Non-metric Multidimensional Scaling Research Articles

Fish biodiversity in modified ecosystems: a case study of Nigeria's Challawa and Tiga dams in the Challawa and Kano rivers

River impoundment is usually accompanied with consequences of alteration in the hydrological system and change in the biodiversity composition of the ecosystem. This study investigated the impact of the dams built on Challawa (that is, Challawa George-Dam) and Kano (that is, Tiga Dam) on the fish biodiversity of the reservoir and below-dam sections of the two rivers. Fish sampling was done using long lines, Malian traps, cast and gill nets from stations on the reservoir and below-dam sections of the rivers. Ten fish species were identified from the reservoir and the below-dam sections of Challawa River belonging to nine families and four orders. Fish communities of the reservoir and below-dam sections of Kano River consisted of 28 species belonging to 12 families and 7 orders. Results of the Shannon diversity index (H^') indicated that the two reservoirs have relatively higher fish species diversity measures (that is, Challawa=1.948 & Kano=2.294) than the below-dam parts (that is, Challawa=1.833 & Kano=2.247) of their respective rivers. Non-metric Multidimensional Scaling (NMDS) analysis produced two-dimensional maps with stress values of 0.0554 and 0.0537, an indication that the model provided good representation of the original data in reduced-dimensional space. The ordination map indicated wide dissimilarities between fish communities of the impounded and below-dam sections. Furthermore, a one-way analysis of similarity indicated significant difference (P=0.0001) and high dissimilarities (R=0.643) between fish communities in the two sections of Challawa River and also in Kano River (P=0.001, R=0.929). Analysis of Similarity Percentage indicated 74.45% of the dissmilarities between fish communities in the two sections were cummulatively contributed by four species in Challawa River and 72.18% by five species in Kano River. The distinct differences in fish abundance and richness between the two sections is ascribed to increased ecosytem productivity often associated with the inundated portion of dammed river. It is recommended that more water flow across the dams should be encouraged as a mitigating measure to boost basin sizes of the rivers at the below-dam sections. Key words: Diversity, dam, impound, reservoir, community, freshwater and fish species

The influence of temperature on the impacts of caffeine in mussels: Evaluating subcellular impacts and model predictions

In aquatic ecosystems, the presence of pharmaceuticals, particularly caffeine (CAF), has been linked to wastewater discharge, hospital waste, and the disposal of expired pharmaceutical products containing CAF. Additionally, rising temperatures due to climate change are anticipated in aquatic environments. This study aimed to assess the toxicity of various CAF concentrations under current (17 °C) and projected (21 °C) temperature conditions, using the mussel Mytilus galloprovincialis as a bioindicator species. Subcellular impacts were evaluated following 28 days of exposure to four CAF concentrations (0.5; 1.0; 5.0; 10.0 μg/L) at the control temperature (17 °C). Only effects at an environmentally relevant CAF concentration (5.0 μg/L) were assessed at the highest temperature (21 °C). The overall biochemical response of mussels was evaluated using non-metric Multidimensional Scaling (MDS) and the Integrated Biomarker Response (IBR) index, while the Independent Action (IA) model was used to compare observed and predicted responses. Results showed that at 17 °C, increased CAF concentrations were associated with higher metabolism and biotransformation capacity, accompanied by cellular damage at the highest concentration. Conversely, under warming conditions (21 °C), the induction of antioxidant enzymes was observed, although insufficient to prevent cellular damage compared to the control temperature. Regarding neurotoxicity, at 17 °C, the activity of the acetylcholinesterase enzyme was inhibited up to 5.0 μg/L; however, at 10.0 μg/L, activity increased, possibly due to CAF competition for adenosine receptors. The IA model identified a synergistic response for most parameters when CAF and warming acted together, aligning with observed results, albeit with slightly lower magnitudes.

