Distinct Habitats Research Articles

Data-driven identification of major axes of functional variation in bacteria.

The discovery of major axes of correlated functional variation among species and habitats has revealed the fundamental trade-offs structuring both functional and taxonomic diversity in eukaryotes such as plants. Whether such functional axes exist in the bacterial realm and whether they could explain bacterial taxonomic turnover among ecosystems remains unknown. Here, we use a data-driven approach to leverage global genomic and metagenomic datasets to reveal the existence of major axes of functional variation explaining both evolutionary differentiation within Bacteria and their ecological sorting across diverse habitats. We show that metagenomic variation among bacterial communities from various ecosystems is structured along a few axes of correlated functional pathways. Similar clusters of traits explained phylogenetic trait variation among >16,000 bacterial genomes, suggesting that functional turnover among bacterial communities from distinct habitats does not only result from the differential filtering of similar functions among communities, but also from phylogenetic correlations among these functions. Concordantly, functional pathways associated with trait clusters that were most important for defining functional turnover among bacterial communities were also those that had the highest phylogenetic signal in the bacterial genomic phylogeny. This study overall underlines the important role of evolutionary history in shaping contemporary distributions of bacteria across ecosystems.

Fisheries measures protect European seabass groups with distinct habitat use differently

Abstract We investigated the movements of European seabass, Dicentrarchus labrax, to understand habitat use and connectivity to evaluate how individual seabass are protected by the spatiotemporal fisheries restrictions in place. We tagged seabass with acoustic transmitters in a study area in the Port of Zeebrugge (Belgium) in the southern North Sea. The 370,200 detections of 57 seabass in the study area revealed high residency in the period from late March–May to September–November, as well as high site fidelity (70.7%). Whereas the majority of seabass left the area in winter, 13 seabass stayed in the harbour experiencing temperatures as low as 2.8°C. Two groups of seabass were identified having different core movement areas in the inner and outer harbours, although movement between the two areas was possible. The distinct differences in habitat use between these groups resulted in a significantly different level of exposure to fisheries under the same policy framework. By quantifying the level of protection of seabass, based on the spatiotemporal fisheries management in place, our study underlines the importance of taking into account movement behaviour when evaluating conservation measures.

The Impact of Weir Construction in Korea's Nakdong River on the Population Genetic Variability of the Endangered Fish Species, Rapid Small Gudgeon (Microphysogobio rapidus).

Microphysogobio rapidus, an endemic cyprinid fish species found exclusively in Korea, has been identified in only two tributaries of the Nakdong River. The species predominantly occupies the near-gravel bottom waters within shallow sections of the middle and lower reaches of the river, characterized by swift currents. M. rapidus is currently recognized as a critically endangered species due to its distinct habitat preference, as well as the negative impacts of stream dam development and water environment pollution. In this study, we used 10 microsatellite markers to examine the genetic diversity of M. rapidus in the upper Nam (UN), lower Nam (LN), and Deokcheon Rivers (DC) in Korea, with a specific focus on assessment of the impact of dam development. Fish sampled from the UN and LN showed a greater average number of alleles and allelic richness (A = 18.3-18.4, AR = 13.8) compared to those from DC (A = 11.8, AR = 11.5). The observed heterozygosity among the fish examined ranged from HO = 0.748 (LN) to 0.766 (DC). All three fish groups exhibited a significant departure from Hardy-Weinberg equilibrium (HWE) (p < 0.05). Despite having the largest effective population size (Ne = 175 and 157, respectively), the fish sampled from UN and LN showed the highest inbreeding coefficients (FIS = 0.056-0.053, respectively), which were highly significant (p < 0.01). In contrast, the fish sampled from DC exhibited the smallest effective population size (Ne = 61) and showed an inbreeding coefficient close to zero (p > 0.05). BOTTLENECK analysis and estimated M-ratio values (0.341-0.372) revealed indications of past population size reduction in all fish groups examined. No significant genetic differentiation (FST < 0.05) was detected using the DAPC, STRUCTURE, and AMOVA among the fish studied. However, pairwise comparisons of FST between fish sampled from the Nam and Deokcheon Rivers revealed significant values (p < 0.001) ranging from 0.013 to 0.014. In addition, the closest genetic distance (0.026) was observed between UN and LN, while the greatest distance (0.087) was found between UN and DC. Analysis of gene flow rates among the fish examined indicated asymmetrical gene exchange within the Nam River, which was 31.51% in the downstream direction (from UN to LN), with a minimal gene flow rate (0.41%) in the upstream (from LN to UN) direction. The opposite trend was recorded between DC and LN, with a higher gene flow rate (29.74%) in the upstream direction compared to the downstream direction (0.12%). Our study highlighted the importance of implementing long-term conservation efforts focused on maintaining river integrity by removing water barriers such as weirs that impede fish migration and implementing active protection measures, such as aquaculture breeding and reasonable stocking practices, to preserve M. rapidus in the study area.

