Species Diversity Research Articles

AM-MSFF: A Pest Recognition Network Based on Attention Mechanism and Multi-Scale Feature Fusion.

Traditional methods for pest recognition have certain limitations in addressing the challenges posed by diverse pest species, varying sizes, diverse morphologies, and complex field backgrounds, resulting in a lower recognition accuracy. To overcome these limitations, this paper proposes a novel pest recognition method based on attention mechanism and multi-scale feature fusion (AM-MSFF). By combining the advantages of attention mechanism and multi-scale feature fusion, this method significantly improves the accuracy of pest recognition. Firstly, we introduce the relation-aware global attention (RGA) module to adaptively adjust the feature weights of each position, thereby focusing more on the regions relevant to pests and reducing the background interference. Then, we propose the multi-scale feature fusion (MSFF) module to fuse feature maps from different scales, which better captures the subtle differences and the overall shape features in pest images. Moreover, we introduce generalized-mean pooling (GeMP) to more accurately extract feature information from pest images and better distinguish different pest categories. In terms of the loss function, this study proposes an improved focal loss (FL), known as balanced focal loss (BFL), as a replacement for cross-entropy loss. This improvement aims to address the common issue of class imbalance in pest datasets, thereby enhancing the recognition accuracy of pest identification models. To evaluate the performance of the AM-MSFF model, we conduct experiments on two publicly available pest datasets (IP102 and D0). Extensive experiments demonstrate that our proposed AM-MSFF outperforms most state-of-the-art methods. On the IP102 dataset, the accuracy reaches 72.64%, while on the D0 dataset, it reaches 99.05%.

Impact of intense sanitization procedures on bacterial communities recovered from floor drains in pork processing plants

BackgroundPork processing plants in the United States (US) cease operations for 24–48 h every six or twelve months to perform intense sanitization (IS) using fogging, foaming, and further antimicrobial treatments to disrupt natural biofilms that may harbor pathogens and spoilage organisms. The impact such treatments have on short-term changes in environmental microorganisms is not well understood, nor is the rate at which bacterial communities return.MethodsSwab samples were collected from floor drains to provide representative environmental microorganisms at two US pork processing plants before, during, and after an IS procedure. Samples were collected from four coolers where finished carcasses were chilled and from four locations near cutting tables. Each sample was characterized by total mesophile count (TMC), total psychrophile count (TPC), and other indicator bacteria; their biofilm-forming ability, tolerance of the formed biofilm to a quaternary ammonium compound (300 ppm, QAC), and ability to protect co-inoculated Salmonella enterica. In addition, bacterial community composition was determined using shotgun metagenomic sequencing.ResultsIS procedures disrupted bacteria present but to different extents depending on the plant and the area of the plant. IS reduced TPC and TMC, by up to 1.5 Log10 CFU only to return to pre-IS levels within 2–3 days. The impact of IS on microorganisms in coolers was varied, with reductions of 2–4 Log10, and required 2 to 4 weeks to return to pre-IS levels. The results near fabrication lines were mixed, with little to no significant changes at one plant, while at the other, two processing lines showed 4 to 6 Log10 reductions. Resistance to QAC and the protection of Salmonella by the biofilms varied between plants and between areas of the plants as well. Community profiling of bacteria at the genus level showed that IS reduced species diversity and the disruption led to new community compositions that in some cases did not return to the pre-IS state even after 15 to 16 weeks.DiscussionThe results found here reveal the impact of using IS to disrupt the presence of pathogen or spoilage microorganisms in US pork processing facilities may not have the intended effect.

Rectifying a century of misidentifications: a taxonomic re-evaluation of sipo snakes (Colubridae: Chironius) on Trinidad

