Field Investigation Research Articles

Field Investigation of Serpentinite With Induced Polarization and the K‐Means Clustering Technique

Field Investigation of Serpentinite With Induced Polarization and the K‐Means Clustering Technique

Geosites of Northern Mountainous Adygeya (Southwestern Russia): A Novel Vision

Territorial inventories of geosites remain on the international agenda, and they can help in acquiring information for solving pure geological research tasks. New field investigations in the northern part of Mountainous Adygeya (geoheritage-rich territory in the western Greater Caucasus) permitted us to extend our knowledge of its geosites. Five geosites were described qualitatively and assessed semi-quantitatively, namely the Polkovnitskaya River Valley (ammonite-bearing concretions of Aptian glauconitic sandstones), the Little Khadzhokh River Valley (Aptian glauconitic sandstones with fossils and trace fossils), the Shakhan and Middle Khadzhokh River Valley (Upper Jurassic variegated siliciclastics, Hauterivian fluvial and deltaic sandstones, mixed ancient and modern clastic material), the Big Khadzhoh Waterfall (splendid waterfall and exposures of locally folded Oxfordian–Kimmeridgian limestones), and the Verblyud Mountain (small, camel-shaped cuesta’s remnant). They were ranked nationally (one geosite), regionally (three geosites), and locally (one geosite). Close examination of the considered geosites permitted to register pure geological peculiarities (changes in the dip direction between sedimentary packages), which indicate the tectonic activity across the Jurassic–Cretaceous transition. Additionally, complex accessibility patterns were established in some geosites, and these patterns should be addressed in further refinements of the semi-quantitative approaches to geosite assessment.

An Investigation of a Community Chickenpox Outbreak with a Fatal Case, Songkhla Province, Thailand, October 2022

In October 2022, a suspected chickenpox death was notified. A field investigation was done to verify the diagnosis and cause of death, describe the epidemiological characteristics, identify risk factors, and control the outbreak. We conducted a descriptive study and a matched case-control study. A case was defined as a person with multiple stages of skin lesions on at least two body areas in Subdistrict from 1 Aug 2022 to 24 Oct 2022. We reviewed medical records and searched for cases house-to-house. For the matched case-control study, cases were chickenpox cases residing in Bo Tru Subdistrict, from 1 Aug 2022 to 14 Oct 2022. Controls were neighbors without symptoms or chickenpox history, matched by age. Samples were tested using the reverse transcription polymerase chain reaction technique. Environmental surveys were performed. We identified 30 cases including the deceased, who was 49 years old. The median (interquartile range) age of the cases was 11 (7–38) years. Seventeen were elementary-school students. None of the cases received chickenpox vaccination or had a history of chickenpox. The secondary attack rate among household contacts was 41.2% (14/34). Reverse transcriptase polymerase chain reaction tests from three cases were all positive. Being a close contact with a case and sharing personal utensils were risk factors. We strengthened the surveillance system for early detection and treatment and provided risk communication in the community. Chickenpox cases should be isolated from susceptible persons. Standard treatment guidelines for complicated cases should be distributed among healthcare services.

Influence Mechanism of Water Level Variation on Deformation of Steep and Toppling Bedding Rock Slope

The construction of major hydropower projects globally is challenged by slope deformation in reservoir areas. The deformation and failure mechanisms of large rock slopes are complex and poorly understood, making prevention and management extremely challenging. In order to explore the influence mechanism of the water level variation on the deformation of steep toppling bedding rock slopes, this paper takes the right bank slope near the dam area of the Longtou Hydropower Station as an example, and field investigations, deformation monitoring, physical simulation tests and numerical analyses are carried out. It is found that the slope deformation response is obvious under the influence of the reservoir water level variation, which is mainly reflected in the change in the slope groundwater level, rock mechanical parameters and seepage field in the slope body. The toe of the slope produces plastic deformation and maximum displacement. With the increase in the reservoir water level, the plastic zone expands and the displacement increases, which leads to the intensification of the slope deformation. This paper puts forward that the deformation and failure modes of the steep and toppling bedding rock slope caused by water level variation are due to shear dislocation, bending deformation and toppling fracture. This study reveals the influence mechanism of the water level variation on the deformation of steep and toppling bedding rock slopes, which can provide theoretical support for the construction of major hydropower projects.