A chromosome-level genome assembly of Stenchaetothrips biformis and comparative genomic analysis highlights distinct host adaptations among thrips

Insects have a limited host range due to genomic adaptation. Thysanoptera, commonly known as thrips, occupies distinct feeding habitats, but there is a lack of comparative genomic analyses and limited genomic resources available. In this study, the chromosome-level genome of Stenchaetothrips biformis, an oligophagous pest of rice, is assembled using multiple sequencing technologies, including PacBio, Illumina short-reads, and Hi-C technology. A 338.86 Mb genome is obtained, consisting of 1269 contigs with a contig N50 size of 381 kb and a scaffold N50 size of 18.21 Mb. Thereafter, 17,167 protein-coding genes and 36.25% repetitive elements are annotated. Comparative genomic analyses with two other polyphagous thrips, revealing contracted chemosensory-related and expanded stress response and detoxification gene families in S. biformis, potentially facilitating rice adaptation. In the polyphagous thrips species Frankliniella occidentalis and Thrips palmi, expanded gene families are enriched in metabolism of aromatic and anthocyanin-containing compounds, immunity against viruses, and detoxification enzymes. These expansion gene families play crucial roles not only in adapting to hosts but also in development of pesticide resistance, as evidenced by transcriptome results after insecticides treatment. This study provides a chromosome-level genome assembly and lays the foundation for further studies on thrips evolution and pest management.

Coordination between leaf and root traits in Mediterranean coastal dune plants.

Plant trait-based functional spectra are crucial to assess ecosystem functions and services. Whilst most research has focused on aboveground vegetative traits (leaf economic spectrum, LES), contrasting evidence on any coordination between the LES and root economic spectrum (RES) has been reported. Studying spectra variation along environmental gradients and accounting for species' phylogenetic relatedness may help to elucidate the strength of coordination between above- and belowground trait variation. We focused on leaf and root traits of 39 species sampled in three distinct habitats (front, back and slack) along a shoreline-inland gradient on coastal dunes. We tested, within a phylogenetic comparative framework, for the presence of the LES and RES, for any coordination between these spectra, and explored their relation to variation in ecological strategies along this gradient. In each habitat, three-quarters of trait variation is captured in two-dimensional spectra, with species' phylogenetic relatedness moderately influencing coordination and trade-off between traits. Along the shoreline-inland gradient, aboveground traits support the LES in all habitats. Belowground traits are consistent with the RES in the back-habitat only, where the environmental constraints are weaker, and a coordination between leaf and root traits was also found, supporting the whole-plant spectrum (PES). This study confirms the complexity when seeking any correlation between the LES and RES in ecosystems characterized by multiple environmental pressures, such as those investigated here. Changes in traits adopted to resist environmental constraints are similar among species, independent of their evolutionary relatedness, thus explaining the low phylogenetic contribution in support of our results.

Microbe-driven elemental cycling enables microbial adaptation to deep-sea ferromanganese nodule sediment fields

