Search Results (419)

Wildfires can significantly alter soil physicochemical conditions and microbial communities in forest ecosystems. This study aimed to characterize the culturable soil fungal community and evaluate biological activity in Banco Totumo Bijibana, a protected dry tropical forest in Atlántico, Colombia, affected by a wildfire in 2014. Twenty soil samples were collected for microbiological (10 cm depth) and physicochemical (30 cm) analysis. Basal respiration was measured using Stotzky’s method, nitrogen mineralization via Rawls’ method, and fungal diversity through culture-based identification and colony-forming unit (CFU) counts. Diversity was assessed using Simpson, Shannon–Weaver, and ACE indices. The soils presented low organic matter (0.70%) and nitrogen content (0.035%), with reduced biological activity as indicated by basal respiration (0.12 kg C ha⁻¹ d⁻¹) and mineralized nitrogen (5.61 kg ha⁻¹). Four fungal morphotypes, likely from the genus Aspergillus, were identified. Simpson index indicated moderate dominance, while Shannon–Weaver values reflected low diversity. Correlation analysis showed Aspergillus-3 was positively associated with moisture, whereas Aspergillus-4 correlated negatively with pH and sand content. The species accumulation curve reached an asymptote, suggesting an adequate sampling effort. Although no control site was included, the findings provide a baseline characterization of post-fire soil microbial structure and function in a dry tropical ecosystem. Full article

Background/Objectives: Selective serotonin reuptake inhibitors (SSRIs), widely prescribed for anxiety disorders, may negatively impact the gut microbiota, contributing to dysbiosis. Considering the gut–brain axis’s importance in mental health, probiotics could represent an effective adjunctive strategy. This study evaluated the effects of Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 on microbiota composition, metabolic activity, and immune markers in fecal samples from patients with anxiety on SSRIs, using the SHIME^® (Simulator of the Human Intestinal Microbial Ecosystem) model. Methods: The fecal microbiotas of four patients using sertraline or escitalopram were inoculated in SHIME^® reactors simulating the ascending colon. After stabilization, a 14-day probiotic intervention was performed. Microbial composition was assessed by 16S rRNA sequencing. Short-chain fatty acids (SCFAs), ammonia, and GABA were measured, along with the prebiotic index (PI). Intestinal barrier integrity was evaluated via transepithelial electrical resistance (TEER), and cytokine levels (IL-6, IL-8, IL-10, TNF-α) were analyzed using a Caco-2/THP-1 co-culture system. The statistical design employed in this study for the analysis of prebiotic index, metabolites, intestinal barrier integrity and cytokines levels was a repeated measures ANOVA, complemented by post hoc Tukey’s tests to assess differences across treatment groups. For the 16S rRNA sequencing data, alpha diversity was assessed using multiple metrics, including the Shannon, Simpson, and Fisher indices to evaluate species diversity, and the Chao1 and ACE indices to estimate species richness. Beta diversity, which measures microbiota similarity across groups, was analyzed using weighted and unweighted UniFrac distances. To assess significant differences in beta diversity between groups, a permutational multivariate analysis of variance (PERMANOVA) was performed using the Adonis test. Results: Probiotic supplementation increased Bifidobacterium and Lactobacillus, and decreased Klebsiella and Bacteroides. Beta diversity was significantly altered, while alpha diversity remained unchanged. SCFA levels increased after 7 days. Ammonia levels dropped, and PI values rose. TEER values indicated enhanced barrier integrity. IL-8 and TNF-α decreased, while IL-6 increased. GABA levels remained unchanged. Conclusions: The probiotic combination of Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 modulated gut microbiota composition, metabolic activity, and inflammatory responses in samples from individuals with anxiety on SSRIs, supporting its potential as an adjunctive strategy to mitigate antidepressant-associated dysbiosis. However, limitations—including the small pooled-donor sample, the absence of a healthy control group, and a lack of significant GABA modulation—should be considered when interpreting the findings. Although the SHIME^® model is considered a gold standard for microbiota studies, further clinical trials are necessary to confirm these promising results. Full article

