Taxonomic Structures Research Articles

Comparison Between Environmental DNA Metabarcoding and Traditional Survey Method to Identify Community Composition and Assembly of Stream Fish.

Environmental DNA (eDNA) metabarcoding has been widely used in freshwater systems, contributing to the advancements in the monitoring of fish diversity and community species composition. Nevertheless, the accuracy and reliability of eDNA metabarcoding in assessing functional structures and revealing the mechanisms underlying fish community assembly remain unclear. In this study, we combined a traditional survey method (electrofishing) and eDNA metabarcoding to conduct fish stock monitoring in the upper reaches of the Huishui stream. We assessed taxonomic and functional structures, as well as community assembly mechanisms, during dry and wet seasons. The results revealed that, compared with electrofishing surveys, eDNA metabarcoding detected a greater number of species and higher functional richness in both seasons. Despite significant differences in fish taxonomic composition between the seasons, both eDNA and traditional methods indicated that environmental filtering dominated the process of fish community assembly in both dry and wet seasons. We showed that eDNA metabarcoding is comparable to the electrofishing method in monitoring the community composition of stream fish and can accurately and reliably determine fish community assembly mechanisms. Combining functional traits and eDNA is a robust approach for monitoring stream fish community compared to taxonomic uncertainty.

Temporal dynamics of the bacterial community structure and functions associated with marine sponges collected off Karah Island, Terengganu, Malaysia

The marine sponge microbiome has been investigated for decades, yet its temporal fluctuation/stability is poorly understood. This study aimed to describe the seasonal dynamics of the bacterial composition and predicted functions associated with two tropical marine sponge species (Aaptos suberitoides and Xestospongia testudinaria) collected off Karah Island, Malaysia, in the three seasons (dry season, pre- and post-monsoon season) using 16S rRNA gene amplicon sequencing and Functional Annotation of Prokaryotic Taxa (FAPROTAX). The bacterial taxonomic structures demonstrated divergences among A. suberitoides, X. testudinaria, and seawater, regardless of seasons. Chloroflexi, Proteobacteria, Cyanobacteria, Actinobacteriota, and Acidobacteriota comprised the core bacterial communities in two marine sponge species throughout the seasons, however, there were differences in bacterial composition between the two marine sponges. In addition, A. suberitoides was enriched with Dadabacteria, Spirochaetota, and Bdellovibrionota, whereas X. testudinaria abundantly harbored Poribacteria, PAUC34f, and Anck6. At the genus level, SAR202 clade and Candidatus Synechococcus spongiarum group dominated marine sponge samples throughout the year. Several genera, such as SAR202 clade, Candidatus Synechococcus spongiarum group, and Entotheonellaceae, were discovered only in marine sponge samples. Spirochaeta and Dadabacteriales displayed higher relative abundances in A. suberitoides, while Poribacteria and PAUC34f were more abundant in X. testudinaria. SAR202 clade was positively correlated with dissolved oxygen (DO), pH, phosphate, and ammonia in A. suberitoides. Likewise, Candidatus Synechococcus spongiarum group was negatively correlated with salinity and nitrate in X. testudinaria. Predicted functions by FAPROTAX annotated the phototrophic-related functions in both marine sponges, which might be attributed to a sponge-specific taxon Candidatus Synechococcus spongiarum group. The functions “predatory or exoparasitic” and “fermentation” were highly detected in A. suberitoides, which might be related to the bacterial genera Bdellovibrio and Spirochaeta, respectively. This study guides a deep understanding of the bacterial community structures associated with tropical marine sponges and their temporal behavior.

The Mycobiota of Library Books in Russia.

