Variation In Distribution Patterns Research Articles

Bacterial community composition and metabolic characteristics of three representative Marine areas in northern China

Bacteria are essential components of ecosystems, participating in nutrient cycling and biogeochemical processes, and playing a crucial role in maintaining the stability of marine ecosystems. However, the biogeographic distribution patterns of bacterial diversity and metabolic functions in the estuarine and coastal areas of northern China remain unclear. Here, we used metagenomic sequencing to investigate the bacterial community composition and metabolic functions in sediments from the adjacent waters of the Yellow River Estuary, the Yellow Sea Cold Water Mass, and the adjacent waters of the Yangtze River Estuary. Among the 9164 species that were found, the most dominant microbial communities are Pseudomonadota, Actinomycetota, Bacteroidota, and Bacillota, but there are significant differences in the species composition in these three typical habitats. Amino acid metabolism and carbohydrate metabolic pathways were highly enriched. Glycoside hydrolases (GHs) predominate in carbon metabolism across all samples. In nitrogen metabolic pathway, genes related to organic degradation and synthesis are more abundant in the Yellow River Estuary than the other two habitats. In sulfur metabolic pathway, genes involved in assimilatory sulfate reduction are significantly enriched. Assimilatory sulfate reduction might be crucial for sulfur metabolism in coastal regions, with a full assimilatory nitrate reduction pathway found in Desulfobacterota. This research offers insights into the compositional diversity, metabolic functions, and biogeographic distribution patterns of bacterial communities in sediments from typical marine areas of northern China.

Biocrusts Mediate the Niche Distribution and Diversity of Ammonia-Oxidizing Microorganisms in the Gurbantunggut Desert, Northwestern China

Biological soil crusts (biocrusts) play pivotal ecological roles in regulating nitrogen cycling within desert ecosystems. While acknowledging the essential role played by ammonia-oxidizing microorganisms in nitrogen transformation, there remains a paucity of understanding concerning how disturbances to biocrusts impact the diversity and spatial distribution patterns among ammonia oxidizer communities within temperate deserts. This investigation delved into assessing how 4 years’ worth of removing biocrust influenced niche differentiation between nitrifying archaea and bacteria while also examining its effects on shaping community structures of predominant ammonia-oxidizing archaea (AOA) within the Gurbantunggut Desert soils. Despite notable variations in abundance of ammonia-oxidizing microbes across distinct soil depths throughout different seasons, it became apparent that removing biocrust significantly altered both the abundance and niche pattern for AOA alongside their bacterial counterparts during winter and summer periods. Notably dominating over their bacterial counterparts within desert soils, AOA displayed their highest archaeal to bacterial amoA gene copy ratio (6549-fold higher) at a soil depth of 5–10 cm during summer. Moreover, substantial impacts were observed upon AOA diversity along with compositional changes following such perturbation events. The aftermath saw an emergence of more diffuse yet dynamic AOA communities, especially noticeable amidst winter when nitrogen and water limitations were relatively alleviated. In summary, our findings underscore how interactions between biocrust coverages alongside factors like soil temperature, total carbon content, or NO3−_N concentrations govern niches occupied by ammoxidation communities whilst influencing assemblage processes too. The sensitivity shown by dominant AOAs towards biocrust removal further underscores how biocrust coverage influences nitrogen transformation processes while potentially involving other communities and functions in desert ecosystems.

Geostatistical modelling improves prediction of Macrophomina phaseolina abundance and distribution in soybean fields.

