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Microbial communities are crucial for important ecosystem functions in the open ocean, such as primary production and nutrient cycling. However, few studies have addressed the distribution of microplankton communities in the remote oligotrophic region of the Pacific Ocean. Moreover, the biogeochemical and physical drivers of microbial community structure are not fully understood in these areas. This research aims to investigate the patterns of prokaryotic and protists communities' distribution in the North Pacific Subtropical Front (NPSF). The NPSF is a vast oligotrophic region with layered surface water and strong ocean currents. Despite its considerable size, its community distribution and function are poorly studied. We used a 16S and 18S rRNA gene sequencing approach to identify and characterize the water column microbial communities at two depths, the surface (3–5 m) and the deep chlorophyll maximum (DCM, 108–130 m). We aimed to elucidate the horizontal distribution patterns of these communities and to dissect the factors intricately shaping their distribution in the NPSF. Results showed that the community structure of both prokaryotes and protists was significantly influenced by depth, temperature, and longitude. Regarding alpha diversity, both communities presented a higher diversity at the surface. The prokaryotes also demonstrated to have a higher diversity in samples placed further east. The prokaryotes were dominated by Proteobacteria and Cyanobacteria, and the eukaryotic communities were dominated by Syndiniales. Combining biological and hydrographic data analysis showed the influence of vertical currents near the frontal jet in shaping the vertical distribution of both prokaryotic and protist communities. Even though most studies do not consider anomalies that emerge at each depth, these occurrences are capable of having a strong impact and influence on community structure. This study marks a significant advance in unraveling the intricate community structure and distribution dynamics of marine microbial communities within the North Pacific Ocean. [ABSTRACT FROM AUTHOR]

Antarctic krill (Euphausia superba) is a harvested species that has an important role in the Southern Ocean food web. Knowledge on the demography of Antarctic krill is necessary for a better understanding of the distribution of life stages and their relation with predator species. In addition, such information is essential for krill fisheries management by CCAMLR (Commission on the Conservation of Antarctic Marine Living Resources). A large part of the Indian sector of the Southern Ocean is understudied and large-scale krill surveys of this region are scarce. Therefore, a survey was carried out during the austral summer of 2018/2019 on board RV Kaiyo-maru in the region from 80 to 150°E. Krill was collected using a Rectangular Midwater Trawl (RMT). Previous studies suggest that part of the Antarctic krill population resides in the upper surface of the water column, but traditional trawls and echosounders have not been able to fully investigate this stratum due to sampling constraints. To overcome this knowledge gap, the upper surface (0-2 m) was sampled using a Surface and Under Ice Trawl (SUIT) in addition to the standard survey net. Results show that there were differences in the horizontal and vertical distribution of post-larval krill between the area west and east of approximately 120°E. These differences coincided with variation in environmental properties. Early calyptopis larvae were found throughout the survey area. Their relatively low numbers suggested ongoing spawning that started early in the season. Juveniles were found mainly in the western side of the sampling area and large densities of this developmental stage were found to reside in the upper two meters of the water column. The quantitative estimation of krill in the upper surface indicated that undersampling this part of the population may influence estimates of, for example, recruitment. [ABSTRACT FROM AUTHOR]

Microbial communities are crucial for important ecosystem functions in the open ocean, such as primary production and nutrient cycling. However, few studies have addressed the distribution of microplankton communities in the remote oligotrophic region of the Pacific Ocean. Moreover, the biogeochemical and physical drivers of microbial community structure are not fully understood in these areas. This research aims to investigate the patterns of prokaryotic and protists communities’ distribution in the North Pacific Subtropical Front (NPSF). The NPSF is a vast oligotrophic region with layered surface water and strong ocean currents. Despite its considerable size, its community distribution and function are poorly studied. We used a 16S and 18S rRNA gene sequencing approach to identify and characterize the water column microbial communities at two depths, the surface (3–5 m) and the deep chlorophyll maximum (DCM, 108–130 m). We aimed to elucidate the horizontal distribution patterns of these communities and to dissect the factors intricately shaping their distribution in the NPSF. Results showed that the community structure of both prokaryotes and protists was significantly influenced by depth, temperature, and longitude. Regarding alpha diversity, both communities presented a higher diversity at the surface. The prokaryotes also demonstrated to have a higher diversity in samples placed further east. The prokaryotes were dominated by Proteobacteria and Cyanobacteria, and the eukaryotic communities were dominated by Syndiniales. Combining biological and hydrographic data analysis showed the influence of vertical currents near the frontal jet in shaping the vertical distribution of both prokaryotic and protist communities. Even though most studies do not consider anomalies that emerge at each depth, these occurrences are capable of having a strong impact and influence on community structure. This study marks a significant advance in unraveling the intricate community structure and distribution dynamics of marine microbial communities within the North Pacific Ocean.

