Variation In Diversity Research Articles

Integrating microbial profiling and machine learning for inference of drowning sites: a forensic investigation in the Northwest River.

Drowning incidents present significant challenges for forensic investigators in determining the exact site of occurrence. Traditional forensic methods often rely on physical evidence and circumstantial clues, but the emerging field of forensic microbiology offers a promising avenue for enhancing precision and reliability in site inference. Our study investigates the application of microbiome analysis in inferring drowning sites, focusing on microbial diversity in water samples and lung tissues of drowned animals from different sites in the Northwest River. We utilized 16S rDNA sequencing to analyze microbial diversity in water samples and lung tissues, revealing distinct microbial signatures associated with drowning sites. Our findings highlight variations in species richness and diversity across different sampling points, indicating the influence of environmental factors on microbial community structure. Machine learning models trained on microbial data from lung tissues demonstrated high accuracy in predicting drowning sites, with cross-validation accuracy ranging from 83.53% ± 3.99% to 95.07% ± 3.17%. Notably, the Gradient Boosting Machine (GBM) method achieved a classification accuracy of 95.07% ± 3.17% for different sampling points at a submersion time of 1 day. Moreover, our cross-species site inference results revealed that utilizing data from drowned mice to predict the drowning sites of rabbits in location W5 achieved an accuracy of 72.22%. In conclusion, our study underscores the potential of microbiome analysis in forensic investigations of drowning incidents. By integrating microbial data with traditional forensic techniques, there is significant potential to enhance the reliability of scene inferences, thereby making substantial contributions to case investigations and judicial trials.IMPORTANCEBy employing advanced techniques like microbial profiling and machine learning, the study aims to enhance the accuracy of determining drowning sites, which is crucial for both legal proceedings. By analyzing microbial diversity in water samples and drowned animal lung tissues, the study sheds light on how environmental factors and victim-related variables influence microbial communities. The findings not only advance our understanding of forensic microbiology but also offer practical implications for improving investigative techniques in cases of drowning.

Variation in coral rubble cryptofauna is scale-dependent and driven by small-scale habitat characteristics

Motile cryptofauna living in dead coral rubble represent some of the greatest biodiversity and basal energetic resources on tropical coral reefs. Yet we know relatively little about how and why coral rubble cryptofauna communities change over space and time. As human impacts increase the degradation of living hard corals to dead coral rubble on many reefs worldwide, understanding the communities that will succeed in these degraded environments and the factors paramount to their success becomes increasingly central to coral reef ecology and conservation. Using a remote and uninhabited oceanic atoll in the Pacific Ocean, we quantified the natural spatial variability in motile cryptofauna diversity and community structure in coral rubble across scales (m to km) and tested whether variability at smaller scales could be explained by gradients in microhabitat. We show that coral rubble cryptofauna communities are most variable at intra-site scales (m) rather than inter-site scales (100s m) or between reef zones (km scales). We also show that a substantial amount of variation in cryptofauna density (55%) and phyla-level community structure (31%) is explained by small-scale habitat characteristics, specifically the substrate type below the rubble and the variability in macroalgal cover on individual rubble pieces. Our findings highlight the need to study small-scale processes that are relevant to motile cryptofauna and their community interactions if we are to elucidate the structuring forces of these diverse cryptic assemblages on coral reefs.

The Metagenomic Properties of Uşak Tarhana Dough

This study investigated the bacterial diversity of geographically indicated Uşak tarhana using metagenomics. Tarhana dough samples were collected from local producers in different regions of the Uşak province. The samples were analyzed for their chemical and microbiological properties. The microbiota was examined through metagenomic analysis using high-throughput sequencing, followed by bioinformatic processing with QIIME2 and DADA2 tools. Taxonomic analyses revealed that Lactiplantibacillus plantarum and Fructilactobacillus sanfranciscensis were the dominant species in most samples. In Silico analysis confirmed the presence of Fructilactobacillus sanfranciscensis in the tarhana fermentation microbiota. Diversity analyses, including Shannon and Chao1 indices, indicated significant variation in microbial diversity and homogeneity among the samples. Differences in microbiota diversity were observed between tarhana produced in the northern and southern regions of Uşak. The bacterial diversity of the tarhana samples showed partial differences at the micro-local level, and these results suggested that the slight variation in bacterial diversity between the northern and southern regions might be related to mild climatic transition.