Charcoal rot, caused by the soilborne fungus Macrophomina phaseolina (Mp) poses a serious threat to soybean health and harvests at a global scale. Mp exhibits varying distribution patterns across fields, which complicates our ability to predict disease occurrences and outbreaks. Therefore, determining the spatial distribution of Mp abundance and its relation with soil physicochemical properties would help to inform precision management decisions for mitigating charcoal rot. To achieve this, Mp colony forming units (CFU) and edaphic properties were evaluated in 297 soybean fields located in the main soybean growing regions across 7 Departments of Paraguay. A pattern of decreasing CFU density was observed from the south-eastern to the western part of the country. While several edaphic factors are positively correlated with Mp CFU, pH showed a significant negative correlation with CFU. Both spatial and non-spatial model suggest that cation exchange capacity, percentage of clay, and pH could be potential predictors of Mp CFU abundance. Including spatial dependence of edaphic factors improved the prediction of Mp CFU more effectively than classical statistical models. We demonstrated that the occurrence of Mp shows a significant spatial clustering pattern as indicated by Moran's I. Our findings will help growers and policy-makers make informed decisions for managing Mp by improving our ability to predict which agricultural fields and soils are at greatest risk for charcoal rot.

Unravelling spatial scale effects on elevational diversity gradients: insights from montane small mammals in Kenya

BackgroundMontane ecosystems play crucial roles as global biodiversity hotspots. However, climatic changes and anthropogenic pressure increasingly threaten the stability of montane community dynamics, such as diversity-elevation interactions, creating a challenge in understanding species biogeography and community ecology dynamics in these crucial conservation areas. We examined how varying sampling spatial grains influence small mammal diversity patterns within Kenya’s tallest montane ecosystems.MethodsEmploying a combination of multidimensional alpha diversity metrics and multisite beta diversity characteristics (species richness, phylogenetic and functional diversity and divergence, and multisite beta diversity) alongside spatial generalized additive multivariate regression analyses, we tested how spatial scaling influences elevational diversity gradient patterns and their associations with environmental and human activity variables.ResultsThe diversity-elevation associations were generally homogeneous across spatial grains; however, idiosyncratic patterns emerged across mountains. The total (taxonomic, phylogenetic, and functional) beta diversity, nestedness, and turnover resultant components monotonically increased or decreased with varying spatial grains. The associations between the diversity patterns and the environmental and human footprint variables increased with spatial grain size but also presented variations across mountains and indices. Species richness and phylogenetic and functional richness indices were more strongly influenced by spatial scale variations than were the divergence and community structure indices in both the diversity distribution patterns and their associations with the environmental and human variables.ConclusionsThe diversity-elevation and diversity-environment (including human activity pressure) relationships across spatial grains suggest that montane small mammal diversity patterns portray subtle but systematic sensitivity to sampling spatial grain variation and underscore the importance of geographical context in shaping these elevational diversity gradients. For improved effectiveness, conservation efforts should consider these spatial effects and the unique geographical background of individual montane ecosystems.

Urbanization and plant diversity in urban fringes: Differential responses across life forms

Urban fringe areas, as critical transition zones between urban expansion and natural environments, provide essential ecosystem services that enhance the overall health and sustainability of urban environments. However, previous studies have focused on urban built–up areas while neglecting the unique conditions of urban fringe zones. This study investigated the spatial distribution patterns of plant diversity across different life forms in Jiangdong New District and their responses to urbanization levels. The results indicate that hot and cold spots of diversity for trees and shrubs show similarity, while diversity in herbaceous plants differs significantly. Nighttime light intensity, POI (Point–of–Interest) density, and road density are primary influencing factors, with nighttime light intensity and POI density having the greatest combined impact, and herbs showing the highest sensitivity to these factors. Further analysis reveals that in the northwestern forest, grassland, and farmland mosaic areas, urbanization levels are positively correlated with tree and shrub diversity but negatively correlated with herb diversity. In the southeastern nursery planting area, urbanization levels consistently relate to the diversity of these three plant types. These findings underscore the necessity of adopting diverse conservation and management strategies in urban fringe areas to address the ecological needs and functional contributions of different plant types. This provides new perspectives on urban planning and ecological conservation that can help improve the overall health and sustainability of urban ecosystems.