Diversity and distribution of small-sized planktonic ciliate communities in the East China Sea

Ciliates are an important ecological component in the microbial food web, but few studies have been conducted on the spatial distribution of small-sized planktonic ciliate communities in the East China Sea (ECS). Investigating ciliate communities using conventional morphological approaches is particularly difficult for the small, fragile, and naked species. Therefore, we applied DNA metabarcoding analysis to explore the spatial pattern of small-sized planktonic ciliate community structure within the surface, deep chlorophyll maximum (DCM), and bottom layers. Results showed the cosmopolitan species, Leegaardiella sp., was dominant and widespread in the ECS. The relative abundance of the mixotrophic family Tontonnidae decreased in the deeper layer. We characterized water masses of the ECS using environmental variables. In nano-sized ciliate communities, non-metric multidimensional scaling (NMDS) plots revealed a correlation with temperature, salinity, density, and depth. The circulation patterns were similar to cluster analysis results, suggesting that hydrographic conditions shaped small-sized ciliate community composition.

Environmental DNA metabarcoding reveals fish diversity, community assembly and one invasive species prevalence in a National Park of Liaohe in September

The escalating environmental changes are imposing multiple pressures on biodiversity conservation, thereby, more attention has been paid to fish diversity and community assembly patterns. Fish diversity in Liaohe River has deteriorated significantly due to overfishing, environmental pollution and other reasons, in addition, no fish survey related research has been published in Liaohe National Park in recent years. In order to study the diversity of fish species in the area and to investigate the presence of any invasive species. This study used eDNA metabarcoding to explore the distribution and diversity of fish communities in the Liaohe National Park. The study showed that a total of 54 species of fish from six orders, 14 families, and 39 genera were detected, meantime, the invasive species Lepomis cyanellus was found at two sampling sites. The α-diversity results showed that estuarine sites had the highest species diversity. The spatial structure of fish communities in the upstream and downstream reaches were similar as indicated by non-metric multidimensional scaling. In our study, the fish community is influenced by both deterministic and stochastic processes, with the stochastic processes being the main factor. The potential existence of L. cyanellus in Liaohe National Park might be resulted from aquaculture, ornamental pet trade, other economic fish farming, artificial release. The relatively low number of fish species in this study may be attributed to the limited number of sampling events and sampling sites. In addition to these factors, over exploitation of resources, water pollution, and the invasion of alien species have directly impacted the biodiversity of aquatic life. The results of this study lay a foundation for the future biodiversity investigation in National Parks of China, meantime, the use of eDNA monitoring is crucial to prevent, to control and limit the spreading of invasive species in advance.

Environmental factors modulate the distribution of elasmobranchs in southern Mozambique

Investigating the spatiotemporal ecology of elasmobranchs is an important precursor to their effective management. Understanding long-term patterns in the movement and habitat use of threatened species can improve management plans so that they yield increased conservation benefits. We investigated the spatiotemporal and environmental drivers that underpin the abundance and distribution of elasmobranchs around reef habitats in southern Mozambique to highlight reefs that are important (“hotspots”) to the regional elasmobranch community. Visual belt transects (n = 738), supported by video recordings, were completed on 16 reef sites off the coast of southern Mozambique from 2018 to 2022. Nine elasmobranch species were encountered annually (Carcharhinus amblyrhynchos, Triaenodon obesus, Stegostoma tigrinum, Neotrygon caeruleopunctata, Pateobatis jenkinsii, Taeniurops meyeni, Mobula kuhlii, Mobula alfredi, Mobula birostris) and 11 individual environmental and spatiotemporal parameters (horizontal water visibility, tidal range and state, moon illumination, temperature on the reef, cloud cover, time of day, day of the year, transect distance from shore, transect depth, and the region that the transect occurred in) were measured. All species, (bar P. jenkinsii) were significantly more abundant around certain reefs in the sampled region. Total counts for most species were highest in the austral summer however two species’ (M. birostris and S. tigrinum) were most abundant in the winter months. The tidal state, tidal range, and moon illumination correlated significantly with the numbers of each of the nine elasmobranch species. Non-Metric Multidimensional Scaling (NMDS) indicated that species’ responses to the measured parameters grouped taxonomically. Environmental influences resulted in strong seasonal patterns of reef use by large-bodied and pelagic elasmobranch species (e.g. manta rays). The measured environmental parameters also resulted in daily, monthly, and seasonal patterns of abundance of reef-resident stingray and shark species. Banning extraction of elasmobranch species around the reefs where they aggregate and reflecting species distributions within fisheries regulations may significantly benefit the regional elasmobranch community.