Intraspecific variability of rice root knot nematodes across diverse agroecosystems for sustainable management

In the rice agroecosystems of Southeast Asia, rice root knot nematode (Meloidogyne graminicola) significantly impairs yield, representing a major species within the ‘graminis-group’ known for its morphological similarities with other root knot nematodes (RKNs). This study delves into the variations in reproductive potential, morphology, morphometrics, and genetic diversity among thirty RKN populations in rice across three distinct agroecological zones in Jharkhand, India. Despite notable differences in reproductive potential among the populations, morphological and morphometric correlations to reproductive potential were inconclusive. However, male and juvenile morphometrics were crucial for identifying intraspecific variability. Genetic analysis utilizing five molecular markers (ITS, 18 S rRNA, D2-D3 of 28 S, COX-I, and COX-II) affirmed the populations as M. graminicola, with ITS marker revealing significant intraspecific variability. Phylogenetic analysis underscored the close relationship between M. oryzae and M. graminicola, distinct from other mitotic RKN species. Low genetic distance and nucleotide diversity, coupled with high haplotype diversity, negative Tajima’s D, and Fu’s Fs of haplotype network analysis, suggested that all M. graminicola populations are expanding. These findings highlight the urgent need for comprehensive management strategies against M. graminicola, providing valuable insights for growers, extension officials, and plant breeders to develop targeted management approaches and resistance breeding programs.

Staphylococci and mammaliicocci: which species are important for udder health on organic dairy farms?

Variation in species distribution and diversity of staphylococci and mammaliicocci (SaM) causing intramammary infections in dairy cattle is associated with different management practices. Disparate selective pressures on organic dairies could potentially result in population differences of these mastitis-causing bacteria. The species-specific effect on quarter somatic cell count of SaM for a population of certified organic dairies has not been described previously. The current study presents data from a longitudinal study of 10 certified organic dairy farms. The objective was to estimate how quarter milk somatic cell count (qmSCC) varied as a result of infection with the most frequently isolated SaM species. Aerobic culture of quarter milk samples to identify IMI was conducted in parallel with determination of qmSCC. A linear hierarchical repeated measures mixed model was used to estimate qmSCC for quarters with an IMI caused by a given SaM species, compared with culture-negative quarters. The model included days in milk at time of sampling to adjust qmSCC estimates for each SaM species. The final data set consisted of 648 quarters with an IMI due to 10 different SaM spp. and 1,972 culture-negative quarters. S. chromogenes was the most frequent species, followed by S. aureus, S. haemolyticus, and S. simulans. A large amount of variability was observed in the somatic cell score for culture-negative quarters and those infected with many SaM spp., especially S. chromogenes, S. haemolyticus, S. simulans, and S. aureus. Somatic cell score was significantly higher in quarters infected with S. agnetis, S. aureus, S. chromogenes, S. devriesei, S. haemolyticus, S. hyicus, S. simulans, S. warneri, and S. xylosus compared with culture-negative quarters. The highest cell count was for quarters infected with S. warneri, followed by S. aureus, S. agnetis, and S. hyicus. The relative distribution of various SaM species and their effect on qmSCC in this population of small to midsize organic farms was similar to previous studies. Although the increase in qmSCC was modest for most SaM species observed, the widespread prevalence of these intramammary pathogens could potentially contribute to sizeable increases in bulk tank SCC.