Characteristics of Microbial Diversity and Metabolic Versatility in Dynamic Mid-Okinawa Trough Subsurface Sediments

Large-scale and multi-sample datasets have revealed that microbial diversity and geographic distribution patterns are distinct across various habitats, particularly between hydrothermal vent and cold seep ecosystems. To date, our understanding of the effects of spatial and geochemical gradients on marine microbial communities remains limited. Here, we report the microbial diversity and metabolic versatility of a remote seafloor sediment ecosystem at different sites (GC-2, -4, -5, -6, -8) in the Mid-Okinawa Trough (Mid-OT) using high-throughput metagenomic sequencing technology. Desulfobacteraceae (3.1%) were detected in a high abundance at GC-2 with intense methane concentrations (353 μL/L), which showed a clear correlation with cold seeping. Whereas Candidatus Brocadiaceae (1.7%), Rhodobacteraceae (0.9%), and Rhodospirillaceae (0.7%), which are commonly involved in denitrification and sulfur oxidation, were enriched at GC-8. Concurrently investigating the potential of deep-sea microbial metabolism, we gained insights into the adaptive capabilities and metabolic mechanisms of microorganisms within seafloor environments. Utilizing the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, the analysis of functional modules revealed a significant enrichment (71–74%) of genes associated with metabolic pathways. These results expand our knowledge of the relationship between microbial biodiversity and metabolic versatility in deep-sea extreme environments.

Assessment of Lepidopteran Pest Dynamics in Maize: Dominance of Spodoptera frugiperda and Implications for Targeted Management in Himachal Pradesh, India

Maize (Zea mays L.) plays a crucial role in the agricultural economy of India, particularly in Himachal Pradesh, where it serves as a vital crop for food, feed, and fodder. This study assessed the distribution, and relative abundance of lepidopteran pests infesting maize during the kharif, 2022-23 across two agro-climatic zones of Himachal Pradesh. Surveys identified five key lepidopteran pests: Spodoptera frugiperda, Chilo partellus, Mythimna separata, Agrotis ipsilon, and Euproctis spp. Among all, S. frugiperda is the only pest occurring among the major three crop stages of maize. The findings revealed that S. frugiperda was the most dominant pest, with relative abundance values of 19.57 per cent in Zone I and 18.94 per cent in Zone II during the seedling stage, increasing to 30.87 per cent and 30.40 per cent during the vegetative stage, respectively. In contrast, other pests like C. partellus, M. separata, A. ipsilon, and Euproctis spp. exhibited variable distribution patterns, with some showing limited occurrence. In conclusion, this study underscores the necessity for targeted pest management strategies to address dominant and subdominant lepidopteran pests in maize cultivation in Himachal Pradesh. The results offer valuable insights that can inform focused pest control efforts, with the potential to significantly enhance sustainable maize production, crop resilience and overall productivity in the region.

Distribution Patterns of Urban Spontaneous Vegetation Diversity and Their Response to Habitat Heterogeneity: A Case Study of Five Cities in Heilongjiang Province, China.

Spontaneous vegetation is an important component of urban biodiversity and an excellent agent for exploring the mutual feedback mechanism between urbanization and urban ecosystems. Rapid urbanization has had a significant impact on the composition, structure, and distribution patterns of urban spontaneous vegetation diversity. Studying the diversity distribution patterns and causes of urban plant communities is beneficial for understanding the formation and maintenance mechanisms of plant diversity in specific urban habitats. This study selected five cities in different climate subregions of Heilongjiang Province as research targets and conducted field research using uniform sampling and typical sampling methods. The composition, distribution pattern, and driving factors of spontaneous vegetation were analyzed. The results showed the following: (1) A total of 633 examples of spontaneous vegetation were recorded, belonging to 93 families and 341 genera, mainly consisting of herbaceous plants and native plants. (2) The diversity index and similarity index of spontaneous vegetation in gravel-type abandoned land habitats are higher than those in other habitat types, while the diversity index of spontaneous vegetation in trees and shrubs is lower, and there is no significant difference in regards to different habitats. (3) Urban population density is a key factor affecting the diversity of native plants, while woody plant coverage, patch area, and landscape trait index are key factors affecting non-native plants. (4) The results of canonical correspondence analysis (CCA) showed that the total explanatory power of environmental characteristic factors in regards to the distribution pattern of spontaneous vegetation was 7.5%. The closest distance between adjacent patches, the coverage of woody plants in patches, the distance from the city edge, the patch area, and the surface impermeability of the buffer zones were key factors affecting the distribution of dominant species in spontaneous vegetation communities. The research results will provide an important reference for the conservation of urban biodiversity and the construction of low-maintenance urban green space plant landscapes in Heilongjiang Province.

