Search Results (11,564)

Reservoirs serve functional purposes such as irrigation and power generation. However, concerns are raised due to the alterations of the connected riverine ecosystems. Chironomidae (Diptera), a diverse aquatic macroinvertebrate group, are vital to the functioning of ecosystems and serve as water quality indicators. Their holometabolous development includes the pupal stage after four larval stages. The chironomid pupal skin (exuvia) is used in environmental assessments, where the Chironomid Pupal Exuvial Technique (CPET) is a recognized standard. The CPET method is adaptable to different freshwater environments and here was applied in the study of 28 man-made lakes in the Pannonian Lowlands and Dinaric Western Balkan Ecoregion in Croatia to obtain information on chironomid diversity and analyze the potential influence of environmental factors on the chironomid community. The lake surface was skimmed with an exuvial hand net (mesh size of 300 µm) along the lake edge with a transect length of 10 m in the area of accumulated debris of organic and inorganic matter. Individual exuviae were mounted in a Berlese mounting medium and identified by morphological characteristics to the lowest taxonomic level. During the study, 5698 chironomid pupal skins were collected, and 141 taxa (including 97 species) belonging to five subfamilies were identified. The tribe Tanytarsini comprised 40% of the identified taxa, with Paratanytarsus spp. being the most abundant. In the Dinaric ecoregion, Paratanytarsus bituberculatus dominated, while Microchironomus tener and the genus Cricotopus were the dominant taxa in the Pannonian ecoregion. Community structure in the Pannonian ecoregion was influenced by total organic carbon (TOC) and orthophosphates (PO₄³⁻), indicating higher anthropogenic pressure compared to the Dinaric ecoregion, where water conductivity influenced Chironomidae assemblages. The research has provided valuable and useful information on the chironomid diversity in man-made and highly altered water bodies, as some of the most vulnerable aquatic habitats to anthropogenic influence. The CPET method could be a useful tool for the ecological studies and bioassessment of water quality in Croatia. Full article

The impacts of hydropower plants and their reservoirs on floodplains can potentially create new environmental filters and reduce the exchange of organisms and access to habitats. In this study, we aimed to compare the fish assemblage associated with aquatic macrophytes between floodplain lakes under natural conditions and a regulated floodplain lake in the Environmental Protection Area of Rio Pandeiros, Brazil. We tested the hypothesis that in the regulated floodplain lake, there would be a lower richness and a greater of abundance of macrophytes and fish than is natural. We also verified the influence of the seasons, macrophyte bank richness, and biomass on the fish assemblage abundance. The fish assemblages differed between the regulated and natural floodplains due to the higher richness and abundance of fish in the natural floodplains. The presence of non-native and generalist species in the regulated floodplain influenced the dissimilarity between the floodplains. Migratory species have been found only in natural floodplains. Fish abundance was negatively related to macrophyte richness on the regulated lake. There was a lower fish abundance and macrophyte richness in the regulated lake. There was no evidence that macrophyte biomass affected the abundance and richness of fishes. Our results confirm that the Pandeiros small hydroelectric dam affects the fishes’ assemblage and the macrophyte community, since the regulated floodplain lake has a lower richness and abundance of fish. The regulated floodplain lake is connected to a reservoir created by a small hydroelectric dam, which will be removed in the coming years. The removal of this dam might change these dynamics, and this must be evaluated when the change is implemented. Full article

Understanding the driving mechanisms of diversity across multiple dimensions is a fundamental task in biodiversity conservation. Here, we examined the alpha and beta diversity of macroinvertebrates in the taxonomic, functional, and phylogenetic dimensions in mountain streams of northwestern Hubei Province, China. We also assessed how much local environmental, land use, climatic, and spatial variables affected these diversities. We found that (1) there were generally weak or no correlations of alpha and beta diversity between taxonomic, functional, and phylogenetic dimensions; (2) compared to both functional and phylogenetic beta diversity, which was mainly determined by nestedness, taxonomic beta diversity was mostly molded by turnover and was much higher; and (3) local environmental variables predominantly influenced taxonomic and functional dimensions of alpha and beta diversity, while spatial factors primarily drove phylogenetic dimension. These results suggest that regulating local habitats is crucial for lotic biodiversity conservation efforts, though spatial processes cannot be overlooked. Furthermore, our findings verify the supplemental role of functional and phylogenetic data in enriching insights provided by taxonomic data alone. This underscores the importance of a multidimensional approach for a more nuanced understanding of community assembly mechanisms, which is crucial for efficient ecosystem management and biodiversity conservation. Full article