BackgroundFerromanganese nodule-bearing deep-sea sediments cover vast areas of the ocean floor, representing a distinctive habitat in the abyss. These sediments harbor unique conditions characterized by high iron concentration and low degradable nutrient levels, which pose challenges to the survival and growth of most microorganisms. While the microbial diversity in ferromanganese nodule-associated sediments has been surveyed several times, little is known about the functional capacities of the communities adapted to these unique habitats.ResultsSeven sediment samples collected adjacent to ferromanganese nodules from the Clarion–Clipperton Fracture Zone (CCFZ) in the eastern Pacific Ocean were subjected to metagenomic analysis. As a result, 179 high-quality metagenome-assembled genomes (MAGs) were reconstructed and assigned to 21 bacterial phyla and 1 archaeal phylum, with 88.8% of the MAGs remaining unclassified at the species level. The main mechanisms of resistance to heavy metals for microorganisms in sediments included oxidation (Mn), reduction (Cr and Hg), efflux (Pb), synergy of reduction and efflux (As), and synergy of oxidation and efflux (Cu). Iron, which had the highest content among all metallic elements, may occur mainly as Fe(III) that potentially functioned as an electron acceptor. We found that microorganisms with a diverse array of CAZymes did not exhibit higher community abundance. Instead, microorganisms mainly obtained energy from oxidation of metal (e.g., Mn(II)) and sulfur compounds using oxygen or nitrate as an electron acceptor. Chemolithoautotrophic organisms (Thaumarchaeota and Nitrospirota phyla) were found to be potential manganese oxidizers. The functional profile analysis of the dominant microorganisms further indicated that utilization of inorganic nutrients by redox reactions (rather than organic nutrient metabolism) is a major adaptive strategy used by microorganisms to support their survival in the ferromanganese nodule sediments.ConclusionsThis study provides a comprehensive metagenomic analysis of microbes inhabiting metal-rich ferromanganese nodule sediments. Our results reveal extensive redundancy across taxa for pathways of metal resistance and transformation, the highly diverse mechanisms used by microbes to obtain nutrition, and their participation in various element cycles in these unique environments.7UX-FAbsHcrvGN6PxGni8JVideo

Plant economic strategies in two contrasting forests

BackgroundPredicting relationships between plant functional traits and environmental effects in their habitats is a central issue in terms of classic ecological theories. Yet, only weak correlation with functional trait composition of local plant communities may occur, implying that some essential information might be ignored. In this study, to address this uncertainty, the objective of the study is to test whether and how the consistency of trait relationships occurs by analyzing broad variation in eight traits related to leaf morphological structure, nutrition status and physiological activity, within a large number of plant species in two distinctive but comparable harsh habitats (high-cold alpine fir forest vs. north-cold boreal coniferous forest).ResultsThe contrasting and/or consistent relationships between leaf functional traits in the two distinctive climate regions were observed. Higher specific leaf area, photosynthetic rate, and photosynthetic nitrogen use efficiency (PNUE) with lower N concentration occurred in north-cold boreal forest rather than in high-cold alpine forest, indicating the acquisitive vs. conservative resource utilizing strategies in both habitats. The principal component analysis illuminated the divergent distributions of herb and xylophyta groups at both sites. Herbs tend to have a resource acquisition strategy, particularly in boreal forest. The structural equation modeling revealed that leaf density had an indirect effect on PNUE, primarily mediated by leaf structure and photosynthesis. Most of the traits were strongly correlated with each other, highlighting the coordination and/or trade-offs.ConclusionsWe can conclude that the variations in leaf functional traits in north-cold boreal forest were largely distributed in the resource-acquisitive strategy spectrum, a quick investment-return behavior; while those in the high-cold alpine forest tended to be mainly placed at the resource-conservative strategy end. The habitat specificity for the relationships between key functional traits could be a critical determinant of local plant communities. Therefore, elucidating plant economic spectrum derived from variation in major functional traits can provide a fundamental insight into how plants cope with ecological adaptation and evolutionary strategies under environmental changes, particularly in these specific habitats.

Distinct habitat and biogeochemical properties of low‐oxygen‐adapted tropical oceanic phytoplankton