Delineation of Management Zones for Site‐Specific Soil Nutrient Management for Sustainable Crop Production

ABSTRACTSoil nutrients deficiencies are one of the major causes of soil degradation in different parts of World, adversely impacting crop production. Delineation of soil nutrients management zones (MZs) is one of the commonly used techniques for evaluating spatial distribution pattern of soil parameters for adoption of site‐specific nutrient management. We, therefore, conducted the present study to understand the spatial distribution pattern of soil nutrients and their associated soil properties, and to delineate soil nutrients MZs in a north‐western Indian Himalayan (NWIH) region. A total of 18,930 representative surface (0–15 cm depth) soil samples were collected and processed. The processed soil sample were analyzed for pH, and electrical conductivity (EC), soil organic carbon (SOC), available N (AN), available P (AP), available potassium (AK), exchangeable Ca (Ex. Ca), exchangeable Mg (Ex. Mg), available S (AS), available Zn (AZn), available Fe (AFe), available Cu (ACu), available Mn (AMn) and available B (AB). The values of studied soil parameters varied widely with coefficient of variation ranging from 11.8% to 156%. Semivariogram analysis revealed stable, exponential and Gaussian best‐fit models for different soil parameters with weak (AP and AB), moderate (rest of soil parameters) and strong (AS) spatial dependence. Varied distribution pattern of soil parameters was visualized from ordinary kriging interpolation. Five soil nutrient management zones (MZs) were identified (using fuzzy performance index and normalized classification entropy values) by employing the techniques of principal component analysis and fuzzy c‐means clustering. Principal components with Eigen value > 1 were considered for further analysis. The soil parameters of identified MZs differed significantly. Thus, the study highlighted the usefulness of MZ delineation technique for site‐specific soil nutrient management in different cultivated areas for sustainable crop production. The developed MZ maps could suitably be used for efficient management of agronomic inputs especially fertilizer nutrients for improved environmental and economic efficiency.

Biological Adaptations in Rhabdomyosarcoma Tumor Cells in lymph nodes: A Case Report of RMS with FUS::TFCP2 translocation

Abstract Introduction/Objective The WHO classification categorizes Rhabdomyosarcoma (RMS) into four main subtypes based on clinicopathological and molecular features. However, TFCP2-rearranged RMS, a rare tumor, does not neatly fit into any of these subtypes. Literature review identified only two reported cases of RMS with FUS::TFCP2 fusion and a round cell component. Methods/Case Report We present a rare case of RMS in lymph nodes with FUS::TFCP2 translocation in a 29-year- old female with a history of spindle cell rhabdomyosarcoma in the bilateral maxilla. The original tumor exhibited a distinctive spindle and epithelioid phenotype, coexpressing myogenic markers, epithelial markers, and ALK. FUS::TFCP2 translocation was confirmed, representing an uncommon subset of RMS. After chemotherapy, radiation, and surgery, the patient developed multiple bilateral pathologically enlarged cervical lymph nodes. Excision revealed metastatic rhabdomyosarcoma involving lymph nodes with a predominantly round cell and epithelioid morphology, with approximately 5% spindle cell growth, resembling the pattern identified in the primary resection. Results (if a Case Study enter NA) NA Conclusion Previous reports suggest that RMS with FUS::TFCP2 fusion displays a biphasic pattern, comprising solid proliferation of round cells in superficial areas and spindle cells in deeper regions. The altered cell morphology observed in our case may be attributed to the varied distribution pattern of each component with lesion depth and the cellular stress response. Previous literature reported that radiation stress potentially leads to biological adaptations of tumor cells and tumor radioresistance. Our findings underscore the distinctive phenotype of RMS with FUS::TFCP2 fusion, characterized by the coexpression of myogenic and epithelial markers, along with ALK positivity. Understanding the cellular adaptations of RMS cells could inform the development of novel clinical interventions aimed at enhancing radiosensitization and improving therapeutic efficacy, ultimately enhancing patient survival.