Under the dual pressures of rapid urbanization and intensifying global climate change, China has proposed governance policies aimed at promoting ecological urban construction. Wetland landscapes play a key role in sustaining human and social well-being. As a significant city in the middle reaches of the Yangtze River, Wuhan’s wetland resources play an irreplaceable role in maintaining the regional ecological balance and promoting sustainable economic and social development. However, urbanization poses a severe challenge to the ecological service functions of wetlands. Consequently, in this study, we analyzed the spatial–temporal evolution patterns of the sub-functional systems of carbon sequestration, biodiversity conservation, water yield, and water purification in five wetland types in Wuhan City from 2000 to 2020 by using the CASA model and InVEST model. Then, a wetland multi-functional assessment framework was constructed to quantify the comprehensive multi-function score. It is imperative to unravel the underlying mechanisms driving the changes in wetland functions and to explore the equilibrium point between wetland conservation and urban sustainable development. Our results show that the wetland area of Wuhan City decreased from 5077.33 km² in 2000 to 4696.60 km² in 2020, and the wetland multi-functions exhibited significant spatial heterogeneity from 2000 to 2020. Wetland carbon sequestration increased from 0.94 Tg in 2000 to 1.11 Tg in 2020. The wetland habitat quality declined from 0.13 in 2000 to 0.11 in 2020. The water production of the wetlands increased from 5.43 × 10⁹ t in 2000 to 22.59 × 10⁹ t in 2020. The wetland N loss decreased from 55,850.58 t in 2000 to 49,209.93 t in 2020. The highest multi-function score was in paddy fields, which increased from 0.41 ± 0.12 to 0.51 ± 0.12, followed by tidal flats, which increased from 0.39 ± 0.14 to 0.50 ± 0.16, and the lowest was rivers, which also increased from 0.33 ± 0.12 to 0.41 ± 0.14. The multi-function score was closely related to the wetland type and urban development direction over the past two decades, and it was negatively correlated with production and living density, providing new ideas for wetland ecological protection and construction in Wuhan City. Full article

Small-sized fish are a vital food source for large predatory commercial fish and play a key role in marine food webs, bridging lower and higher trophic levels. They are indispensable in maintaining the energy flow and material cycling within aquatic ecosystems. This study utilized bottom-trawl survey data from 2017 to 2020 along the south inshore of Zhejiang, China, complemented by concurrent environmental data, to examine the influence of environmental factors on the resource density and seasonal distribution patterns of four dominant small-sized fish species. The research findings indicated that SSH (sea surface height) and Chl (chlorophyll-a concentration) emerged as the key environmental factors influencing resource densities, with all four species exhibiting similar preferences toward these variables. However, significant disparities were observed in their preferences for SST (sea surface temperature), SSS (sea surface salinity), and DO (dissolved oxygen). The various species’ resource density and distribution patterns underwent significant seasonal variations. Additionally, the seasons and regions with the highest resource densities consistently aligned, occurring predominantly in autumn within the northern waters of the study area. This research further elucidated the environmental predilections and seasonal spatial distribution traits of small-sized fish in the south inshore of Zhejiang, an important feeding ground for economic fish species in the East China Sea. This provides scientific backing for forecasting alterations in coastal fishery resources under environmental and climate change scenarios and supports ecosystem-based fisheries management strategies. Full article

Green stormwater infrastructure (GSI) is increasingly implemented worldwide to address stormwater issues while providing co-benefits such as habitat provision. However, research on public perceptions of GSI’s ecosystem benefits is limited, and barriers such as perception and maintenance hinder biodiversity promotion in GSI. Through an online survey (n = 781), we explored how residents in four Northeast US urban areas—Prince George’s County and Montgomery County, MD, New York City, and Philadelphia, PA—perceived the benefits and concerns regarding two types of bioswales (biodiverse and turf). Biodiverse swales feature various plants to promote biodiversity, whereas turf swales are primarily grass-covered. Our analyses included paired-samples t-tests, independent t-tests, one-way repeated measures ANOVA tests, and one-way ANOVA tests to compare perceptions across bioswale types, aspects of benefit/concern, and locations. Both bioswale types were recognized for enhancing green spaces and neighborhood aesthetics. Residents perceived greater environmental and social benefits from biodiverse swales than turf swales, particularly for habitat provision. While overall concerns for both bioswale types were low, potential issues like pest cultivation and the unappealing appearance of biodiverse swales remain significant barriers. Notably, implementing biodiverse swales alleviated initial concerns, especially about pests, suggesting familiarity can enhance acceptance. Location-specific differences in perception were observed, with New York City showing higher perceived benefits and concerns and Montgomery County exhibiting the lowest concerns. This variance is likely due to distinct urban environments, levels of environmental awareness, and demographic profiles. Full article

