Abundance Distribution Research Articles

Occurrence, abundance and seasonal distribution of benthic macro invertebrates in relation to the water quality and bottom soil properties in a fish pond

Occurrence, abundance and seasonal distribution of benthic macro invertebrates in relation to the water quality and bottom soil properties in a fish pond

National assessment on the status, trends and impacts of marine non-indigenous species for the European Union marine strategy framework directive

The Marine Strategy Framework Directive (MSFD) of the European Union aims to enhance the protection of marine ecosystems by assessing Good Environmental Status using several descriptors. Descriptor 2 of the MSFD states that the status of marine non-indigenous species (NIS) should be assessed using specified criteria regarding newly introduced NIS, abundance, and spatial distribution of established NIS, as well as proportions of native species groups adversely altered due to NIS. The current study presents a national NIS indicator assessment for the six sub-basins associated with the Finnish marine waters. The study additionally aimed to develop a methodology to assess changes in native species communities over time. A new biodiversity index was created for this purpose by combining the Gini-Simpson index, and species and phyla richness into a Community Biodiversity Index (CBI). CBI was calculated to measure changes in biodiversity within the soft-bottom benthic communities of the study area, and correlation analyses were conducted between the index scores and NIS proportion. Overall, 34 NIS have been recorded from the Finnish marine waters by 2022, and more than half of them have arrived since 1992. Spatial distribution of three established non-indigenous taxa (Marenzelleria spp., Cercopagis pengoi and Neogobius melanostomus) has expanded during the latest assessment periods and nowadays cover most of the national marine waters. Meanwhile, abundance of Marenzelleria spp. in benthic communities has increased heavily in most sub-basins. The study outcomes indicated that NIS proportion correlated significantly with the CBI within the soft-bottom benthic communities. This correlation was significantly negative for the samples with a higher NIS proportion than the median, suggesting that when NIS became more dominant, biodiversity of the communities decreased. The current study provides an applicable method to evaluate changes in biodiversity for various species groups, and how to link them to changes in the distribution and abundance of established NIS. It can be concluded that the national biological monitoring program has severe temporal and spatial gaps, as the national monitoring data enabled the assessment on native species groups, adversely altered due to NIS to be completed only for one species group, soft-bottom macrozoobenthos. Most importantly, the study emphasised the crucial need for management actions to prevent further NIS introductions.

Attachment and proliferation of human gingival fibroblasts seeded on barrier membranes using Wharton's jelly-derived stem cells conditioned medium: An in vitro study.

The effect of Wharton's jelly mesenchymal stem cells conditioned medium (WJMSCs-CM) and zinc oxide nanoparticles (ZnO-NPs) on cultured human gingival fibroblasts on various barrier membranes was investigated in this study. In this study, human gingival fibroblasts were prepared and cultured on three membranes: collagen membrane, acellular dermal matrix (ADM) with ZnO-NPs, and ADM without ZnO-NPs. WJMSCs-CM was given to the testing groups, while control groups received the same membranes without WJMSCs-CM. Following 48 and 72 h, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) tests were performed to assess cell survival. Cell proliferation on the membranes was also evaluated using 4',6-diamidino-2-phenylindole (DAPI) staining after 48 and 72 h. Field emission scanning electron microscopy was used to determine membrane surface structure and cell adhesion. Nanoparticles were also subjected to an energy-dispersive x-ray analysis to identify their chemical structure. Two-way analysis of variance was used to conduct the statistical analysis. The p-value ≤.05 was considered significant. When ADM-ZnO-NPs were combined with CM, fibroblast viability, and adhesion significantly differed from ADM-ZnO-NPs alone. DAPI results confirmed cell proliferation in all six groups on both experiment days. The abundance and concentrated distribution of cells during cell proliferation were found in CM-containing membranes, specifically the ADM-ZnO-NPs membrane, demonstrating the improved biocompatibility of the ADM-ZnO-NPs membrane for cell proliferation. The other groups did not significantly differ from one another. WJMSCs-CM positively affected the viability and proliferation of gingival fibroblasts, but only marginally. Under certain conditions, ZnO-NPs below a specific concentration increased the biocompatibility of the membranes.