Assessing spider community structure and ecological dynamics across urban and natural environments

AbstractThis study explores the diversity and distribution of spider populations across urban and natural‐semi natural habitats in Gongju‐si, South Korea. This study aims to investigate the ecological dynamics of spider populations across different habitat types and assess their implications for urban planning, particularly in terms of maintaining biodiversity through habitat heterogeneity and informed urban development strategies. Employing methodologies such as sweeping, manual collection, and pit‐fall traps, the research identifies 128 spider species and evaluates alpha and beta diversity, nestedness, and species interactions using advanced statistical and ecological tools. The findings indicate significant variations in spider diversity across different habitats, with urban areas exhibiting notable biodiversity despite human influences. Natural habitats, especially forests, demonstrate higher biodiversity and more intricate species interactions. Nestedness analysis reveals distinct community structures across habitats, while association rule learning highlights complex interspecies relationships. The study underscores the importance of maintaining habitat heterogeneity and incorporating ecological principles in urban planning to support biodiversity. It offers valuable insights into the roles of various habitats in ecological networks, emphasizing the necessity for balanced urban development and effective conservation strategies.

Spatial variation in toll-like receptor diversity in koala populations across their geographic distribution

The koala (Phascolarctos cinereus) is an iconic Australian species that is listed as endangered in the northern parts of its range due to loss of habitat, disease, and road deaths. Diseases contribute significantly to the decline of koala populations, primarily Chlamydia and koala retrovirus. The distribution of these diseases across the species’ range, however, is not even. Toll-like receptors (TLRs) play a crucial role in innate immunity by recognising and responding to various pathogens. Variations in TLR genes can influence an individual’s susceptibility or resistance to infectious diseases. The aim of this study was to identify koala TLR diversity across the east coast of Australia using 413 re-sequenced genomes at 30 × coverage. We identified 45 single-nucleotide polymorphisms (SNP) leading to 51 alleles within ten TLR genes. Our results show that the diversity of TLR genes in the koala forms four distinct genetic groups, which are consistent with the diversity of the koala major histocompatibility complex (MHC), another key immune gene family. The bioinformatics approach presented here has broad applicability to other threatened species with existing genomic resources.

Non-biting Midges (Diptera: Chironomidae) from Continental Salt Marshes in Serbia

Continental salt marshes represent specific inland saltwater bodies with unique ecological characteristics a fact that is mirrored by specific flora and fauna. However, there is still limited data on their biota in Serbia, which is especially true for aquatic macroinvertebrates, including chironomids (Diptera: Chironomidae). Here we investigated diversity and seasonal variations of chironomid community in six salt marshes distributed in the northern and southern part of Serbia. We recorded a total of 25 taxa, of which two are new for the Serbian chironomid fauna. Most of the recorded species are common in freshwaters and six of them are halotolerant. Chironomid community structure fluctuated in relation to the seasons. The highest diversity was recorded in the spring and summer months for the majority of studied salt marshes. Low diversity and dominance of halotolerant taxa were recorded in Pannonian salt marshes in the northern part of the country, suggesting higher salinity of these habitats comparing to the southern ones. The present findings represent the first inventory of chironomid larvae for these unique and highly endangered habitats in Serbia, which can help to fill the gaps in the knowledge of distributional ranges of halotolerant and halophilic species and provide baseline for future surveys.

Variation in mangrove species diversity across gradients of climate-change-induced environmental conditions and hydrological restoration

Increasing drought, elevated temperatures, and salinization are significant challenges to reestablishing species in mangrove restoration areas. In this study, we assessed how the diversity of two key mangrove faunal groups, molluscs and brachyuran crustaceans (hereafter referred to as crabs), varies across a gradient of disturbed, restored, and natural (undisturbed) mangroves. We also explored the environmental factors driving these variations in ten sites across the southern Gulf of Mexico, one of the regions with the largest mangrove coverage globally. A total of 15 species were recorded (10 mollusks and 5 crabs), with higher abundance in natural (612 individuals) than in restored (554 individuals) and degraded (98 individuals) sites. Community structure analysis revealed that certain species were restricted to specific restoration conditions: for example, the crab Minuca vocator was found only in restored sites, while the mollusc Vitta virginea was exclusive to natural sites. In contrast, species like the crab Minuca rapax were present across all site types. Salinity emerged as the primary environmental factor influencing community structure, with disturbed sites exhibiting significantly higher salinity levels than restored and natural sites. All sites were classified as hypersaline, which presents challenges for species that cannot tolerate such conditions. This study provides a valuable baseline for understanding the ecological conditions that shape mangrove restoration outcomes, offering insights into the effects of environmental factors on species diversity and the success of restoration efforts.