This study provides new insights into the oviposition strategy of Eriogaster catax (Linnaeus, 1758) (Lepidoptera, Lasiocampidae), an endangered species of moth found in semi-natural habitats within agricultural landscapes. Protected under various European directives and listed as Data Deficient by the IUCN, E. catax inhabits warmer regions of the Western Palearctic. Despite noted geographic variations in its ecological preferences, few studies have statistically significant data on its ecology. Our six-year study, conducted within the largest known population of E. catax. in Romania, reveals critical data on its oviposition preferences, including the species’ tendency to utilize Prunus spinosa L. and Crataegus monogyna Jacq. shrubs at an average height of 80.48 ± 34.3 cm, with most nests placed within the 41–80 cm range and containing an average of 186 ± 22 eggs. The study also addresses the species’ vulnerability to human activities such as bush trimming, agricultural burning, and uncontrolled grazing, particularly due to its low oviposition height. These findings underscore the negative impact of overgrazing and burning practices, particularly when conducted on a large scale, on the conservation of E. catax. The detailed ecological requirements identified in this study are essential for developing effective conservation strategies and habitat management practices. Furthermore, the study highlights the importance of local community involvement and public education in raising awareness about biodiversity and the conservation of endangered species. Full article

Free-living amoebae (FLA) are prevalent in diverse environments, representing various genera and species with different pathogenicity. FLA-induced infections, such as the highly fatal amoebic encephalitis, with a mortality rate of 99%, primarily affect immunocompromised individuals while others such as Acanthamoeba keratitis (AK) and cutaneous amebiasis may affect immunocompetent individuals. Despite the prevalence of FLA, there is a lack of standardized guidelines for their detection near human habitats. To date, no studies on the isolation and identification of FLA in environmental soil samples in Warsaw have been published. The aim of this study was to determine the presence of amoebae in soil samples collected from Warsaw parks and squares frequented by humans. The isolated protozoa were genotyped. Additionally, their pathogenic potential was determined through thermophilicity tests. A total of 23 soil samples were seeded on non-nutrient agar plates (NNA) at 26 °C and monitored daily for FLA presence. From the total of 23 samples, 18 were positive for FLA growth in NNA and PCR (78.2%). Acanthamoeba spp. was the most frequently isolated genus, with a total of 13 positive samples (13/18; 72.2%), and the T4 genotype being the most common. Moreover, Platyamoeba placida (3/18; 16.7%), Stenamoeba berchidia (1/18; 5.6%) and Allovahlkampfia sp. (1/18; 5.6%), also potentially pathogenic amoebae, were isolated. To our knowledge, this is the first report of FLA presence and characterization in the Warsaw area. Full article

Soil microorganisms are critical to the occurrence of Cordyceps sinensis (Chinese Cordyceps), a medicinal fungi used in Traditional Chinese Medicine. The over-collection of Chinese Cordyceps has caused vegetation degradation and impacted the sustainable occurrence of Cordyceps. The effects of Chinese Cordyceps collection on soil microorganisms have not been reported. Metagenomic analysis was performed on the soil of collecting and non-collecting areas of production and non-production areas, respectively. C. sinensis collection showed no alteration in alpha-diversity but significantly affected beta-diversity and the community composition of soil microorganisms. In Cordyceps production, Thaumarchaeota and Crenarchaeota were identified as the dominant archaeal phyla. DNA repair, flagellar assembly, propionate metabolism, and sulfur metabolism were affected in archaea, reducing the tolerance of archaea in extreme habitats. Proteobacteria, Actinobacteria, Acidobacteria, Verrucomicrobia, and Nitrospirae were identified as the dominant bacterial phyla. The collection of Chinese Cordyceps enhanced the bacterial biosynthesis of secondary metabolites and suppressed ribosome and carbon metabolism pathways in bacteria. A more complex microbial community relationship network in the Chinese Cordyceps production area was found. The changes in the microbial community structure were closely related to C, N, P and enzyme activities. This study clarified soil microbial community composition and function in the Cordyceps production area and established that collection clearly affects the microbial community function by altering microbial community structure. Therefore, it would be important to balance the relationship between cordyceps production and microbiology. Full article