Antarctic krill (Euphausia superba) is a harvested species that has an important role in the Southern Ocean food web. Knowledge on the demography of Antarctic krill is necessary for a better understanding of the distribution of life stages and their relation with predator species. In addition, such information is essential for krill fisheries management by CCAMLR (Commission on the Conservation of Antarctic Marine Living Resources). A large part of the Indian sector of the Southern Ocean is understudied and large-scale krill surveys of this region are scarce. Therefore, a survey was carried out during the austral summer of 2018/2019 on board RV Kaiyo-maru in the region from 80 to 150˚E. Krill was collected using a Rectangular Midwater Trawl (RMT). Previous studies suggest that part of the Antarctic krill population resides in the upper surface of the water column, but traditional trawls and echosounders have not been able to fully investigate this stratum due to sampling constraints. To overcome this knowledge gap, the upper surface (0-2 m) was sampled using a Surface and Under Ice Trawl (SUIT) in addition to the standard survey net. Results show that there were differences in the horizontal and vertical distribution of post-larval krill between the area west and east of approximately 120˚E. These differences coincided with variation in environmental properties. Early calyptopis larvae were found throughout the survey area. Their relatively low numbers suggested ongoing spawning that started early in the season. Juveniles were found mainly in the western side of the sampling area and large densities of this developmental stage were found to reside in the upper two meters of the water column. The quantitative estimation of krill in the upper surface indicated that undersampling this part of the population may influence estimates of, for example, recruitment.

Objective To investigate the distributions of vitamin K1 and K2 in infants of different age groups by comparing the serum levels of vitamin K1 and K2 in them. Methods 1 177 infants from 0 to 3 months were divided into 6 age groups. Those born/treated in the subject units (pediatrics, neonatology, child health care, obstetrics) were selected as the study subjects and grouped by age: 0～3 days (591 cases), 4～7 days (255 cases), 8～5 days (104 cases), 1 month (118 cases), 2 months (40 cases), and 3 months (69 cases). General data of the infants were collected, and the serum vitamin K1 and K2 levels were determined by HPLC-mass spectrometry (LCMS) on a unified platform, and analyzed from the distribution of vitamin K1 and K2 at different ages. Results The distributions of vitamin K1 and K2 levels were statistically significant (P <0.001); newborns were highly vulnerable to vitamin K1 deficiency, and vitamin K2 deficiency was higher than vitamin K1 with age. Conclusion Maintaining the normal growth of vitamin K1 and K2 is crucial for the normal growth and development of infants of all ages, so we should pay close attention to the monitoring and supplement of vitamin K1 and K2. [ABSTRACT FROM AUTHOR]

Microzooplankton (MZP) are an important part of the microbial food web and play a pivotal role in connecting the classic food chain with the microbial loop in the marine ecosystem. They may play a more important role than mesozooplankton in the lower latitudes and oligotrophic oceans. In this article, we studied the species composition, dominant species, abundance, and carbon biomass of MZP, including the relationship between biological variables and environmental factors in the eastern equatorial Indian Ocean during the spring intermonsoon. We found that the MZP community in this ocean showed a high species diversity, with a total of 340 species. Among these, the heterotrophic dinoflagellates (HDS) (205 species) and ciliates (CTS) (126 species) were found to occupy the most significant advantageous position. In addition, CTS (45.3%) and HDS (39.7%) accounted for a larger proportion of the population abundance, while HDS (47.1%) and copepod nauplii (CNP) (46.4%) made a larger contribution to the carbon biomass. There are significant differences in the ability of different groups of MZP to assimilate organic carbon. In this sea area, MZP are affected by periodic currents, and temperature is the main factor affecting the distribution of the community. The MZP community is dominated by eurytopic species and CNP. CTS are more sensitive to environmental changes than HDS, among which Ascampbelliella armilla may be a better habitat indicator species. In low-latitude and oligotrophic ocean areas, phytoplankton with smaller cell diameters were found to occupy a higher proportion, while there was no significant correlation between the total concentration of integrated chlorophyll a and the biological variables of MZP. Therefore, we propose that the relationship between size-fractionated phytoplankton and MZP deserves further study. In addition, the estimation of the carbon biomass of MZP requires the establishment of more detailed experimental methods to reflect the real situation of organisms. This study provides more comprehensive data for understanding the diversity and community structure of MZP in the eastern equatorial Indian Ocean, which is also of good value for studying the adaptation mechanism and ecological functions of MZP in low-latitude and oligotrophic ocean ecosystems.

