part of the surveyed floodplain include alluvial sod, sod-meadow and meadow soils. Morphological signs of gley formation in meadow soils are observed in the lower part of the soil profile and are expressed moderately. Soils are characterized generally by favorable agrochemical and morphological properties, with the exception of areas subjected to pasture digression. The vegetation cover of the central and near-river part of the floodplain massif of the right bank is mainly represented by legume-cereal-grass communities formed both in inter-ridge depressions and on flat ridges. On the high floodplain of the left bank, legume-cereal-grass meadows, grass-clover and tufted hairgrass meadows are common, horsetail–butterbur, clover-cereal and cereal communities are common in the near-river part of the left bank. Despite the relatively high productivity and the presence of valuable forage species of cereals and legumes, the qualitative characteristics of hay deviate from optimal ones due to the participation of low-nutritious, unattractive, weedy and poisonous species in the herbage. On the pasture, as a result of pasture digression, there is a decrease in species diversity with the dominance of tufted hairgrass and low-value species of various grasses. In the most disturbed areas, the total projective vegetation coverage is reduced to 50%. The soil cover of the studied territory of the Kolva floodplain is currently not contaminated with hydrocarbons, with the exception of a few spots of petroleum products with a total area of 6 m2. The effect of oil pollution on the vegetation cover of the Kolva floodplain is not manifested. Background values of the content of petroleum products in soils are slightly higher in the left-bank part compared to the right-bank part.

Later-melting rather than thickening of snowpack enhance the productivity and alter the community composition of temperate grassland

Snowpack is closely related to vegetation green-up in water-limited ecosystems, and has effects on growing-season ecosystem processes. However, we know little about how changes in snowpack depth and melting timing affect primary productivity and plant community structure during the growing season. Here, we conducted a four-year snow manipulation experiment exploring how snow addition, snowmelt delay and their combination affect aboveground net primary productivity (ANPP), species diversity, community composition and plant reproductive phenology in seasonally snow-covered temperate grassland in northern China. Snow addition alone increased soil moisture and nutrient availability during early spring, while did not change plant community structure and ANPP. Instead, snowmelt delay alone postponed plant reproductive phenology, and increased ANPP, decreased species diversity and altered species composition. Grasses are more sensitive to changes in snowmelt timing than forbs, and early-flowering forbs showed a higher sensitivity compared to late-flowering forbs. The effect of snowmelt delay on ANPP and species diversity was offset by snow addition, probably because the added snow unnecessarily lengthens the snow-covering duration. The disparate effects of changes in snowpack depth and snowmelt timing necessitate their discrimination for more mechanistic understanding on the effects of snowpack changes on ecosystems. Our study suggests that it is essential to incorporate non-growing-season climate change events (in particular, snowfall and snowpack changes) to comprehensively disclose the effects of climate change on community structure and ecosystem functions.

Seasonal dynamics of the Upper Ob zoobenthos

results of studies of the seasonal dynamics of the Upper Ob zoobenthos in the city of Novosibirsk are presented. Zoobenthos rivers Ob the growing season of 2022, the Ob was represented by 6 systematic classes: bivalves (Bivalvia) and gastropods (Gastropoda), small-lobed worms (Oligochaeta),leeches (Hirudinea), multi-legged crayfish (Amphipoda), insects (Insecta), including from the orders of mayflies (Efemeroptera), brooks (Trichoptera) and diptera (Diptera) from the families of bell mosquitoes (Chironomidae) and woodlice (Ceratopogonidae). A total of 43 species of invertebrates have been found. The largest number of taxa was observed in summer — 27, the minimum in autumn — 16. During the entire growing season, chironomid larvae and gastropods were observed in the benthic fauna. In the spring, the maximum species diversity was noted in the family of bell mosquitoes (Chironomidae) — 18 out of 24 of the total composition. The larvae of chironomids played the main role in the number, in the biomass — an autoacclimatizant — a gastropod mollusk (Viviparus viviparus (L.), belonging to a benthic non-feed for fish. The specific weight of this species in the total biomass reached 92.7%. In summer, V. viviparus (L.) dominated both in abundance and in biomass. The zoobenthos of the autumn period was characterized by a decrease in species diversity and abundance compared to previous seasons: 16 species from 5 classes were oted in the species composition, the number decreased by almost 2 times. The gastropod mollusk V. viviparus (L.) dominated in all indicators, as in summer. The average number of zoobenthos during the growing season was 527 copies/m2, the average biomass was 532,388 g/m2, of which 222 copies/m2 and 531,463 g/m2 were autoacclimatizant gastropod mollusk V. viviparus (L.).