Genetic diversity is crucial for determining the evolutionary potential of a species and is essential for developing optimal conservation strategies. The impact of habitat fragmentation on the genetic diversity of food-deceptive orchids seems to be unpredictable because of their specialized seed and pollen dispersal mechanisms. The habitat of deceptive Cypripedium flavum was severely fragmented during the past half century. This study investigated the genetic diversity and structure of seven fragmented Cypripedium flavum populations in Shangrila County using AFLP markers. A total of 376 alleles were identified, with a range of 70 to 81 alleles per locus. The species exhibited considerable genetic diversity, as evidenced by an average Nei’s gene diversity (H) of 0.339 and a Shannon’s information index (I) of 0.505, with all loci being polymorphic. Based on Molecular Variance (AMOVA), 8.75% of the genetic differentiation was found among populations, while the remaining 91.25% of genetic variation occurred within populations. Population structure analysis revealed that the C. flavum germplasm can be categorized into five distinct groups, among which there was significant gene flow. Despite habitat fragmentation, C. flavum still retained a high level of genetic diversity, and the substantial gene flow (5.0826) is a key factor in maintaining the genetic diversity. These findings offer valuable insights for the conservation and potential use of C. flavum genetic resources. Full article

Wild bees are vital for the pollination of native plants and crops, providing essential ecosystem services. Climate change is known to impact biodiversity and species distributions, but insects adapted to desert ecosystems may exhibit unique physiological, behavioral, and evolutionary responses. The desert pallid bee (C. pallida), a solitary bee native to the arid southwestern United States and northern Mexico, primarily forages on yellow palo verde (P. microphylla), blue palo verde (P. florida), and desert ironwood (O. tesota). This study used MaxEnt to estimate the current and projected geographical overlap of suitable habitats for C. pallida and its host plants. Here, we used MaxEnt to estimate the current and forecasted overlapping geographically suitable habitat of C. pallida with all three host plants. We forecasted potential environmentally suitable areas for each species to the year 2040 using the current distribution model and climate projections with moderate CO₂ levels. We found a continued spatial alignment in the suitable area of the bee and its host plants with a 70% increase in the range overlap area, though shifted to higher average altitudes and a slight northern expansion. These findings may provide insight to stakeholders on the conservation needs of desert-dwelling pollinators. Full article

Crepidotus subg. Dochmiopus contributes to more than half of Crepidotus species and exhibits highly hidden diversity. However, C. subg. Dochmiopus is challenging to study because the basidiomata of C. subg. Dochmiopus species are usually small and white, inconspicuous interspecific distinctions, and possess a familiar complex. In this study, we utilized a variety of characteristics for species identification, including habitat, presence or absence of a stipe in mature specimens, pileipellis and cheilocystidia patterns, whether the lamellae edges are fimbriated, and other characteristics. Above all, cheilocystidia and pileipellis patterns will be important in C. subg. Dochmiopus research. Based on the present specimens, we constructed a multigene phylogenetic tree (ITS + LSU) and recognized four new species: C. lamellomaculatus sp. nov., C. capitatocystidiatus sp. nov., C. succineus sp. nov., C. clavocystidiatustustus sp. nov. Detailed morphological descriptions, photographs, line drawings and comparisons with closely related taxa for the new species are provided. The current phylogenetic analysis does not support the previously classifications, indicating that the classification of Crepidotus requires re-evaluation. But the existing molecular datasets and species’ descriptions are insufficient to fully resolve the classification. Further integration of new gene segments and a comprehensive review of morphological characteristics will reveal a natural classification for Crepidotus. Full article

Mangroves are one of the world’s most productive and ecologically important ecosystems, and they are threatened by the widespread invasion of Spartina alterniflora Loisel in China. As few studies have examined the spatial pattern differences of S. alterniflora invasion and the nearby mangroves in different latitudes, we chose the Zhangjiang Estuary and the Dandou Sea, two representative mangrove–salt marsh ecotones in the north and south of the Tropic of Cancer, as the study areas for comparison. The object-based image analysis and visual interpretation methods were combined to construct fine-scale mangrove and S. alterniflora maps using high-resolution satellite imagery from 2005 to 2019. We applied spatial analysis, centroid migration, and landscape indexes to analyze the spatio–temporal distribution changes of mangroves and S. alterniflora in these two ecotones over time. We used the landscape expansion index to investigate the S. alterniflora invasion process and expansion patterns. The annual change rates of mangrove and S. alterniflora areas in the Zhangjiang Estuary showed a continuous growth trend. However, the mangrove areas in the Dandou Sea showed a fluctuating trend of increasing, decreasing, and then increasing again, while S. alterniflora areas kept rising from 2005 to 2019. Spartina alterniflora showed larger annual change rates compared with mangroves, indicating rapid S. alterniflora invasion in the intertidal zones. The opposite centroid migration directions of mangroves and S. alterniflora and the decreasing distances between the mangrove and S. alterniflora centroids indirectly revealed the fierce competition between mangroves and S. alterniflora for habitat resources. Both regions saw a decrease in mangrove patch integrality and connectivity. The integrality of mangrove patches in the Zhangjiang Estuary was always higher than those in the Dandou Sea. We observed the growth stage (2011–2014) and outbreak stage (2014–2019) of S. alterniflora expansion in the Zhangjiang Estuary and the outbreak stage (2005–2009) and plateau stage (2009–2019) of S. alterniflora expansion in the Dandou Sea. The expansion pattern of S. alterniflora varies in time and place. Since the expansion of S. alterniflora in the outbreak stage is rapid, with a large annual change rate, early warning of S. alterniflora invasion is quite important for the efficient and economical removal of the invasive plant. Continuous and accurate monitoring of S. alterniflora is highly necessary and beneficial for the scientific management and sustainable development of coastal wetlands. Full article