Studying the distribution characteristics of bioaerosols and their interaction with the environment is crucial for dairy farms. The distribution of aerosols differs in dairy farming from farming of other livestock, and their sensitivity to environmental factors varies across sites. Field experiments were conducted in an intensive commercial dairy farm in Northern China to investigate the horizontal and vertical distribution of culturable bacterial bioaerosols. Concentration levels and particle size ranges were analyzed, and the impact of multiple environmental factors on culturable bacterial bioaerosols was assessed. Significant variations in culturable bacterial bioaerosol concentrations were observed across eight functional zones, ranging from 1.14 × 103 to 7.35 × 103 CFU/m3. Culturable bacterial bioaerosols exhibited consistent carrier distribution patterns across six different size ranges. Vertical analysis revealed significantly higher culturable bacterial bioaerosol concentrations at a 1 m height compared to 4 m (p < 0.05), while similar size distributions were observed at different heights of the same sampling location. The top three environmental factors influencing culturable bacterial bioaerosol concentrations were PM100 concentration, wind direction, and air temperature. This study provides insights into the distribution characteristics of culturable bacterial bioaerosols on dairy farms and their response to environmental factors. The findings serve as a reference for evaluating bioaerosol emissions and establishing daily disinfection management measures on dairy farms. [ABSTRACT FROM AUTHOR]

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Disentangling the role of factors responsible for juvenile fish dispersal is essential to understand the ecology of individual species, setting the corresponding conservation status and evaluating the potential risk in case of invasion. Because of their small body size and high sensitivity to environmental conditions, juvenile fish movements have largely been explained by external factors such as wind-induced water currents. In this study, early hatched pikeperch (Sander lucioperca) of hatchery origin were marked with oxytetracycline hydrochloride, stocked into a bay near the dam of a deep reservoir, and then monitored at approximately 10-day intervals using fix-frame trawling for 43 and 51 days after stocking, in 2007 and 2008, respectively. In both years, marked pikeperch were captured throughout the study period in the bay and closed dam section of the reservoir. After one month, individuals were captured in the middle section of the reservoir, approximately 5 km upstream from the stocking site. Four individuals were recaptured in the tributary section of the reservoir, about 10 km upstream from the stocking site during the last sampling in 2007. The farthest distance detection followed periods of strong wind. During daytime sampling, marked pikeperch were captured in both the warm epipelagic layer above the thermocline and the cold bathypelagic layer below the thermocline. The later sampling represented a community of vertically migrating individuals originally thought to consist only of reservoir-born and reservoir-experienced fish. This study suggested the high mobility and flexibility of 0+ pikeperch, as well as their unexpected behavioral plasticity. [ABSTRACT FROM AUTHOR]

Soil carbon and nitrogen levels are key indicators of soil fertility and are used to assess ecological value and safeguard the environment. Previous studies have focused on the contributions of vegetation, topography, physical and chemical qualities, and meteorology to soil carbon and nitrogen change, but there has been little consideration of landscape and ecological environment types as potential driving forces. The study investigated the horizontal and vertical distribution and influencing factors of total carbon and total nitrogen in soil at 0–20 and 20–50 cm depths in the source region of the Heihe River. A total of 16 influencing factors related to soil, vegetation, landscape, and ecological environment were selected, and their individual and synergistic effects on the distributions of total carbon and total nitrogen in soil were assessed. The results show gradually decreasing average values of soil total carbon and total nitrogen from the surface layer to the bottom layer, with larger values in the southeast part of the sampling region and smaller values in the northwest. Larger values of soil total carbon and total nitrogen at sampling points are distributed in areas with higher clay and silt and lower soil bulk density, pH, and sand. For environmental factors, larger values of soil total carbon and total nitrogen are distributed in areas with higher annual rainfall, net primary productivity, vegetation index, and urban building index, and lower surface moisture, maximum patch index, boundary density, and bare soil index. Among soil factors, soil bulk density and silt are most closely associated with soil total carbon and total nitrogen. Among surface factors, vegetation index, soil erosion, and urban building index have the greatest influence on vertical distribution, and maximum patch index, surface moisture, and net primary productivity have the greatest influence on horizontal distribution. In conclusion, vegetation, landscape, and soil physical properties all have a significant impact on the distribution of soil carbon and nitrogen, suggesting better strategies to improve soil fertility. [ABSTRACT FROM AUTHOR]

The aim of the paper is to introduce the concept of quasi bi-slant submersions from almost contact metric manifolds onto Riemannian manifolds as a generalization of semi-slant and hemi-slant submersions. We mainly focus on quasi bi-slant submersions from cosymplectic manifolds. We give some non-trivial examples and study the geometry of leaves of distributions which are involved in the definition of the submersion. Moreover, we find some conditions for such submersions to be integrable and totally geodesic.

Studying the distribution characteristics of bioaerosols and their interaction with the environment is crucial for dairy farms. The distribution of aerosols differs in dairy farming from farming of other livestock, and their sensitivity to environmental factors varies across sites. Field experiments were conducted in an intensive commercial dairy farm in Northern China to investigate the horizontal and vertical distribution of culturable bacterial bioaerosols. Concentration levels and particle size ranges were analyzed, and the impact of multiple environmental factors on culturable bacterial bioaerosols was assessed. Significant variations in culturable bacterial bioaerosol concentrations were observed across eight functional zones, ranging from 1.14 × 103 to 7.35 × 103 CFU/m3. Culturable bacterial bioaerosols exhibited consistent carrier distribution patterns across six different size ranges. Vertical analysis revealed significantly higher culturable bacterial bioaerosol concentrations at a 1 m height compared to 4 m (p < 0.05), while similar size distributions were observed at different heights of the same sampling location. The top three environmental factors influencing culturable bacterial bioaerosol concentrations were PM100 concentration, wind direction, and air temperature. This study provides insights into the distribution characteristics of culturable bacterial bioaerosols on dairy farms and their response to environmental factors. The findings serve as a reference for evaluating bioaerosol emissions and establishing daily disinfection management measures on dairy farms.