Facial Skin Microbiome Composition and Functional Shift with Aging.

The change in the skin microbiome as individuals age is only partially known. To provide a better understanding of the impact of aging, whole-genome sequencing analysis was performed on facial skin swabs of 100 healthy female Caucasian volunteers grouped by age and wrinkle grade. Volunteers' metadata were collected through questionnaires and non-invasive biophysical measurements. A simple model and a biological statistical model were used to show the difference in skin microbiota composition between the two age groups. Taxonomic and non-metric multidimensional scaling analysis showed that the skin microbiome was more diverse in the older group (≥55 yo). There was also a significant decrease in Actinobacteria, namely in Cutibacterium acnes, and an increase in Corynebacterium kroppenstedtii. Some Streptococcus and Staphylococcus species belonging to the Firmicutes phylum and species belonging to the Proteobacteria phylum increased. In the 18-35 yo younger group, the microbiome was characterized by a significantly higher proportion of Cutibacterium acnes and Lactobacillus, most strikingly, Lactobacillus crispatus. The functional analysis using GO terms revealed that the young group has a higher significant expression of genes involved in biological and metabolic processes and in innate skin microbiome protection. The better comprehension of age-related impacts observed will later support the investigation of skin microbiome implications in antiaging protection.

Rodents mediate the relationship between seed rain, seed bank, and plant community with increased grazing disturbance.

Seed rain and the soil seed bank represent the dispersal of seeds in space and time, respectively, and can be important sources of recruitment of new individuals during plant community regeneration. However, the temporal dynamics of seed rain and the mechanisms by which the seed rain and soil seed bank may play a role in plant community regeneration with increased grazing disturbance remain unclear. Seed rain, soil seed bank, aboveground vegetation, and rodent density were sampled along a grazing gradient in an alpine marsh on the eastern Tibetan Plateau. We described the temporal dynamics of seed dispersal using Bayesian generalized mixed models, and nonmetric multidimensional scaling and the structural equation model were used to examine the effects of grazing disturbance on the relative role of seed rain and soil seed bank on aboveground plant community regeneration. The temporal dynamics of seed rain changed from a unimodal to a bimodal pattern with increased grazing disturbance. Both species diversity and seed density of the seed rain and seed bank increased significantly with increased grazing disturbance. Increased grazing disturbance indirectly increased the similarity of composition between seed rain, seed bank, and aboveground plant community by directly increasing species diversity and abundance of aboveground plant community. However, increased grazing disturbance also indirectly decreased the similarity of seed rain, soil seed bank, and aboveground plant community by directly increasing rodent density. The similarity between seed rain and aboveground plant community was greater than that of the soil seed bank and aboveground plant community with increased grazing disturbance. Grazing disturbance spreads the risk of seed germination and seedling establishment by changing the temporal dynamics of seed dispersal. Plants (positive) and rodents (negative) mediated the role of seed rain and soil seed bank in plant community regeneration. The role of seed rain in plant community regeneration is higher than the seed bank in disturbed alpine marshes. Our findings increase our understanding of the regeneration process of the plant community, and they provide valuable information for the conservation and restoration of alpine marsh ecosystems.