2D crumpled nitrogen-doped carbon nanosheets anode with capacitive-dominated behavior for ultrafast-charging and high-energy-density Li-ion capacitors

The synergistic effect of abundant mesopore distribution and nitrogen doping enables 2D crumpled nitrogen-doped carbon nanosheets as anode materials for Li-ion capacitors with large capacitive-capacities and ultrahigh rate performance.

Variations in microbial community compositions and processes imposed under contrast geochemical contexts in Sicilian mud volcanoes, Italy.

Terrestrial mud volcanoes represent surface features of channels for subsurface methane transport and, therefore, constitute an important source of methane emission from natural environments. How microbial processes regulate methane emissions in terrestrial mud volcanoes has yet to be fully addressed. This study demonstrated the geochemical characteristics and microbial communities of four mud volcano and seep sites in two geological settings of Sicily, Italy. At sites within the accretionary wedge that exhibited higher methane and sulfate concentrations, the communities were dominated by members capable of catalyzing methane and sulfate metabolisms and organic degradation. In particular, both anaerobic and aerobic methanotrophs were abundant and their abundance distribution coincided with the geochemical transition. In contrast, the sites near Mount Etna were characterized by high fluid salinity, CO2, and low methane and sulfate concentrations, with communities consisting of halophilic organic degraders and sulfur metabolizers, along with a minor presence of aerobic methanotrophs. Substantial variations in community composition and geochemistry across spatial and vertical redox gradients suggest that physicochemical contexts imposed by the geology, fluid path, and source characteristics play a vital role in shaping community composition and cycling of methane, sulfur and organic carbon in Sicily mud volcanoes.

Latitudinal richness patterns in a temperate forest region: disentangling the effects of evenness, density and aggregation

It is well known that species diversity declines with increasing latitude. However, the underlying causes and mechanisms remain ambiguous due to effects of scale, the shape of the species abundance distributions (SAD), the total number of individuals (N) and the spatial aggregation of individuals (AGG). In this study, we examine how SAD, N and AGG contribute to the latitudinal richness gradient. Our study is based on a dataset that includes tree, shrub, and herbaceous plants collected from 445 permanent forest plots scattered across an expansive temperate forest region, covering latitudes from 39.71°N to 53.37°N. We compared multiple diversity patterns along the latitude between three life forms (trees, shrubs and herbs) and analyzed the effects of SAD, N and AGG on the latitudinal richness gradient. Our results reveal a general decline in most diversity measures along the latitudinal gradient, with the exception of herbaceous plants. Furthermore, we observed consistent effects of AGG and SAD on the latitudinal richness gradient across all three life forms. Specifically, a decreasing species evenness with increasing latitude led to a reduction in richness, while the simultaneous decrease in spatial aggregation, along with the effects of total number of individuals, collectively contributed to the decline in species richness with increasing latitude. However, the effect of total abundance varies among life forms, with a negligible effect on tree richness, a negative effect on shrub richness, and a significantly positive effect on herbaceous richness. These findings highlight the dependency of the “more-individuals hypothesis” on specific life forms. Our study shows that decomposing species richness into community structure components provides an opportunity for linking specific processes to latitudinal diversity gradients.

Spatiotemporal variations in migratory bird diversity and abundance along the coast of Gochang getbol.

Tidal flats provide critical habitat for migratory waterbird species; however, populations of migratory waterbirds have significantly declined due to tidal flat loss and degradation caused by human activities, particularly in Asia. Gochang getbol is one of tidal flats located on the southwest coast of South Korea and a center of clam production. Using bird monitoring data collected at five zones (zone1 to zone5) established across Gochang getbol and near coastal area, we examined distribution patterns of migratory bird diversity and conservation-related species along the coast of Gochang getbol. The intensity of human activity ‒ mudflat culture (mostly bivalve) and aquaculture was relatively high at zone2 and zone3, occupying > 30% of 2km circular area surrounding most sample points of these zones. Zone1 and particularly zone4 contained more natural/semi-natural habitats (less disturbed mudflats and wetlands) and zone5 had smallest mudflat than others. Shannon diversity, species richness, and abundance of migratory birds differed between zones (Anova test, P ≤ 0.02) except Shannon diversity in winter. In fall, all values were higher at zone4 than zone3 and zone5. In winter, zone1 showed greatest species richness and higher abundance than zone2, zone3, and zone5. In spring, while most differences were found between zone4 and zone5, abundance at zone4 was somewhat higher than zone2. The results from the fourth corner analysis indicated that abundance of species foraging at mudflat level was positively associated with zone1 (winter) but negatively with zone3 (fall). Sandpipers were positively associated with zone4. Abundance distribution maps of conservation-related species, created by inverse distance-weighted interpolation modeling, also showed high abundance of most conservation-related species at zone4 and 1. The findings of our study suggest the importance of natural/semi-natural habitat, and the possible link between human activity and distribution patterns of migratory birds in Gochang getbol. While we need further investigation on direct response of migratory birds to human activity, areas with low human activity with more natural/semi-natural habitat, e.g., zone4 and zone1 may be crucial for the conservation of migratory birds.