On the basis of the comparison and analysis of the chemical properties of contaminated and uncontaminated soils in a coalbed methane well site in Lyuliang city, the horizontal distribution characteristics of soil contamination caused by CBM produced water were discussed. Results indicate that both the moisture content and pH value of contaminated soil were higher than these of uncontaminated soil. The contaminated soil moisture content decreased first and then stabilized with the increase of the distance between the profile and CBM produced water, whereas, there was no significant change for pH value in horizontal direction. Na+ and Cl- were the main contaminantions in produced water and their content, in contaminated soil were obviously higher than these in uncontaminated soil. Herein, they varied greatly in horizontal direction at 0-10 cm depth, with no obvious change rule. Whereas, the values near the CBM produced water at 10-30 cm depth were higher and, changed obviously then tended to be stable with the increase of the distance between the profile and CBM produced water. Furthermore, the values decreased with increasing horizontal distance at 30-70 cm depth.

Marine causeways are becoming more common in many coastal regions to improve vehicular transportation and social integration across landscapes segmented by bays and estuaries. The construction of barrier-type structures has profound implications by altering the geomorphological, hydrodynamic, and ecological conditions in the coastal marine environment. This study investigates the impact of one such newly constructed marine causeway in an enclosed bay in the Arabian Gulf. We hypothesized that the underwater structure of the bridge affects hydrodynamic and physicochemical conditions in the bay. Through extensive physicochemical monitoring, we found that the bridge acted as a physical barrier diminishing tidal currents, thereby resulting in decreased water exchange and heightened stagnation within the bay. Consequently, environmental gradients intensified and nutrient dynamics altered across the bridge. This will have implications for the plankton dynamics, ecosystem function, and overall health of the bay and its surrounding waters. Based on these results, it is recommended to increase efforts to mitigate the stagnation in the bay. Additionally, future coastal development needs to avoid further compromising the water exchange ability of the bay. Our findings also highlight the importance of continuous monitoring and adaptive management strategies to mitigate the environmental impacts of such developments. [Display omitted] • Field surveys conducted inside and outside the marine causeway in an enclosed bay. • A rapid decrease in ocean current was observed across the bridge. • The blockage effect demonstrated the bridge piers as a significant physical barrier. • Spatial gradients in physical and chemical properties inside and outside the bridge. • Changes in chemical characteristics in the bay due to the blockage effect. [ABSTRACT FROM AUTHOR]

Tropical forests play a vital role in preserving world biodiversity and supporting ecological services. Moreover, the spatial distribution of species diversity and its causes are one of the core issues in community ecology. Therefore, the aim of this study was to explore the horizontal distribution characteristics of shrub community diversity in the tropical region of Hainan and reveal the relationship between species diversity and environmental factors under anthropogenic disturbances. Based on a survey of 39 shrubland plots, we evaluated shrub community diversity by calculating Hill number and Pielou evenness index. Regression analysis was employed to determine the horizontal distribution pattern, and Pearson correlation and redundancy analysis were applied to reveal the relationship between species diversity and environmental factors. The results reveal that species richness increased from west to east and the horizontal distribution of shrubland species diversity in Hainan was largely determined by rainfall and edaphic factors and not by topographic factors. Rainfall factors were the most influential. Although there was a significant human disturbance in Hainan shrublands, environmental factors were still influencing the distribution of these shrublands, and there was a lower shrub diversity in areas with poor moisture conditions, which should be studied more. Our results are of great significance to the study of tropical vegetation and regional biodiversity conservation. [ABSTRACT FROM AUTHOR]