Temperature and Precipitation Explain Bee Diversity on Flowers Along an Elevation Gradient in the Mexican Transition Zone

Although ecologists have identified the key factors influencing species distribution along elevation gradients, each mountain’s distinct characteristics, including its geology and biotic colonization processes, are often overlooked. The uniqueness of each mountain ecosystem implies that species distribution and the factors affecting them may vary across regions and taxonomic groups. The Mexican Transition Zone (MTZ) in central Mexico is a mountainous region of significant ecological and evolutionary importance, shaped by distinct biotic colonization and distribution patterns across its elevation gradient. However, most research in this region has focused on specific taxa, neglecting the vast diversity within the MTZ. In this study, we investigated the variations in flower-visiting bee diversity along an elevation gradient within the MTZ (10 sampling sites distributed from 4 to 3425 m a.s.l..), focusing on understanding the environmental factors influencing their distribution. Our findings reveal a declining bee diversity with increasing elevation, primarily driven by decreasing temperatures. However, when considering bee abundance, we identified precipitation as the predominant factor influencing bee diversity. Therefore, water and resource availability are critical in shaping bee diversity in this region. Furthermore, as elevation increased, we observed distinct and unique bee communities, highlighting the rarity and uniqueness of highland bee species as integral components of mountain ecosystems.

Assessing grain boundary variability through phase field crystal simulations

Characterization of grain boundaries (GBs) typically focuses exclusively on ideal minimum-energy structures, thus offering a limited perspective on the potential structural diversity and related property variations of GBs. In this study, phase field crystal (PFC) simulations are employed to systematically explore alternative GB states through γ-surface sampling. A large number of tilt and twist GBs are examined in both fcc and bcc bicrystal structures. It is demonstrated that identifying variants in GB structure necessitates considering a set of microscopic degrees of freedom (DOF), comprising the components of relative crystal translation, in addition to the GB's five macroscopic DOF. Taking GB energy and excess volume as examples of key GB properties, a significant spread in GB energy is revealed, stemming from variations in the microscopic DOF, while maintaining constant macroscopic DOF. In addition, the significant variations found in GB excess volume and energy when GB variants are considered challenge the common assumption of a strong correlation between them. Taken together, the findings underscore the importance of recognizing a range of GB structures and properties for each macroscopic GB configuration, rather than relying on singular ideal minimum-energy GB structures, as is usually done. Published by the American Physical Society 2024

Genetic diversity and virulence variability of Sclerotinia sclerotiorum in Eastern and Northeastern India

Genetic diversity and virulence variability of Sclerotinia sclerotiorum in Eastern and Northeastern India

Two decades of body length measurements of larval and juvenile fish populations in English rivers

Long-term datasets provide context and understanding of complex ecological processes, including temporal variations in species diversity and ecosystem dynamics. This dataset is comprised of body length measurements (mm) of more than 380,000 larval or juvenile fish of 30 species from five English river catchments collected almost monthly over two decades. Such information can be used to determine growth rates, future recruitment success, population structure and compliance with monitoring protocols and conservation objectives. The dataset provides a baseline for analysing the impacts of anthropogenic disturbances such as climate change, pollution and habitat degradation, and, given that many fish populations are size structured with a positive relationship between fish body length and various biological attributes such as swimming ability, survival and fecundity, it will be invaluable for investigating natural and human- induced disturbances.