The Effect of SARS-CoV-2 on the Gut and Its Microbiome: What We Know and What We Would Like to Know

In the present review, we consider theoretical background and results of the first studies of SARS-CoV-2 effect on the intestine and its microbiome. The data obtained indicate the long-term virus persistence in the cells of intestinal mucosa. In addition, acceleration of microbial cells and microbial metabolites translocation associated with inflammatory processes in the intestinal endothelial cells caused by the virus was also discussed. COVID-19 has a great impact on structure and functional activity of the intestinal microbiome. The decrease in species diversity and minor species dominations that are not found in the microbiome of healthy controls were observed. The gut microbiome is considered to be an important influencer on COVID-19 progression and outcome.

Elevational and seasonal patterns of plant pollinator networks in two highland tropical ecosystems in Costa Rica.

Many plant species in high montane ecosystems rely on animal pollination for sexual reproduction, however, our understanding of plant-pollinator interactions in tropical montane habitats is still limited. We compared species diversity and composition of blooming plants and floral visitors, and the structure of plant-floral visitor networks between the Montane Forest and Paramo ecosystems in Costa Rica. We also studied the influence of seasonality on species composition and interaction structure. Given the severe climatic conditions experienced by organisms in habitats above treeline, we expected lower plant and insect richness, as well as less specialized and smaller pollination networks in the Paramo than in Montane Forest where climatic conditions are milder and understory plants are better protected. Accordingly, we found that blooming plants and floral visitor species richness was higher in the Montane Forest than in the Paramo, and in both ecosystems species richness of blooming plants and floral visitors was higher in the rainy season than in the dry season. Interaction networks in the Paramo were smaller and more nested, with lower levels of specialization and modularity than those in the Montane Forest, but there were no seasonal differences within either ecosystem. Beta diversity analyses indicate that differences between ecosystems are likely explained by species turnover, whereas within the Montane Forest differences between seasons are more likely explained by the rewiring of interactions. Results indicate that the decrease in species diversity with elevation affects network structure, increasing nestedness and reducing specialization and modularity.

Метазойный микрозоопланктон Севастопольской бухты в весенний период: видовое разнообразие и структура сообщества

The original results of studies of metazoan microzooplankton (MM) in different locations of the Sevastopol Bay and the nearest open seashore at the end of the spring hydrological season are presented. Using the Primer 5 software package, changes in the abundance, species composition and structure of the MM community were analyzed. Samples were taken in 3 areas of Sevastopol Bay, differing in the degree of pollution and trophicity of the water. MM sampling, temperature and salinity measurements were carried out in three layers of the water column: from the surface to a 10-meter depth. The abundance of organisms, species diversity indices (Margalef, Pielou, Simpson, Shannon), the degree of similarity and difference of communities were calculated for successive layers: surface, middle (0-5 m) and bottom (5-10 m), as well as on average for the whole column of water. The species diversity of the MM community during the study period was generally moderately high. The middle layer of water at all stations was characterized by the highest species richness. In spatial terms, a decrease in species diversity was observed in the direction from the open seashore into the bay. Against the backdrop of an increase in water temperature from the end of May to the first ten days of June, a significant increase in the abundance of MM was recorded. In May, the average abundance in the 10-meter layer in different water areas ranged from 10 to 40 thousand ind./m3, and at the end of the first ten days of June it increased by 1.5-3.6 times. In both periods there was a trend of increasing abundance from open waters deeper into the bay, coinciding with the temperature trend of local water areas. The absolute maximum of abundance was noted in June in the surface layer in the inner part of the bay – more than 720×103 ind./m3. Quantitative changes in abundance were accompanied and largely determined by changes in the qualitative composition of MM. At the beginning of the period, the main role in the abundance and determination of similarities/differences in the community structure was played by native species of copepods, rotifers, and mollusk veligers. When the water warmed above 18-19 ºС, the role of the heat-loving invader, the copepod Oithona davisae Ferari and Orsi, 1984, sharply increased. The maximum abundance of the non-native species in the local water areas from open waters to the internal waters of the bay increased by more than an order of magnitude: from 23 to 550 ×103 ind./m3. The direction of changes in the abundance of O. davisae in the local water areas studied coincided with an increase in the level of their pollution and trophicity: from the open seashore towards the depths of the bay, both the absolute and relative abundance of the invader and its role in the community structure increased. This testifies to the indicator properties of this species. In general, the changes in abundance, species diversity and community structure of MM in local water areas reflect both seasonal and spatial changes in their trophic status in the natural gradient of the open seaside – the internal space of the Sevastopol Bay and can be used for its indirect assessment.