Distribution and carbon biomass of planktonic foraminifera were investigated from the euphotic zone of the Eastern Indian Ocean during a two-month cruise, 'Shiyan I' (10 April–13 May 2014). Foraminifera species were collected through plankton net sampling at 44 locations (80.00°–96.10° E, 10.08° N–6.00° S). The temperature (°C) ranged between 12.82 and 31.8 °C, the salinity ranged between 32.5 and 35.5, and chlorophyll-a concentrations ranged between 0.005 µg/L and 0.89 µg/L. A total of 20 taxa were identified based on the spherical chamber shell, spines, and a final whorl which were examined under light microscopy and scanning electron microscopy. Dominant species that were characterized by the high dominant index Y > 0.14–0.46 were Globigerina bulloides, Globigerinoides ruber white, Globigerinella siphonifera, Turborotalita quinqueloba, and Globigerinella calida, contributing to the community up to 86%. The shell size of collected taxa was from 51 to 508 μm and the total carbon biomass was estimated to be between 0.062 µg C m–3 and 26.52 µg C m–3. The high carbon biomass was recorded at two stations in the equator zone. Due to its large size, Globorotalia menardii had total carbon biomass of 3.9 µg C m–3, followed by G. calida 0.68 µg C m−3, Trilobatus sacculifer 0.38 µg C m–3, Orbulina universa 0.56 µg C m–3, and G. ruber white 0.22 µg C m–3, respectively. The Pearson correlation analysis showed that the temperature and chlorophyll-a were two explanatory environmental variables that were found to be highly significant (p < 0.05) and that triggered the distribution and abundance of dominant foraminifera species in the study region. Overall, high abundances and carbon biomass were derived from the euphotic zone and equatorial region of the Eastern Indian Ocean. [ABSTRACT FROM AUTHOR]

We investigate the characteristics of a dust-devil-like vortex (DDLV) observed using thermal image velocimetry (TIV) at a sports ground in Tokyo. Thermal image velocimetry provides unique observations of the two-dimensional velocity distribution for a DDLV with high spatio–temporal resolution (i.e., tens of cm s−1) near the ground. Two DDLVs were detected, one each in summer and winter, and the quantitative features of the larger, stronger DDLV in the winter are examined. The size and strength of the detected DDLV, which are quantified using TIV, are within the ranges reported in past observations and numerical simulations of dust devils. The vortex appears at the boundary of a cold-air current near a 55-m building wall, and persists for more than 3 min. [ABSTRACT FROM AUTHOR]

[Display omitted] Chemical prelithiation is regarded as a crucial method for improving the initial Coulombic efficiency (ICE) of Li-storage anodes. Herein, a substituent-engineered Li-cyanonaphthalene chemical prelithiation system is designed to simultaneously enhance the ICE and construct a multifunctional interfacial film for SiO electrodes. X-ray photoelectron spectroscopy (XPS), electron energy-loss spectroscopy (EELS), nuclear magnetic resonance (NMR) spectroscopy and atomic force microscopy (AFM) prove that the Li-cyanonaphthalene prelithiation reagent facilitates the formation of a rectified solid electrolyte interface (SEI) film in two ways: (1) generation of a gradient SEI film with an organic outer layer (dense N-containing organics, ROCO 2 Li) and an inorganic LiF-enriched inner layer; (2) homogenization of the horizontal distribution of the composition, mechanical properties and surface potential. As a result, the prelithiated SiO electrode exhibits an ICE above 100%, enhanced CEs during cycling, better cycle stability and inhibition of lithium dendrite formation in the overcharged state. Notably, the prelithiated hard carbon/SiO (9:1)‖LiCoO 2 cell displays an enhancement in the energy density of 62.3%. [ABSTRACT FROM AUTHOR]

In this study, the species diversity and geographical distribution pattern of wild Gesneriaceae in Guizhou Province were studied based on the establishment of a list and geographical distribution database of wild Gesneriaceae in Guizhou Province. The species composition, endemism, horizontal distribution, vertical distribution and similarity were analyzed, through the literature and a field investigation, and the hotspots of Gesneriaceae in Guizhou were determined by a complementary algorithm. The results are as follows:(1)There are 153 species(including subspecies)of Gesneriaceae in Guizhou Province, belonging to 2 tribes, 8 subtribes, and 28 genera. These plants are distributed among 75 county-level administrative districts. There are 128 species endemic to China and 45 endemic to Guizhou, and the vertical distribution is the most abundant at altitudes section of 900-1 300 m.(2)The calculation of the provincial similarity coefficient showed that Guizhou and Guangxi had the highest similarity. Finally, 10 hot spots were selected, representing 75% of the Gesneriaceae plants.(3)Guizhou Province is a typical karst plateau mountainous area that is rich in species of Gesneriaceae, especially Oreocharis, Primulina, Petrocodon and Paraboea, which have high species diversity and regional specificity. This study can provide a theoretical reference for the conservation and sustainable utilization of Gesneriaceae plant resources in Guizhou Province. [ABSTRACT FROM AUTHOR]

This research article attempts to investigate anti-invariant Lorentzian submersions and the Lagrangian Lorentzian submersions (LLS) from the Lorentzian concircular structure [in short (LCS)n] manifolds onto semi-Riemannian manifolds with relevant non-trivial examples. It is shown that the horizontal distributions of such submersions are not integrable and their fibers are not totally geodesic. As a result, they can not be totally geodesic maps. Anti-invariant and Lagrangian submersions are also explored for their harmonicity. We illustrate that if the Reeb vector field is horizontal, the anti-invariant and LLS can not be harmonic.