AbstractWe use data collected by Biogeochemical Argo (BGC‐Argo) float, over a 5‐year period (2016–2021), to study the dynamics of a unique low‐oxygen‐adapted phytoplanktonic community in the eastern tropical North Pacific. We isolate this community using a model that partitions vertical profiles of chlorophyll a (Chl a) and particulate backscattering into the contributions of three communities of phytoplankton: C1, the community in the mixed‐layer; C2, at the deep Chl a maximum; and C3, in low‐oxygen waters at the base of the euphotic zone. We find that C3 has a similar chl‐specific particulate backscattering to C2, both lower than C1. C2 and C3 contribute significantly to integrated stocks of Chl a, both at around 41%, and both around 30% of integrated particulate backscattering (after removing a background signal attributed to nonalgal particles). Found at depths of around 100 m, the peak biomass of C3 is lower than C2 (located at around 60 m), and yet, C3 makes similar contributions to integrated stocks, because it has a broader peak than C2. In relation to C1 and C2, C3 thrives in a lower temperature, higher density, lower light, lower oxygen, and higher saline habitat. This work illustrates how BGC‐Argo floats, in combination with simple conceptual models, can be used to observe the dynamics of unique communities of phytoplankton in extreme environments. The projected climate‐driven changes in oxygen minimum zones add urgency to understand the vulnerabilities of these communities both in terms of stocks and composition.

Change in the faunal composition of mosquitoes (Diptera: Culicidae) along a heterogeneous landscape gradient in the Brazilian Amazon.

This study aimed to evaluate the influence of different anthropic landscape profiles on the diversity and distribution of mosquito species in a rural settlement of the Brazilian Amazon. Eight field collections were conducted at 18 sampling points interspersed throughout 2020-2021. Plastic containers, bamboo internodes, and tires were used as traps to capture immature mosquitoes in three distinct habitats: forest, forest edge, and peridomicile. A total of 15,547 individuals, distributed in 26 species of culicids, were collected. The most abundant species were Culex urichii (8,376 specimens), Culex (Melanoconion) (2,473 specimens), and Aedes albopictus (1,252 specimens). Forest habitat showed the highest abundance, and forest edge showed the highest species richness. Different types of environments influenced both the abundance and richness of mosquitoes. The species composition was also significantly different between the analyzed sites, mainly between forest and peridomicile environments. The change in species dominance could largely explain this change in mosquito community composition. Haemagogus janthinomys, an important sylvatic arbovirus vector, was found in peridomicile habitats and Ae. albopictus, a vector associated with human environments, was found in forest habitats, thus providing evidence of species spillover. Our results indicated that landscape changes affect mosquito communities, influencing their richness and abundance. These changes may have implications for future arboviral outbreaks in this rural settlement due to the possible establishment of sylvatic vector species in anthropic environments.

Shark teeth zinc isotope values document intrapopulation foraging differences related to ontogeny and sex

Trophic ecology and resource use are challenging to discern in migratory marine species, including sharks. However, effective management and conservation strategies depend on understanding these life history details. Here we investigate whether dental enameloid zinc isotope (δ66Znen) values can be used to infer intrapopulation differences in foraging ecology by comparing δ66Znen with same-tooth collagen carbon and nitrogen (δ13Ccoll, δ15Ncoll) values from critically endangered sand tiger sharks (Carcharias taurus) from Delaware Bay (USA). We document ontogeny and sex-related isotopic differences indicating distinct diet and habitat use at the time of tooth formation. Adult females have the most distinct isotopic niche, likely feeding on higher trophic level prey in a distinct habitat. This multi-proxy approach characterises an animal’s isotopic niche in greater detail than traditional isotope analysis alone and shows that δ66Znen analysis can highlight intrapopulation dietary variability thereby informing conservation management and, due to good δ66Znen fossil tooth preservation, palaeoecological reconstructions.

Assessment of Habitat Risks Caused by Human Activities and Integrated Approach to Marine Spatial Planning: The Case of Sriracha District—Sichang Island

According to the Thailand’s National Strategy (2017-2036) and National Reform Plans, various tools, techniques, or methods are necessary to collect and investigate data for the effective preservation and protection of the country’s natural resources. We aimed to apply various tools and methods for integrated coastal management in Thailand. This study used the InVEST models, including the habitat quality (HQ) and habitat risk assessment (HRA) models, to evaluate the natural habitat quality and cumulative human activity risk in the Sriracha district and Sichang Islands, Thailand. The HQ model revealed the presence of abundant ecological services and high quality natural habitats. We observed habitat degradation in the mooring zone, city area, forests, and coral reefs, with moderate risk to distinct habitats. Our findings identified two potential scenarios. Conservation scenarios exhibited a lower HRA ratio compared to current and development scenarios. Overall, the results showed the effectiveness of the InVEST model in evaluating habitat risk under both present and simulated conditions. Our study highlights the importance of informed management plans and policy-making processes to achieve planned coastal management goals.