The island of Trinidad has several endemic reptile species that in some cases are morphologically indistinguishable, or almost so, from their mainland counterparts. In particular, many snakes from the island have not been examined thoroughly with modern scientific methods and may therefore be misidentified. At least two species of sipo snakes (Chironius carinatus, C. septentrionalis) are reported to inhabit Trinidad, both being considered species already inhabiting the mainland, though their identities are based solely on morphology. Here, we evaluate the molecular distinctiveness of these Trinidadian snakes and assess their relationships to other members of the genus. We constructed a multi-locus data set (12S rRNA, 16S rRNA, cyt b, ND4, cmos, NT3, Rag-1, Rag-2) including novel sequences and those available on GenBank to perform Bayesian and maximum likelihood phylogenetic analyses. Our phylogenetic reconstruction elucidates the identity of both Trinidad species, which have been misidentified since their discovery, and we provide a literature review of their taxonomic history. More specifically, our results suggest that the Trinidad population of Chironius carinatus is an undescribed species, that we describe herein as Chironius nigelnoriegai sp. nov., and is the sister to C. flavopictus. Our results also demonstrate that the Trinidad population previously identified as C. septentrionalis is instead the mainland species C. cochranae, a member of a clade with C. foveatus, C. laurenti, and C. multiventris. Finally, we generated a time tree and inferred that our new species separated from C. flavopictus approximately 4 million years ago in the Pliocene, a time when the island of Trinidad detached from Northern Venezuela. This work contributes to a better understanding of species diversity of Trinidad and we hope that it assists in conservation efforts towards this important endemic region. These findings support the prospect of rapid speciation on Trinidad and implies that more extensive surveys of island squamates will reveal additional cryptic diversity. http://zoobank.org/urn:lsid:zoobank.org:pub:500DB91B-62CD-4051-9831-0BEEAC64C8E2

The relationship between landscape pattern and plant species diversity in east Dongting lake wetland based on different Eco-environment

Exploring the impact factors associated with biodiversity and the relationship between them has always been a concerned issue in recent years. However, the previous research mostly focus on theoretical layer. Accordingly, the relationship between landscape pattern and biodiversity is to be analyzed in this research. The landscape pattern determines the function and ecological process of the landscape, and affects the species flow, information flow and energy flow in the landscape. Land use patterns has inevitably left an impact on the landscape pattern. Landscape pattern determines the function and ecological process of landscape and thus plays a significant role in biodiversity. East Dongting Lake National Nature Reserve is taken as the research object of the paper, and the remote sensing image data of three different time periods are collected, including 2000, 2010 and 2020. With an interpretation of the vegetation landscape pattern changes inside the protected area to collect and analyze the vegetation coverage. By comparing landscape patterns and the dynamic changes of land use in different periods of time, the correlation between landscape pattern characteristics and regional biodiversity is to be analyzed. Research shows: (1) From 2000 to 2020, the vegetation coverage of East Dongting Lake increased, but the landscape shape, scale, diversity and uniformity index decreased to varying degrees. (2) At the class level of landscape type, the relationship between landscape index and biodiversity is different. A complex relationship between farmland landscape and biodiversity. There is a significant positive correlation between the index of grassland landscape type and the index of regional biodiversity. (3) The correlation analysis results at the landscape level show that the landscape characteristic index is positively correlated with the regional biodiversity index. The grassland landscape in the area is the main habitat of biological species. At the same time, as the main grain producing area, the impact of farmland landscape cannot be ignored. This study has certain theoretical guiding significance for the protection and management of biodiversity in the region in terms of maintaining landscape pattern in particular the grassland landscape area and increasing vegetation coverage in the process of land use.

Symbiotic bacteria and fungi proliferate in diapause and may enhance overwintering survival in a solitary bee.

Host-microbe interactions underlie the development and fitness of many macroorganisms, including bees. Whereas many social bees benefit from vertically transmitted gut bacteria, current data suggests that solitary bees, which comprise the vast majority of species diversity within bees, lack a highly specialized gut microbiome. Here we examine the composition and abundance of bacteria and fungi throughout the complete life cycle of the ground-nesting solitary bee Anthophora bomboides standfordiana. In contrast to expectations, immature bee stages maintain a distinct core microbiome consisting of Actinobacterial genera (Streptomyces, Nocardiodes) and the fungus Moniliella spathulata. Dormant (diapausing) larval bees hosted the most abundant and distinctive bacteria and fungi, attaining 33 and 52 times their initial copy number, respectively. We tested two adaptive hypotheses regarding microbial functions for diapausing bees. First, using isolated bacteria and fungi, we found that Streptomyces from brood cells inhibited the growth of multiple pathogenic filamentous fungi, suggesting a role in pathogen protection during overwintering, when bees face high pathogen pressure. Second, sugar alcohol composition changed in tandem with major changes in fungal abundance, suggesting links with bee cold tolerance or overwintering biology. We find that A. bomboides hosts a conserved core microbiome that may provide key fitness advantages through larval development and diapause, which raises the question of how this microbiome is maintained and faithfully transmitted between generations. Our results suggest that focus on microbiomes of mature or active insect developmental stages may overlook stage-specific symbionts and microbial fitness contributions during host dormancy.