Association of methyl donor nutrients dietary intake and sleep disorders in the elderly revealed by the intestinal microbiome.

Currently, sleep disorders (SD) in the elderly are gaining prominence globally and are becoming a significant public health concern. Methyl donor nutrients (MDNs), such as vitamin B6, vitamin B12, folate, and choline, have been reported to have the potential to improve sleep disorders. Moreover, MDNs help to maintain gut flora homeostasis, and are closely associated with the development of SD. Nevertheless, there has been a lack of comprehensive human studies examining the association between MDNs intake and SD. In our study, we comprehensively evaluated the association between MDNs intake and SD in the elderly and used 16S rRNA gene sequencing to explore the underlying mechanism. We found that the SD group (n = 91) had a lower methyl-donor nutritional quality index (MNQI) and a trend toward lower intake compared to the control group (n = 147). Based on the intestinal microbiome, the beta diversity of the intestinal flora was higher in the high methyl-donor nutritional quality (HQ) group compared to the low methyl-donor nutritional quality (LQ) group, and it was lower in the SD group compared to the control group. This suggests that MDNs may regulate sleep by modulating the abundance distribution of the microbiota. Subsequently, we performed correlation analyses between the relative abundance of the microbiota, MDNs intake, and the Pittsburgh Sleep Quality Index (PSQI), identifying five genera with potential regulatory roles. The KEGG pathway analysis indicated that energy metabolism and one-carbon metabolism might be the pathways through which MDNs modulate sleep. This study offers dietary guidance strategies for managing SD in the elderly and provides insights for targeted microbiota intervention.

Seasonal Variations in Ostracod Community Structure and Physicochemical Parameters in Khanki Headworks, Pakistan

Protozoans, rotifers, ostracods and copepods are principal groups of zooplanktons. These organisms are crucial biotic elements, and impact all functional features of aquatic ecosystems. Objective: To assess the impacts of environmental variables on the abundance, biodiversity and seasonal distribution of ostracods in Khanki Headworks, Pakistan. To evaluate the contribution of ostracods as bio-monitors of contamination in freshwater ecosystems. Methods: Month wise separate water samples were taken for different environmental variables from four sampling sites (each with 3 sub-sites), for study period of one year (February 2021 to January 2022), whereas, samples of microcrustaceans (ostracods) were collected with planktonic net (mesh size: 37µm). Results: In total, 5 species of ostracods, associated to 4 genera and 2 families were identified from February 2021 to January 2022. Heterocypris incongruence was the most abundant species, whereas, Dolerocypris sinensis was noted as least abundant species. Ostracods abundance and biodiversity were monitored highest in June and minimum in the month of January. Results of Pearson correlation showed that physicochemical parameters, electrical conductivity (EC), temperature, turbidity, total dissolved solids (TDS) and pH have positive effects on the density and diversity of ostracods. In contrast, dissolved oxygen (DO) showed negative relationship with the abundance and diversity of planktonic ostracods. These findings were further validated by Canonical correspondence analysis (CCA). Conclusions: This investigation revealed that physicochemical parameters generally govern the population dynamics of ostracods.