Large‐scale sampling of beetle communities in Laos shows that conversion of natural forests into plantations leads to a decline in family richness and abundance

AbstractRapid economic development can pose a threat to the biodiversity of tropical countries. In Laos, this is manifested by the conversion of natural forests into plantations, even though this area is one of the biodiversity hotspots of Southeast Asia. Beetle communities can be good indicators of the impact of anthropogenic pressure on natural ecosystems. In this study, we analyzed for the first time a large‐scale inventory of Coleoptera to assess the ecological and anthropogenic drivers of beetle communities in Laos. We examined beetle communities (described at the family level) across the country, located in distinct habitat types, in order to understand the impact of the conversion of natural forest into plantations. We found that beetle abundance had declined in plantations compared to natural forests. At the same time, we observed fewer beetle families in plantations overall, but at the scale of sampling sites there was no difference in local richness compared to natural forests, suggesting a homogenization of beetle communities in anthropogenic habitats. Although results are certainly sensitive to our coarse classification of beetle specimens into families, the negative impact of the conversion of natural tropical forests into agriculture area can still be clearly demonstrated. Our findings highlight that it is possible to make use of unstructured large‐scale inventories to explore how beetle communities responds to landscape changes induced by human activities. We suggest that sampling beetle communities can be used as an ecological indicator to monitor anthropogenic impacts on tropical ecosystems.

Reef-Insight: A Framework for Reef Habitat Mapping with Clustering Methods Using Remote Sensing

Environmental damage has been of much concern, particularly in coastal areas and the oceans, given climate change and the drastic effects of pollution and extreme climate events. Our present-day analytical capabilities, along with advancements in information acquisition techniques such as remote sensing, can be utilised for the management and study of coral reef ecosystems. In this paper, we present Reef-Insight, an unsupervised machine learning framework that features advanced clustering methods and remote sensing for reef habitat mapping. Our framework compares different clustering methods for reef habitat mapping using remote sensing data. We evaluate four major clustering approaches based on qualitative and visual assessments which include k-means, hierarchical clustering, Gaussian mixture model, and density-based clustering. We utilise remote sensing data featuring the One Tree Island reef in Australia’s Southern Great Barrier Reef. Our results indicate that clustering methods using remote sensing data can well identify benthic and geomorphic clusters in reefs when compared with other studies. Our results indicate that Reef-Insight can generate detailed reef habitat maps outlining distinct reef habitats and has the potential to enable further insights for reef restoration projects.

River-influenced beluga (Delphinapterus leucas) summer habitat use in western Hudson Bay, Canada

River estuaries along western Hudson Bay, Canada, are important summer habitats for beluga whales ( Delphinapterus leucus (Pallas, 1776)) and subject to increasing industrial development activities including vessel traffic. The feasibility of establishing a National Marine Conservation Area (NMCA) in western Hudson Bay is under consideration, requiring baseline studies and habitat monitoring. In this study, beluga whale locations were identified using aerial photographs collected during summer 2018 of the Seal, Knife, Churchill, and Nelson River estuaries. Sentinel 2 wavelength bands were used to outline river plume boundaries for the Seal, Knife, and Churchill Rivers. Multiple discriminant analysis was used to differentiate between beluga habitat areas according to their environmental characteristics including concentration of total suspended sediments (TSS), and coloured dissolved organic matter (CDOM). The Seal River estuary, Knife River estuary, Churchill River outer estuary, Churchill River estuary, and Nelson River estuary were identified as distinct habitat areas. Resource selection functions and model selection were used to determine that habitat variables related to prey availability were important for beluga habitat selection, including TSS, CDOM, and the distance to river mouth or river plume. Identification of preferred habitat and habitat areas in this study are imperative for future management decisions including establishment of an NMCA.