To investigate the characteristics of rhizosphere soil microbial communities associated with Schisandra sphenanthera across different altitudinal gradients and to reveal the driving factors of microbial community dynamics, this study collected rhizosphere soil samples at four elevations: 900 m (HB1), 1100 m (HB2), 1300 m (HB3), and 1500 m (HB4). High-throughput sequencing and molecular ecological network analysis were employed to analyze the microbial community composition and species interactions. A null model was applied to elucidate community assembly mechanisms. The results demonstrated that bacterial communities were dominated by Proteobacteria, Acidobacteriota, Actinobacteriota, and Chloroflexi. The relative abundance of Proteobacteria increased with elevation, while that of Acidobacteriota and Actinobacteriota declined. Fungal communities were primarily composed of Ascomycota and Basidiomycota, with both showing elevated relative abundances at higher altitudes. Diversity indices revealed that HB2 exhibited the highest bacterial Chao, Ace, and Shannon indices but the lowest Simpson index. For fungi, HB3 displayed the highest Chao and Ace indices, whereas HB4 showed the highest Shannon index and the lowest Simpson index. Ecological network analysis indicated stronger bacterial competition at lower elevations and enhanced cooperation at higher elevations, contrasting with fungal communities that exhibited increased competition at higher altitudes. Altitude and soil nutrients were negatively correlated with soil carbon content, while plant nutrients and fungal diversity positively correlated with soil carbon. Null model analysis suggested that deterministic processes dominated bacterial community assembly, whereas stochastic processes governed fungal assembly. These findings highlight significant altitudinal shifts in the microbial community structure and assembly mechanisms in S. sphenanthera rhizosphere soils, driven by the synergistic effects of soil nutrients, plant growth, and fungal diversity. This study provides critical insights into microbial ecology and carbon cycling in alpine ecosystems, offering a scientific basis for ecosystem management and conservation. Full article

Desert plant communities play a vital role in sustaining the stability of arid ecosystems; however, they demonstrate limited resilience to environmental changes. A critical aspect of understanding community assembly mechanisms is determining whether soil texture heterogeneity affects vegetation diversity in arid deserts, especially under conditions of extreme water scarcity and restricted nutrient availability. This study systematically examined the relationships between plant diversity and soil physicochemical properties across four soil texture types—sand, sandy loam, loamy sand, and silty loam—by selecting four representative desert systems in the Hami region of Xinjiang, China. The objective was to elucidate the mechanisms through which soil texture may impact desert plant species diversity. The findings revealed that silty loam exhibited distinct characteristics in comparison to the other three sandy soil types. Despite its higher nutrient content, silty loam demonstrated the lowest vegetation diversity. The Shannon–Wiener index (H′), Simpson dominance index (C), Margalef richness index (D), and Pielou evenness index (Jsw) for silty loam were all lower compared to those for sand, sandy loam, and loamy sand. However, silty loam exhibited higher values in electrical conductivity (EC), urease activity (SUR), and nutrient content, including soil organic matter (SOM), ammonium nitrogen (NH⁴⁺-N), and available potassium (AK), than the other three soil textures. This study underscores the significant regulatory influence of soil texture on plant diversity in arid environments, offering new insights and practical foundations for the conservation and management of desert ecosystems. Full article