Метазойный микрозоопланктон Севастопольской бухты в весенний период: видовое разнообразие и структура сообщества

The original results of studies of metazoan microzooplankton (MM) in different locations of the Sevastopol Bay and the nearest open seashore at the end of the spring hydrological season are presented. Using the Primer 5 software package, changes in the abundance, species composition and structure of the MM community were analyzed. Samples were taken in 3 areas of Sevastopol Bay, differing in the degree of pollution and trophicity of the water. MM sampling, temperature and salinity measurements were carried out in three layers of the water column: from the surface to a 10-meter depth. The abundance of organisms, species diversity indices (Margalef, Pielou, Simpson, Shannon), the degree of similarity and difference of communities were calculated for successive layers: surface, middle (0-5 m) and bottom (5-10 m), as well as on average for the whole column of water. The species diversity of the MM community during the study period was generally moderately high. The middle layer of water at all stations was characterized by the highest species richness. In spatial terms, a decrease in species diversity was observed in the direction from the open seashore into the bay. Against the backdrop of an increase in water temperature from the end of May to the first ten days of June, a significant increase in the abundance of MM was recorded. In May, the average abundance in the 10-meter layer in different water areas ranged from 10 to 40 thousand ind./m3, and at the end of the first ten days of June it increased by 1.5-3.6 times. In both periods there was a trend of increasing abundance from open waters deeper into the bay, coinciding with the temperature trend of local water areas. The absolute maximum of abundance was noted in June in the surface layer in the inner part of the bay – more than 720×103 ind./m3. Quantitative changes in abundance were accompanied and largely determined by changes in the qualitative composition of MM. At the beginning of the period, the main role in the abundance and determination of similarities/differences in the community structure was played by native species of copepods, rotifers, and mollusk veligers. When the water warmed above 18-19 ºС, the role of the heat-loving invader, the copepod Oithona davisae Ferari and Orsi, 1984, sharply increased. The maximum abundance of the non-native species in the local water areas from open waters to the internal waters of the bay increased by more than an order of magnitude: from 23 to 550 ×103 ind./m3. The direction of changes in the abundance of O. davisae in the local water areas studied coincided with an increase in the level of their pollution and trophicity: from the open seashore towards the depths of the bay, both the absolute and relative abundance of the invader and its role in the community structure increased. This testifies to the indicator properties of this species. In general, the changes in abundance, species diversity and community structure of MM in local water areas reflect both seasonal and spatial changes in their trophic status in the natural gradient of the open seaside – the internal space of the Sevastopol Bay and can be used for its indirect assessment.

Сравнительная характеристика тестикулярной и уретральной микробиоты у пациентов с различными видами азооспермии и сопутствующим варикоцеле.

Introduction. Everywhere, about 15% of couples of reproductive age have the problem of infertility, with the male factor being the main cause in 50% of cases. The lack of effective treatment for male infertility is largely due to the multifactorial etiology of this disease. One of these factors is infections of the urogenital tract, the diagnostic search for which requires the development of new methods. Today, next generation sequencing (NGS), using the nucleotide sequence in the 16S rRNA region of the bacterial genome, is the most modern and highly sensitive method for determining the microbiome. Aim: to study and compare the structure of the testicular and urethral microbiota in patients with various types of azoospermia and concomitant varicocele. Materials and methods. The study included 107 infertile patients with various types of azoospermia, in some cases, with concomitant varicocele, who applied to the Center for Reproductive and Cellular Medicine of the State Budgetary Healthcare Institution of the Children's City Clinical Hospital in Krasnodar, Ministry of Health of the Republic of Krasnodar region. As a result of sample preparation, 31 samples did not meet the quality criteria and were excluded from the study. In all cases, patients underwent micro-TESE (multifocal testicular biopsy), as well as collection of biological material from the urethra. When studying the structure of the microbiome of testicular tissue, amplicons of the bacterial 16S rRNA gene were analyzed using high-throughput next-generation sequencing (NGS). Data were processed using the QIIME program (version 1.9.1). Results. Comparative characteristics of the structure of the microbiota of the urethra and testicles were carried out using average values in groups, at the level of phyla and families. When comparing the urethral microbiota, a similarity in the species composition of the microbiota was revealed in patients with nonobstructive azoospermia (NOA) and obstructive azoospermia (ОА), while the species composition of the testicular microbiota in patients with ОА is similar to that in patients with varicocele. As a result of data analysis, 6 phyla and 12 families of bacteria were identified that are common to both testicular and urethral tissue. When comparing the frequency of occurrence of these bacteria, differences were identified in the comparison groups. Conclusions. The microbiota of the urethra in men has a wide taxonomic composition, which has characteristics in infertile patients, caused, in our opinion, by disruption of the GTB, in particular, in patients with varicocele. The structure of the microbiota of testicular tissue has a decrease in species diversity in patients with non-obstructive azoospermia with the dominant Enterobacteriaceae_A family, in contrast to patients with obstructive azoospermia and patients with NOA and concomitant varicocele. The current situation and the discrepancy in scientific publications and expert opinions require further expansion of the range of scientific interdisciplinary research.