Nestedness in community ecology predicts that species in a species-poor site should be a subset of species of a species-rich site. A variety of ecological mechanisms have been offered to explain community nestedness; however, few studies have systematically discussed the issue of scale dependence when interpreting community nestedness. This study conducted surveys of anuran species data in the vicinity of Chengdu, Sichuan, in the summers of 2019–2020, using the transect method. The study area was divided into 23 sampling sites and 8 regions to explore the relationship between environmental factors and the nested distribution pattern of anuran communities under different sampling extents (with sampling buffers set at 1 km, 2 km, and 5 km). The WNODF (weighted-nestedness metric based on overlap and decreasing fill) results indicated that anurans exhibited a strong nested pattern at both the sampling sites scale and the regional scale. The habitat matrix test results suggested that a small-scale study area requires a correspondingly small habitat-sampling extent to effectively test for habitat nestedness. As the study area expands, the habitat-sampling range can be appropriately increased. The nested pattern of anurans in the vicinity of Chengdu can only be explained by habitat nestedness, as a Spearman’s correlation analysis showed that other environmental factors (area size, connectivity index, concentration index, proximity index, and distance to the city center) were not significantly correlated with the nested sequences of sampling points and regions. Therefore, regarding the conservation strategies for anurans in the vicinity of Chengdu, we recommend prioritizing the protection of areas with higher habitat diversity. Full article

Background/Objectives: Research-engaged academic institutions offer the opportunity to couple undergraduate education/citizen science projects with antimicrobial biodiscovery research. Several initiatives reflecting this ethos have been reported internationally (e.g., Small World, Tiny Earth, MicroMundo, Antibiotics Unearthed). These programs target soil habitats due to their high microbial diversity and promote initial screening with non-selective, nutrient media such as tryptic soy agar (TSA). However, evaluation of published outputs to date indicates that isolate recovery on TSA is consistently dominated by the genera Bacillus, Pseudomonas, and Paenibacillus. In this study, we evaluated the potential of soil extract agar to enhance soil isolate diversity and antibiosis induction outcomes in our undergraduate Antibiotics Unearthed research program. Methods: We comparatively screened 229 isolates from woodland and garden soil samples on both tryptic soy agar (TSA) and soil extract agar (SEA) for antimicrobial activity against a panel of clinically relevant microbial pathogens. Results: On one or both media, 15 isolates were found to produce zones of clearing against respective pathogens. 16S rRNA gene sequencing linked the isolates with three genera: Streptomyces (7), Paenibacillus (6), and Pseudomonas (2). Six of the Streptomyces isolates and one Pseudomonas demonstrated antimicrobial activity when screened on SEA, with no activity on TSA. Furthermore, incorporation of the known secondary metabolite inducer N acetyl-glucosamine (20 mM) into SEA media altered the pathogen inhibition profiles of 14 isolates and resulted in broad-spectrum activity of one Streptomyces isolate, not observed on SEA alone. In conclusion, SEA was found to expand the diversity of culturable isolates from soil and specifically enhanced the recovery of members of the genus Streptomyces. SEA was also found to be a superior media for antibiosis induction among Streptomyces isolates when compared to TSA. It was noted that Paenibacillus isolates’ antibiosis induction demonstrated a strain-specific response with respect to the growth media used. Conclusions: The authors propose SEA inclusion of in soil screening protocols as a cost-effective, complementary strategy to greatly enhance outcomes in undergraduate/citizen science-engaged antimicrobial biodiscovery initiatives. Full article