Soil community history strengthens belowground multitrophic functioning across plant diversity levels in a grassland experiment

Biodiversity experiments revealed that plant diversity loss can decrease ecosystem functions across trophic levels. To address why such biodiversity-function relationships strengthen over time, we established experimental mesocosms replicating a gradient in plant species richness across treatments of shared versus non-shared history of (1) the plant community and (2) the soil fauna community. After 4 months, we assessed the multitrophic functioning of soil fauna via biomass stocks and energy fluxes across the food webs. We find that soil community history significantly enhanced belowground multitrophic function via changes in biomass stocks and community-average body masses across the food webs. However, variation in plant diversity and plant community history had unclear effects. Our findings underscore the importance of long-term community assembly processes for soil fauna-driven ecosystem function, with species richness and short-term plant adaptations playing a minimal role. Disturbances that disrupt soil community stability may hinder fauna-driven ecosystem functions, while recovery may require several years.

Community Diversity and Dynamics of Fish Assemblages in Lake Kanyaboli, Western Kenya

ABSTRACTAlthough Lake Kanyaboli provides a sanctuary for fish species that are considered extinct (e.g., Oreochromis esculentus, Oreochromis variabilis and Haplochromis spp.) in Lake Victoria, comprehensive data on species diversity and abundance are lacking. This study, conducted over a year (February 2020 to February 2021), addressed this gap by assessing the temporal variation in fish diversity, abundance and catch (biomass) in Lake Kanyaboli. The primary fish data collected in the lake were supplemented with secondary data, and physico‐chemical variables were used to correlate with fish assemblages. Fish catches decreased over time from 1981 to 2020, with the highest catch observed in 1981 (250 mt). Fish species composition data showed heterogeneity over the years, ranging from 9 to 15 species. O. esculentus, haplochromines, Oreochromis niloticus, Protopterus aethiopicus and Clarias sp. were present in all the reviewed years (from 1981 to 2020), whereas Coptodon zillii was non‐existent post‐1981 results. The February 2020 to February 2021 survey recorded 14 species dominated by Cichlidae (10 species), whereas Protopteridae and Anabantidae recorded one taxon each. Interestingly, Bagrus sp. was recorded in the current study, suggesting fish movement from the Yala River to the lake. The annual fish catch in the lake comprised tilapias (50%, O. esculentus, O. variabilis, O. niloticus and Oreochromis leucostictus), Clarias sp. (23%), P. aethiopicus (20%), haplochromines (7%), Cyprinids (0.03%) and Anabantidae (0.01%). There were no significant monthly differences in fish abundance and fish catches. The decline in fish catch in Lake Kanyaboli over the years is consistent with most tropical lakes and reservoirs in developing countries due to overexploitation. This study highlights the need for biomonitoring in Lake Kanyaboli to protect its fish population, including the endangered O. esculentus and O. variabilis, and ensure the long‐term sustainability of the ecosystem.

Effects of cotton peanut rotation on crop yield soil nutrients and microbial diversity