Shenzhen’s Policies on Intangible Cultural Heritage Inheritance and Practices of Digital Dissemination

This paper examines the protection and transmission of intangible cultural heritage in sports dance within Shenzhen, focusing on specific practices such as the Longgang Dragon Dance, Bao'an Qilin Dance, Longgang Qilin Dance, and Nanshan Yi Dance. Through comprehensive field investigations and direct interviews, it explores the current state of intangible cultural heritage preservation and transmission in Shenzhen. The analysis details the implementation of relevant policies and identifies that the potential contributions of online communities and grassroots organizations in promoting the conservation and inheritance of these cultural forms remain underexploited. The study proposes that heritage custodians more systematically leverage digital technologies to enhance the propagation of intangible cultural heritage. This, in turn, will foster the high-quality development of Shenzhen's cultural heritage.

Retain in the City, Return Flow, or Blind Direction: A Study on the Differentiation Mechanism of Migrant Workers’ Migration Willingness under the Background of China’s Strategy for Integrated Urban–Rural Development

Against the backdrop of urban–rural integration development in China, the government has further strengthened its support for rural migrant workers’ urban employment and entrepreneurship, as well as their urbanization. Nevertheless, influenced by the current urban–rural development environment and public policies, a portion of rural migrant workers have evolved into two distinct groups: those with clear intentions to settle in cities or return to their hometowns and those trapped in a “neither-nor” situation, who are unable to fully integrate into urban life or seamlessly return to the countryside. This study, based on field investigations conducted in 21 cities across seven major geographical regions in China, reveals a ternary differentiation in migration intentions among rural migrant workers: “Retain in the cities”, “Return flow”, and “Blind direction”. In advancing the urban–rural integration strategy, the “clearly-oriented” groups, choosing to stay or return, can serve as dynamic forces in reconciling resources between urban and rural areas, thereby fostering closer urban–rural ties. Conversely, the “aimless wandering” group, characterized by stagnation, confusion, frequent mobility, and recurrent unemployment, poses numerous negative impacts on urban–rural interaction and coordination, hindering the in-depth integration of urban and rural areas to some extent. Drawing upon the internationally recognized Push-Pull Theory and Social Integration Theory within the field of population migration, this study conducts an empirical analysis of large-scale sample data to explore the characteristic factors and formation mechanisms underlying the “staying”, “returning”, and “blind direction” intentions, with a particular focus on the internal dynamics shaping and evolving the “aimless wandering” group. Finally, grounded in the empirical findings, this study advocates a collaborative approach between the Chinese government and various sectors of society to address the issue by promoting employment guidance, enhancing security measures, and other initiatives that encourage rural migrant workers to either stay in cities or return to their hometowns. It aims to provide policy recommendations for a definitive resolution of the rural migrant worker issue during the crucial period of urban–rural integration development.

Palaeolithic investigations at Morpani, Central Narmada Basin, India

Morpani is a recently discovered Palaeolithic complex in the central Narmada Basin (Madhya Pradesh, India), discovered during the course of field investigations carried out by the Narmada Basin Palaeoanthropology Project. This site is situated in a region of the Gondwana Supergroup formations, south of the Narmada River. Regions to the north of the river, dominated by rock outcrops of the Vindhyan Supergroup formation present a multitude of Palaeolithic sites, in stark contrast to the southern region, dominated by the Gondwana Supergroup and Deccan Trap formations. This site is one of the few Palaeolithic sites in this southern region, and this paper reports on the recent Palaeolithic investigations undertaken at the site and the results of the lithic analyses of the recovered lithic assemblage. These investigations were carried out to qualify the nature of the Palaeolithic occupation in this region, as well as probe into the possible factors for the underrepresentation of the archaeological record here, especially when juxtaposed to the rich archaeological context noted to the north of the river. Lithic analyses indicates that Morpani represents an expedient lithic assemblage, located along the banks and bed of an ephemeral stream channel, and in regions where suitable raw material clasts are available. More work and collections are needed to securely characterise and attribute the technological features of this Palaeolithic site.