In the forest ecosystems of Central European Russia, the influence of forest edges on the spatial distribution of Drosophilidae was studied for the first time. The research was conducted during the period of 2021–2022 in the Republic of Mordovia. Beer traps baited with fermented beer and sugar were used to collect Drosophilidae. Two study plots were selected, differing in their forest edges, tree stands, and adjacent open ecosystems. In both cases, the forest directly bordered an open ecosystem. Edges serve as transitional biotopes, where both forest and meadow (open area) faunas coexist. Knowing that many drosophilid species prefer forest habitats, we designated forest interior sites as control points. Traps were set at heights of 1.5 m (lower) and 7.5 m (upper) on trees. A total of 936 specimens representing 27 species were collected. Nine species were common across all traps, while ten species were recorded only once. At the forest edges, 23 species were captured across both heights, compared to 19 species in the forest interiors. However, the total abundance at the forest edges was 370 specimens, while it was 1.5 times higher in the forest interiors. Both abundance and species richness varied between plots. Margalef’s index was higher at the forest edges than in the forest interiors, particularly at 1.5 m height at the edge and at 7.5 m height in the forest interior. Shannon and Simpson indices showed minimal variation across traps at different horizontal and vertical positions. The highest species diversity was observed among xylosaprobionts (9 species) and mycetophages (8 species). All ecological groups were represented at the forest edges, whereas only four groups were recorded in the forest interiors, with the phytosaprophagous species Scaptomyza pallida being absent. In general, both species richness and drosophilid abundance increased in the lower strata, both at the forest edge and within the interior. Using the R package Indicspecies, we identified Gitona distigma as an indicator species for the forest edge and Scaptodrosophila rufifrons as an indicator for the forest interior in the lower tier for both plots. In addition, Drosophila testacea, D. phalerata, and Phortica semivirgo were found to be indicator species for the lower tier in both plots, while Leucophenga quinquemaculata was identified as an indicator species for the upper tier at the second plot. Full article

Urban green spaces (UGS) are essential for residents’ well-being, environmental quality, and social cohesion. However, previous studies have typically employed undifferentiated analytical frameworks, overlooking UGS types and failing to adequately measure the structural disparities of different UGS types within residents’ walking distance. To address this, this study integrates Gaussian Two-Step Floating Catchment Area models, Simpson’s index, and the Gini coefficient to construct an accessibility–diversity–equality assessment framework for UGS. This study conducted an analysis of accessibility, diversity, and equity for various types of UGSs under pedestrian conditions, using the high-density city of Shenzhen, China as a case study. Results reveal high inequality in accessibility to most UGS types within 15 min to 30 min walking range, except residential green spaces, which show moderate-high inequality (Gini coefficient: 0.4–0.6). Encouragingly, UGS diversity performs well, with over 80% of residents able to access three or more UGS types within walking distance. These findings highlight the heterogeneous UGS supply and provide actionable insights for optimizing green space allocation to support healthy urban development. Full article

Long-term monitoring of small mammal communities provides critical insights into biodiversity conservation by detecting ecosystem degradation and quantifying anthropogenic impacts. Using 13 years (2005–2017) of standardized live-trapping data from the Diannan area, China, we analyzed 22 small mammal species to assess population dynamics and community restructuring through co-occurrence network analysis, species composition trends, and multi-index diversity evaluation (Shannon–Wiener, Margalef, Simpson, and Pielou). The research results showed that, except for the two dominant species, Eothenomys miletus and Apodemus chevrieri, whose populations showed an increasing trend during the survey period, the populations of all other species showed a decreasing trend, and some species even faced local extinction. The species diversity index significantly decreased, and the complexity of the co-occurrence network structure also appeared at the local level. We observed a decrease in the diversity of small mammals and the interactions between species. Pearson correlation and redundancy analysis (RDA) revealed that temperature, precipitation, and sunshine duration were the primary environmental drivers of the observed temporal variations in small mammal community structure. These results emphasize the necessity of further conservation efforts to protect local ecosystems and mitigate the negative impact of human activities on the environment. Full article