Abstract-Numerous studies of microorganisms isolated from the surface of cultural heritage objects, including library documents, are regularly carried out in different countries. Although the micromycete composition in each case varies, some species are constantly isolated. The structure of micromycete communities that inhabit library documents was studied in 57 cities of Russia located in seven federal districts (Northwestern, Central, Southern, Volga, Ural, Siberian, and Far Eastern). Micromycetes of 95 species from 32 genera were isolated and identified. The mycobiota of the library documents represented by Ascomycota has more than 90% of the species richness; Mucoromycota make up 3-9% and Basidiomycota, 3-4%. The Aspergillaceae family was the leading family: it accounted for 48.5-67.3% of the total species richness. In all regions, species diversity is moderate: the Shannon index ranged from 2.7 to 3.3. The Mcintosh species richness index is high everywhere (48-126), except in the Ural district (15.3). The McIntosh (0.76-0.84) and Pielow (0.80-0.91) dominance indices indicate a high level of species evenness in the mycobiota. The obtained values demonstrate the stability the document mycobiota in libraries from different regions. Significant species similarity between the districts was revealed by calculation of binary coefficients: the Jaccard coefficient was from 0.44 to 0.60; the Sørensen's qualitative measure of similarity was from 0.63 to 0.75; the quantitative similarity measure of Sørensen was from 0.44 to 0.71, and Morisita-Horn was from 0.66 to 1.0. The groups of dominant species in different regions are quite similar. The study of the ecological diversity of mycobiota on library books demonstrated the moderate diversity and the stability of the community. A high degree of similarity of taxonomic structures was established regardless of the climate conditions of the regions. Cosmopolitans characterized by high frequency of occurrence formed the major core of the library book mycobiota: Alternaria alternata, Aspergillus niger, Cladosporium cladosporioides, Mucor plumbeus, and Penicillium aurantiogriseum.

Terrestrial plastisphere as unique niches for fungal communities

Global prevalence of microplastics underscores the urgent need to investigate the ecology and biogeochemistry of the plastisphere. However, plastisphere mycobiome, particularly in terrestrial environments, remains largely unexplored. We conducted a comparative analysis of soil and plastisphere fungal communities using 125 experimental microcosms. Our results revealed distinct taxonomic structures between these two environments, with the genera Penicillium and pathogenic Alternaria being specifically enriched in the plastisphere. In comparison with soil communities, plastisphere communities exhibited weaker associations with environmental variables. Stochastic processes were found to be primary drivers of plastisphere fungal community assembly. Limited dispersal of fungal communities on soil microplastics was obtained, suggesting potential implications for taxa isolation or even diversity loss. The expanding plastisphere would pose critical planetary ecology challenges. Our findings highlight plastisphere act as unique niches for fungal communities that are less influenced by environmental variables, providing new insights into the ecology of the soil plastisphere.

Which is better? Taxonomy induction with learning the optimal structure via contrastive learning

A taxonomy represents a hierarchically structured knowledge graph that forms the infrastructure for various downstream applications, including recommender systems, web search, and question answering. The exploration of automated induction from text corpora has yielded notable taxonomies such as CN-probase, CN-DBpedia, and Zhishi.schema. Despite these efforts, existing taxonomies still face two critical issues that result in sub-optimal hierarchical structures. On the one hand, commonly observed taxonomies exhibit a coarse-grained and “flat” structure, stemming from a noticeable lack of diversity in both nodes and edges. This limitation primarily originates from the biased and homogeneous data distribution. On the other hand, the semantic granularity among “siblings” within these taxonomies remains inconsistent, presenting a challenge in accurately and comprehensively identifying hierarchical relations. To address these issues, this study introduces a novel taxonomy induction framework composed of three meticulously designed components. Initially, we established a seed schema by leveraging statistical information from external data sources as distant supervision to append nodes and edges containing “generic semantics”, thereby rectifying biased data distributions. Subsequently, a clustering algorithm is employed to group the nodes based on their similarities, followed by a refinement operation of the hierarchical relations among these nodes. Building on this seed schema, we propose a fine-grained contrastive learning method in the expansion module to strengthen the utilization of taxonomic structures, consequently boosting the precision of query-anchor matching. Finally, we meticulously scrutinized the hierarchical relations between each query and its siblings to ensure the integrity of the constructed taxonomy. Extensive experiments on real-world datasets validated the efficacy of our proposed framework for constructing well-structured taxonomies.