Music Characteristics and Regional Differences in (SHE) Ethnic Minority Folk Songs: A Comparative Analysis of Ningde and Eastern Fujian Regions

Tucked away in the stunning province of Fujian in southeast China, the region has a cultural tapestry as varied and vibrant as its breath-taking scenery. Through the analysis and coding of folk songs from four different geographical regions in China (Fujian and Ningde), this paper aimed to determine the degree of mutual interaction and integration of the musical cultures of the Shen and Han nationalities into modernity. It did this by developing a new musical characteristic density map for machine music classification. The nationality known as (SHE) is a small ethnic group in the area. The traditional cultural heritage as well as the growth of the (SHE) nationality have lagged behind the rapid advancement of modern times. This study investigates how to incorporate the culture of the (SHE) nationality into modern culture in order to fully realise the goal of "going out," starting from the conventional cultural heritage and creative growth of the (SHE) nationality. This paper discusses the formation of the (SHE) Minority folk songs in the context of protecting intangible cultural heritage. It does this by using the methods of literature research, field investigation, and comprehensive analysis to gather first-hand fresh field data from the components of historical evolution, protection process, inheritance method, development dilemma, and countermeasures. Questions of development and inheritance. The world will recognise the allure of the traditional culture of the (SHE) nationality as it is continuously enhanced and vibrant.

Condition assessment of concrete structures using automated crack detection method for different concrete surface types based on image processing

In the inspection and diagnosis of concrete construction, crack detection is highly recommended in the earliest phases to prevent any potential risks later. However, the flaws in concrete surfaces cannot be reliably and effectively identified using traditional crack detection techniques. The suggested algorithm is a supportive tool for agents or authorities to use in crack detection mechanisms to monitor and assess the current condition of buildings or bridges. The researchers aim to establish an intelligent model for automatic crack detection on different concrete surfaces based on image processing technology. Three different concrete surfaces—bridge decks, walls, and concrete cubes—are used to test the model. A subset of the public dataset of bridge decks and walls from SDNET (2018) and 150*150*150 mm of concrete cubes taken from the material laboratory of the faculty of engineering at Ain Shams University are applied to the model. The model F1-score measures are 98.87%, 97.43%, and 74.11% for detecting cracks in bridges, walls, and concrete cubes, respectively. The validation of the applicability of the suggested novel approach is based on a comparison with recent methods for crack recognition. The contribution of this study is that it could be applied to detect cracks efficiently on three different types of concrete surfaces, including uneven concrete surfaces, random noise, voids, dents, colour changes, and stain marks. The proposed method is transparent in its workflow and has a lower computational cost compared with deep learning frameworks. Thus, the outcomes of this model demonstrate its effectiveness in concrete defect field investigation.

A field investigation of 3 masks proposed as respiratory protection for wildland firefighters: a randomized controlled trial in British Columbia, Canada.