Streptococcus agalactiae (SA) is a severe prevalent pathogen, resulting in high morbidity and mortality in the global tilapia industry. With increasing bacterial resistance to antibiotics, alternative strategies are urgently needed. This study aims to investigate the antibacterial activity and the underlying mechanisms of the natural product xanthohumol (XN) against SA infection in tilapia (Oreochromis niloticus). The results showed that XN could significantly reduce the bacterial loads of SA in different tissues (liver, spleen and brain) after treatment with different tested concentrations of XN (12.5, 25.0 and 50.0 mg/kg). Moreover, XN could improve the survival rate of SA-infected tilapia. 16S rRNA gene sequencing demonstrated that the alpha-diversity index (Chao1 and Shannon_e) was significantly increased in the XN-treated group (MX group) compared to the SA-infected group (CG group) (p < 0.05), and the Simpson diversity index significantly decreased. The Bray–Curtis similarity analysis of non-metric multidimensional scaling (NMDS) and principal coordinate analysis (PCA) showed that there were significant differences in microbial composition among groups. At the phylum level, the relative abundance of the phyla Actinobacteria, Proteobacteria and Bacteroidetes decreased in the MX group compared to the CG group, while the relative abundance of the phyla Fusobacteria, Firmicutes and Verrucomicrobia increased. Differences were also observed at the genus level; the relative abundance of Mycobacterium decreased in the MX group, but the abundance of Cetobacterium and Clostridium_sensu_stricto_1 increased. Metabolomics analysis revealed that XN changed the metabolic profile of the liver and significantly enriched aspartate metabolism, glycine and serine metabolism, phosphatidylcholine biosynthesis, arginine and proline metabolism, glutamate metabolism, urea cycle, purine metabolism, methionine metabolism, betaine metabolism, and carnitine synthesis. Correlation analysis indicated an association between the intestinal microbiota and metabolites. In conclusion, XN may be a potential drug for the prevention and treatment of SA infection in tilapia, and its mechanism of action may be related to the regulation of the intestinal microbiota and liver metabolism. Full article

The present study analyzed the vegetation diversity in three forests located in southern Romania and assessed their degree of similarity. Data were collected using frame quadrat sampling and species taxonomic identification. The methodology included the calculation of ecological indices (Shannon–Wiener, equitability, maximum entropy, Menhinick, Margalef, McIntosh, Gleason, and Simpson) and statistical analysis using ANOVA and Duncan tests (p < 0.05). Similarity between forests was evaluated using the Jaccard and Dice/Sørensen coefficients. The results showed that biodiversity increases with area size, and the forest ecosystem in Vlădila exhibited the highest number of woody and herbaceous species. Although the forest ecosystem in Studinița had the greatest floristic diversity, according to the Shannon–Wiener index, it also showed higher equitability (0.911 compared to 0.673 in Vlădila) due to a more uniform species distribution. The forest ecosystem in Studinița acted as an intermediate zone between those in Grădinile and Vlădila. Variations in diversity among the three areas reflect ecological differences influenced by location-specific factors such as soil type, climatic conditions, and human interventions. This suggests that ecological conditions and the physical characteristics of forests significantly impact the number and types of species that can coexist within an ecosystem. Full article

Syrphid flies (Syrphidae) are among the most significant groups of insect pollinators with approximately 6300 described species worldwide. Within China, more than 15% species have been reported but their diversity and distribution pattern are not well understood. Based on recent collections and published literature records, this study aimed to assess the species diversity, richness, evenness, and distribution pattern of Syrphidae in China. Biodiversity was measured using various indices such as Simpson’s diversity index, the Shannon–Wiener diversity index, Simpson’s reciprocal index, the Shannon equitability index, and the Margalef index. The results indicated that most of the indices showed highest values within Sichuan, Shaanxi, Yunnan, Taiwan, Tibet, and Gansu provinces. However, the lowest values of most of these indices were seen in Tianjin, Chongqing, and Hongkong. The ranges of these values were 0.69–5.55, 0.67–1.00, and 1.44–46.26 for the Shannon–Wiener index, Simpson’s index, and the Margalef index, respectively. Based on UMAP (Uniform Manifold Approximation and Projection) clustering approaches, all provinces of China were divided into two groups where group 1 showed 16 provinces having similar values to each other in a UMAP1 and UMAP2 plot, whereas 17 provinces were categorized into group 2. This clustering was further refined by a hierarchical clustering dendrogram where group 2 was further refined into two subgroups, where three provinces were separated into one small group including Hongkong, Chongqing, and Tianjin because of the lowest values of most of the indices. These results provide significant insights into the species richness and distribution of syrphid flies and inform strategies to help maintain these pollinators to support sustainable agriculture. Full article