Elucidating the ecological patterns of sympatric sea-bob shrimp species Xiphopenaeus dincao and X. kroyeri: A temporal and spatial approach

We evaluated the abundance and spatio-temporal distribution of adult individuals of sympatric shrimp species, X. kroyeri and X. dincao, under the influence of environmental variables. The study period took place from July 2021 to June 2022 in Ubatuba Bay, southeastern coast of Brazil. Monthly sampling of specimen and environmental variables occurred using a shrimp fishing boat along four transects of different depths. The abundance peak was differential: X. dincao occurring in the autumn and X. kroyeri in the winter. There was spatial segregation between the species, with X. dincao predominating in more restricted and shallower habitats, while X. kroyeri showed higher abundance in deeper depths. Temporal differentiation of the highest abundance and the habitat partitioning between the species demonstrate different strategies in resource use, following a scenario that reduces competitive pressures and maintains coexistence stability. The closed fishing season appears to offer more protection for X. dincao. Although both periods do not cover the peak of X. kroyeri abundance, its abundance increased in the following months. Our findings describe the population and ecological characteristics of two sea-bob shrimp species, previously regarded as monotypic, and contribute to a deeper understanding of the actual status of these populations.

Бага Ойгорын палеолитын хадны зургийн дурсгал

In 2004, Ts. Turbat made a discovery of a significant site of engraved rock art, dating back to the Upper Paleolithic period. Situated on the south bank of the Baga Oigor River, this remarkable site lies within the protective zone of the World Heritage site of the Mongolian Altai rock art complex. The Baga Oigor-VI complex boasts an impressive array of 41 depictions featuring animals such as horses, ibex, argali, deer, cattle, and snakes from the Upper Paleolithic period, complemented by an additional 16 images originating from the Bronze Age, constituting a total of 57 images. Noteworthy is the superior preservation status of this monument, eclipsing that of comparable sites and presenting unparalleled clarity in visibility. The scarcity of open Paleolithic rock art sites across the globe that bear resemblance to this exceptional find underscores its singular nature. The geographically nearest analogous site of significance is the Gobustan monument in the South Caucasus followed by largest concentration of similar monuments in Iberian peninsula. Beyond the renowned ochre paintings of the Khoid Tsenkher Cave, an extensive exploration of carved rock art open air monuments is underway, elevating the Mongolian Altai region to the status of a pivotal hub in the realm of ancient art. The sheer abundance and widespread distribution of these monuments contribute to its characterization as a veritable “cradle of prehistoric art”.

Automatic differentiation of Eucalyptus species through Sentinel-2 images, Worldview-3 images and LiDAR data

Eucalyptus constitutes one of the most common tree genera used in forest plantations worldwide. In Europe, Eucalyptus trees are especially common in the Northwest of the Iberian Peninsula, E. nitens and E. globulus being the most commonly cultivated species. Each species presents particularities that lend to different exploitation strategies and industrial usages. Therefore, updated knowledge about the abundance and spatial distribution of the different species is important for forest planning. This is a special challenge for areas where forest land is highly fragmented. Remote sensing has been used to efficiently monitor the distribution of the Eucalyptus genera, however little research has been able to map specific Eucalyptus species. This study evaluates the efficiency of Sentinel-2 data, Worldview-3 images, and Airborne LiDAR data in the differentiation of E. nitens and E. globulus. Supervised classifications were performed using neural networks for these data sets both individually and in combination. The highest accuracies were obtained when using Sentinel-2 data in combination with LiDAR point clouds and when using Sentinel-2 data in a multitemporal approach. The best time of year to differentiate between the two species is during the emergence of spring shoots. Worldview-3 images have a moderate capacity to differentiate between the two species, although this is increased when textural metrics are included. This study can serve as the basis for generating Eucalyptus species distribution maps, which will allow for improved forest management and planning.

Controls on long-term changes in bathyal bivalve biomass: The Pleistocene glacial–interglacial record in the eastern Mediterranean

The biomass of aquatic organisms largely determines the mass and energy flow within an ecosystem, but the long-term impact of environmental change on biomass is not well constrained for a number of clades. Here, we test the hypothesis that bivalve biomass is negatively impacted by warming climate over time. This study is based on a fossil marine bivalve fauna recovered from hemipelagic sediments deposited in the eastern Mediterranean during climate cycles (marine isotope stages (MIS) 22–18; 900–712 kyr B.P.) of the Early–Middle Pleistocene Transition. We reconstruct individual shell biomasses from fossils and discuss the various biotic and abiotic factors that controlled long-term shell biomass patterns across this important interval in the Earth climate system. The results are contrary to the original hypothesis, suggesting that the response to temperature is not universal. Nevertheless, a decrease in median biomass is observed during the MIS 19 warm period and can be possibly attributed to the combined effect of multiple drivers that cooperated at that critical time in the past, including higher temperature and primary productivity, reduced ventilation of the sea floor, biodiversity changes due to geographic range shifts, and considering species- and age-specific thermal tolerances. Generally, bivalve biomass at the community level is determined by relative abundance and shell biomass-frequency distribution. In our study, the relative abundance and median biomass of small species do not increase or decrease, respectively, in warmer periods. However, larger species are negatively affected by warming both in terms of relative abundance and biomass.