Diversity of the genus Chondrilla L. (Asteraceae) in Eastern Europe

Abstract. Kashin AS, Parkhomenko AS, Kondratieva AO, Kritskaya TA, Bogoslov AV, Shilova IV. 2024. Diversity of the genus Chondrilla L. (Asteraceae) in Eastern Europe. Biodiversitas 25: 1901-1910. The genus Chondrilla (Asteraceae) has a complex taxonomic structure due to widespread apomictic reproduction. This study aimed to identify the variability and clarify the status of Chondrilla species growing in Eastern Europe (European Russia and Western Kazakhstan). The study of morphological variability in Chondrilla species was assessed using 28 morphometric parameters. Moreover, 840 specimens from 28 populations of 8 Chondrilla species from Eastern Europe were analyzed. Principal Component Analysis (PCA), Nonmetric Multi-Dimensional Scaling (NMDS), recursive decomposition, and random forest algorithm were used for analysis. The ordination methods divided the studied samples into two groups: the first group included samples of C. ambigua and C. pauciflora, and the second group included all remaining samples. Following the resulting binary trees, obtained by recursive decomposition method and the random forest algorithm, a determination key was compiled for the Chondrilla species of Eastern Europe. The high level of morphological variation in Chondrilla and its distribution characteristics revealed in this study by numerical taxonomy and recursive decomposition methods, along with our previous studies results, show that only C. ambigua is a morphologically and genetically well-separated species, including C. pauciflora as a triploid cytotype; C. canescens, C. graminea, C. latifolia and C. juncea are synonyms with the priority name C. juncea and should be considered as subspecies; and C. brevirostris and C. laticoronata are hybrids with C. ambigua as maternal parent.

Alpine plant communities and current topographic microrefugia vary with regional climates

Topographic microrefugia on slopes are assumed to be critical for the persistence of alpine plant species and the maintenance of alpine plant community diversity in a warming climate. They create microclimates, some of which are cooler and/or wetter than others, which may buffer continuing climate change. However, the current relationship of plant communities to microtopography at individual slope scale could differ among regional climates, and if so resilience in new climates would also differ.Vegetation cover and topographic site characteristics at a fine scale were recorded in the field in three alpine regions of the Rocky Mountains, USA: Glacier National Park, MT, the Indian Peaks Area, CO, and Taos Ski Valley, NM. Elements of alpine slopes were identified and transformed into ordinal variables. Two indicators of insolation were calculated from slope angle, slope aspect, and latitude, and soil depth indicators and elevation were recorded. In each region, the contribution of these variables to the variation in the plant community composition were compared using nonmetric multidimensional scaling and random forest models.The partitioned variance explained by the topographic and topography-derived climatic variables differed among the three regions. Variables related to moisture conditions were more important in the snowiest, northern region and the central region, while those related to energy were more important in the southern region with higher radiation and temperature. Lower correlations of mesoscale variables set microrefugia in a hierarchical context.The more extreme regional topographically derived climatic variables better explain the differentiation of alpine plant communities. These variables may not play the same role in potentially novel future climates. Because topographic features mediate regional climates to niche dimensions, setting microrefugia in a multiscale framework can focus research on climate change impacts.

Navigating divergent perspectives on critical habitat designation: Insights from the little bustard (Tetrax tetrax) conservation in Spain

The designation of critical habitats is a conservation tool extensively used worldwide. Although the effectiveness of this tool has been proved globally, its implementation in Spain is scarce, probably due to the ambiguous character of its definition in policy and other related problems. This study provides insight into some of these aspects and how different groups of experts interpret the concept of critical habitat. We used the little bustard (Tetrax tetrax) as a case study of an endangered species for which critical habitats must be designated. We interviewed 47 experts of the species, from researchers to environmental agency technicians, about the objectives that critical habitats should address, and which facilitating and constraining aspects should be considered in such designation. By grouping the answers in different categories and running ordination analyses (Non-Metric Multidimensional Scaling) we found that researchers mainly focused on ecological objectives for critical habitats, compared to the rest of the respondents who also considered socioeconomic aspects as basic objectives for critical habitats. Only 36% of the experts mentioned ecological factors as constraints to such designation, while socioeconomic constraints were mentioned by all but two of the experts (96%). These results suggest differences in the conceptualization of critical habitat between scientists and managers, from pure ecological requirements of the species to the actual implications and socioeconomic constraints of its implementation, respectively. Integrating multiple stakeholders and views will reflect these differences into the operational understanding of critical habitats and will ensure that future critical habitat designations are effective management tools.