Wildland firefighters are exposed through the lungs and skin to particulate matter, fumes, and vapors containing polycyclic aromatic hydrocarbons (PAH). Wearing respiratory protection should reduce pulmonary exposure, but there is uncertainty about the most effective and acceptable type of mask. Firefighters from 6 unit crews working with the British Columbia Wildfire Service were approached and those consenting were randomly allocated within each crew to a "no mask" control group or to use 1 of 3 types of masks: X, half-face respirator with P100/multi gas cartridge; Y, cloth with alpaca filter; Z mesh fabric with a carbon filter. Crews were followed for 3 consecutive firefighting days. The mask allocated was constant for each firefighter throughout. All participants completed a brief questionnaire at the start and end of each day, giving information on mask use, respiratory symptoms, and assessment of mask qualities. Spot urine samples were collected pre and post shift to assess 1-hydroxypyrene (1-HP) concentration as an indicator of total PAH absorption. Skin wipe samples from the hands and throat were collected pre and post shift and analyzed for PAH concentration. On each day monitored, 4 participants carried sampling pumps to measure total particulates and PAHs on particles and in vapor phase. The primary outcome was the concentration of urinary 1-HP at the end of the fire day. Secondary outcomes were changes in respiratory and eye symptoms during the course of the shift, reported mask use, and perception of mask qualities. The analysis used a 3-level random intercept regression model that clustered observations within individuals and crews. We aimed to detect any relation of allocated mask type to the 4 outcomes, having allowed for estimated exposure. Information was collected from 89 firefighters, including 14 women: 49% (37/75) of male firefighters were bearded. Nineteen fire days were monitored for a total of 263 firefighter × days, 64 to 68 for each intervention group. The end of shift 1-HP was higher than the start of the shift. Urinary 1-HP was more strongly related to PAHs on the skin than in the breathing zone. Men with beards had higher end-of-shift urinary log 1-HP/creat (ng/g) than other firefighters. None of the groups allocated a mask had lower 1-HP than the no-mask group, either in the study group overall or when stratified by beard-wearing. Among those without either beards or a failed fit-test, Mask Z reduced at the end of shift 1-HP where airborne PAH concentration was high. End-of-shift symptoms were related to particle mass in the breathing zone but was not mitigated by any of the masks. Hours electing not to wear a mask increased from the first to third shift for all mask types. Mask Z was rated as more comfortable than other types. Mask X was rated highest on fit and perceived protection. Mask Y gained the lowest ratings on fit, comfort and feelings of protection. Allocated masks did not provide protection overall, but the results highlighted the need for a wider understanding of the circumstances in which wearing efficient protection is well-advised.

Estimating Chlorophyll-a and Phycocyanin Concentrations in Inland Temperate Lakes across New York State Using Sentinel-2 Images: Application of Google Earth Engine for Efficient Satellite Image Processing

Harmful algae blooms (HABs) have been reported with greater frequency in lakes across New York State (NYS) in recent years. In situ sampling is used to assess water quality, but such observations are time intensive and therefore practically limited in their spatial extent. Previous research has used remote sensing imagery to estimate phytoplankton pigments (typically chlorophyll-a or phycocyanin) as HAB indicators. The primary goal of this study was to validate a remote sensing-based method to estimate cyanobacteria concentrations at high temporal (5 days) and spatial (10–20 m) resolution, to allow identification of lakes across NYS at a significant risk of algal blooms, thereby facilitating targeted field investigations. We used Google Earth Engine (GEE) as a cloud computing platform to develop an efficient methodology to process Sentinel-2 image collections at a large spatial and temporal scale. Our research used linear regression to model the correlation between in situ observations of chlorophyll-a (Chl-a) and phycocyanin and indices derived from Sentinel-2 data to evaluate the potential of remote sensing-derived inputs for estimating cyanobacteria concentrations. We tested the performance of empirical models based on seven remote-sensing-derived indices, two in situ measurements, two cloud mitigation approaches, and three temporal sampling windows across NYS lakes for 2019 and 2020. Our best base model (R2 of 0.63), using concurrent sampling data and the ESA cloud masking—i.e., the QA60 bitmask—approach, related the maximum peak height (MPH) index to phycocyanin concentrations. Expanding the temporal match using a one-day time window increased the available training dataset size and improved the fit of the linear regression model (R2 of 0.71), highlighting the positive impact of increasing the training dataset on model fit. Applying the Cloud Score+ method for filtering cloud and cloud shadows further improved the fit of the phycocyanin estimation model, with an R2 of 0.84, but did not result in substantial improvements in the model’s application. The fit of the Chl-a models was generally poorer, but these models still had good accuracy in detecting moderate and high Chl-a values. Future work will focus on exploring alternative algorithms that can incorporate diverse data sources and lake characteristics, contributing to a deeper understanding of the relationship between remote sensing data and water quality parameters. This research provides a valuable tool for cyanobacteria parameter estimation with confidence quantification to identify lakes at risk of algal blooms.

