Dominant Species Research Articles

Diversidad y usos potenciales de arvenses en fincas familiares, municipio Contramaestre, Santiago de Cuba, Cuba

Weeds are eliminated from agroecosystems without knowing their potential for agricultural use. The objective of this work was to evaluate the diversity and potential uses of weed species in three family farms in the Contramaestre municipality, Santiago de Cuba, Cuba. A unique sampling was carried out on each farm from which a general list was prepared that allowed the determination of the representativeness of the weeds, as well as the evaluation of the botanical composition, alpha diversity indicators and the most dominant species. Potential uses were determined through bibliographic analysis. 77 310 individuals were sampled, belonging to 21 families, 36 genera and 41 species. The families that contributed the most were Poaceae, Asteraceae, Fabaceae, Malvaceae and Cleomaceae; meanwhile, Cleome, Sida and Commelina were the ones who contributed the most. The alpha diversity indicators are within the range established for correct diversity and abundance, although species richness is considered moderate to low; Cleome viscosa, Cleome gynandra and Cleome spinosa were the most dominant species. Medicinal use predominated, which was attributed to several of the weeds found; to a lesser extent, beekeeping, food, domestic, fruit and ornamental uses were recognized.

A Comparative Study on Chemical Speciation of Trace Metals as a Function of Solution pH: A Multivariate Analysis and Simulation Approach

ABSTRACT Biogeochemical activity of trace elements in the environment significantly relies on their chemical speciation. Solution pH influences the chemical speciation and biogeochemical activity of trace elements in the soil-plant continuum. The current study was conducted to simulate the influence of solution pH on chemical fractions of 11 trace elements (arsenic, lead, zinc, copper, chromium, cadmium, mercury, nickel, strontium, antimony, and selenium) using Visual Minteq, a chemical equilibrium model used for the calculation of metal speciation, sorption etc. Results delineated that pH-mediated variations in the chemical speciation of trace elements differed with their type. The results of the current study revealed a dominance of chemical trace element species at acidic (1–6), neutral (7.0), and alkaline (8–14) pH. Divalent trace elements (zinc, cadmium, copper, chromium, nickel, and lead) were the dominant species at acidic pH. However, mercury dominance has a narrow pH range (1–3), while strontium dominance has a wider pH range (1–13). Nitrate, sulfate, and phosphate fractions of trace elements also occurred at pH <8. However, at pH >8, trace elements existed in hydroxide (OH) fractions. In the case of arsenic (arsenite As3+ and arsenate As5+), selenium (selenite Se4+ and selenate Se6+), and antimony (antimonite Sb3+ and antimonate Sb5+), their dominant species get oxidized with increasing pH. Multivariate analysis was conducted for various metals for their dominance as a function of pH. Moreover, Principal Component Analysis verified a linear relation of trace element fractions with pH. Results revealed that solution pH affects the chemical fractions and the phytoavailable fraction of trace elements in growth culture and associated health hazards through soil-plant transfer.

Diversity and Characteristics of Fusarium solani Species Complex (FSSC) Isolates Causing Collar Rot and Fruit Rot of Passion Fruit in Taiwan.

Fusarium solani species complex (FSSC) is a causal agent of collar rot and fruit rot in passion fruit worldwide. This study investigated the diversity and characteristics of FSSC isolates causing collar rot and fruit rot in Taiwanese passion fruit. Thirty-five FSSC isolates were harvested from collar rot and fruit rot samples of passion fruit from various cultivars and different geographical locations in Taiwan. The majority of these FSSC isolates caused collar rot and fruit rot disease of varying virulence in the stems and fruits of the purple and yellow cultivars of passion fruit. FSSC isolates were categorized into four groups: F. solani-melongenae (FSSC 21; n = 29), F. solani (FSSC 5; n = 1), F. liriodendri (FSSC 24; n = 1), and an unknown group (n = 4) based on the phylogenetic analysis of internal transcribed sequence (ITS), translation elongation factor 1 alpha (TEF-1α), and RNA polymerase II subunit 2 (RPB2) sequences. In Taiwan, F. solani-melongenae was the dominant species causing collar rot and fruit rot in passion fruit. F. solani-melongenae was a homothallic fungus that produced perithecia in diseased tissues. However, F. solani and F. liriodendri did not produce perithecia. The unknown FSSC group showed morphological characteristics similar to F. solani-melongenae and produced perithecia. Phylogenetic analysis based on the ITS and TEF-1α sequences demonstrated that the Taiwanese FSSC isolates were distinct from the Brazilian and Chinese FSSC isolates. In summary, FSSC isolates causing collar rot and fruit rot of Taiwanese passion fruit showed high diversity, potentially associated with the geographical locations.