Large‐scale integrative taxonomy of Swedish grass flies (Diptera, Chloropidae) reveals hitherto unknown complexity of a dark taxon

AbstractThe study of biodiversity is fundamental to preserving life on Earth but a challenging endeavour due to the taxonomic neglect associated with hyperdiverse lineages. To overcome this problem, we have implemented for the first time a Large‐scale integrative taxonomic (LIT) approach on the hyperdiverse insect family Chloropidae. This lineage of flies is a great fit for implementing emerging protocols such as LIT due to their ecological relevance, abundance and global distribution, poorly known genetic diversity and challenging taxonomy. In this study, we test cost‐effective barcoding workflows on nonoptimally preserved chloropid flies from Sweden and then apply targeted morphological validation to accelerate the species recognition process. Our dataset yielded DNA barcodes of 63 species that represent almost one‐third of the species diversity from Sweden and 15% of the European diversity. Applying LIT allowed us to uncover two new species and address for the first time three troublesome species complexes through a comprehensive framework. We also provide previously unknown DNA barcodes for 35% of the described species found and address distribution patterns with a focus on grassland environments. We have thus contributed significantly to overcoming the taxonomic neglect of this hyperdiverse lineage by tackling the diversity of chloropids using complementary sources of data, scalable techniques and quickly translating multiple sources of evidence into named species.

Diversity of Helminths of Insectivorous Mammals (Mammalia: Eulipothyphla) from Large Forest Protected Areas of the Middle Volga Region (European Russia)

Insectivores (Eulypotiphla) are a substantial component of Russian forest ecosystems. The parasites of these animals also form an important part of natural biocenoses and act as one of the factors in the formation of biodiversity. The Mordovia Nature Reserve and National Park “Smolny” are large, forested areas located in the center of European Russia. We studied the helminth fauna of insectivores in these protected areas in 2018–2022. In total, using the method of complete helminthological necropsy, we examined 478 individuals of shrews, moles, and hedgehogs and recorded 34 species of parasitic worms, i.e., 8 trematode, 7 cestode, 1 acanthocephalan, and 18 nematode species. The most diverse helminth fauna was found in Sorex araneus (22 species). The composition of helminths in Sorex isidon (12), Neomys fodiens (9), Sorex minutus, and Erinaceus roumanicus (8 species each) turned out to be less diverse. The lowest species diversity of helminths was observed in Neomys milleri (3) and Talpae europaea (2 species). Taking into account the newly obtained data, we conducted a review of the helminth diversity in shrews, hedgehogs, and moles in the Middle Volga region. According to our literature data, the helminth fauna of insectivores in this region consists of 52 species, including 14 cestodes, 13 trematodes, 22 nematodes, and 3 acanthocephalans. Most of them belong to the Palearctic faunal complex (36 species). The helminth fauna of insectivores in the studied protected areas was compared with the helminth fauna of micromammals in other areas of the Middle Volga region. Our comparative analysis showed a high and average degree of similarity in the helminth fauna within individual species and genera of Eulipotyphla.

Parallel patterns of genetic diversity and structure in circumboreal species of the Sphagnum capillifolium complex.

Shared geographical patterns of population genetic variation among related species is a powerful means to identify the historical events that drive diversification. The Sphagnum capillifolium complex is a group of closely related peat mosses within the Sphagnum subgenus Acutifolia and contains several circumboreal species whose ranges encompass both glaciated and unglaciated regions across the northern hemisphere. In this paper, we (1) inferred the phylogeny of subg. Acutifolia and (2) investigated patterns of population structure and genetic diversity among five circumboreal species within the S. capillifolium complex. We generated RAD sequencing data from most species of the subg. Acutifolia and samples from across the distribution ranges of circumboreal species within the S. capillifolium complex. We resolved at least 14 phylogenetic clusters within the S. capillifolium complex. Five circumboreal species show some common patterns: One population system comprises plants in eastern North America and Europe, and another comprises plants in the Pacific Northwest or around the Beringian and Arctic regions. Alaska appears to be a hotspot for genetic admixture, genetic diversity, and sometimes endemic subclades. Our results support the hypothesis that populations of five circumboreal species within the S. capillifolium complex survived in multiple refugia during the last glacial maximum. Long-distance dispersal out of refugia, population bottlenecks, and possible adaptations to conditions unique to each refugium could have contributed to current geographic patterns. These results indicate the important role of historical events in shaping the complex population structure of plants with broad distribution ranges.