Background and Aims Cotton-peanut rotation is a sustainable farming practice that enhances land utilization and promotes the sustainable development of agriculture. Crop rotation can reduce the occurrence of pests and diseases, as different crops have varying levels of resistance to such threats. Additionally, by alternating the types of crops grown, the soil environment is changed, which can lead to the elimination of favorable conditions for pathogens and pests, thereby alleviating the impact of these issues. Furthermore, cotton-peanut rotation can improve soil fertility.To investigate the effects of different crop rotation systems on crop yield, soil nutrients, and soil microbial communities. Methods: Using high-throughput sequencing technology, investigate the soil microbial diversity in the root zone after cotton-peanut rotation.Various planting patterns, including cotton continuous cropping (MC), peanut continuous cropping (HC), peanut-cotton-peanut rotation (HR), and fallow (X), were established to assess variations in crop yield, soil nutrients, and soil microbial diversity. Results: Significant differences were observed in crop yield, soil nutrients, and soil microbial community structure among different planting patterns. The HR system significantly increased the output compared with the HC and MC systems. Additionally, HR exhibited significantly lower total nitrogen (N) and basic nitrogen (BN) contents than HC and MC, whereas MC showed lower total potassium (K) and available potassium (AK) contents. HR led to a decrease in soil bacterial diversity but an increase in fungal diversity, with Ascomycota and Mortierellomycota being dominant. Various bacteria (Chloroflexi, Bacteroidota, and Actinobacteriota) associated with organic matter degradation and nutrient cycling were found across different planting systems, enhancing material cycling efficiency. Furthermore, Planctomycetota bacteria related to crop nutrient synthesis and Glomeromycota bacteria aiding plant nutrient absorption were significantly higher in the MC system than in the HR or HC systems. Redundancy analysis indicated a significant negative correlation between crop rotation and soil fungal community, whereas Ascomycota exhibited a significant negative correlation with organic matter.Conclusion: Peanut-cotton rotation can mitigate soil nutrient loss, enhance beneficial microorganism diversity, suppress harmful bacterial populations, stabilize ecosystems, and boost crop yield.

A global perspective on the abundance, diversity and mobility of antibiotic resistance genes in Escherichia coli.

Escherichia coli (E. coli), a ubiquitous opportunistic pathogen, poses a growing threat to human health due to the increasing prevalence of antibiotic resistance. However, a comprehensive understanding of the global distribution, diversity, and transmission of antibiotic resistance genes (ARGs) in E. coli remains lacking, hindering effective strategies to combat resistance. In this study, we analyzed 94,762 E. coli genome sequences obtained from the NCBI database using advanced bioinformatics tools. ARGs were identified by comparing sequences against a custom ARG database using BLAST. Mobile genetic element (MGE)-associated ARGs were identified by matching with ISfinder databases. Global distribution of ARGs was analyzed by clustering mobile ARG sequences with 99% genetic similarity. Our analysis revealed that 50.51% of the E. coli genome sequences contained ARGs, totaling 301,317 identified ARG sequences. These ARGs were categorized into 12 major classes and 229 subtypes. Notably, ARGs associated with multi-drug resistance (MDR), β-lactams, macrolide-lincosamide-streptogramins (MLS), tetracyclines, and aminoglycosides were particularly abundant, with the subtypes mdtK, macB, and ampC being especially prevalent. Additionally, significant differences in ARG abundance and diversity were observed across countries, with higher diversity found in high-income nations. Furthermore, 9.28% of the ARG sequences were linked to MGEs, accounting for 98.25% of all ARG subtypes. Notably, 4.20% of mobile ARGs were identified in over 20 countries, with β-lactam and aminoglycoside ARGs being the most widespread. This study provides a comprehensive overview of the global distribution and transmission of ARGs in E. coli. The high abundance of MDR and β-lactam-related ARGs, along with their widespread transmission across countries, highlights the urgent need for global surveillance and control measures. Furthermore, the strong association between ARGs and MGEs underscores the role of horizontal gene transfer in the spread of resistance. The observed variations in ARG diversity between countries suggest that socioeconomic factors, such as healthcare infrastructure and antibiotic usage patterns, significantly influence ARG prevalence. These findings are crucial for informing global strategies to mitigate the spread of antibiotic resistance and improve public health outcomes.

Dietary Diversity, Rather Than Quality, Parallels a Reduction in Metabolic Syndrome and a Favorable Gut Microbiome: The Dietary Diversity Score