Linguistic landscape as a way to construct multiple identities in the context of globalization: the case of an ancient town in China

ABSTRACT This article explores the linguistic landscape (LL) of Wuzhen, an ancient town with a history of more than 2,000 years and became the permanent venue for the World Internet Conference in 2014. The LL of Wuzhen is influenced by various factors, including globalization, urbanization, the tourism industry, heritage conservation, and government planning. In light of this, the study has made several field investigations into Wuzhen, examining the LL of four different areas and capturing 1602 photos of signs. Simultaneously, semi-structured interviews are conducted with residents to discuss their perceptions of the local LL and identity. The findings indicate that Wuzhen reshapes its local public space through various semiotic practices, constructing multiple identities that integrate traditionality, modernity, and internationality. It has also been found that LL should be regarded as a crucial semiotic resource anchored in sociocultural and historical space, whose mobility in the context of globalization and urbanization provides more possibilities for identity construction and reconstruction in peripheral regions.

Field investigation of the feasibility of MICP for Mitigating Natural Rainfall-Induced erosion in gravelly clay slope

Rainfall-induced erosion on slopes is a prevalent natural process leading to soil loss. One promising application of microbially induced carbonate precipitation (MICP) is to mitigate rainfall-induced erosion. Conducting field tests is an essential step to verify and improve its performance. In the current work, field tests were conducted to assess the feasibility of using MICP to mitigate rainfall-induced erosion on a gravelly clay slope in Longyan, Fujian, China. A temporary laboratory was set up to cultivate bacteria, and a non-sterilizing method was employed to prepare large volumes of bacterial suspensions in a single batch. Slopes were treated by spraying solutions onto their surfaces. The amount of discharged soils and 3D surface scanning results were used for evaluating the erosion intensity of the slopes. The results demonstrated that the method could effectively mitigate the surface erosion caused by natural rainfall and prevent erosion-induced collapse. Notably, approximately one year after the treatment, the grass had started to grow on the heavily cemented slope, indicating that the MICP method is both effective and eco-friendly for soil stabilization method. However, further improvements are needed to enhance the uniformity and long-term durability of the MICP treatment.

Study on the protection of Mongolian Chor music as cultural heritage in Northern China

The Mongolians in northern China have a vast distribution and a long history. Chor music is the cultural heritage of Mongolian in the north. After the rise of "Intangible Cultural Heritage upsurge" in the 21st century, scholars and folk artists rose to protect it and there were successively studies on Chor music theory, Chor music form and Chor historical evolution. However, scholars only focus on the research on the origin, classification, evolution and protection of Chor music, while the research on the relationship between Chor music and modern culture, summarizing that Chor music can be widely spread and recognized in modern society is lacking. This study mainly adopts qualitative methods in empirical research with literature research, field investigation and interview etc. to discusses the modern forms of Chor music, analyze the adaptation techniques in modern Chor works and identifies the musical elements recognized by the public. Therefore, we draw the conclusion of four-dimensional protection methods which includes preservation, innovation, crossover and communication.

Morphological characteristics and controlling factors of the piedmont fan systems in the Zanskar region, Northwest Himalaya, India