Tree demographic strategies largely overlap across succession in Neotropical wet and dry forest communities.

Secondary tropical forests play an increasingly important role in carbon budgets and biodiversity conservation. Understanding successional trajectories is therefore imperative for guiding forest restoration and climate change mitigation efforts. Forest succession is driven by the demographic strategies-combinations of growth, mortality and recruitment rates-of the tree species in the community. However, our understanding of demographic diversity in tropical tree species stems almost exclusively from old-growth forests. Here, we assembled demographic information from repeated forest inventories along chronosequences in two wet (Costa Rica, Panama) and two dry (Mexico) Neotropical forests to assess whether the ranges of demographic strategies present in a community shift across succession. We calculated demographic rates for >500 tree species while controlling for canopy status to compare demographic diversity (i.e., the ranges of demographic strategies) in early successional (0-30 years), late successional (30-120 years) and old-growth forests using two-dimensional hypervolumes of pairs of demographic rates. Ranges of demographic strategies largely overlapped across successional stages, and early successional stages already covered the full spectrum of demographic strategies found in old-growth forests. An exception was a group of species characterized by exceptionally high mortality rates that was confined to early successional stages in the two wet forests. The range of demographic strategies did not expand with succession. Our results suggest that studies of long-term forest monitoring plots in old-growth forests, from which most of our current understanding of demographic strategies of tropical tree species is derived, are surprisingly representative of demographic diversity in general, but do not replace the need for further studies in secondary forests.

An expanded phylogeny of the genus Pseudamnicola (Gastropoda; Truncatelloidea; Hydrobiidae) across the Mediterranean Basin.

The genus Pseudamnicola Paulucci, 1878, is commonly found throughout the Mediterranean region. The genus displays considerable levels of endemism, accompanied by notable systematic and taxonomic ambiguity. However, the application of molecular data has proven highly effective in clarifying taxonomy and unveiling the diversity of cryptic species within the genus. Therefore, we employed all cytochrome c oxidase subunit I sequence data available and generated new ones from Greece to infer the phylogeny of the genus throughout its Mediterranean range and estimate the divergence times as well as the ancestral area of diversification. Our phylogenetic and time-estimate analyses demonstrate that with 36 to 38 extant Pseudamnicola species and genetic divergences across species ranging from 0.5% to 11.9% on average, the genus underwent relatively recent diversification during late Miocene (6.53 Ma), and the primary speciation events occurred during Plio-Pleistocene. The Italian Peninsula and Islands and the Ionian Drainages as defined by the Freshwater Ecoregions of the World are the ancestral regions of the genus following two different dispersal routes. Our study contributes to deepening our understanding of Pseudamnicola phylogeny by using data from throughout its range for the first time. This phylogeny provides evidence and confirms previous studies that relatively recent habitat isolation, followed by founder and dispersal events, has been one of the primary reasons for the evolution of the genus Pseudamnicola in the Mediterranean basin.

The urea treatment of silver birch (Betula pendula Roth) logs promotes wood decay and wood discoloration

ABSTRACT Silver birch Betula pendula Roth is a widely distributed tree species in northern Europe, the wood of which is extensively used to produce plywood and veneer. However, birch wood is highly susceptible to fungal decay and discoloration. This study investigated the effectiveness of urea treatment against fungi causing discoloration in birch logs. The effect of urea treatment was evaluated in two settings, i.e. in the forest and in the log yard. In the forest, 80 one-meter-long stem segments were produced and half of them were treated with 35% urea solution and the other half with water. To simulate mechanical bark injury, half of the segments were deliberately damaged before storage. In the log yard, 60 stem segments were similarly prepared to assess fungal species colonizing wood during long-term storage. The results showed that urea-treated and bark-damaged logs exhibit the highest rate of wood discoloration, which increased with prolonged storage. Fungal isolation from wood samples identified a higher diversity of fungal species in samples from the log yard. The most frequently isolated fungi were ascomycetes from the genus Ophiostoma. In conclusion, the results demonstrated that the urea treatment is an ineffective measure against fungi causing discoloration in birch wood.