Pre-exposure of abundant species to disturbance improves resilience in microbial metacommunities.

Understanding factors influencing community resilience to disturbance is critical for mitigating harm at various scales, including harm from medication to gut microbiota and harm from human activity to global biodiversity, yet there is a lack of data from large-scale controlled experiments. Factors expected to boost resilience include prior exposure to the same disturbance and dispersal from undisturbed patches. Here we set up an in vitro system to test the effect of disturbance pre-exposure and dispersal represented by community mixing. We performed a serial passage experiment on a 23-species bacterial model community, varying pre-exposure history and dispersal rate between three metacommunity patches subjected to different levels of disturbance by the antibiotic streptomycin. As expected, pre-exposure caused evolution of resistance, which prevented decrease in species abundance. The more abundant the pre-exposed species had been in the undisturbed community, the less the entire community changed. Pre-exposure of the most dominant species also decreased abundance change in off-target species. In the absence of pre-exposure, increasing dispersal rates caused increasing spread of the disturbance across the metacommunity. However, pre-exposure kept the metacommunity close to the undisturbed state regardless of dispersal rate. Our findings demonstrate that pre-exposure is an important modifier of ecological resilience in a metacommunity setting.

Seasonal activities, morphological characteristics, and veterinary importance of Haemaphysalis mageshimaensis in Ishigaki and Yonaguni, Okinawa, Japan.

Ticks are of veterinary importance as they transmit various pathogens to animals. In Yaeyama, Okinawa, Japan, Haemaphysalis longicornis became the dominant tick species after the eradication of Rhipicephalus (Boophilus) microplus in the 1990s. However, any recent changes remained unclear due to lack of surveys. We surveyed questing ticks in pastures on Ishigaki and Yonaguni islands of Yaeyama, from September 2022 to May 2024. A total of 18,435 ticks, including 14,784 from Ishigaki and 3,651 from Yonaguni, were collected. The ticks collected in Ishigaki and Yonaguni included 7,637 and 2,697 larvae, 5,870 and 829 nymphs, and 1,277 and 125 adults, respectively. Morphological analysis classified all collected adults and nymphs as either Haemaphysalis mageshimaensis or H. longicornis. We observed that H. mageshimaensis was dominant in both Ishigaki and Yonaguni, accounting for 99 % and 96 % of the populations, respectively, compared to H. longicornis. While adults and nymphs of H. longicornis were active in spring, summer, and autumn, H. mageshimaensis was active year-round. We found that the differences in the body colour and length, density and number of hairs on the second palp segment, and degree of protrusion on the outer edge of the third palp segment may be useful for differentiating H. mageshimaensis from H. longicornis. PCR screening of DNAs from selected ticks showed that 9.7 % of H. mageshimaensis and 25 % of H. longicornis were infected with Theileria orientalis. Our findings indicate that H. mageshimaensis has overtaken H. longicornis as the dominant species in Yaeyama, highlighting the need for year-round tick control measures.

Profiles of Killer Systems and Volatile Organic Compounds of Rowanberry and Rosehip-Inhabiting Yeasts Substantiate Implications for Biocontrol