Gut microbiome structure and function in asymptomatic diverticulosis

BackgroundColonic diverticulosis, the most common lesion found in routine colonoscopy, affects more than 50% of individuals aged ≥ 60 years. Emerging evidence suggest that dysbiosis of gut microbiota may play an important role in the pathophysiology of diverticular disease. However, specific changes in microbial species and metabolic functions in asymptomatic diverticulosis remain unknown.MethodsIn a cohort of US adults undergoing screening colonoscopy, we analyzed the gut microbiota using shotgun metagenomic sequencing. Demographic factors, lifestyle, and medication use were assessed using a baseline questionnaire administered prior to colonoscopy. Taxonomic structures and metabolic pathway abundances were determined using MetaPhlAn3 and HUMAnN3. We used multivariate association with linear models to identify microbial species and metabolic pathways that were significantly different between asymptomatic diverticulosis and controls, while adjusting for confounders selected a priori including age at colonoscopy, sex, body mass index (BMI), and dietary pattern.ResultsAmong 684 individuals undergoing a screening colonoscopy, 284 (42%) had diverticulosis. Gut microbiome composition explained 1.9% variation in the disease status of asymptomatic diverticulosis. We observed no significant differences in the overall diversity of gut microbiome between asymptomatic diverticulosis and controls. However, microbial species Bifidobacterium pseudocatenulatum and Prevotella copri were significantly enriched in controls (q value = 0.19 and 0.14, respectively), whereas Roseburia intestinalis, Dorea sp. CAG:317, and Clostridium sp. CAG: 299 were more abundant in those with diverticulosis (q values = 0.17, 0.24, and 0.10, respectively). We observed that the relationship between BMI and diverticulosis appeared to be limited to carriers of Bifidobacterium pseudocatenulatum and Roseburia intestinalis (Pinteraction = 0.09).ConclusionsOur study provides the first large-scale evidence supporting taxonomic and functional shifts of the gut microbiome in individuals with asymptomatic diverticulosis. The suggestive interaction between gut microbiota and BMI on prevalent diverticulosis deserves future investigations.

Ecological Diversity of Micromycetes in Aerial Environments of Russian Libraries

The structure of micromycete communities in the library aerial environment was investigated in 57 Russian cities located in seven federal districts (Northwestern, Central, Southern, Volga, Ural, Siberian, and Far Eastern). A total of 107 micromycete species belonging to 41 genera were isolated and identified. Due to mostly similar conditions, the aerial ecosystem of internal spaces of the library storage facilities was relatively stable, with moderate diversity and high evenness, as was confirmed by the relevant indices: the Shannon index varied from 2.7 to 3.4, the McIntosh diversity index, from 22.7 to 140.8, and the Menhinick index, from 2.1 to 3.0. The Simpson’s dominance index and the Berger–Parker index did not exceed 0.11 and 0.24, respectively. The McIntosh and Pielou’s evenness indices were 0.71–0.78 and 0.79–0.85, respectively. High similarity of the taxonomic structures, independent of climatic conditions of the studied regions, was revealed, as was confirmed by the values of the Stugren–Radulescu and Morisita–Horn coefficients: 0.08‒0.77 and 0.04‒0.47, respectively. The typical members of the studied mycobiota were Aspergillus versicolor (7.5‒14.3), Cladosporium cladosporioides (17.5‒40.5), C. herbarum (0.8‒53.6), and Penicillium aurantiogriseum (6.5‒32.4). Most other species were scarce, with frequencies of occurrence not exceeding 7.1%.

Freshwater input significantly reduces specific and functional diversity of small subarctic estuaries

Estuaries face mounting anthropic pressures. Climate change is projected to increase heavy precipitations, while agricultural and logging activities reduce land permeability, leading to more frequent flooding events that lower estuarine salinity. These hyposaline conditions pose physiological challenges for marine species, potentially reducing taxonomic diversity and biomass, and ultimately, ecosystem functions and services. Polar and subpolar estuaries, historically understudied, will undergo significant changes in freshwater discharge timing and variability due to predicted shifts from snow to rainfall regimes in these high latitudes. The investigation of biotic communities structure through functional traits is crucial for understanding biodiversity changes, evaluating ecosystem tolerance, and addressing the loss of function under stressful conditions. Therefore, our study aims to characterize the taxonomic and functional diversity of hard-substrate benthic communities along a salinity gradient in small subarctic estuaries. We hypothesize that communities closer to the riverine input will be less taxonomically diverse and abundant and with smaller individuals, leading to a loss of functions due to environmental filtering. To test our hypotheses, we measured traditional (biomass, taxonomic richness and diversity) and functional (functional richness and Rao's quadratic entropy) indices, as well as observed traits, of epibenthic hard-substrate macroalgae and macroinvertebrates along a four-level salinity gradient found in five small subarctic estuaries in Quebec (Canada). As predicted, freshwater inputs induced a decrease in biomass, taxonomic richness, functional richness, and Rao's quadratic entropy, with a fivefold reduction in total biomass of the epibenthic community from marine to low salinity zones. Freshwater inputs significantly shaped both taxonomic and functional trait structures, as the proportion of suspension feeders and long-distance dispersers decreased with rising freshwater inputs. While there was no clear trend for the size-class structure of invertebrate taxa, macroalgae were smaller at low salinities. Estuarine communities in subarctic regions may be vulnerable to future alterations in flooding patterns caused by global change, potentially affecting key ecosystem services such as suspended matter filtration. Functional trait indices were found to be efficient and serve as a valuable complement to taxonomic measures in detecting community shifts along salinity gradients, highlighting their usefulness in developing effective conservation and management strategies.