The distribution of macrobenthos in the intertidal area of Buntal Bay, Sarawak was studied based on systematic sampling conducted in 2014. This study aimed to determine the intertidal macrobenthic horizontal distribution and their relationship with environmental parameters. An analysis of the intertidal flat marobenthos community suggested that polychaetes dominated the community in terms of the number of individuals and species followed by crustaceans and molluscs. Polychaetes of families Nephtyidae, Spionidae, Capitellidae, and Magelonidae contributed to the high densities of macrobenthos. Multivariate analysis performed by the Biotic and Environmental linking analysis indicated that communities in Transect 1 and Transect 2 were best correlated with food availability (sediment chlorophyll a), and heterogeneity of sediment type (percentage of fine sand and very fine sand). Heterogeneity of sediment characteristic and food availability were identified as potentially playing a key role in the shaping of the intertidal macrobenthic distribution in Buntal Bay.

Tropical forests play a vital role in preserving world biodiversity and supporting ecological services. Moreover, the spatial distribution of species diversity and its causes are one of the core issues in community ecology. Therefore, the aim of this study was to explore the horizontal distribution characteristics of shrub community diversity in the tropical region of Hainan and reveal the relationship between species diversity and environmental factors under anthropogenic disturbances. Based on a survey of 39 shrubland plots, we evaluated shrub community diversity by calculating Hill number and Pielou evenness index. Regression analysis was employed to determine the horizontal distribution pattern, and Pearson correlation and redundancy analysis were applied to reveal the relationship between species diversity and environmental factors. The results reveal that species richness increased from west to east and the horizontal distribution of shrubland species diversity in Hainan was largely determined by rainfall and edaphic factors and not by topographic factors. Rainfall factors were the most influential. Although there was a significant human disturbance in Hainan shrublands, environmental factors were still influencing the distribution of these shrublands, and there was a lower shrub diversity in areas with poor moisture conditions, which should be studied more. Our results are of great significance to the study of tropical vegetation and regional biodiversity conservation.

Soil total organic carbon (TOC) and total nitrogen (TN) in estuarine areas show distinct heterogeneities in horizontal and vertical distributions due to complex influencing factors, and clarifying the horizontal and vertical distributions and their influencing factors is of great significance. In this study, the eastern Chongming Island in the Yangtze River estuary in China was selected as the study area, and the horizontal and vertical distributions of soil TOC and TN in different layers of 0–20 cm, 20–40 cm, and 40–60 cm were exhibited in maps and analyzed in different community types. Then, a total of 17 potential factors in aspects of soil, vegetation, atmosphere, landscape, and position were adopted and their single and synergistic effects on the spatial patterns of TOC and TN were identified from different perspectives. Results indicated that the mean values of TOC and TN in the entire study area decreased from surface to bottom layers. TOC and TN showed distinct spatial heterogeneities in different sampling sites and community types; they were generally high in the inner part and low in the alongshore areas in surface soils and showed opposite spatial characteristics in bottom soils; and woodland showed the highest TOC and TN in surface soils and the lowest values in bottom soils of different community types. TOC and TN in different layers, as well as the variations of TOC and TN across layers, exhibited specific and different spatial patterns under the complex factors. In soil factors, pH and available phosphorus showed the closest correlations with TOC and TN in different layers; in land surface factors, plant diversity and growth condition contributed the most to the horizontal distribution while plant growth condition and bare soil index exerted the highest influences on the vertical distribution.

The relationship between larval supply and settlement is an integral part of the demographic processes of benthic marine organisms that determine their distribution at subsequent life stages. In ascidians, a strong positive relationship between larval supply and settlement has been previously documented, but only at small spatial scales (one location) and short time scales (less than one day). We investigated how this relationship might scale up by sampling larval abundance and settlement of a colonial ascidian (Botryllus schlosseri) across mesoscales (100 s of m) of the anthropogenic seascape of a 1.5-ha marina. Settlement varied vertically with a linear decrease in settlement with increasing depth. This pattern corresponded to the vertical distribution of larvae in the morning, when they were most abundant. However, larval abundance explained only 26% of the variation in settlement at the meso-spatial scale (i.e. the combined effect of the horizontal and vertical dimensions). This weakening of the relationship between larval supply and settlement suggests that the two processes may become decoupled at larger spatial and temporal scales. Our study underscores how changing the scales of sampling may affect our understanding of larval dispersal and settlement processes. [ABSTRACT FROM AUTHOR]

In this paper, we introduce bi-slant submersions from almost Hermitian manifolds onto Riemannian manifolds as a generalization of invariant, anti-invariant, semi-invariant, slant, semi-slant and hemi-slant Riemannian submersions. We mainly focus on bi-slant submersions from Kaehler manifolds. We provide a proper example of bi-slant submersion, investigate the geometry of foliations determined by vertical and horizontal distributions, and obtain the geometry of leaves of these distributions. Moreover, we obtain curvature relations between the base space, the total space and the fibers, and find geometric implications of these relations. [ABSTRACT FROM AUTHOR]