Environmental and hydrological synergies shaping phytoplankton diversity in the Hetao irrigation district

Phytoplankton are crucial primary producers in freshwater ecosystems, driving matter and energy flow across trophic levels, essential for biodiversity and ecological balance. Most research emphasizes environmental factors shaping their diversity, while the role of hydrological connectivity remains poorly understood. This study collected 81 phytoplankton samples from the Hetao Irrigation District along a gradient from upstream to downstream and utilized high-throughput sequencing to evaluate the spatial distribution patterns of phytoplankton diversity. The study analyzed the impacts of environmental factors, hydrological connectivity (water surface ratio, Wp), and human activities (land-use intensity, LUI) on phytoplankton diversity. The results revealed that the phytoplankton community comprised 9 phyla, 158 families, 378 genera, and 1189 species. There were significant differences in phytoplankton diversity among different water bodies, with a gradual increase in phytoplankton diversity from west to east across the five major irrigation areas. Lake Ulansuhai had relatively low phytoplankton diversity. The ASV number, Chao1 index, and ACE index showed significant positive correlations with dissolved oxygen (DO), pH, and water temperature (WT). The Shannon index and Pielou'e evenness (Pielou_e) index showed significant positive correlations with the water surface ratio (Wp). The partial least squares model indicated that environmental factors directly influenced phytoplankton diversity. Hydrological connectivity indirectly affected phytoplankton diversity by altering environmental factors. We emphasize that hydrological connectivity is as important as environmental factors in driving phytoplankton diversity in the Hetao Irrigation District. This study provides key insights for water quality assessment and biodiversity conservation in the region.

Spatial patterns and driving factors of plant diversity along the urban-rural gradient in the context of urbanization in Zhengzhou, China.

Plant diversity is the basis for human survival and development, directly affecting the function and stability of urban ecosystems. Its distribution pattern and causes have been a central issue in ecological and landscape gardening research. Rapid urbanization in Zhengzhou City has led to the fragmentation of urban green spaces and damage to ecosystems, seriously affecting urban biodiversity conservation. Understanding the distribution pattern of plant diversity in the region and its relationship with environmental factors is crucial for maintaining and enhancing urban plant diversity. Plant data from 178 sample plots in the built-up area of Zhengzhou City were collected and combined with environmental factors, and the characteristics of plant diversity, richness patterns, and their main environmental explanations in Zhengzhou City were explored. Results showed that there were 596 plant species belonging to 357 genera and 110 families in the study area. There were five dominant families and four dominant genera. Four distinct spatial patterns of plant diversity were identified along the urban-rural gradient. Urbanization factors such as GDP per capita, house prices, and imperviousness within 500 m from the patch significantly influenced plant diversity. There was an imbalance between the spatial pattern of plant diversity and application of urban landscape greening in Zhengzhou City. Future studies should focus on the application of native plants, curb plant homogenization, and reduce anthropogenic interference, which are conducive to protecting and enhancing urban plant diversity. These results can provide a basis for understanding the distribution pattern and influence mechanism of urbanization factors on plant diversity and serve as a reference for policymakers and planners of plant diversity conservation in Zhengzhou City.

Ecogeographic Study of Ipomoea Species in Mauritius, Indian Ocean.