Andean grassland ecosystems in Peru are characterized by diverse plant species adapted to environmental factors including weather, soil type, elevation, slope orientation, and soil moisture. This study evaluated the floristic composition, alpha diversity, indicator species, and suitable species for Andean livestock in the Sillapata micro-watershed, Junín region, Peru, across rainy and dry seasons. Data collection involved 100 m linear transects, and analyses included floristic composition and dissimilarity, Shannon-Wiener (H′) and Simpson (D) diversity indices, and the identification of indicator and suitable species using QGIS vs 3.28.14 and R software vs 4.3.2. Results revealed a total of 130 species classified into 74 genera and 23 families, with Asteraceae and Poaceae as the dominant families, exhibiting variations in richness and dissimilarity between control points and seasonal periods. Alpha diversity (H′) ranged from 2.07 to 3.1867, while Simpson’s index (D) ranged from 0.7644 to 0.9234. Six indicator species were identified, along with 11 families containing suitable species, predominantly Poaceae (38–60%), Cyperaceae (11–15%), and Asteraceae (3–9%). The findings indicate that the studied ecosystem exhibits a heterogeneous floristic composition with medium to low and variable diversity, influenced by seasonal climatic changes and the current grassland management regime, which involves rotational grazing with cattle adapted to high-altitude conditions. Full article

(1) Although lotus ponds exhibit ecological benefits in wetland restoration, their efficacy in water purification and eutrophication mitigation remains unclear. (2) This study utilized Jinluo lotus pond as the experimental group and the adjacent river as the control. Five sampling points were established in each area, with water samples collected in June 2022, April 2025, and May 2025. (3) The pH, BOD, COD, TN, and NH₃-N concentrations in Jinluo lotus pond water are higher than those in rivers, while the TP, NO₃-N, Chl-a, and algal cell density in rivers are higher. However, there was no significant difference in the nine parameters (p > 0.05) in June 2022. The pH, DO, algal cell density, and algal biomass of the Jinluo lotus pond were significantly higher (p < 0.05 for DO); the concentrations of BOD, COD, TN, TP, NH₃-N, NO₃-N, PI, and Chl-a in rivers are higher, with significant differences in Chl-a (p < 0.05) in April 2025. The BOD, COD, TP, NO₃-N, and PI of the Jinluo lotus pond were relatively high (p < 0.05 for PI); the pH, TN, NH₃-N, DO, Chl-a, algal cell density, and algal biomass of rivers are higher, with significant differences in Chl-a (p < 0.05) in May 2025. The results showed that there was no significant difference in the four diversity indicators in June 2022, April 2025, and May 2025. There was no significant difference in the algal diversity indices, including species richness (S), Shannon–Wiener diversity index (H), Simpson diversity index (P), and Pielou evenness index (E) between Jinluo lotus pond and rivers. (4) Conclusions and Recommendations: The Jinluo lotus pond and adjacent rivers suffer from severe nutrient overload, especially with BOD, COD, and TN all being classified as Class 5 water. Expanding natural and constructed reed communities is recommended to enhance nutrient removal. However, given the limited purification capacity of lotus ponds, maintaining or increasing their area may not be justified. Full article