We study anti-invariant and Lagrangian submersions from trans-Sasakian manifolds onto Riemannian manifolds. We prove that the horizontal distributions of such submersions are not integrable and their fibers are not totally geodesic. Consequently, they cannot be totally geodesic maps. We also check that the harmonicity of such submersions. In particular, we show that they cannot be harmonic in the case when the Reeb vector field is horizontal. [ABSTRACT FROM AUTHOR]

In the present paper, we introduce a new kind of Riemannian submersion such that the fibers of such submersion are generic submanifolds in the sense of Ronsse that we call generic submersion. Some examples are given for generic submersion. Necessary and sufficient conditions are found for the integrability and totally geodesicness of the distributions which are mentioned in the definition. The geometry of the fibers is investigated. New results are obtained by considering the parallelism condition of canonical structures. [ABSTRACT FROM AUTHOR]

The distribution of macrobenthos in the intertidal area of Buntal Bay, Sarawak was studied based on systematic sampling conducted in 2014. This study aimed to determine the intertidal macrobenthic horizontal distribution and their relationship with environmental parameters. An analysis of the intertidal flat marobenthos community suggested that polychaetes dominated the community in terms of the number of individuals and species followed by crustaceans and molluscs. Polychaetes of families Nephtyidae, Spionidae, Capitellidae, and Magelonidae contributed to the high densities of macrobenthos. Multivariate analysis performed by the Biotic and Environmental linking analysis indicated that communities in Transect 1 and Transect 2 were best correlated with food availability (sediment chlorophyll a), and heterogeneity of sediment type (percentage of fine sand and very fine sand). Heterogeneity of sediment characteristic and food availability were identified as potentially playing a key role in the shaping of the intertidal macrobenthic distribution in Buntal Bay. [ABSTRACT FROM AUTHOR]

This document is an erratum for an article titled "Diversity and community structure of microzooplankton in the eastern Indian Ocean during the inter-monsoon period." The erratum corrects an error in the listing of the editor's name and affiliation. The original version of the article has been updated to reflect this correction. The document also includes information about the publication date, citation, and copyright information. [Extracted from the article]

Con el fin de caracterizar la distribución horizontal (repartición de los hábitats) y la utilización del recurso alimentario (tipo y tamaño de las presas) del ensamblaje de reptiles del bosque seco estacional al norte de la región Caribe de Colombia, en el departamento del Cesar, se realizaron cinco salidas de campo con una duración de doce días cada una. Los muestreos se realizaron en jornadas diurnas y nocturnas, en un diseño de transectos replicados a lo largo de diferentes hábitats que incluyeron: pastizales, bordes e interiores de bosque. Se realizaron análisis descriptivos de uso de hábitat en un perfil de vegetación por cada época climática y análisis de amplitud y sobreposición de nicho. Se registraron 38 especies de 14 familias del orden Squamata. Las especies se distribuyeron de manera homogénea entre zonas abiertas y boscosas. Se encontraron registros de 31 categorías de presa en 109 estómagos de seis especies de serpientes (61 estómagos) y siete de lagartos (48 estómagos) con un porcentaje de estómagos vacíos de 38 %. Las presas de mayor importancia para los lagartos fueron Coleoptera y Araneae, y para las serpientes fueron los anfibios. La mayoría de las especies presentaron un amplio espectro de dieta y entre especies similares, como entre Anolis auratus y A. gaigei, se presentó uso de recursos similares. En síntesis, el ensamblaje de reptiles presentó una distribución homogénea en los hábitats evaluados (áreas abiertas y boscosas) y el recurso alimentario fue variado entre las diferentes especies; la estacionalidad de la zona presenta un papel fundamental en la estructura del ensamblaje de reptiles, presentándose menos abundancia durante la época seca, tanto en las áreas abiertas como en las boscosas.

Dynamic climate changes have become noticeable in recent decades, especially in the vulnerable region of the West Antarctic. The relatively simple food web of this area relies on krill – Euphausia superba. Presumably, as a result of climatic fluctuations, a decrease in the number of this crustacean has been recorded, followed by an increase in the population of the gelatinous zooplankter Salpa thompsoni. In the research presented herein, population and morphometric analyses of Salpa thompsoni have been conducted. Specimens for this research were collected from the Drake Passage, using a Bongo net in the summer season of 2010. It has been found that the horizontal distribution of this gelatinous zooplankter was significantly irregular (Kruskal-Wallis test, p < 0.001). In the northern part of the investigated area, both blastozooids and oozooids were recorded, which confirms the dynamic development of this species. The central part of the Drake Passage was characterized by the dominance of blastozooids, with embryos found at different stages of the development. Only in the region of the South Shetland Islands, the salpid population was characterized by reduced or even stopped reproduction. The immense reproductive efficiency observed in the Salpa thompsoni population was mostly induced by the favourable thermal conditions. These observations may suggest that the ongoing climat changes in the West Antarctic will promote the population expansion of this species.