Yeasts produce numerous antimicrobial agents such as killer toxins, volatile organic compounds (VOCs), and other secondary metabolites, establishing themselves in developing natural and sustainable biocontrol strategies for agriculture and food preservation. This study addressed the biocontrol potential of yeasts, isolated from spontaneous fermentations of rosehips (Rosa canina L.) and rowanberries (Sorbus aucuparia L.), focusing on their killer phenotypes and VOCs production. Yeasts were isolated using spontaneous fermentations with Hanseniaspora uvarum and Metschnikowia pulcherrima identified as the dominant species, comprising approximately 70% of the yeast population. Among 163 isolated strains, 20% demonstrated killing activity, with Saccharomyces cerevisiae exhibiting the strongest killing efficiency, as well as Pichia anomala and M. pulcherrima showing broad-spectrum antagonistic activity. This study identified dsRNA-encoded killer phenotypes in S. cerevisiae, S. paradoxus, and Torulaspora delbrueckii, revealing multiple distinct killer toxin types. The biocontrol potential of wild berry-inhabiting yeasts was demonstrated in a real food system, grape juice, where the S. cerevisiae K2-type killer strain significantly reduced fungal contaminants. The selected H. uvarum, M. pulcherrima, S. cerevisiae, and S. paradoxus yeast strains representing both berries were applied for VOC analysis and identification by gas chromatography-linked mass spectrometry. It was revealed that the patterns of emitted volatiles are yeast species-specific. Statistically significant differences between the individual VOCs were observed among killing phenotype-possessing vs. non-killer S. paradoxus yeasts, thus revealing the involvement of killer systems in multi-level biocontrol enablement. The performed studies deepen our understanding of potential yeast biocontrol mechanisms, highlight the importance of produced antimicrobials and volatiles in ensuring antagonistic efficacy, and prove the relevance of isolated biocontrol yeasts for improving food safety.

Cyperus esculentus var. sativus Adapts to Multiple Heavy Metal Stresses Through the Assembly of Endophytic Microbial Communities

Interactions between plants and their endophytes alter their metabolic functions and ability to cope with abiotic stresses. In this study, high-throughput sequencing was used to analyze the species diversity and functions of endophytes in Cyperus esculentus var. sativus (CES) tubers under different heavy metal stress conditions. The results indicated that the number of observed endophytic species in the tubers increased under heavy metal stress (p &lt; 0.05), leading to changes in species diversity and composition. The response of tuber endophytes to different metal concentrations varied, with certain endophytic bacteria and fungi, such as Pseudomonas, Novosphingobium, and Fusarium, showing increased abundance and becoming the dominant species in the tubers. Additionally, new endophytic genera, Actinophytocola and Monosporascus, emerged at specific metal concentrations (p &lt; 0.05). Fatty acid salvage was enriched in the endophytes of CES, which may play an important role in assisting CES in responding to multiple heavy metal stresses. These findings showed that CES tuber endophytes undergo adaptive changes to support the ability of plants to cope with heavy metal stress.

Delineating the emergence of thermally tolerant Symbiodiniaceae genotypes across the dominant coral species of a turbid reef: Adaptation and resilience strategy.

Climate change-induced rise in sea surface temperatures has led to an increase in the frequency and severity of coral bleaching events, ultimately leading to the deterioration of coral reefs, globally. However, the reef-building corals have an inherent capacity to acclimatize to thermal stress on pre-exposure to high temperatures by altering their endosymbiotic Symbiodiniaceae community composition towards a thermal tolerant composition. This reorganisation may become an important tool in coral's resilience to rapid environmental change. Therefore, it is crucial to delineate the Symbiodiniaceae community in our reef to predict their resilience capacity. Our study aims to analyse the symbiont community associated with common reef corals in a heat-stressed, marginal turbid reef of Palk Bay, India. We employed next-generation sequencing-based high-resolution analyses of internal transcribed spacer two (ITS2) amplicons within the SymPortal framework to examine the diversity and organization of Symbiodiniaceae communities. The results revealed a dominance of heat-tolerant Durusdinium (D1-D4) and Cladocopium (C15) across coral species (Acropora cytherea, Acropora digitifera, Favites abdita, and Porites lobata) and reef environment (seawater, and reef sediment), with the presence of 18 ITS2 type profiles in our samples. To our knowledge, this is the first comprehensive study to delineate Symbiodiniaceae communities at fine scale resolution (ITS2 type profile) from scleractinian corals in India, establishing a baseline for future research in a marginal reef ecosystem. Several studies have highlighted the importance turbid reefs as prospective climate refugia under the future threat of climate change. Therefore, this study is crucial for researchers, scientists, stakeholders, and policymakers to identify reef sites and coral species with resilience capacity for devising future reef restoration and management strategies.