Objective Diet plays a crucial role in the development of metabolic syndrome (MetS). While dietary recommendations primarily focus on quality of food intake, the relevance and mechanisms of dietary diversity for the prevention of obesity and metabolic diseases are unclear. Here, we investigate the respective associations of dietary diversity and quality with MetS and gut microbiota composition. Methods Pooled data from 2 independent population-based cohorts of the Study of Health in Pomerania (n = 6753) were used. Based on a validated food frequency questionnaire a novel dietary diversity score (DDS) and an established dietary quality score (DQS) were calculated. Both were correlated with anthropometric data and clinical components of MetS as well as with intestinal microbial composition (16S rRNA gene sequencing). Results DDS was associated with a healthier metabolic phenotype and lower MetS risk in both cross-sectional (odds ratio [OR], 0.90; 95% CI, 0.82–0.93; p < 0.001) and longitudinal analyses of 5-year follow-up data (OR, 0.89; 95% CI, 0.79–0.99; p = 0.029). In contrast, there were hardly any favorable associations between DQS and MetS, neither cross-sectionally nor longitudinally. DDS explained 42.6% more beta diversity variation in gut microbiota than DQS and was linked to a more favorable microbial composition (e.g., less Escherichia/Shigella [q = 0.00576] and greater Ruminococcaceae [q = 0.01263] abundance). Conclusions Dietary diversity, as determined by the novel DDS, reduces MetS risk, whereas dietary quality was less important in that regard. Greater dietary diversity was paralleled by greater microbiota diversity and a healthier gut microbiome. Future dietary recommendations should emphasize dietary diversity rather than absolute consumption of nutritional components.

The Taxonomic and Functional Diversity of Leaf-Litter Dwelling Ants in the Tropical Dry Forest of the Colombian Caribbean

There have been few advances in understanding the organization and dynamics of ants in tropical dry forests. The latter are a seriously threatened ecosystem, and ants are important indicators of diversity, disturbance, and restoration in forest ecosystems. Using diversity data and morphofunctional traits, we evaluated the spatial and temporal variation of taxonomic and functional ant groups; in addition, we explored the variation in functional traits and diversity among communities. Ants were sampled during the dry and rainy seasons using mini-Winkler bags. A total of 9 subfamilies, 57 genera, and 146 species were collected. Ant species composition and richness varied both spatially (75 to 119 species) and temporally (121 and 127 species). The fragments from N2 and N3 showed higher diversity than those from N1. The dissimilarity among all areas was moderate (50–60%), mainly attributable to species turnover processes (77%). Twenty functional groups were identified. The N3 fragments had the highest functional diversity, with lower resistance to species loss, while the N1 and N2 fragments reduced functional diversity and increased similarity among species. Our results highlight the importance of integrating a functional analysis with the taxonomic assessment of ants as an important contribution to understanding the organization and dynamics of this community of insects that inhabit the tropical dry forest.

From nature to urbanity: exploring phyllosphere microbiome and functional gene responses to the Anthropocene.

The Anthropocene exerts various pressures and influences on the stability and function of the Earth's ecosystems. However, our understanding of how the microbiome responds in form and function to these disturbances is still limited, particularly when considering the phyllosphere, which represents one of the largest microbial reservoirs in the terrestrial ecosystem. In this study, we comprehensively characterized tree phyllosphere bacteria and associated nutrient-cycling genes in natural, rural, suburban, and urban habitats in China. Results revealed that phyllosphere bacterial community diversity, richness, stability, and composition heterogeneity were greatest at the most disturbed sites. Stochastic processes primarily governed the assembly of phyllosphere bacterial communities, although the role of deterministic processes (environmental selection) in shaping these communities gradually increased as we moved from rural to urban sites. Our findings also suggest that human disturbance is associated with the reduced influence of drift as increasingly layered environmental filters deterministically constrain phyllosphere bacterial communities. The intensification of human activity was mirrored in changes in functional gene expression within the phyllosphere microbiome, resulting in enhanced gene abundance, diversity, and compositional variation in highly human-driven disturbed environments. Furthermore, we found that while the relative proportion of core microbial taxa decreased in disturbed habitats, a core set of microbial taxa shaped the distributional characteristics of both microbiomes and functional genes at all levels of disturbance. In sum, this study offers valuable insights into how anthropogenic disturbance may influence phyllosphere microbial dynamics and improves our understanding of the intricate relationship between environmental stressors, microbial communities, and plant function within the Anthropocene.