Ground-ivy (Glechoma hederacea L., Lamiaceae) habitats in NE Slovenia

Ground-ivy (Glechoma hederacea L.) is a widespread stoloniferous plant that grows in several ecologically diverse habitats: in the open, at the forest edge, and in understorey. The vegetation of ground-ivy habitats was studied in NE Slovenia in terms of floristic richness and diversity, biological spectrum, phytogeography and syntaxonomy. We identified five clusters of ecologically distinct habitats with the occurrence of ground-ivy, differentiated according to environmental conditions and flora composition: eutrophic forest edges, trampled habitats, forests, which are divided into two groups with different soil moisture, and meadows. The habitats were assessed using Ellenberg indicator values, thus confirming the ecological differentiation of ground-ivy habitats. Ground-ivy coexists with 169 plant species from 49 families. The highest plant species richness and Shannon diversity is found in meadows (100 plant species), while the lowest diversity is found in trampled habitats (12 plant species). Plant species coexisting with ground-ivy belong to 10 geoelements of which circumboreal, sub-cosmopolitan, Euro-Caucasian and Eurasian geoelements are represented in all habitats. The most represented life form is the hemicryptohytes with up to 88 % of all species per relevé. The syntaxon Molino-Arrhenatheretea dominates in the meadows, the shrub species of the forest edges belong to the syntaxon Rhamno-Prunetea, while Querco-Fagatea predominates in the forests. Ruderal species of the syntaxon Stellarietea mediae occurred in all habitats except in the understorey where light is a limiting factor. A non-negligible proportion of species belongs to Galio-Urticetea, a community characteristic of eutrophic forest edges, an optimal habitat for ground-ivy.

Eco-Physiological Responses of Avicennia marina (Forssk.) Vierh. to Trace Metals Pollution via Intensifying Antioxidant and Secondary Metabolite Contents.

Mangrove is one of the most precious ecosystems with the greatest losses due to climate change, human activities, and pollution. The objective of this study is to assess the accumulation and distribution of some trace metals (Cu, Cd, Ni, Pb, and Zn) in sediments and Avicennia marina roots and leaves and to discuss the antioxidant potential of A. marina under metallic pollution stress. Sediments, leaf, and root samples of A. marina were collected from five sites along the Red Sea Coast of Egypt. Several ecological pollution indices, including the geo accumulation index (Igeo), contamination factor (CF), pollution load index (PLI), bioconcentration factor (BCF), and translocation factor (TF), were used to assess the pollution load. Cu, Cd, Ni, Pb, and Zn average concentrations in sediments were 167.4, 0.75, 110.65, 39.79, and 220 μg g-1, respectively, and the average values of these metals in A. marina roots were 44.9, 0.5, 87.96, 39.02, and 54.68 μg g-1, respectively, while in leaves their concentration were 50.46, 0.5572, 88.24, 40.08, and 56.08 μg g-1, respectively. The values of the Igeo, CF, and PLI index indicated that location 1 and 5 are moderate-to-heavily contaminated sites. On the other hand, leaves and roots of A. marina grown in polluted locations 1 and 5 showed high accumulation of malondialdehyde (MDA), low chlorophyll a and chlorophyll b contents concomitant with a decrease in total soluble sugars. High total antioxidant capacity was associated with a significant increase in activity levels of antioxidant enzymes (Catalase, Polyphenol oxidase, Polyphenol peroxidase, and Ascorbic acid oxidase), accumulation of secondary metabolites (total phenols, flavonoids, and tannins), and proline and carotenoids content increase. Overall, the present study suggests that the mangrove habitat of the Egyptian Red Sea coast is under the stress of anthropogenic activities, which necessitates a conservation plan to avoid further contamination and protect the unique biota of this distinctive habitat.

Variability in leaf traits reveals contrasting strategies between forest and grassland woody communities across southern Brazil