Spatiotemporal Variations in Phytoplankton Community Structure and Diversity: A Case Study for a Macroalgae–Oyster Reef Ecosystem

The estuarine area of Luanhe River is an important fisheries ground in China’s Bohai Sea. In 2016, Tangshan Marine Ranching Co., Ltd. constructed a 2 km2 artificial oyster–macroalgae reef area by placing artificial reefs on the seabed adjacent to the Luanhe River Estuary. This action resulted in sustainable annual economic outputs through the fishing and sea cucumber put-and-take fishery. Although Luanhe River runoff and reef construction are important to the local phytoplankton community and fisheries’ production, little is known about how these factors affect phytoplankton community structure in the local coastal ecosystem. In this study, we conducted field surveys to investigate the spatiotemporal variations in species composition, abundance, dominant species, diversity indexes, niche width and overlap, and interspecific connection of the phytoplankton community in the ecosystem of oyster–macroalgal reefs. From July 2016 to August 2017, we collected data before and after reef construction in areas inside and outside of the benthic reefs in both the flood and dry seasons of Luanhe River runoff. We found a total of 79 species, with the majority represented by diatoms and dinoflagellates. The dominant species were Paralia sulcata and Coscinodiscus sp. The total species number and abundance increased from May to September. The species number in the reef area was greater than that outside the reef. Species abundance from August to September was greater in the reef area than in the control area, which was opposite the situation from May to June. We found more phytoplankton abundance in the flood season compared with that in the dry season. Our results suggest that reef construction can benefit the local phytoplankton community and that further studies of the relationship among oysters, macroalgae, and phytoplankton in the system are warranted. Moreover, we provide baseline data about variations in the phytoplankton community in a sea ranch area.

Study of endophytic fungi of Ipomoea pes-caprae reveals the superiority of in situ plant conservation over ex situ conservation from a mycological view

In nature conservation, ex situ and in situ conservation strategies are discussed for protecting endangered species of plants and animals. However, the impacts of these strategies on the microbes associated with these species are rarely considered. In our study, we chose the endophytic fungi of the pantropical creeping plant Ipomoea pes-caprae as representative coastal plant in two natural coastal populations and two botanical gardens in Taiwan as collection sites in order to investigate the potential effect of ex situ plantation on the biodiversity of microbes intimately associated with this plant. In a culture-dependent approach, endophytic fungi were isolated under axenic conditions and identified to species, genus, or higher taxonomic ranks with DNA barcodes and morphology. In addition to yielding ca. 800 strains and over 100 morphospecies, a principal component analysis (PCA) of the distribution of the dominant fungal species showed clear differences in the composition of endophytic fungal species depending on the sampling sites. We conclude that the endophytic fungi from the original site are replaced by other species in the ex situ plantations. Due to the limitations of ex situ conservation of microbes and from a mycological and microbial perspective, in situ conservation should outweigh ex situ approaches.

Arbuscular mycorrhizal colonization defines root ecological strategies in an extreme arid environment

The symbiosis between mycorrhizae fungi and plant roots is essential for plant establishment in nearly all terrestrial ecosystems. However, the role of mycorrhizal colonization (colM) in shaping root ecological strategies remains poorly understood. Emerging research identifies colM as a key trait influencing the multidimensional covariation of root traits within the Root Economic Space (RES), where a ‘collaboration gradient’ is proposed. At one end of this gradient, species with larger root diameters (RD) rely on colM for resource acquisition through an ‘outsourcing’ strategy, while at the other end, species with finer roots and greater exploration capacity employ a ‘do it yourself’ strategy to acquire resources independently. Although the RES framework has improved our understanding of root strategies, the relationship between colM and root traits in desert ecosystems remains underexplored, particularly in hyper-arid environments, where limited resources can constrain both plant and mycorrhizal survival. In this study, we examine the root ecological strategies of 32 dominant shrub species in Chile’s Coastal Atacama Desert, focusing on the link between specific root traits and colM. We found that larger RD correlated with higher levels of colM, supporting the ‘outsourcing’ strategy within the ‘collaboration gradient’ hypothesis of the RES. Additionally, RD and colM emerged as playing key roles in defining both dimensions of root ecological strategies. Moreover, we identified colM as a central hub trait in the root phenotypic network, underscoring its role in survival strategies under hyper-arid conditions. These findings emphasize the critical importance of colM in modulating plant ecological strategies and highlight the need to further investigate how AM enhances root lifespan and optimizes resource uptake in extreme environments.