The wild relatives of crops play a critical role in enhancing agricultural resilience and sustainability by contributing valuable traits for crop improvement. Shifts in climatic conditions and human activities threaten plant genetic resources for food and agriculture (PGRFA), jeopardizing contributions to future food production and security. Studies and inventories of the extant agrobiodiversity, in terms of numbers and distribution patterns of species and their genetic diversity, are primordial for developing effective and comprehensive conservation strategies. We conducted an ecogeographic study on Ipomoea species and assessed their diversity, distribution, and ecological preferences across different topographic, altitudinal, geographical, and climatic gradients, at a total of 450 sites across Mauritius. Species distribution maps overlaid with climatic data highlighted specific ecological distribution. Principal Component Analysis (PCA) revealed species distribution was influenced by geographical factors. Regional richness analyses indicated varying densities, with some species exhibiting localized distributions and specific ecological preferences while the other species showed diverse distribution patterns. Field surveys identified 14 species and 2 subspecies out of 21 species and 2 subspecies of Ipomoea reported in Mauritius. A gap in ex situ germplasm collections was observed and several species were identified as threatened. Further investigations and a more long-term monitoring effort to better guide conservation decisions are proposed.

Analysis of the Interrelation and Seasonal Variation Characteristics of the Spatial Niche of Dominant Fishery Species-A Case Study of the East China Sea.

The spatial niche has garnered significant attention in ecological research, particularly regarding species distribution patterns. The East China Sea, known for its favorable natural conditions and abundant fishery resources, exhibits diverse spatial distribution patterns among species, shaped by their seasonal physiological needs. This study utilized a habitat suitability index model to explore the spatial distribution patterns of key fishery resources in the East China Sea across four seasons and their interactions. Two methodologies were employed to identify key environmental factors and assess the ecological niche overlap among different species and seasons. Results indicated that the initial method identified water temperature as the critical factor for hairtail, while the subsequent method emphasized water temperature and salinity for hairtail, salinity for small yellow croaker, and water depth for Bombay duck. The main spatial habitat overlap was observed between paired species, likely driven by predator-prey interactions. During summer and autumn, increased overlap among multiple species was primarily influenced by synchronized life cycles. An overlap index formula quantified the seasonal species overlap, showing an increase from spring to winter, reflecting changes in convergent habitat preferences. The peak overlap occurred in winter, driven by overwintering, reduced food competition, and enhanced coexistence potential, while the lowest overlap was noted in spring as overwintering ended and predation and competition intensified.

Global burden of benign prostatic hyperplasia, urinary tract infections, urolithiasis, bladder cancer, kidney cancer, and prostate cancer from 1990 to 2021

BackgroundThe burden of common urologic diseases, including benign prostatic hyperplasia (BPH), urinary tract infections (UTI), urolithiasis, bladder cancer, kidney cancer, and prostate cancer, varies both geographically and within specific regions. It is essential to conduct a comprehensive and precise assessment of the global burden of urologic diseases.MethodsWe obtained data on incidence, prevalence, mortality, and disability-adjusted life-years (DALYs) for the aforementioned urologic diseases by age, sex, location, and year from the Global Burden of Disease (GBD) 2021. We analyzed the burden associated with urologic diseases based on socio-demographic index (SDI) and attributable risk factors. The trends in burden over time were assessed using estimated annual percentage changes (EAPC) along with a 95% confidence interval (CI).ResultsIn 2021, BPH and UTI were the leading causes of age-standardized incidence rate (ASIR) and age-standardized prevalence rate (ASPR), with rates of 5531.88 and 2782.59 per 100,000 persons, respectively. Prostate cancer was the leading cause of both age-standardized mortality rate (ASMR) and age-standardized DALYs rate (ASDR), with rates of 12.63 and 217.83 per 100,000 persons, respectively. From 1990 to 2021, there was an upward trend in ASIR, ASPR, ASMR, and ASDR for UTI, while urolithiasis showed a downward trend. The middle and low-middle SDI quintile levels exhibited higher incidence, prevalence, mortality, and DALYs related to UTI, urolithiasis, and BPH, while the high and high-middle SDI quintile levels showed higher rates for the three cancers. The burden of these six urologic diseases displayed diverse age and sex distribution patterns. In 2021, a high body mass index (BMI) contributed to 20.07% of kidney cancer deaths worldwide, while smoking accounted for 26.48% of bladder cancer deaths and 3.00% of prostate cancer deaths.ConclusionsThe global burden of 6 urologic diseases presents a significant public health challenge. Urgent international collaboration is essential to advance the improvement of urologic disease management, encompassing the development of effective diagnostic screening tools and the implementation of high-quality prevention and treatment strategies.