Suchozemští plži kontinentálních zaplavovaných luk u řeky Labe mezi Lysou nad Labem a Mělníkem [Terrestrial gastropods of the continental flooded meadows by Elbe river between Lysá nad Labem and Mělník

Mollusc fauna in three localities of continental flooded meadows in Úpor-Černínovsko Nature Reserve and in Káraný – Hrbáčkovy tůně Nature Reserve in the Middle Polabí lowland were studied. No species of conservation importance were found there, and most of the species found belong to generalists. The sites form a gradient from un-mowed to completely mowed meadow. Management resulted in a decrease in species diversity and, conversely, an increase in abundance towards the completely mowed site characterized by a high abundance of Vertigo pygmaea, species of early succession stage.

Effects of Long-Term Exclosure on Main Plant Functional Groups and Their Biochemical Properties in a Patchily Degraded Alpine Meadow in the Source Zone of the Yellow River, West China

This study aimed to understand the response of vegetation community characteristics in the degraded alpine meadow of the Source Zone of the Yellow River to exclosure of various lengths. Artificial fences were erected to prevent livestock grazing and let the degraded meadow recover naturally as a means of restoration. The research focused on a typical degraded alpine meadow in which four plots were fenced off for three periods of 1 year (E1), 4 years (E4), and 10 years (E10), plus a freely grazed plot as the control. The study compared and analyzed the differences in plant community characteristics, carbon (C), nitrogen (N), and phosphorus (P) reserves, as well as the stoichiometric characteristics of main functional groups in the alpine meadow over different exclosure durations. The results indicated that E10 long-term exclosure significantly increased the aboveground biomass of gramineous plants but reduced the aboveground biomass of miscellaneous grasses. However, when compared to E4 short-term exclosure, E10 resulted in a reduction in the aboveground biomass of Cyperaceae plants. On the other hand, E4 medium-term exclosure significantly increased the aboveground biomass of Gramineae and Cyperaceae. Exclosure significantly increased the nitrogen (N) and phosphorus (P) reserves of the aboveground plant communities. Among these communities, the plant communities in the E10 long-term exclosure had the highest N and P reserves. However, this exclosure length also led to a significant reduction in plant diversity. Furthermore, except for Cyperaceae, all functional groups were observed in E10 and E4 plots. The carbon–nitrogen ratio and carbon–phosphorus ratio of these groups were significantly lower than those of groups G and E1. Medium-term exclosure (E4) has a positive impact on the aboveground biomass as well as plants’ nitrogen and phosphorus reserves. However, long-term exclosure (E10) has been observed to decrease species diversity and nutrient utilization efficiency of alpine meadow vegetation, which can be detrimental to the sustainable development of the alpine meadow ecosystem. Therefore, it is not recommended to implement long-term exclosure. Instead, a moderate level of grazing should be adopted after 4 years of exclosure.

Ginsenoside Rb1 enhanced immunity and altered the gut microflora in mice immunized by H1N1 influenza vaccine.