Background and aims: Spatially segregating root systems is a fundamental mechanism by which plants can avoid competition for resources. Understory roots contribute substantially to total forest fine-root biomass, but the strategy of function-based fine root placement between trees and understory species at the plant community level is unknown. The aim of this study was to determine the differences between trees and understory plants in the deployment of fine roots.Methods: We collected fine roots of trees and understory species in two subtropical coniferous forests, sorted the fine roots into absorptive and transport roots, determined the vertical placement of these two types of fine roots, and examined the abiotic and biotic factors that may regulate the horizontal allocation of fine roots.Results: We found that the contribution of absorptive shrub roots to absorptive roots of the woody plants was higher than the contribution of total shrub fine roots to the total fine roots of the woody plants in the topsoil. Understory plants allocated a greater proportion of their absorptive roots to transport roots (RatioA/T) and more total fine-root biomass than trees in the topsoil. Trees had a lower RatioA/T in the topsoil; but increased their contribution of fine-root biomass to the total fine-root biomass and RatioA/T with depth. The proliferation of shrub fine roots in the topsoil was affected more by soil structure (rock-fragment content and bulk density) than by nearby stems, and the growth of tree fine roots was inhibited by nearby dense and/or large stems.Conclusions: Our results provide evidence of an elaborate differentiation of root deployment between trees and understory plants. The roots of understory plants dominated the topsoil by possessing a higher branching capacity of absorptive roots than trees, filling the readily occupied macropores and being less affected by nearby stems. Trees enhance their resource foraging towards deeper soil by increasing their advantage of occupying soil volume and branching capacity of absorptive roots with depth. We also suggested that the roots of understory plants may affect ecosystemic carbon and nutrients cycling more than expected because of the disproportionately higher investment of absorptive roots in the topsoil. [ABSTRACT FROM AUTHOR]

Akyol [Conformal anti-invariant submersions from cosymplectic manifolds, Hacettepe Journal of Mathematics and Statistics 2017; 462: 177-192] defined and studied conformal antiinvariant submersions from cosymplectic manifolds. The aim of the present paper is to define and study the notion of conformal slant submersions (it means the Reeb vector field ξ is a vertical vector field) from cosymplectic manifolds onto Riemannian manifolds as a generalization of Riemannian submersions, horizontally conformal submersions, slant submersions, and conformal antiinvariant submersions. More precisely, we mention many examples and obtain the geometries of the leaves of vertical distribution and horizontal distribution, including the integrability of the distributions, the geometry of foliations, some conditions related to total geodesicness, and harmonicity of the submersions. Finally, we consider a decomposition theorem on the total space of the new submersion. [ABSTRACT FROM AUTHOR]

This study examines the occurrence of vascular epiphytic species in Central Amazonian black-water floodplain forests (igapó) and considers whether their horizontal and vertical distribution is influenced by the flood pulse, as is the case with tree species (phorophytes). Research was conducted in sixteen forest plots the Jaú National Park. In these, epiphytes on all phorophytes with DBH ≥ 10 cm were identified. We measured flood height using the watermark left by the last high-water period, then estimated the height relative to the ground of every epiphytic individual. We recorded 653 individuals in 37 species, distributed on 109 phorophytes. Igapó floodplain forests have much lower richness and abundance of vascular epiphyte species than do other Amazonian forests. This may reflect the limitation of available sites for colonization (only 24.9% of studied trees were occupied by epiphytes). Holoepiphytes predominated, and the combined presence of a flood-pulse, linked to the nutrient-poor soil poor seems to limit the occurrence of nomadic vines. Horizontal distribution of epiphytes followed the distribution of phorophytes, which in turn followed the flood-level gradient. Also flooding interacted strongly with vertical zonation to determine species richness. As already well-reported for trees, and unlike reports of epiphytes in other floodplains, flooding strongly influenced richness and distribution of vascular epiphytes in the studied igapó forests. [ABSTRACT FROM AUTHOR]

A literature survey revealed that no prior investigation has been conducted on the horizontal distribution of a two-phase refrigerant in mini-channel tubes, which may be of importance for the cooling of heat-generating objects. In this study, we investigated R-134a distribution into four flat tubes inside a horizontal plane. In order to simulate the battery of an electric vehicle, a 600-W power supply was used during our tests. Tests were conducted with mass fluxes ranging from 280 to 480 kg m −2 s −1 and an inlet quality of 0.2. The effects of inlet port orientation and heat exchanger inclination on flow distribution were investigated. Results indicated that the effects of heat exchanger inclination on flow distribution were more prevalent than those of inlet port orientation. However, these effects are weakened as mass flux increases. Flow distribution deteriorated as the inclination of the heat exchanger increased. Header pressure drop constituted a significant portion of heat exchanger pressure drop and became more pronounced as mass flux increased. [ABSTRACT FROM AUTHOR]