Spatiotemporal Distribution and Dispersal Pattern of Early Life Stages of the Small Yellow Croaker (Larimichthys Polyactis) in the Southern Yellow Sea

Nursery habitats play a significant role in completing fish life cycles, and they are now recognized as essential habitats. Monthly variations in nursery ground distributions of Larimichthys polyactis were investigated in the southern Yellow Sea in 2019. Bayesian hierarchical models with integrated nested Laplace approximation were utilized to model the preferential nursery habitats of L. polyactis larvae. The study analyzed the spatial and temporal distributions of the larvae and juveniles based on three environmental variables: sea surface temperature, sea surface salinity, and depth. Additionally, this study examined the utilization of habitats by different fish life stages and ontogenetic shifts. A total of 3240 individuals were collected from April to June, with the peak occurring in May (0.05 ind./m3), and the distribution areas varied between different months. The prediction of the model reveals the ecological adaptability of L. polyactis to temperature variations. The optimal temperature for L. polyactis density ranges from 12.5 °C to 16.5 °C in April and 16.5 °C to 17.5 °C in May, demonstrating a broad temperature tolerance for L. polyactis survival. In addition, there are variations in distribution patterns among different developmental stages. Larimichthys polyactis spawn in the inshore and nearshore waters, and after hatching, larvae in the pre-flexion stage tend to remain aggregated near the spawning beds. However, larvae in the advanced development stage (post-flexion) and juveniles move towards the sandy ridge habitats along the coast and start to migrate offshore in June. This study provides valuable insights for the effective management of fishery resources in the area and can be utilized to identify marine areas with specific habitat features that require conservation.

Community structure and assembly of myxomycetes in northern Chinese forests under geographic barriers

ABSTRACT The study of myxomycete biogeography has a long-standing history and has consistently drawn scholarly interest. Nevertheless, studies focusing specifically on the spatial and temporal distribution patterns of myxomycete diversity are relatively limited, with even fewer investigating the mechanisms driving the generation and maintenance of myxomycete diversity. Therefore, this study selected two geographically distant sampling sites within northern Chinese forests to investigate myxomycete species composition, community structure, environmental drivers, and assembly patterns under geographic barriers. We established plots in the Altai Mountains (ALE) and the Greater Khingan Mountains (GKM), gathered bark and litter, and conducted 80-day moist chamber cultures of myxomycetes. Additionally, myxomycete specimens were collected in the field simultaneously to supplement the data set. This study collected 541 myxomycete specimens belonging to 73 species from 28 genera, spanning 12 families and eight orders. The ALE and the GKM had 20 identical species, accounting for 27% of the total species. Myxomycetes from both regions exhibited abundant occurrence 18 days after cultivation, with the quantity on bark substrates notably higher than on litter. Arcyria pomiformis and Comatricha elegans were the most common species in moist chamber cultures. Mantel test outcomes revealed that environmental factors had no significant impact on myxomycete community similarity between the two areas, aligning with findings from the neutral community model analysis, indicating a predominant influence of stochastic processes on myxomycete community structure in moist chamber cultures. This study represents the first application of a quantitative framework to analyze myxomycete community assembly cultivated in moist chambers.

Phylotranscriptomic and ecological analyses reveal the evolution and morphological adaptation of Abies.