Similar functional composition of fish assemblages despite contrasting levels of habitat degradation on shallow Caribbean coral reefs.

Functional trait-based approaches provide an opportunity to assess how changes in habitat affect the structure of associated communities. Global analyses have found a similarity in the composition of reef fish functional traits despite differences in species richness, environmental regimes, and habitat components. These large-scale patterns raised the question of whether this same stability can be observed at smaller spatial scales. Here, we compared the fish trait composition and their functional diversity in two Caribbean shallow coral reefs with contrasting levels of habitat degradation: Limones (>30% cover), constituted mainly by colonies of Acropora palmata and Bonanza, a reef with extensive areas of dead Acropora structures, dominated by algae. To characterize the functional structure of fishes on each reef, we calculated the community-weighted mean trait values (CWM), functional richness, functional evenness, functional dispersion, and functional originality. Despite the differences in habitat quality, reefs exhibited a similar proportion and common structure on fish functional traits. Functional richness and functional evenness differed significantly, but functional dispersion and functional originality did not show differences between reefs. The greater niche complexity driven by the high availability of microhabitats provided by A. palmata may explain the higher functional richness in Limones, whereas the reef degradation in Bonanza may contribute to a higher functional evenness because of a similar distribution of abundance per fish trait combinations. Our results suggest that widespread degradation on Caribbean reefs has limited the type, variety, and range of traits, which could lead to a functional homogenization of fish communities even at local scales.

Experience in assessing the abundance and spatial distribution of geese on the Taimyr Peninsula using the aerial survey method

The Taimyr Peninsula is a key region for reproduction of waterfowl of European and Asian wintering populations. The uniqueness of Taimyr is that birds migrate there from both the west and the east, following five out of eight global flyways: East Atlantic, Black Sea/Mediterranean, West Asian/East African, Central Asian, and East Asian/Australasian. The study develops the topic of conservation ornithology and sustainable use of biological resources raised at the First All-Russian Ornithological Congress by Dr. Evgeny Syroechkovsky. Russia lacks the system of state monitoring and assessment of waterfowl populations, in particular with the use of aerial survey methods. In 2019, counts of geese in the tundra zone of the Taimyr Peninsula were carried out from the board of an ultralight aircraft specially designed for aerial surveys. New data on the abundance and spatial distribution of geese were obtained. We substantiated the methodology for the survey flight routing with no transects and the use of GIS, remote sensing, and generalized additive models (GAM) for interpreting the results and extrapolating estimates of goose abundance. A database of the results of aerial surveys was compiled (http://rggsurveys.ru). According to our estimate, for the first time made by statistical modeling for the tundra zone of the Taimyr Peninsula, more than 1.5 million White-fronted geese, about 450000 Bean geese, 78400 Red-breasted geese, and 43000 Lesser White-fronted geese nest and moult on Taimyr. Comparison of these figures with modern estimates of the world populations of these species demonstrates the key role of the Taimyr Peninsula in maintaining populations of rare and economically important Anseriformes.

Heteroatom-Doped Carbon-Shelled Iron Phosphide Microcuboids as Freestanding Negative Electrodes for Long Cycling Sodium-Ion Batteries