Highly Efficient Removal of Organic Pollutants with HCO3−-Enhanced Ru(III)/NaClO Process

The design of efficient advanced oxidation processes (AOPs) in the presence of bicarbonate has long attracted considerable attention in the field of environmental catalysis. In this study, sodium bicarbonate (NaHCO3) as one of the most abundant substances in actual water, was introduced to a NaClO/Ru(III) system to enhance the removal of acid orange 7(AO7). NaHCO3 could significantly improve the removal efficiency of the Ru(III)/NaClO process in HCO3− at a pH range of 6.9–10.0. Ru(V)=O was identified as a dominant reactive species involved in the degradation of pollutants in the NaHCO3/NaClO/Ru(III) system. HCO3− interacts with Ru(III) to generate Ru(III)-HCO3−, which enhances the activation performance of Ru(III) under neutral or alkaline conditions. The removal of AO7 was significantly enhanced with increasing NaHCO3 concentration, and the rate constant increased more than 2-fold to 4-fold as NaHCO3 concentrations increased from 0 to 100 mM at pH 6.9 and 8.5. This study proposed a novel strategy to enhance the Ru(III)/NaClO process with environmentally friendly inorganic ligands and highlights its potential applications in the removal of pollutants.

Seasonal carbon fluxes from vegetation and soil in a Mediterranean non-tidal salt marsh

Abstract. Salt marshes are important ecosystems for carbon sequestration. However, while studies of atmospheric carbon exchange fluxes have broadly been performed in tidal salt marshes, they are scarce in non-tidal salt marshes. In this study we measured, throughout 1 year, instantaneous net carbon dioxide (CO2) exchange rates from four halophytes which are dominant species of their corresponding habitat (Sarcocornia fruticosa in a halophilous scrub, Halimione portulacoides and Elytrigia atherica in a salt meadow, and Salicornia patula in a glasswort sward) of a Mediterranean non-tidal salt marsh. Soil CO2 and methane (CH4) fluxes from these habitats were also measured. E. atherica, a perennial herbaceous species, showed the highest photosynthetic rates during the entire year, but S. patula, an annual succulent herb, also had remarkable photosynthetic rates in summer. Interestingly, the woody fraction of the two perennial shrubs, S. fruticosa and H. portulacoides, showed CO2 uptake during most of the daily measurements. Regarding the studied habitats, the halophilous scrub and the salt meadow showed higher soil CO2 emissions than the glasswort sward, and the overall emissions were higher than those reported for tidal salt marshes. Both soil absorption and emission of CH4 were detected. In particular, CH4 emissions were remarkably high, similar to those found in low-salinity marshes and, in general, higher than those reported for salt marshes with a high water table salinity. Soil mineralization quotients of the halophilous scrub and the salt meadow were lower than those measured at the glasswort sward, suggesting a higher soil carbon sequestration potential of the first two habitats.

Temporal trends of community and climate changes in the anthropocene: 21-year dynamics of four major functional groups in a rocky intertidal habitat along the Pacific coast of Japan

The influence of climate change on marine organism abundance has rarely been assessed (1) at the functional-group level; (2) simultaneously in major functional groups within the same ecosystem; (3) for &amp;gt;10 years; and (4) at metapopulation/community scales. A study simultaneously addressing these gaps would greatly enhance our understanding of the influence of climate change on marine ecosystems. Here, we analyzed 21 years of abundance data at the functional-group and species levels on a regional scale for four major functional groups (benthic algae, sessile animals, herbivorous benthos, and carnivorous benthos) in a rocky intertidal habitat along the northeastern Pacific coast of Japan. We aimed to examine the 21-year trends in regional abundance at both functional-group and species levels, plus their driving mechanisms and their dependence on species properties (thermal niche, calcification status, and vertical niche). Significant temporal trends in abundance were detected at functional-group levels for benthic algae (increasing) and herbivores and carnivores (both decreasing); they followed the temporal population trends of the dominant species. At species level, the metapopulation size of 12 of 31 species were increasing and 4 of those were decreasing, depending on the thermal niche and species calcification status. At both functional-group and species levels, temporal trends in abundance are caused by the direct or indirect influence of warming and ocean acidification. Comparing these results with community responses to marine heat waves in the same study area offered two implications: (1) long-term ecosystem changes associated with global warming will be unpredictable from the community response to marine heat waves, possibly owing to a lack of knowledge of the influence of calcifying status on species’ responses to climate change; and (2) thermal niches contribute greatly to predictions of the influence of warming on population size, regardless of the time scale.