Linking carbon storage with land use dynamics in a coastal Ramsar wetland

Coastal wetland ecosystems make an important contribution to the global carbon pool, yet their extent is declining due to aquaculture-related land use changes. We conducted an extensive investigation into the carbon stock and area coverage of macrophytes in a tropical coastal Ramsar wetland, Kolleru in Andhra Pradesh, India. A total of 72 quadrats of size 1 × 1 m2 were laid in the wetland, 19 species of macrophytes were collected and analyzed for carbon content using a CNHS analyzer. To assess changes in the wetland macrophytes, Normalized Difference Vegetation Index (NDVI) was estimated using Landsat time series data from 1975 to 2023. The importance value index (IVI) of macrophytes scored highest for the Ipomoea aquatica (41.4) and the lowest for Ottelia alismoides (1.9). Non-metric multidimensional scaling (NMDS) significantly (r = 0.1905, p = 0.0361) revealed a clear separation of macrophytes in ordination space. ANOVA indicated highly significant (p < 0.0001) variations in the carbon content of aboveground and belowground components of macrophytes. Among the different macrophytes, the highest carbon content was found in Phragmites karka (0.6 g. g−1) and the lowest was recorded in Utricularia stellaris (0.2 g. g−1). On an average, emergents in the Kolleru wetland sequester 1525 ± 181 g C m−2 yr−1, rooted floating species sequester 858 ± 101 g C m−2 yr−1, submerged macrophytes sequester 480 ± 60 g C m−2 yr−1, and free-floating macrophytes sequester 221 ± 90 g C m−2 yr−1. Land cover mapping revealed a decrease in spread of aquatic vegetation from 225.2 km2 in 1975 to 100.6 km2 in 2023. Although macrophytes are vital carbon sinks, the wetland conversion into fishponds has resulted in a loss of 55.3 % of carbon storage. Therefore, immediate restoration of macrophyte cover is vital for the proper functioning of carbon sequestration and mitigation of climate change impacts.

Faecal egg count reduction tests and nemabiome analysis reveal high frequency of multi-resistant parasites on sheep farms in north-east Germany involving multiple strongyle parasite species

Anthelmintic resistance in sheep parasitic gastrointestinal nematodes is widespread and a severe health and economic issue but prevalence of resistance and involved parasite species are unknown in Germany. Here, the faecal egg count reduction test (FECRT) was performed on eight farms using fenbendazole, ivermectin and moxidectin and on four farms using only moxidectin. A questionnaire was used to obtain data on management practices to potentially identify risk factors for presence of resistance. All requirements of the recently revised WAAVP guideline for diagnosing anthelmintic resistance using the FECRT were applied. Nematode species composition in pre- and post-treatment samples was analysed with the nemabiome approach. Using the eggCounts statistic package, resistance against fenbendazole, ivermectin and moxidectin was found on 7/8, 8/8 and 8/12 farms, respectively. No formal risk factor analysis was conducted since resistance was present on most farms. Comparison with the bayescount R package results revealed substantial agreement between methods (Cohen's κ = 0.774). In contrast, interpretation of data comparing revised and original WAAVP guidelines resulted in moderate agreement (Cohen's κ = 0.444). The FECR for moxidectin was significantly higher than for ivermectin and fenbendazole. Nemabiome data identified 4 to 12 species in pre-treatment samples and treatments caused a small but significant decrease in species diversity (inverse Simpson index). Non-metric multidimensional scaling and k-means clustering were used to identify common patterns in pre- and post-treatment samples. However, post-treatment samples were scattered among the pre-treatment samples. Resistant parasite species differed between farms. In conclusion, the revised FECRT guideline allows robust detection of anthelmintic resistance. Resistance was widespread and involved multiple parasite species. Resistance against both drug classes on the same farm was common. Further studies including additional drugs (levamisole, monepantel, closantel) should combine sensitive FECRTs with nemabiome data to comprehensively characterise the anthelmintic susceptibility status of sheep nematodes in Germany.