Piedmont fans are prominent geomorphic features formed at the transition between mountain slopes and valley floors. This study investigates the morphology of alluvial fans in the Zanskar Basin (ZB) to uncover the key variables influencing their development and morphodynamics. Utilizing advanced GIS and remote sensing techniques, along with field investigations, we conducted a detailed spatial analysis of 103 alluvial fans along the Doda, Tsarap, and Zanskar rivers. This approach allowed for precise mapping and characterization of these fans within complex depositional settings of ZB, particularly where fans merge into bajadas. Our analysis revealed distinct characteristics for the fans, including Fan Area (FA), Fan Slope (SF), Radius (R), Base Length of Fan (BF), Fan Maximum Entrenchment (FME), and Flow Expansion Angle (FEA). A morphometric analysis was then conducted to evaluate the correlation between the fans and their upstream basins. The linear regression analysis demonstrated both positive and negative correlations between these parameters, highlighting the important role of the upstream basins in controlling sediment delivery to fans. The findings suggest that larger basins contribute to the morphological development of fan systems, with larger, less steep fans forming as a result of greater flows and increased sediment supply from basins with denser drainage networks. Lower values of Mountain Front Sinuosity, Valley Floor Width to Valley Height ratio and Basin Elongation suggest that upstream basins in the ZB are significantly influenced by tectonic forces, resulting in linear mountain fronts, V-shaped valleys and elongated upstream basins. The F-99 fan, in particular, has developed a prominent stepped-fan morphology, attributed to differential uplift, vertical incision, and lateral migration of channels across the fan surface. Along the various fronts of the Zanskar, fan morphology is controlled by a complex interplay of long-term tectonic processes, climate, upstream lithology, and basin characteristics. Tectonic forces, particularly the NW-SE-trending ZSZ/STD and ZCT, exert first-order control on fan morphology by influencing sediment-flux and accommodation space. This influence is evident in tectonically modified landforms such as active mountain fronts, fan terraces, elongated basin shapes, wine-glass valleys and triangular facets, all indicating recent uplift and active tectonics in the region. Our results indicate that ZSZ and ZCT exert significant tectonic control over the geometry and evolution of fans, alongside substantial climatic influences.

Floristic analysis of Carex (Cyperaceae), the largest cosmopolitan genus in Yunnan, China

Through specimen examination and field investigation, we present an extensive Carex checklist for Yunnan, China. Yunnan harbors 195 Carex species, encompassing 22 new records and recently published taxa. Prof. Wu Zhengyi’s classification of Chinese seed plants into 15 area-types, widely accepted by phytogeographers for decades, serves as our framework. Type 1 families and genera, deemed cosmopolitan, are often excluded in floristic statistics due to their perceived lack of floristic indication. We analyzed the floristic characteristics of Yunnan’s Carex, particularly representative Type 1 genera, reveals a predominantly temperate nature rather than tropical. The substantial presence of species affiliated with the Sino-Himalaya area-subtype indicates a strong association with the Sino-Himalayan Forest Subkingdom. As a globally distributed genus, Carex holds significant floristic indication at the species level. This study shows the significant value of this cosmopolitan genus in floristic research. For accurate elucidation of floristic characteristics, it is imperative to conduct species-level analyses of Cosmopolitan Area-Type genera when studying the flora of a specific floristic region.

Study on the chain-type failure mechanism of large-scale ancient landslides

Large-scale ancient landslides are widely distributed in Southwest China, yet their reactivation mechanisms remain complex and poorly understood. On 25 July 2020, one such landslide in Liujing Village, Wulong District, Chongqing, China, experienced reactivation. This event exhibited variable movement characteristics across different areas and times, ultimately manifesting as a chain-type failure. Combining field investigations and drilling works, this study describes the fundamental characteristics of the Zhongbao landslide and the variation rules of the seepage field and the stability by numerical simulations. The failure mechanism is preliminarily revealed, and the failure influencing factors are discussed. The results show that, the landslide’s progression was influenced by the stratigraphic lithology and the morphology of the sliding surface, resulting in two distinct turns during its movement. By analyzing the landslide’s spatial morphology, direction of sliding, material composition, extent of the accumulation area, and dynamic behavior, we have categorized the Zhongbao landslide into five principal zones. The failure process can be segmented into four stages: initiation, shear-out, acceleration, and accumulation blockage. Heavy rainfall served as the primary trigger for the landslide, while the microtopography of the sliding surface significantly influenced the failure dynamics. The insights gained from this study offer valuable guidance for understanding the reactivation mechanisms of similar chained ancient landslides in the geologically analogous regions of Southwest China.