Cellular mechanisms of ion and acid-base regulation in teleost gill ionocytes.

The mechanism(s) of sodium, chloride and pH regulation in teleost fishes has been the subject of intense interest for researchers over the past 100 years. The primary organ responsible for ionoregulatory homeostasis is the gill, and more specifically, gill ionocytes. Building on the theoretical and experimental research of the past, recent advances in molecular and cellular techniques in the past two decades have allowed for substantial advances in our understanding of mechanisms involved. With an increased diversity of teleost species and environmental conditions being investigated, it has become apparent that there are multiple strategies and mechanisms employed to achieve ion and acid-base homeostasis. This review will cover the historical developments in our understanding of the teleost fish gill, highlight some of the recent advances and conflicting information in our understanding of ionocyte function, and serve to identify areas that require further investigation to improve our understanding of complex cellular and molecular machineries involved in iono- and acid-base regulation.

Insight into physico-chemical properties and microbial community structure of biogas slurry from household biogas plants of sub-Himalaya for its implications in improved biogas production.

Numerous metagenomics studies, conducted in both full-scale anaerobic digesters and household biogas plants, have shed light on the composition and activity of microbial flora essential for optimizing the performance of biogas reactors, underscoring the significance of microbial community composition in biogas plant efficiency. Although the efficiency of household biogas plants in the sub-Himalayan region has been reported, there is no literature evidence on the microbial community structure of such household biogas plants in the sub-Himalayan region. The current study evaluated the physico-chemical properties and bacterial community structure from the slurry samples of household biogas plants prevalent in the sub-Himalayan region. The slurry samples were observed to be rich in nutrients; however, their carbon and nitrogen contents were higher than the recommended standard values of liquid-fermented organic manure. The species richness and diversity indices (Chao1, Shannon, and Simpson) of household biogas plants were quite similar to the advanced biogas reactors operating at mesophilic conditions. 16S rRNA gene amplicon sequencing reveals microbial diversity, showing a higher abundance of Firmicutes (70.9%) and Euryarchaeota (9.52%) in advanced biogas reactors compared to household biogas plants. Microbial analysis shows a lack of beneficial microbes for anaerobic digestion, which might be the reason for inefficient biogas production in household biogas plants of the sub-Himalayan region. The lack of efficient bacterial biomass may also be attributed to the digester design, feedstock, and ambient temperatures. This study emphasized the establishment of efficient microbial consortia for enhanced degradation rates that may increase the methane yield in biogas plants.

Diversity and endemism of hard-shelled benthic foraminifera in permanently oxygen-depleted bottom waters: An analysis from the eastern Pacific

Benthic foraminifera are single-celled organisms inhabiting all marine environments. Despite their high tolerance to oxygen depletion, the prevailing hypothesis anticipates a reduction in their diversity in permanently oxygen-depleted environments, including oxygen minimum zones. Here we re-evaluate diversity and study the endemism of benthic foraminifera in the eastern Pacific, an oceanic area hosting the largest permanently oxygen-depleted waters of the world. We focus our analysis on the oxygen-depleted bottom waters and study how they compare with well-oxygenated waters. By utilizing extensive datasets of quantitative information on benthic foraminifera assemblages obtained from morphological traits, we present evidence that challenge traditional viewpoints. Contrary to prior inferences primarily derived from regional studies, our findings reveal that the median diversity (species richness and the Shannon index) calculated on both, living and dead assemblages does not decrease in the most oxygen-depleted bottom-waters. The analysis of unique (endemic) and shared species shows a divide between the neritic-bathyal oxygen-depleted bottom waters with low number of endemic species, and the well-oxygenated abyss hosting high number of unique species. These patterns could be explained by the long-term species exchange in the upper ocean and the isolation of the lower ocean.