The Populations of Two Differently Medicine-Used Plants of Hedyotis diffusa and Hedyotis corymbosa Shoot-Assembling Rich Bacterial and Fungal Communities with Varied Compositions but Conserved Structures.

The plant-colonized microbial communities have closely micro-ecological effects on host plant growth and health. There are many medicinal plants in the genus Hedyotis, but it is yet unclear about the shoot-assembled bacterial and fungal communities (SBFC) of Hedyotis plants. Hence, eight plant populations of Hedyotis diffusa (HD) and H. corymbosa (HC) were evaluated with 16S rRNA gene and ITS sequences, for comparing the types, abundance, or/and potential functions of SBFC at plant species- and population levels. In tested HD- and HC-SBFC, 682 fungal operational taxonomic units and 1,329 bacterial zero-radius operational taxonomic units were identified, with rich species compositions and varied alpha diversities. Notably, the SBFC compositions of HD and HC plant populations were exhibited with partly different types and abundances at phylum and genus levels but without significantly different beta diversities at plant species and population levels. Typically, the SBFC of HD and HC plant populations were presented with abundance-different biomarkers, such as Frankiaceae and Bryobacteraceae, and with similar micro-ecological functions of microbial metabolisms of lipids, terpenoids,and xenobiotics. Taken together, HD- and HC-SBFC possessed with varied rich compositions, conservative taxonomic structures, and similar metabolic functions, but with small-scale type and abundance differences at plant species- and population- levels.

Promising the future, encoding the past: AI hype and public media imagery

In recent years, “AI hype” has taken over public media, oscillating between sensationalism and concerns about the societal implications of AI growth. The latest historical wave of AI hype indexes a period of increased research, investment, and speculation on machine learning, centred around generative AI, a novel class of machine learning that can generate original media from textual prompts. In this paper, I dive into the production of AI hype in online media, with the aim of prioritising the normative and political dimension of AI hype. Formulating AI as a promise reframes it as a normative project, centrally involving the formation of public and institutional confidence in the technology. The production and dissemination of images, in this context, plays a pivotal role in reinforcing these normative commitments to the public. My argument is divided into four sections. First, I examine the political relevance of stock images as the dominant imagery used to convey AI concepts to the public. These stock images encode specific readings of AI and circulate through public media, significantly influencing perceptions. Second, I look at the dominant images of AI as matters of political concern. Third, as generative AI increasingly contributes to the production of stock imagery, I compare the epistemic work performed by AI-generated outputs and stock images, as both encode style, content, and taxonomic structures of the world. I employ an entity relationship diagram (ERD) to investigate the political economy of AI imagery in digital media, providing a snapshot of how AI hype is materialised and amplified online. With this study, I reaffirm AI’s normative character at the forefront of its political and ethical discourse.

Acemoglu’s Scientific Palette and Disruptive Technologies

Daron Acemoglu and his co-authors adopt a mainstream approach in articles. In their books, they exhibit a biased analysis by employing taxonomic structures, selectively choosing historical examples, and downplaying significant factors like globalization, status emulation, and collective consciousness. Their analyses, centered on individual decision-making, overlook the evolutionary perspective. In this article, I argue that since the early 1980s, the new ICT-based wave of monopolization/oligopolization and globalization affected income distribution negatively within countries but positively between countries. The recent advancement of Artificial Intelligence (AI), which is also dealt with by Acemoglu and Simon Johnson in their book Power and Progress, seems to increasingly affect income inequality and to strengthen the power of Big Tech. An evolutionary institutional perspective, wherein the social selection mechanism itself adjusts to changing social conditions, might provide a counterbalance to anxious AI concerns.