Similar phylogeographic history in a fig species and its obligate pollinators forms parallel genetic structure

Abstract Closely related and co-distributed species usually share a common phylogeographic history, but it is still largely unclear whether ecologically interacting species can respond synchronously to historical climate changes. Here, we focused on a fig-pollinator mutualism comprising Ficus pumila var. pumila and its obligate pollinators (morphospecies Wiebesia pumilae), and collected samples across most of their distribution ranges. We employed both cytoplasmic DNA sequences and nuclear microsatellite loci to reveal the species composition within the pollinator and to test whether the two mutualists exhibited similar postglacial phylogeographic patterns. In the three cryptic pollinator species observed here, two dominant cryptic species were parapatric, covering the north and the south of the plant’s distribution range, respectively. Similar current spatial genetic structure was detected in the two dominant cryptic pollinator species and the plant, with an eastern and a western genetic cluster. Moreover, for these three species, evidence for postglacial expansion was found, and their potential refugia at the last glacial maximum were located in the east and the west of their distribution ranges. These results suggest their synchronous responses to historical climate changes. Our study therefore shows congruent phylogeographic patterns between obligate mutualists and highlight the role of biogeographic factors in shaping the current biodiversity across trophic levels.

Environmental Factors Affecting the Phytoplankton Composition in the Lake of Tibetan Plateau

Due to the high altitude, unique geographical location, difficult accessibility and low temperature, the environmental factors influencing phytoplankton composition have rarely been investigated in the Selin Co Lake, which is the largest lake in the Tibetan Plateau. Phytoplankton composition can indicate aquatic ecosystem conditions, which may be sensitive to environmental factors in the Tibetan Plateau. In this study, we investigated the main environmental factors that influence phytoplankton species in the Selin Co Lake by analyzing the spatial distribution and applying statistical analyses. We also compared the influential environmental factors in this lake with other lakes around the world. The results suggest that the eleven environmental variables can explain about 46.78% of the phytoplankton’s composition. DO and fluoride were the most significant environmental variables, followed by arsenic and COD, and the other variables had comparatively smaller and more insignificant influences on phytoplankton composition. There were five dominant phytoplankton species in the Selin Co Lake, namely, Microcystis sp., Navicula spp., Chlorella vulgaris, Ankistrodesmus falcatus, and Westella sp. Some of these dominant species were also found in other tropical lakes, suggesting that the phytoplankton community could adapt to environmental changes. A clear understanding of the influential environmental variables affecting phytoplankton composition could help us to make proper water quality protection strategies in future climate change scenarios.

Effects of Different Preservation Methods on the Structure and Diversity of Intestinal Microbiota of Marine Fishes.

The fish intestine is a complex ecosystem where microbial communities are dynamic and influenced by various factors. Preservation conditions during field collection can introduce biases affecting the microbiota amplified during sequencing. Therefore, establishing effective, standardized methods for sampling fish intestinal microbiota is crucial. This study used hybrid groupers (Epinephelus fuscoguttatus♀ × E. lanceolatus♂) to examine the effects of six preservation methods: dry ice (1 day), dry ice (1 day) followed by -80°C storage (5 days), liquid nitrogen (1 day), liquid nitrogen (1 day) with subsequent -80°C storage (5 days), refrigeration at 4°C (3 days), and freezing at -20°C (3 days), with fresh samples as controls. High-throughput 16S rRNA sequencing assessed microbial diversity, community structure, dominant species, and OTU abundance across treatments. Results indicated that dry ice and liquid nitrogen methods, especially with -80°C storage, had minimal impact on microbial diversity and structure. Compared to other preservation methods, refrigeration at 4°C and freezing at -20°C may result in suboptimal reproducibility and altered community structure, particularly affecting rare microbial taxa. This study underscores the need for standardized preservation techniques to ensure accurate fish intestinal microbiota analysis and provides a foundation for future research.