Wild ungulate effects on soil fungal diversity in Mediterranean mixed forests

The effect of wild ungulate density on ecosystems varies according to different factors: climate and physiography conditions, forest type, management history, and herbivore identity. In this study, we evaluated the effect of historically high densities of red deer (Cervus elaphus L.) on the soil fungal communities in Mediterranean ecosystems using 30 paired plots, open on the one hand and exclosure plots on the other one. Plots were established at the end of 2020 in a perimeter-fenced hunting estate of 6600 ha in Toledo, Spain. Three months after plots were established, we analysed fungal communities in 60 soil samples using Illumina 250-bp paired-end sequencing. We estimated changes in total fungal richness and in the richness of trophic groups through Linear Mixed Effects models using fenced/unfenced type and deer habitat use as fixed variables and the location of the plots and the main tree host species as random variables. Fungal composition was analysed using non-metric multidimensional scaling and permutational multivariate ANOVA; edaphic characteristics were incorporated to explain differences. Soil fungal communities were not differentially affected by excluding ungulates for three months. Areas with high deer densities had a richer saprotrophic community and where lowland environments were dominated by the main tree hosts Quercus faginea and Quercus ilex. Arbutus unedo was found in mountain areas where there was less herbivore pressure, a greater richness of ectomycorrhizal and lichenized fungi and soils positively associated to nitrogen, phosphorus, potassium and organic matter levels.

The use of ecological niche models improves biogeographic regionalization of the Balsas Depression, Mexico

AbstractAimBiogeographic regionalization classifies zones in terms of their biotas and contributes to understanding the ecological and historical factors that affect the distribution of species. We use Ecological Niche Modeling (ENM) to complement missing information on species distribution and thus improve the accuracy of biogeographic boundaries.LocationBalsas Depression Floristic Province, Mexico.MethodsBased on parameters documented in herbarium collections and environmental variables, ENM was carried out to determine the most suitable environmental conditions for a species to thrive (i.e., the species' ecological niche). The ENM and spatial analysis were used to obtain the biogeographic regionalization of the seasonally dry tropical forest (SDTF) in the Balsas Depression (BD), Mexico, through spatial analysis. Using the Maxent algorithm, we constructed ecological niche models (ENMs) of 134 flowering plant species distributed preferentially in the SDTF (characteristic species), most of them endemic to the BD. Subsequently, we obtained an incidence matrix based on the information from the 134 ENMs, which was used to analyze the turnover of species in Biodiverse software. The turnover matrix was used for Non‐metric Multidimensional Scaling (NMDS) ordination and clustering analyses. Finally, the environmental predictors most related to species turnover were identified using the relative environmental turnover method.ResultsThe clustering analysis divided the SDTF in the BD into four floristic districts — two located in its western part and two in the eastern region. The NMDS differentiated, in the first component, two districts in the western region and one in the eastern. Seven environmental variables contributed significantly to explaining the turnover of species in these districts; the most significant were the elevation, pH, and precipitation of the coldest quarter.Main ConclusionsThe use of ENM for the regionalization of areas with high species richness allows for a more detailed classification of subregions and the distribution patterns of the species that define their limits. This provides a more solid theoretical basis for the investigation of biogeographic patterns.

Temporal and spatial variations and driving factors of phytoplankton in Yongjiang River estuary