Reproducible responses of geochemical and microbial successional patterns in the subsurface to carbon source amendment

Carbon amendments designed to remediate environmental contamination lead to substantial perturbations when injected into the subsurface. For the remediation of uranium contamination, carbon amendments promote reducing conditions to allow microorganisms to reduce uranium to an insoluble, less mobile state. However, the reproducibility of these amendments and underlying microbial community assembly mechanisms have rarely been investigated in the field. In this study, two injections of emulsified vegetable oil were performed in 2009 and 2017 to immobilize uranium in the groundwater at Oak Ridge, TN, USA. Our objectives were to determine whether and how the injections resulted in similar abiotic and biotic responses and their underlying community assembly mechanisms. Both injections caused similar geochemical and microbial succession. Uranium, nitrate, and sulfate concentrations in the groundwater dropped following the injection, and specific microbial taxa responded at roughly the same time points in both injections, including Geobacter, Desulfovibrio, and members of the phylum Comamonadaceae, all of which are well established in uranium, nitrate, and sulfate reduction. Both injections induced a transition from relatively stochastic to more deterministic assembly of microbial taxonomic and phylogenetic community structures based on 16S rRNA gene analysis. We conclude that geochemical and microbial successions after biostimulation are reproducible, likely owing to the selection of similar phylogenetic groups in response to EVO injection.

A revision of Lestidae Calvert, 1901 (Odonata: Zygoptera) from Colombia, with the first record of Lestes dichrostigma Calvert, 1909.

The cosmopolitan family Lestidae Calvert, 1901 has two widely distributed genera in the Americas: Archilestes Selys, 1862, and Lestes Leach, 1815. In Colombia, this family is represented by 11 species. In this study, we present a diagnosis of Lestidae species in Colombia based on a thorough review of the countrys main entomological collections. A total of 258 specimens representing ten species were examined. The species L. dichrostigma Calvert, 1909, is recorded for the first time. The presence of L. henshawi Calvert, 1907 is excluded, and the taxonomic status of L. sternalis (Navs, 1930) is discussed. Finally, we present distribution maps, photographs of Lestidae species, taxonomical important structures, and taxonomic keys for both males and females.

Identification of fourth-instar larvae of Aedes albopictus (Skuse) (Diptera: Culicidae) employing scanning electron microscopic tool.

Aedes albopictus is a vector of numerous viruses in tropical and subtropical regions worldwide, including encephalitis and dengue fever. Although the identification keys depend exclusively on the characteristics of the fourth larval instar, the studies were carried out using scanning electron microscopy (SEM) on the morphology of Ae. albopictus are still insufficient, and more research is required. Therefore, the purpose of this study was to present a comprehensive description of Ae. albopictus mosquitoes based on the morphological features of their fourth-instar larvae to distinguish them from other mosquito species. Antennae, feeding mouth brushes, mandibles, maxillae, labia, comb scales, anal papillae, siphon, respiratory spiracles, and pecten teeth were among the morphological features specifically described using SEM. The sensilla trichoidea and the sensilla basiconica are the sensory spicules found on the antennal integument. The labrum is a tessellated membrane with two movable brushes on the sides and one middle brush. The mandibles have four sellar setae on the anterolateral side, and the maxillae, which have a thumb-like structure and a palp located laterally and about four-fifths of the way from the maxillary brush base to the maxillary notch, are the articulating appendages. On the apex of the palp, there are five sensilla. The eighth abdominal segment is a tiny pentagonal structure with 12 comb scales laterally and a respiratory siphon dorsally. The siphon has two rows of pectin teeth, with 12 teeth per row. Four pairs of siphonal tufts and five perispiracular lobes surround the respiratory spiracles. The anal segment has four anal papillae, a ventral brush, a dorsal brush, and an incomplete saddle. The findings demonstrate that the fourth-instar larvae of Ae. albopictus have distinctive morphological features, which are crucial for understanding their key characteristics and identifying them, preventing inaccurate identification, and facilitating the control of diseases transmitted by the mosquito vector. RESEARCH HIGHLIGHTS: A detailed description of various taxonomical interest structures for the fourth-instar larvae of Aedes albopictus is included in this study. Scanning electron microscopy is considered a helpful technique for identifying Ae. albopictus larvae in their fourth instar.