Ant-plant networks exhibit distinct species diversity but similar organization in urban and wild areas of neotropical savannas

Ant-plant networks exhibit distinct species diversity but similar organization in urban and wild areas of neotropical savannas

Metformin-induced changes of the gut microbiota in patients with type 2 diabetes mellitus: results from a prospective cohort study.

The influence of the microbiota on hypoglycemic agents is becoming more apparent. The effects of metformin, a primary anti-diabetes drug, on gut microbiota are still not fully understood. This prospective cohort study aims to investigate the longitudinal effects of metformin on the gut microbiota of 25 treatment-naïve diabetes patients, each receiving a daily dose of 1500 mg. Microbiota compositions were analyzed at baseline, and at 1, 3, and 6 months of medication using 16S rRNA gene sequencing. Prior to the 3-month period of metformin treatment, significant improvements were noted in body mass index (BMI) and glycemic-related parameters, such as fasting blood glucose (FPG) and hemoglobin A1c (HbA1c), alongside homeostasis model assessment indices of insulin resistance (HOMA-IR). At the 3-month mark of medication, a significant reduction in the α-diversity of the gut microbiota was noted, while β-diversity exhibited no marked variances throughout the treatment duration. The Firmicutes to Bacteroidetes ratio. markedly decreased. Metformin treatment consistently increased Escherichia-Shigella and decreased Romboutsia, while Pseudomonas decreased at 3 months. Fuzzy c-means clustering identified three longitudinal trajectory clusters for microbial fluctuations: (i) genera temporarily changing, (ii) genera continuing to decrease (Bacteroides), and (iii) genera continuing to increase(Lachnospiraceae ND3007 group, [Eubacterium] xylanophilum group, Romboutsia, Faecalibacterium and Ruminococcaceae UCG-014). The correlation matrix revealed associations between specific fecal taxa and metformin-related clinical parameters HbA1c, FPG, Uric Acid (UA), high-density lipoproteincholesterol (HDL-C), alanine aminotransferase (ALT), hypersensitive C-reactive protein (hs-CRP), triglyceride (TG) (P < 0.05). Metacyc database showed that metformin significantly altered 17 functional pathways. Amino acid metabolism pathways such as isoleucine biosynthesis predominated in the post-treatment group. Metformin's role in glucose metabolism regulation may primarily involve specific alterations in certain gut microbial species rather than an overall increase in microbial species diversity. This may suggest gut microbiota targets in future studies on metabolic abnormalities caused by metformin.

Comparative microbiome analysis in cystic fibrosis and non-cystic fibrosis bronchiectasis.

Bronchiectasis is a condition characterized by abnormal and irreversible bronchial dilation resulting from lung tissue damage and can be categorized into two main groups: cystic fibrosis (CF) and non-CF bronchiectasis (NCFB). Both diseases are marked by recurrent infections, inflammatory exacerbations, and lung damage. Given that infections are the primary drivers of disease progression, characterization of the respiratory microbiome can shed light on compositional alterations and susceptibility to antimicrobial drugs in these cases compared to healthy individuals. To assess the microbiota in the two studied diseases, 35 subjects were recruited, comprising 10 NCFB and 13 CF patients and 12 healthy individuals. Nasopharyngeal swabs and induced sputum were collected, and total DNA was extracted. The DNA was then sequenced by the shotgun method and evaluated using the SqueezeMeta pipeline and R. We observed reduced species diversity in both disease cohorts, along with distinct microbial compositions and profiles of antimicrobial resistance genes, compared to healthy individuals. The nasopharynx exhibited a consistent microbiota composition across all cohorts. Enrichment of members of theBurkholderiaceaefamily and an increased Firmicutes/Bacteroidetes ratio in the CF cohort emerged as key distinguishing factors compared to NCFB group.Staphylococcus aureusand Prevotella shahii also presented differential abundance in the CF and NCFB cohorts, respectively, in the lower respiratory tract. Considering antimicrobial resistance, a high number of genes related to antibiotic efflux were detected in both disease groups, which correlated with the patient's clinical data. Bronchiectasis is associated with reduced microbial diversity and a shift in microbial and resistome composition compared to healthy subjects. Despite some similarities, CF and NCFB present significant differences in microbiome composition and antimicrobial resistance profiles, suggesting the need for customized management strategies for each disease.

Influence of environmental filtering and spatial processes on macroinvertebrate community in urban lakes in the Taihu Lake Basin, China.