Snake Diversity in Human Landscapes: A Comprehensive Study of Snake Species in Kushinagar, Uttar Pradesh, India

This comprehensive study documents the diversity of snake species within the human landscape of Kushinagar district, Uttar Pradesh, India. Carrying out extensive fieldwork using direct and indirect encounter methods revealed 18 snake species from six families, with the Indian Spectacled Cobra (Naja naja) being the dominant venomous species, along with Russell's viper (Vipera russellii) and the Indian Common Krait (Bungarus caeruleus). Biostatistical analysis showed that the Colubridae family was the most diverse group, comprising 61% of the recorded snake species. Species richness, abundance, and diversity indices were analysed, with the Shannon Diversity Index (H') and Simpson Diversity Index (D) indicating variations in species richness and evenness across different areas. The correlation matrix highlighted ecological interactions, such as predator-prey dynamics and habitat sharing, while non-parametric tests revealed significant differences in abundance among the study areas. The study emphasizes the importance of utilizing additional biostatistical strategies to examine non-normally distributed data and ensure robust conclusions. The findings contribute to understanding snake ecology and provide valuable insights for habitat management and biodiversity conservation planning in the Kushinagar region, which is crucial for protecting these enigmatic animals and their ecosystems.

Evolution of the Hydrothermal Fluids Inferred from the Occurrence and Isotope Characteristics of the Carbonate Minerals at the Pogo Gold Deposit, Alaska, USA

Pogo is identified as a deep-seated, intrusion-related gold deposit. Carbonate minerals have a close spatial relationship to hydrothermal gold mineralization in all of its principal ore zones. The carbon and oxygen isotopic ratios of carbonate minerals (siderite, ankerite, and calcite) present within the deposit illustrate the isotopic evolution of the ore-forming fluid. The initial hydrothermal fluid phase is interpreted to be magmatic in origin. The fluid evolution was characterized by a gradual decrease in δ18O and a slight increase in δ13C with decreasing temperature. The dominant carbon-bearing species was CO2, with methane introduced sporadically. Siderite is associated with early-stage mineralization and occurs with ankerite in main-stage ore assemblages. Calcite is recognized in the later stages of mineralization. Gold in the Pogo deposit occurs as native gold, Au-Bi-Te minerals, inclusions in sulfide minerals, or as “invisible gold”. The latter is found in pyrite, chalcopyrite, arsenopyrite, and quartz, based on ion microprobe analysis. The presence of invisible gold in these minerals has significant metallurgical implications for gold processing at the Pogo mine.

Variation in Species Diversity of Epilithic Bryophytes Along the Karst Rocky Desertification Gradient

Karst rocky desertification is a distinctive landscape formed by the exposure of rock surfaces, where epilithic bryophytes dominate the plant communities. Despite their prevalence, these mosses have received relatively little attention, and the species diversity of lithophilous mosses remains inadequately understood. In this study, we conducted field collections and laboratory identifications of epilithic bryophytes across various karst habitats exhibiting different levels of rocky desertification, aiming to elucidate the patterns of species diversity within these environments. Our findings reveal a total of 47 moss species, belonging to 11 families and 28 genera, with species distribution patterns as follows: PRD (22 species) &gt; MRD (18 species) &gt; SRD (14 species) &gt; NRD (12 species) &gt; LRD (11 species). Notably, the PRD and MRD habitats harbor the highest number of endemic species, each with 8 endemic species, while the other three habitats each contain 5 endemic species. Among these, Eurohypnum leptothallum is a common species across all habitats and represents a dominant species in the karst region. Four distinct moss growth forms were identified in the study area, with proportions as follows: Wefts (75%) &gt; Turfs (15%) &gt; Pentants (8%) &gt; Cushion (2%). The Wefts growth form is ubiquitous across all habitats and is the most prevalent, whereas the proportion of Pendants increases along the rocky desertification gradient, showing a higher degree of adaptation to more severely desertified environments. The α-diversity indices (richness index (R), Simpson index (D), Pielou index (E), and Shannon-Wiener index (H)) exhibit an "M"-shaped distribution along the desertification gradient, indicating the selective effects of desertification processes and the dynamic changes in species over time. The β-diversity index further suggests low species similarity between different habitats, with the similarity index (Cs) between NRD and SRD habitats being as low as 0.08, signifying substantial shifts in species composition. These results provide valuable insights into the changes in species diversity of lithophilous mosses along the rocky desertification gradient and enhance our understanding of the moss species diversity in karst rocky desertification areas.