To explore the temporal and spatial variations in phytoplankton community in small estuaries, we collected surface water samples from Yongjiang River estuary during wet, normal, and dry seasons and determined the main driving factors of phytoplankton community. A total of 358 species belonging to nine phyla and 123 genera were identified in all seasons. During wet, normal, and dry seasons, species number was 276, 154 and 151, and the abundance was (170.45±225.43)×103, (51.92±30.28)×103 and (31.65±12.79)×103 cells·L-1, respectively. Diatoms dominated the phytoplankton community, and the main dominant species were Cyclotella meneghiniana, Skeletonema costatum, and Paralia sulcata. Shannon diversity and Pielou evenness indices decreased from inside mouth to outside mouth in wet season, but there was no obvious spatial difference in normal season or dry season. Results of non-metric multidimensional scaling analysis and analysis of similarities showed that phytoplankton community composition differed significantly among different regions (inside, at and outside mouth) and different seasons. In wet season, phytoplankton abundance was significantly positively correlated with temperature, dissolved inorganic nitrogen, and dissolved reactive phosphorus, but significantly negatively correlated with salinity. In normal season, phytoplankton abundance was significantly negatively correlated with temperature. In dry season, it was not significantly correlated with environmental factors. Results of redundancy analysis showed that temperature, salinity, ammonium and dissolved reactive phosphorus explained the variations in phytoplankton community by 19.5%, 11.9%, 9.4% and 8.2%, respectively. These results revealed high dominance of diatoms and the main driving factors (temperature, salinity and nutrients) of phytoplankton community in Yongjiang River estuary.

Origin of the neonatal gut microbiota and probiotic intervention: a randomized controlled trial.

This study aims to evaluate the origin of the neonatal gut microbiota on the 14th day and probiotic intervention in the third trimester. Samples were obtained from a total of 30 pregnant individuals and their offspring, divided into a control group with no intervention and a probiotic group with live combined Bifidobacterium and Lactobacillus tablets, analyzing by 16S rRNA amplicon sequencing of the V4 region to evaluate the composition of them. Non-metric multidimensional scaling and SourceTracker were used to evaluate the origin of neonatal gut microbiota. We found that the microbiota in the neonatal gut at different times correlated with that in the maternal microbiota. The placenta had more influence on meconium microbiota. Maternal gut had more influence on neonatal gut microbiota on the 3rd day and 14th day. We also found that the maternal gut, vaginal, and placenta microbiota at full term in the probiotic group did not have a significantly different abundance of Bifidobacterium, Lactobacillus, or Streptococcus. However, some other bacteria changed in the maternal gut and their neonatal gut in the probiotic group.

Navigating social-ecological changes: A mixed-method analysis of extensive livestock systems in southern Patagonian forests, Argentina.

Sustainable livestock management plays a crucial role in food production, climate change mitigation, and cultural preservation. Our study aimed to identify and analyse the diversity of social-ecological conditions that characterize extensive livestock systems in southern Patagonia. We integrated data collected from interviews and secondary sources and analysed data using hierarchical cluster analysis and non-metric multidimensional scaling to identify distinct ranching types. A qualitative analysis of key informant interviews identified key social-ecological changes for each type. The results emphasize the impact of administration, production, and biophysical factors on shaping different livestock ranching schemes. Further, we identified three significant social-ecological changes driving the dynamics of these systems, including shifts from (1) sheep to cattle ranching, (2) domestic to feral cattle ranching, and (3) landowners to tenant land managers. These findings have implications for policymakers seeking to develop strategies tailored to diverse realities, ensuring the sustainability of livestock systems in Tierra del Fuego.

Soil Moisture and Litter Coverage Drive the Altitude Gradient Pattern of Soil Arthropods in a Low-Elevation Mountain