Marine resistome of a temperate zone: Distribution, diversity, and driving factors across the trophic gradient

Marine and ocean environments are the most widespread habitats in the world but are still the least studied from the aspect of antibiotic resistance. The indigenous and tetracycline (TET)- and sulfamethoxazole (SXT)-resistant planktonic bacterial communities were simultaneously investigated for the first time along a trophic gradient of a temperate zone, regarding their taxonomic and functional structures as well as biotic and abiotic factors affecting their dynamics as vehicles of antibiotic resistance genes (ARGs), thus impacting the ARGs distribution at seasonal and spatial scales.A total of 80 microbiomes, recovered seasonally from bottom layer and surface waters along a 68-km transect from wastewater-impacted estuary to coastal and pristine open sea in the central Adriatic (Mediterranean Sea), were analysed using 16S rRNA amplicon sequencing, PICRUSt2 bioinformatics and extensive biostatistics. Eighty-one bacterial phyla were identified, with majority (n = 49) in summer when communities were found to be more species enriched across the gradient. Microbial diversity was more site-specific and pronounced in surface microbiomes in winter. Nevertheless, both richness and community diversity decreased with distance from the coast. Although the microbiomes from human-influenced sites significantly differed from those in oligotrophic offshore area, Proteobacteria were still the most abundant phylum during both seasons at the surface and seabed along the gradient, and the major contributors to the marine resistome regarding native and TET- and SXT-resistant microbial communities. Resistome structure was more diverse in winter, whereas peptide, vancomycin and multidrug resistance modules predominated regardless of season, trophic status, or antibiotic. However, multidrug, beta-lactam resistance modules as well as macrolide, phenicol, aminoglycoside, and particularly imipenem resistance genes were much more frequent in winter, suggesting that the diversity of indigenous resistomes is highly dependent on seasonal variations of the water column, driven by thermohaline stratification and nutrients. Moreover, several pathogenic genera stood out as important carriers of multiple resistance traits in TET- and SXT-related resistomes in both seasons, particularly Acinetobacter, Vibrio, Bacillus and Pseudomonas, beside which Proteus, Serratia and Bacteroides prevailed in native resistomes.This study evidenced seasonal and spatial variations of the marine microbiome and resistome and their driving forces along the trophic gradient, providing a comprehensive insight into the diversity and distribution of antibiotic resistance in the marine ecosystem of a temperate zone.

Molecular and morphological studies on Contracaecum rudolphii A and C. rudolphii B in great cormorants (Phalacrocorax carbo sinensis) from Italy and Israel.

The distribution of parasites is shaped by a variety of factors, among which are the migratory movements of their hosts. Israel has a unique position to migratory routes of several bird species leaving Europe to winter in Africa, however, detailed studies on the parasite fauna of birds from this area are scarce. Our study investigates occurrence and distribution of sibling species among Contracaecum rudolphii complex in Phalacrocorax carbo sinensis from Italy and Israel, to acquire further information on the geographical range of these species to gain deeper knowledge on the ecology of these parasites and their bird host. A total of 2383 Contracaecum were collected from the gastric mucosa of 28 great cormorants (18 from Israel and 10 from Italy). A subsample was processed for morphological analyses in light and scanning electron microscopy (SEM), and for molecular analyses through amplification and sequencing of the ITS rDNA and the cox2 mtDNA, and through PCR-RFLP. All the 683 Contracaecum subjected to molecular identification belonged to C. rudolphii s.l., (300 C. rudolphii A and 383 C. rudolphii B). SEM micrographs provided, for the first time, details of taxonomic structures in male specimens from both sibling species, and the first SEM characterization of C. rudolphii B. This work presents the first data on the occurrence of sibling species of C. rudolphii in Israel and provides additional information on the distribution of C. rudolphii A and B in Italy, confirming the high prevalence and intensity of infection observed in Ph. carbo sinensis from other Italian areas.

The Spatial and Taxonomic Structures of Microbial Communities in Dry Steppe Zone Soils of the Selenga Highlands (Western Transbaikal Region)

The Spatial and Taxonomic Structures of Microbial Communities in Dry Steppe Zone Soils of the Selenga Highlands (Western Transbaikal Region)