Studies identifying the relative importance of multiple ecological processes in macroinvertebrate communities in urban lakes at a basin scale are rare. In this study, 14 urban lakes in the Taihu Lake Basin were selected to explore the relative importance of environmental filtering and spatial processes in the assembly of macroinvertebrate communities. Our findings revealed significant spatiotemporal variations in macroinvertebrate communities, both between lakes and across seasons. We found that environmental filtering exerted a greater influence on taxonomic total beta diversity and its individual components (species turnover and nestedness) compared to spatial processes. Key environmental variables such as water depth, water temperature, total dissolved solids, chlorophyll a, and lake surface area were found to be crucial in shaping macroinvertebrate communities within these urban lakes. The observed high spatial heterogeneity in environmental conditions, along with intermediate basin areas, good connectivity and short distances between lakes, and the high dispersal ability of dominant taxa, likely contributed to the dominance of environmental filtering in macroinvertebrate community assembly. Our study contributes to a better understanding of the underlying mechanisms governing macroinvertebrate community assembly in urban lakes, thereby providing valuable insights for studies on community ecology and water environmental protection in urban lakes.

Study on the Diversity and Distribution of Spider Fauna at Sree Krishna College Campus of Thrissur District, Kerala, India

Field survey was conducted to record the diversity of spiders at different sites in the Sree Krishna College Campus of Thrissur district during September 2022 to February 2023. Around 51 species of spiders belonging to 36 genera under 14 families were recorded. Salticidae family was represented with twelve species followed by Araneidae (10 sps.), Oxyopidae (5 sps.), Theridiidae (4 sps.), Lycosidae, (3 sps.), Tetragnathidae (3 sps.) and Sparassidae (3 sps.), Thomisidae (2 sps.), Pholcidae (2 sps.). But, Hersilidae, Linyphiidae, Uloboridae, Cheiracanthiidae and Sicariidae family members were very less. Spider population in different sites exhibited variation in species abundance and richness. Shannon index, Simpson index, Margalef Richness index, Berger-Parker index and Menhinick’s Index evaluated were 3.423, 0.9580, 9.540, 0.9101and 3.709 respectively. The abundance and percent occurrence of different spider species revealed variation in their distribution. For the study the entire campus has been surveyed, by dividing the area into four sites, Site A, Site B, Site C and Site D. Species composition and diversity indices studies revealed that more diversity in the site C followed by Site D, Site B and Site A. These types of surveys are important for the study of the prevalence of the spider population in given habitats and to create a biodiversity database of spider.

Multivariate statistical analysis of bioavailability of heavy metals and mineral characterization in selected species of coastal flora

This study presents a thorough investigation into the concentration of heavy metals and mineral composition within four distinct coastal flora species: Cyperus conglomeratus, Halopyrum mucronatum, Sericostem pauciflorum, and Salvadora persica. Employing rigorous statistical methodologies such as Pearson coefficient correlation, principal component analysis (PCA), analysis of variance (ANOVA), and interclass correlation (ICC), we aimed to elucidate the bioavailability of heavy metals, minerals, and relevant physical characteristics. The analysis focused on essential elements including copper (Cu), iron (Fe), manganese (Mn), zinc (Zn), magnesium (Mg2+), calcium (Ca2+), sodium (Na+), potassium (K+), and chloride (Cl–), all of which are known to play pivotal roles in the ecological dynamics of coastal ecosystems. Through PCA, we discerned distinctive patterns within PC1 to PC4, collectively explaining an impressive 99.65% of the variance observed in heavy metal composition across the studied flora species. These results underscore the profound influence of environmental factors on the mineral composition of coastal flora, offering critical insights into the ecological processes shaping these vital ecosystems. Furthermore, significant correlations among mineral contents in H. mucronatum; K+ with content of Na+ (r = 0.989) and Mg2+ (r = 0.984); as revealed by ICC analyses, contributed to a nuanced understanding of variations in electrical conductivity (EC), pH levels, and ash content among the diverse coastal flora species. By shedding light on heavy metal and mineral dynamics in coastal flora, this study not only advances our scientific understanding but also provides a foundation for the development of targeted environmental monitoring and management strategies aimed at promoting the ecological sustainability and resilience of coastal ecosystems in the face of ongoing environmental challenges.