Energy storage devices (ESDs) have become indispensable for maximum renewable energy penetration and progress towards the elimination of fossil fuels in electricity generation. Also, high-performance ESDs are urgently needed for wearable and flexible devices, electric vehicles, and internet of things (IOT) applications. Lithium-ion batteries (LIBs) presently occupy the largest share of the EES market, however the cost-per watt stored is too high and the finite supply of Li means that they cannot offer a long-term solution to the world’s energy challenge. On the other hand, sodium-ion batteries (SIBs) are regarded as complementary ESDs and potential replacements for LIBs due to their relatively lower cost, abundance, and uniform global distribution of Na.[1] Furthermore, SIBs can operate in a wide temperature range and inert with Al, benefiting the construction of low cost and safe ESDs. Nonetheless, the performance of SIBs is limited by sluggish diffusion of Na+ in Na-insertion materials owing to large size of Na+ (1.02 Å).[2]The major challenge to developing SIBs is the lack of suitable electrode materials capable of efficiently accommodating Na+. SIBs are rocking-chair cells like LIBs, however, Na-ion storage in traditional graphite is extremely poor (< 35 mAh g-1) due to insufficient interlayer spacing.[3] Phosphorous presents the highest theoretical capacity (2596 mAh g-1) for a SIB anode, however, it suffers from poor cycling and large volume expansion (490 %) during sodiation/desodiation.[4,5] Low cost and environmentally benign iron phosphides present slightly better volume expansion and a theoretical capacity of 926 mAh g-1, but its charge storage mechanism is unclear.[6] The lack of suitable SIB anode with high capacity and long cycle life remains a major hurdle to the full-scale development of SIBs.In this work, we synthesized core-shell FeP microcuboids on freestanding carbon cloths substrate as a high capacity (< 800 mAh g-1), long-cycling anode for SIBs. The synthesized FeP microcuboids exhibit distinct physical and morphological features for efficient sodium-ion storage. It possesses a porous core within a 10 nm carbon shell, which enhances the surface area, enable fast Na+ diffusion and buffers the FeP anode against large volume variations during cycling. The integration of different heteroatoms including fluorine and nitrogen successfully improved the electronic conductivity and structural stability. Finally, using techniques such as in-situ X-ray diffraction analysis and ex-situ TEM and electroanalytical methods, we probed the conversion reaction storage mechanism and uncovered a pseudocapacitive dominated storage process. Finally, our work provides crucial insights on the rational design of high-performing metal-based phosphide anodes for alternative-ion batteries.

Non-Arrhenius Ionic Conductivity Behaviour in Antiperovskite Solid Electrolytes for Sodium Metal Batteries

Solid-state sodium metal batteries have been proposed as an alternative to lithium-ion batteries (LIBs) for next-generation applications due to the high abundance and wide distribution of sodium resources.1 Sodium antiperovskites (Na3OX, X = Cl, Br, or BH4) have recently attracted great interest as solid electrolyte candidates due to the relatively low processing temperature (<500 oC), reasonable ionic conductivity (up to 4.4 x 10-3 S cm-1 at room temperature), and great chemical stability against sodium metal anodes.2,3 Typical solid-state ionic conductors have temperature-dependent ionic conductivity that follows Arrhenius behaviour over a broad range of temperatures, corresponding to a constant activation energy Ea. However, this is not the case in Na3OBr, and instead a phenomenon resulting in a higher ionic conductivity and lower activation energy is observed to occur at 255 oC. Similar non-Arrhenius ionic conductivity phenomenon has also been reported in the potassium antiperovskite K3OI. It has been proposed that this behaviour originated from anion disordering, but conclusive experimental evidence to support this claim has not been reported.4 An understanding of the origin of this behaviour could enable the synthesis route to be optimised such that higher ionic conductivities could be achieved.In this work, we combined temperature-resolved bulk and local characterisation methods including Pawley and Rietveld refinements of synchrotron x-ray diffraction (XRD), pair distribution function (PDF), solid-state nuclear magnetic resonance (NMR) spectroscopy, and electrochemical impedance spectroscopy (EIS) to gain an insight into the origin of this non-Arrhenius behaviour. We found that this phenomenon does not originate from anion disordering, as previously speculated, because the lattice parameter of Na3OBr changed linearly with temperature and no major intensity changes were observed in the Na-Br and Na-O signals in the PDF patterns. Other supporting findings that lead us to this conclusion will be discussed in the presentation.References Wang, X. et al. Ultra-stable all-solid-state sodium metal batteries enabled by perfluoropolyether-based electrolytes. Nat. Mater. 21, 1057–1066 (2022).Zheng, J., Perry, B. & Wu, Y. Antiperovskite Superionic Conductors: A Critical Review. ACS Mater. Au 1, 92–106 (2021).Sun, Y. et al. Rotational Cluster Anion Enabling Superionic Conductivity in Sodium-Rich Antiperovskite Na3OBH4. J. Am. Chem. Soc. 141, 5640–5644 (2019).Zheng, J. et al. Antiperovskite K3OI for K-Ion Solid State Electrolyte. J. Phys. Chem. Lett. 12, 7120–7126 (2021).