Coniferous forests are under severe threat of the rapid anthropogenic climate warming. Abies (firs), the fourth-largest conifer genus, is a keystone component of the boreal and temperate dark-coniferous forests and harbors a remarkably large number of relict taxa. However, the uncertainty of the phylogenetic and biogeographic history of Abies significantly impedes our prediction of future dynamics and efficient conservation of firs. In this study, using 1,533 nuclear genes generated from transcriptome sequencing and a complete sampling of all widely recognized species, we have successfully reconstructed a robust phylogeny of global firs, in which four clades are strongly supported and all intersectional relationships are resolved, although phylogenetic discordance caused mainly by incomplete lineage sorting and hybridization was detected. Molecular dating and ancestral area reconstruction suggest a Northern Hemisphere high-latitude origin of Abies during the Late Cretaceous, but all extant firs diversified during the Miocene to the Pleistocene, and multiple continental and intercontinental dispersals took place in response to the late Neogene climate cooling and orogenic movements. Notably, four critically endangered firs endemic to subtropical mountains of China, including A. beshanzuensis, A. ziyuanensis, A. fanjingshanensis and A. yuanbaoshanensis from east to west, have different origins and evolutionary histories. Moreover, three hotspots of species richness, including western North America, central Japan, and the Hengduan Mountains, were identified in Abies. Elevation and precipitation, particularly precipitation of the coldest quarter, are the most significant environmental factors driving the global distribution pattern of fir species diversity. Some morphological traits are evolutionarily constrained, and those linked to elevational variation (e.g., purple cone) and cold resistance (e.g., pubescent branch and resinous bud) may have contributed to the diversification of global firs. Our study sheds new light on the spatiotemporal evolution of global firs, which will be of great help to forest management and species conservation in a warming world.

The plane piston problem in a weakly gravitating generalized Chaplygin gas

The present study examines the behavior of a plane piston problem as it moves at a constant velocity in a generalized Chaplygin gas in the presence of a weak gravitational field. A systematic perturbation approach is utilized to obtain an analytical solution for the flow field up to the first order of ϵ. Also, the basic state solution is derived in case of weak shock waves. Further, we analyze the distribution patterns of flow variables for different values of α graphically. Moreover, an approximate solution for the strong shock wave has been found and discussed. The acquired solutions are highly influenced by generalized Chaplygin gas and the applied gravity, which is intriguing aspect from both a physical and scientific standpoint.

The Effects of Climate Change on the Distribution Pattern of Species Richness of Endemic Wetland Plants in the Qinghai-Tibet Plateau.

Wetland ecosystems in the Qinghai-Tibet Plateau (QTP), the region with the richest biodiversity and the most important ecological barrier function at high altitudes, are highly sensitive to global change, and wetland plants, which are important indicators of wetland ecosystem structure and function, are also threatened by wetland degradation. Therefore, a comprehensive study of changes in the geographical distribution pattern of plant diversity, as well as species loss and turnover of wetlands in the QTP in the context of global climate change is of great importance for the conservation and restoration of wetland ecosystems in the QTP. In this study, species turnover and loss of 395 endemic wetland plants of the QTP were predicted based on the SSP2-4.5 climate change scenarios. The results showed that there were interspecific differences in the effects of climate change on the potential distribution of species, and that most endemic wetland plants would experience range contraction. Under the climate change scenarios, the loss of suitable wetland plant habitat is expected to occur mainly in parts of the southern, north-central and north-western parts of the plateau, while the gain is mainly concentrated in parts of the western Sichuan Plateau, the Qilian Mountains, the Three Rivers Source Region and the northern Tibetan Plateau. Overlaying the analysis of priority protected areas with the established protected areas in the QTP has resulted in the following conservation gaps: the eastern Himalayan region, midstream of the Yarlung Zangbo River, the transition zone between the northern Tibetan Plateau and the Hengduan Mountains, Minshan-Qionglai mountain, Anyemaqen Mountains (southeast) to Bayankala (southeast) mountains, the southern foothills of the Qilian Mountains and the northern Tibetan Plateau region. In the future, the study of wetland plant diversity in the QTP and the optimisation of protected areas should focus on the conservation gaps. This study is of great importance for the study and conservation of wetland plant diversity in the QTP, and also provides a scientific basis for predicting the response of wetland plants to climate change in the QTP.