Influenza is an acute infectious respiratory disease caused by the influenza virus that seriously damages human health, and the essential way to prevent influenza is the influenza vaccine. Vaccines without adjuvants produce insufficient specific antibodies and therefore require adjuvants to boost antibody titers. Microbes and hosts are a community that needs to "promote bacteria," which could provide new value for the immune effect. (1) The H1N1 influenza vaccine, in combination with Ginsenoside Rb1, was co-injected into mice intraperitoneally (I.P.). Then, immunoglobulin G and antibody subtype levels were tested by enzyme-linked immunosorbent assay (ELISA). Moreover, mice were infected with a lethal dose of the H1N1 influenza virus (A/Michigan/45/2015), and survival status was recorded for 14 days. Lung tissues were stained by hematoxylin and eosin (H&E), and ELISA detected inflammatory factor expression levels. (2) Mice were immunized with Ginsenoside Rb1 combined with quadrivalent influenza inactivated vaccine(IIV4), and then IgG levels were measured by ELISA. (3) Fresh stool was collected for fecal 16S rDNA analysis. Ginsenoside Rb1 boosted IgG and antibody subtypes in the H1N1 influenza vaccine, improved survival of mice after virus challenge, attenuated lung histopathological damage, and reduced inflammatory cytokines expression in IL-6 and TNF-α. The results of 16S rDNA showed that Rb1 decreased species diversity but increased species richness compared to the PBS group and increased the abundance of Akkermansiaceae and Murbaculaceae at the Family and Genus levels compared with the HA+Alum group. Ginsenoside Rb1 has a boosting effect on the immune efficacy of the H1N1 influenza vaccine and is promising as a novel adjuvant to regulate the microecological balance and achieve an anti-infective effect.

ОРНІТОФАУНА СЕЛА СОЛОНКА НА ЛЬВІВЩИНІ: АНАЛІЗ СПОСТЕРЕЖЕНЬ ЗА 2010–2023 РОКИ

This article analyzes the avifauna species in Solonka village, a distinct area situated on Povitriana Street, located on the southern outskirts of Lviv city. Data on bird species diversity were collected throughout different seasons from 2010 to 2023. Over this period, a total of 63 bird species were observed. Between 2010 and 2016, there were 46 nesting species. Anthropogenic factors significantly influence the species diversity and population of birds in Solonka village. Gardens, summer cottages, areas adorned with fruit trees, sewage treatment plants, and ornamental plantings near houses provide birds with food, shelter, and nesting opportunities. The primary causes of mortality among both young and adult birds each year are the presence of a large number of stray cats and dogs. During the winter months, local residents actively feed passerine birds. Additionally, each year, some nests and chicks are unintentionally disturbed by children and teenagers. The avian population in the area is predominantly composed of small birds that inhabit trees and shrubs. From 2022 to 2023, we observed birds belonging to six orders: Ancerinae (Anseriformes), Falconidae (Falconiiformes), Galliformes (Galliformes), Columbidae (Columbiformes), Woodpeckers (Piciformes), Old world sparroews (Passeriformes). In 2021, The Bohemian waxwing (Bombycilla garrulous Linnaeus, 1758) were observed. They were registered in separate winters. In the winter of 2022, for the first time during 13 years of observations, the marsh tit (P. palustris Linnaeus, 1758), the crested tit (P. cristatus Linnaeus, 1758), the common redpoll (Acanthis flammea Linnaeus, 1758) and the short-toed brachydactyla (C. brachydactyla Brehm, 1820) and the falcon (Falconidae). Martins and terns (Laridae), the common kingfisher (Alcedo atthis Linnaeus, 1758), and gray heron (Ardea cinerea Linnaeus, 1758) regularly visit reservoirs in the vicinity of Solonka village. The listed species do not nest here. The common moorhen (Gallinula chloropus Linnaeus, 1758) and Eurasian coots (Fulica atra Linnaeus, 1758) nest in the ponds every year. There are known cases of mallard nesting. After 2010 jackdaws and owls stopped nesting on the surveyed territory.
 The migration route of the gray crane (Grus grus Linnaeus, 1758) and the white stork (Ciconia ciconia Linnaeus, 1758) passes through the territory of Solonka village, where these birds are regularly observed during both autumn and spring migrations.
 In general, the number of bird species observed in the area of Solonka village is lower than that in the residential area of Lviv. In Lviv, a total of 84 bird species were recorded between 2006 and 2018. In contrast, our surveys in the Solonka village area have documented only 63 species of birds. This indicates a difference of 20 bird species between the two locations we studied. Our observations span the period from 2010 to 2023. 
 To put this into perspective, in 1994, Lviv was home to 197 bird species. This significant decrease in species diversity over the last three decades can be attributed to various factors, with one of the most prominent being the substantial transformation of biotopes.