Understory vegetation diversity patterns of Platycladus orientalis and Pinus elliottii communities in Central and Southern China.

As a vital component of arbor forests, understory vegetation serves as an essential buffer zone for storing carbon due to its strong capacity for community regeneration. This study aimed to identify the diversity pattern and construction mechanism of Platycladus orientalis and Pinus elliottii understory vegetation based on large-scale sample surveys. The Bayesian Information Criterion value of species abundance distribution (SAD) indicated that the Zipf and Zipf-Mandelbrot models were the best-fitting models. The SAD and gambin fitting results suggested that the Pi. elliottii community had a more balanced structure, with most species being relatively abundant. The multiple regression tree model detected four and six indicator species in P. orientalis and Pi. elliottii communities, respectively. The α-diversity index increased with a rise in altitude and showed a wavy curve with latitude. Linear regression between the β diversity and environmental and geographic distance indicated that the P. orientalis and Pi. elliottii understory communities tended to be dominated by different ecological processes. The partition of β diversity indicated that both communities were dominated by turnover processes, which were caused by environmental classification or spatial constraints. This study helped to understand the diversity maintenance in the P. orientalis and Pi. elliottii understory vegetation communities, and will benefit for diversity restoration and conservation of pure conifer forests.

Probing the Structure Evolution of Na-Cu-Mn-O Based Layered Oxide Cathode Materials in Sodium Ion Batteries

Sodium-ion batteries (SIBs) are considered as potential energy storage devices for large-scale energy storage system and smart power grids applications because of the low cost and abundant distribution of sodium in the earth's crust and ocean [1]. The development of highly efficient cathode materials for superior sodium storage is crucial for the development of SIBs. Among all the cathode materials, sodium transition-metal layered oxides, especially P2 and O3-typed layered oxides are of more interest due to their high theoretical capacity and easy synthesis [2,3]. From a structural point of view, P2 phase has an open pathway from one prismatic site to adjacent sites for more facile Na ion diffusion than O3 homologue. Therefore, the P2 phase shows not only better kinetic properties but improved cyclic stability thanks to its high structural stability.However, the pristine Na2/3MnO2 in P2 phase usually suffer from poor reversibility and dramatic capacity and voltage decay upon cycling, which origins form below issues: 1) the Na+/vacancy order-disorder transition, 2) the phase transition at high charge voltages due to MnO6 layers gliding 3) the Jahn-Teller distortion derived from Mn4+/Mn3+ redox couple, 4) the migration and dissolution of transition metals.[4] Up to now, a variety of improvement methods (doping and coating) have been utilized to stimulate the application of P2-type Na2/3MnO2 material. In particular, copper, as a low cost and environmental friendliness element, has also been introduced to synthesize multiple layered transition metal materials, like Na0.68Cu0.34Mn0.66O2, Na0.68Cu0.34Mn0.50Ti0.16O2, Na2/3Mn0.72Cu0.22Mg0.06O2 and so on. Furthermore, various redox behavior and structural evolution have also been explored. However, the process of structural transition during calcinating at different temperatures have been ignored, which leads to the unexpected neglect of some unique features of metastable phases in sintering materials.In our current work, Na2/3Cu1/3Mn2/3O2 in various phases have been successfully synthesized by sol-gel method and subsequently calcinated at different temperatures. XRD results show that Na2/3Cu1/3Mn2/3O2 calcinated at 600 °C (NCMO-600) is the triclinic phase, with the increasing calcination temperatures, the Na2/3Cu1/3Mn2/3O2 subsequently transfers to the hexagonal phase at 800 °C (NCMO-800). Subsequent electrochemical measurements show that NCMO-800 exhibit the better cycle stability and almost no voltage decay in the long term cycling, while the NCMO-600 sample exhibited rapid voltage attenuation at about 30 cycles. Besides, in situ XRD patterns and XANES spectra for both cathodes indicate slight different structural transition and electronic structure changes during charge and discharge. In a word, the NCMO-600 material exhibit the larger electron transfer at low current densities while the NCMO-800 material show the better cycle stability and rate performance.

Population level behavioural responses to variation in habitat quality across multiple locations in a fragmented landscape

Population level behavioural responses to variation in habitat quality across multiple locations in a fragmented landscape