Rumen microbiota and metabolites play important roles in energy metabolism and immune regulation in the host. However, the underlying mechanisms of their interaction with the host to regulate yak plateau adaptation remain unknown. In this study, the effects of altitude on the rumen microbiome, metabolome, and fermentation parameters of yaks were analyzed. The fiber content of pasture grasses increased with altitude, while crude protein content was significantly higher at an altitude of 2800 m (T2800) compared to an altitude of 4500 m (T4500) (p < 0.05). The acetic acid, propionic acid, and volatile fatty acids of yaks in the T4500 group were significantly higher than in the T2800 group (p < 0.05). Simpson’s index of rumen microorganisms in the T4500 group of yaks was significantly higher than in T2800 and T3500 yaks. The relative abundance of Rikenellaceae_RC9_gut_group and Succiniclasticum was significantly higher in T4500 than in T2800, while Prevotella and Streptococcus were more abundant in T2800 than in T4500. Rumen metabolomics analyses revealed that yak rumen metabolites at different altitudes were influenced by forage and altitude, mainly affecting energy metabolism and fatty acid biosynthesis (such as purine and glycerophospholipid metabolism). In summary, altitude may influence rumen microbes and metabolites through pasture nutrient composition. Full article

This study aimed to investigate the effects of Nano-cAMP on growth performance, gut development, and microbiota composition in broilers. A total of 108 21-day-old yellow-feathered female chicks were randomly divided into three groups with six replicates per group and six chicks per replicate according to the principle of consistent body weight. Experimental treatments included the following: (1) CON group (basal diet), (2) cAMP group (basal diet + 0.02 g/kg cAMP), and (3) Nano-cAMP group (basal diet + 0.37 g/kg Nano-cAMP liposomes). After a 21-day experimental period, results revealed the following: Compared with the CON group, the Nano-cAMP group exhibited a significantly reduced feed-to-gain ratio (p < 0.05). The cAMP group exhibited a significant increase in duodenal index (p < 0.05), whereas the Nano-cAMP group demonstrated greater jejunal villus height (p < 0.05). Both treatment groups showed significant upregulation of cholecystokinin (CCK) and secretin gene expression (p < 0.05). Analysis of alpha-diversity indices (Chao1, Shannon, Simpson) revealed no significant differences in jejunal and cecal microbiota composition between experimental groups (p > 0.05). Notably, the relative abundance of Firmicutes significantly increased (p < 0.05) in the cAMP and Nano-cAMP groups, whereas Proteobacteria, Gemmatimonadota, and Chloroflexi significantly decreased (p< 0.05). The combined relative abundance of three Lactobacillus genera and Bifidobacterium was obviously elevated. Linear discriminant analysis identified Bifidobacterium, Ruminococcus torques group, and uncultured_Thermoanaerobacterales_bacterium as dominant genera in the intestinal tract of Nano-cAMP group. In conclusion, dietary addition of Nano-cAMP promotes jejunal development, modulates appetite hormones mRNA expression, enhances absorption capacity, increases the relative abundance of intestinal probiotics such as Bifidobacterium and cellulose-degrading bacteria such as Ruminococcus torques group, optimizes gut microbiota composition, and ultimately reduces the feed-to-gain ratio in broilers. Full article

Fragments of urban forests can host a remarkable diversity of insects, even in environments that have been greatly transformed. This study evaluates the diversity, abundance, and composition of insects that belong to seven families in four urban forest fragments near Panama City, i.e., Ciudad del Saber (CDS), Parque Natural Metropolitano (PNM), Corozal (COR), and Albrook (ALB). A total of 2038 individuals were collected via Malaise traps and categorized into 403 morphospecies, 75 genera, and 43 subfamilies. The highest richness of morphospecies was observed in CDS (223), whereas PNM exhibited the highest abundance of individuals (862). The alpha diversity indices (Shannon-Wiener > 4.3; Margalef > 21; Pielou ≈ 1.0; and Simpson’s inverse > 0.95) reflected communities that were characterized by high levels of diversity and equity. The level of similarity observed among the fragments was moderate (Diserud–Odegaard index = 0.543), thus indicating differences among the sites evaluated as part of this research in terms of their taxonomic composition. These results provide evidence concerning the variability of entomological communities in tropical urban landscapes and the role of forest fragments as possible reservoirs of biodiversity. Full article