This study sought to investigate the vertical distribution pattern of the soil faunal community in a low-altitude mountain area. On 8 July 2022, a low hill was selected as the study area, and soil arthropods were collected through traps. The leaf litter, vegetation type, and distribution quantity of each sampling site were investigated while the soil faunae were collected. In addition, the soil’s physical and chemical parameters were measured. The results of a one-way ANOVA showed that there were significant differences (p &lt; 0.05) in the soil properties, leaf litter, and plant quantities at different altitudes within the research area. A total of 1086 soil arthropods, belonging to five classes and ten orders, were collected during the study period. The dominant species of soil arthropods at different altitudes were significantly different. The dominant species in low-altitude areas were Armadillidium sp. and Aethus nigritus. However, Eupolyphaga sinensis and Philodromidae were the dominant species in high-altitude areas. The results of a non-metric multidimensional scaling (NMDS) analysis showed that the soil faunae at different altitudes were clustered into two communities: a high-altitude community and a low-altitude community. With the increase in altitude, the species richness of the soil arthropods gradually decreased, and their abundance showed a decreasing trend. A redundancy analysis (RDA) of the soil arthropods and environmental factors showed that soil moisture (p &lt; 0.01), pH (p &lt; 0.01) and defoliation (p &lt; 0.05) had significant effects on the distribution of the soil fauna. The results of a Pearson correlation analysis indicated that different environmental factors had interactive effects on the distribution of the soil arthropods. The quantity and species richness of the soil arthropods in different sample lines were tested using a variance analysis. The results showed that there were significantly smaller quantities of soil arthropods in the sampling line closer to the trekking ladder. This indicates that human tourism, namely mountaineering activities, had a direct impact on the soil fauna. This study can provide a reference for and data support in the development of biodiversity conservation measures for forest parks in low mountain areas.

Ordovician paleobiogeography of the Suborder Cheirurina (Trilobita)

The Suborder Cheirurina is a diverse trilobite clade, ranging from the latest Cambrian to the Devonian. The Ordovician paleobiogeography of the group is explored based on the distribution of genera. Major tectonostratigraphic units and Ordovician ages (Tremadocian, Floian, Dapingian, Darriwilian, Sandbian and Katian) were recorded for each genus. Cluster analysis (agglomerative hierarchical clustering) and non-metric multidimensional scaling (NMDS) were performed independently for each Ordovician age. The results characterize the Ordovician distribution of Cheirurina as two main general patterns. First, there was a marked decrease in endemicity through the Ordovician. Second, latitude seems to play a significant role in the distribution of Cheirurina, at both genus and family levels. Pliomerids and encrinurids occur overwhelmingly at low latitudes. The two main exceptions are Placoparia (Pliomeridae) and Dindymene (Encrinuridae), which are distributed in high latitude terranes. Within Cheiruridae, members of Eccoptochilinae are typical of high latitude Gondwana. Conversely, acanthoparyphines, cheirurines, deiphonines, heliomerines and sphaerexochines are mainly distributed in low or intermediate latitudes.

Dynamic oceanographic influences on zooplankton communities over the northern Gulf of Mexico continental shelf

Dynamic influences of ocean processes on distribution, abundance, and diversity of zooplankton communities were studied over the continental shelf in the northern Gulf of Mexico (GoM) from 2015 to 2017. Zooplankton sampling was conducted on four summer cruises in the northcentral GoM. Sampling was designed in waters potentially influenced by the Loop Current (LC) and/or Mississippi River discharge to assess the impacts of these two mesoscale features on the abundance and diversity of zooplankton. During the three-year study, the LC displayed distinct spatial-temporal variations in penetration and occurrence in the northern GoM. Environmental conditions (i.e., sea surface temperature, salinity, and dissolved oxygen) varied between months and years sampled, and were significantly different among cruises (ANOVA, p < 0.001). The majority of zooplankton consisted of calanoid copepods (65% ± 7.2%, mean ± SD), while non-copepod taxa were primarily chaetognaths, polychaetes, tunicates, and ostracods (23 ± 9.2%). Species abundance and diversity of zooplankton were significantly correlated with sea surface temperature, salinity, and dissolved oxygen (p < 0.05). Canonical correspondence analysis displayed significant associations between mesoscale features and dominant zooplankton groups among cruises and by taxa (Monte Carlo Permutation Test, p < 0.001). In addition, non-metric multidimensional scaling indicated that zooplankton assemblages were distinct, likely caused by Mississippi River plumes during the study period. As one of the few efforts to examine zooplankton dynamics at a low taxon level over the GoM continental shelf regarding the impact of mesoscale features, this study revealed seasonal (i.e. summer) and spatial patterns in distribution, abundance, and diversity of zooplankton communities subjected to the dynamic physicochemical conditions in the northern GoM, which will continue in a changing climate.