Mycobiota of the Library’s Books in Russia

Numerous studies of microorganisms isolated from the surface of cultural heritage objects, including library documents, are regularly carried out in different countries. Although the micromycetes composition in each case varies, some species are constantly isolated. The structure of micromycetes communities inhabiting library documents was studied in 57 cities of Russia located in seven federal districts (Northwestern, Central, Southern, Volga, Ural, Siberian, Far Eastern). Micromycetes of 95 species from 32 genera were isolated and identified. The mycobiota of the library documents represented by Ascomycota occupies more than 90% of the species richness, Mucoromycota – 3–9%, Basidiomycota – 3–4%. The Aspergillaceae family was the leading one: it accounted for 48.5–67.3% of the total species richness. In all regions, species diversity is moderate: the Shannon index ranged from 2.7 to 3.3. The Mcintosh species richness index is sufficiently high everywhere (48.2–126.2), except the Ural (15.3). The McIntosh dominance indices (0.759–0.843) and Pielow (0.80–0.91) indicate a high level of species evenness in the mycobiota. The obtained values demonstrate the stability the documents’ mycobiota in libraries from different regions. Significant species similarity between the districts was revealed by calculation of binary coefficients: the Jaccard coefficient was from 0.44 to 0.60; the Sørensen’s qualitative measure of similarity was from 0.63 to 0.75; the quantitative similarity measure of Sørensen was from 0.44 to 0.71, and Morisita–Horn was from 0.66 to 1.0. Groups of dominant species in different regions are quite similar. The study of the ecological diversity of librarian books mycobiota demonstrates moderate diversity and sufficient stability of the community. A high degree of similarity of taxonomic structures was established regardless of the climatic conditions of the regions. Cosmopolitans characterized by high frequency of occurrence formed the major core of the library’s book mycobiota: Alternaria alternata, Aspergillus niger, Cladosporium cladosporioides, Mucor plumbeus and Penicillium aurantiogriseum.

Hydrological connectivity shapes multiple diversity facets of snail (Mollusca: Gastropoda) assemblages in freshwater floodplain wetlands

Hydrological connectivity is crucial for supporting aquatic biodiversity and serving ecosystem function in river floodplain wetlands. Although the effects of longitudinal connectivity in the composition of snail (Mollusca: Gastropoda) assemblages is well understood, the effects of lateral connectivity are less evaluated. Here, we evaluated the effects of lateral and longitudinal connectivity on multiple facets of alpha and beta diversity (i.e., taxonomic, functional, and phylogenetic) of freshwater snails in 38 floodplain wetlands in the Da Xing'an Mountains of Northeast China. A total of 9,784 snails subjected to 5 orders, 14 families, 24 genera, and 42 species were collected. Overall, the snail alpha diversity was higher in the nearly isolated wetlands and downstream areas. Multivariate analyses revealed that the taxonomic, functional, and phylogenetic structures of snail assemblages in floodplain wetlands differed significantly across the lateral and longitudinal gradients. Waterscape and climate variables appeared to equivalently explain a large proportion of variations in the taxonomic, functional, and phylogenetic structures of snail assemblages. Lateral connectivity and river order were paramount variables that explain the greatest variation in taxonomic, functional, and phylogenetic structures of the snail assemblages. Our study suggests that hydrological connectivity is a key factor controlling the multiple facets of snail diversity in floodplains. Attention should be paid to the effects of changing climate and waterscape on the multi-faceted diversity of snail assemblages. Due to the extant patterns in assemblage structures, floodplain restoration and management should consider the full spectrum of longitudinal and laterally connectedness to maximize aquatic biodiversity.

Abundance trade-offs and dominant taxa maintain the stability of the bacterioplankton community underlying Microcystis blooms.

Microcystis blooms are an intractable global environmental problem that pollute water and compromise ecosystem functioning. Closed-lake management practices keep lakes free of sewage and harmful algae invasions and have succeeded in controlling local Microcystis blooms; however, there is little understanding of how the bacterioplankton communities associated with Microcystis have changed. Here, based on metagenomic sequencing, the phyla, genera, functional genes and metabolic functions of the bacterioplankton communities were compared between open lakes (underlying Microcystis blooms) and closed lakes (no Microcystis blooms). Water properties and zooplankton density were investigated and measured as factors influencing blooms. The results showed that (1) the water quality of closed lakes was improved, and the nitrogen and phosphorus concentrations were significantly reduced. (2) The stability of open vs. closed-managed lakes differed notably at the species and genus levels (p < 0.01), but no significant variations were identified at the phylum and functional genes levels (p > 0.05). (3) The relative abundance of Microcystis (Cyanobacteria) increased dramatically in the open lakes (proportions from 1.44 to 41.76%), whereas the relative abundance of several other dominant genera of Cyanobacteria experienced a trade-off and decreased with increasing Microcystis relative abundance. (4) The main functions of the bacterioplankton communities were primarily related to dominant genera of Proteobacteria and had no significant relationship with Microcystis. Overall, the closed-lake management practices significantly reduced nutrients and prevented Microcystis blooms, but the taxonomic and functional structures of bacterioplankton communities remained stable overall.