Forests and grasslands often form mosaics in subtropical regions such as in southern Brazil. Currently, we observe the processes of woody species encroachment and forest expansion over grasslands due to changes in climate conditions and disturbance regimes. Woody plants occurring across such mosaics can be specialists from one habitat type (forest or grassland) or a generalist species (those occurring in both of these contrasting habitats). Here, we explore if their occurrence in distinct habitats is coordinated by functional traits, considering both intra- and interspecific variability and phylogenetic relatedness between species, thereby assessing changes between habitats from the individual to the community scale. We surveyed forest and grassland vegetation forming mosaics in nine sites in southern Brazil. We found that grassland-forest communities do not differ in phylogenetic diversity, irrespective of considering or not the gymnosperms of the communities. Furthermore, forests presented lower diversity in leaf area than grasslands, with a predominance of large leaves but higher diversity of specific leaf area and leaf dry matter content, with leaves predominantly with an acquisitive resource strategy. When considering species with different habitat preferences, forest-specialist species showed traits related to resource acquisition, while grassland-specialist species showed trait values associated with resource conservation. Generalist species have trait values according to habitat occurrence, showing high intraspecific variability and trait plasticity to establish on both forest and grassland habitats. Assessing the trait variability from woody individuals is important to understanding the contrasting strategies used by different species in grassland-forest mosaics and can be essential to predict the dynamics of these ecosystems, given the changes in climate and disturbances regimes.

Exploration of the interplay between spatially distinct microbial habitats through comparative analysis

ABSTRACT Objectives The oral microbiome is closely associated with systemic diseases, indicating the presence of bacteremia and inflammatory mediators in the systemic circulation. Our research aims to investigate the relationship between the oral microbiome and other microbial habitats. Methods We analyzed 180 specimens from 36 patients, including saliva, buccal swab, plaque, stool, and blood samples from a healthy group (Non_PD, n = 18) and a periodontitis group (PD, n = 18). The final analysis included 147 specimens, with varying sample sizes for each group. Metagenomic analysis was performed using prokaryotic 16S rRNA on the MiSeq platform (Illumina). Results PD saliva showed significant richness differences (P's < 0.05), similar to plaque. Buccal swabs had slight variations. Microbial network analysis revealed altered microbial interactions in the PD group, with decreased interactions in saliva and buccal swabs, and increased interactions in plaque. In our analysis of nine specimens where all paired habitat samples could be analyzed, microorganisms linked to oral periodontitis were found in sterile blood samples, resembling the oral cavity's composition. Conclusions Microbiome differences should consider overall microbial-environment interactions, alongside diversity and richness. Our data cautiously suggest that disease-related changes in the salivary microbiome may be reflected in blood specimens through the oral-blood axis.

Distinct coral reef habitat communities characterised by environmental DNA metabarcoding

Distinct coral reef habitat communities characterised by environmental DNA metabarcoding

Characterization of endophytic bacteriome diversity and associated beneficial bacteria inhabiting a macrophyte Eichhornia crassipes.

The endosphere of a plant is an interface containing a thriving community of endobacteria that can affect plant growth and potential for bioremediation. Eichhornia crassipes is an aquatic macrophyte, adapted to estuarine and freshwater ecosystems, which harbors a diverse bacterial community. Despite this, we currently lack a predictive understanding of how E. crassipes taxonomically structure the endobacterial community assemblies across distinct habitats (root, stem, and leaf). In the present study, we assessed the endophytic bacteriome from different compartments using 16S rRNA gene sequencing analysis and verified the in vitro plant beneficial potential of isolated bacterial endophytes of E. crassipes. Plant compartments displayed a significant impact on the endobacterial community structures. Stem and leaf tissues were more selective, and the community exhibited a lower richness and diversity than root tissue. The taxonomic analysis of operational taxonomic units (OTUs) showed that the major phyla belonged to Proteobacteria and Actinobacteriota (> 80% in total). The most abundant genera in the sampled endosphere was Delftia in both stem and leaf samples. Members of the family Rhizobiaceae, such as in both stem and leaf samples. Members of the family Rhizobiaceae, such as Allorhizobium- Neorhizobium-Pararhizobium-Rhizobium were mainly associated with leaf tissue, whereas the genera Nannocystis and Nitrospira from the families Nannocystaceae and Nitrospiraceae, respectively, were statistically significantly associated with root tissue. Piscinibacter and Steroidobacter were putative keystone taxa of stem tissue. Most of the endophytic bacteria isolated from E. crassipes showed in vitro plant beneficial effects known to stimulate plant growth and induce plant resistance to stresses. This study provides new insights into the distribution and interaction of endobacteria across different compartments of E. crassipes Future study of endobacterial communities, using both culture-dependent and -independent techniques, will explore the mechanisms underlying the wide-spread adaptability of E. crassipesto various ecosystems and contribute to the development of efficient bacterial consortia for bioremediation and plant growth promotion.