Carbon Sequestration Capacity after Ecological Restoration of Open-Pit Mines: A Case Study in Yangtze River Basin, Jurong City, Jiangsu Province

Open-pit mining seriously damages the original vegetation community and soil layer and disturbs the carbon cycle of vegetation and soil, causing instability in the mining ecosystem and decrease in the carbon sequestration capacity of the mining area. With the deepening of environmental awareness and the influence of related policies, the ecological restoration of open-pit mines has been promoted. The mining ecosystem is distinct owing to the disperse distribution of mines and small scale of single mines. However, the carbon sequestration capability of mines after ecological restoration has not been clearly evaluated. Therefore, this study evaluated the carbon sequestration capacity of restoration mines, taking the mines of the Yangtze River Basin in Jurong City, Jiangsu Province as the research objects. Firstly, the visual effects of the vegetation and soil in their current status were determined through field investigation, the methods for sampling and data collection for the vegetation and soil were selected, and the specific laboratory tests such as the vegetation carbon content and soil organic carbon were clarified. Meanwhile, the evaluation system consisting of three aspects and nine evaluation indexes was established by using the analytic hierarchy process (AHP) and fuzzy comprehensive evaluation (FCE). The process of evaluation included the following: the establishment of the judgment matrix, calculation of the index weight, determination of the membership function, and establishment of the fuzzy membership matrix. Finally, the evaluation results of the restoration mines were determined with the ‘excellent, good, normal and poor’ grade classification according to the evaluation standards for each index proposed considering the data of the field investigation and laboratory tests. The results indicated that (1) the evaluation results of the mines’ carbon sequestration capacity were of excellent and good grade at a proportion of 62.5% and 37.5%, which was in line with the field investigation results and demonstrated the carbon sequestration capacity of all the restored mines was effectively improved; and (2) the weights of the criterion layer were ranked as system stability > vegetation > soil with the largest value of 0.547, indicating the stability of the system is the main factor in the carbon sequestration capacity of the mines and the sustainability of the vegetation community and the stability of soil fixation on the slope. The proposed evaluation system effectively evaluates the short-term carbon sequestration capability of the restoration mining system according to the visual effects and the laboratory testing results, objectively reflecting the carbon sequestration capacity via qualitative assessment and quantitative analysis. The evaluation method is relatively applicable and reliable for restoration mines and can provide a reference for similar ecological restoration engineering.

Metagenomics-resolved genomics provide novel ecological insights into resistome community coalescence of wastewater in river environment

The discharge of wastewater into rivers can lead to resistome coalescence, thereby enhancing the spread risk of antibiotic resistance genes (ARGs) through mixing of exogenous wastewater resistome communities with indigenous riverine communities. At present, the understanding on the role of resistome community coalescence in the dissemination of ARGs is still very limited, and little is known about the process and its ecological implications. To bridge the gap, this study has conducted field-based surveys and microcosm experiments to deeply dissect the coalescence of resistome community in wastewater within river environment, utilizing genome-centric metagenomic analysis approach. The field investigation suggests resistome coalescence enhances the abundance and diversity of ARGs in the receiving river. Furthermore, the microcosm experiments reveal the effect of mixing ratio on resistome coalescence in the water-sediment system and decipher the temporal attenuation dynamics of the coalesced resistome in the environment. The results show the higher proportion of wastewater has a greater impact on ARGs in the water, whereas the effect of mixing ratio is lesser in the sediments. Temporally, the source-specific ARGs originating from wastewater exhibit decreasing trends over the experimental duration, and relatively, the attenuation in the water is more pronounced than that in the sediments. Interestingly, natural light not only facilitates the attenuation of ARGs in the water but may also induce their deposition at the water-sediment interface. Variance partitioning analyses suggest the microbiome, mobilome, and abiotic factors collectively shape the coalescence of the resistome communities in the environment. The study provides empirical evidence on resistome coalescence in river systems, which is instrumental in gaining a better understanding of the spread mechanism of ARGs in the environment.

Microbial nitrogen cycling in Microcystis colonies and its contribution to nitrogen removal in eutrophic Lake Taihu, China

Cyanobacterial blooms induced by excessive loadings of nitrogen (N) and other nutrients are a severe ecological problem in aquatic ecosystems. Previous studies of N removal have primarily focused on sediment-water interface, yet the role of cyanobacterial colonies has recently been attracting more research attention. In this study, N cycling processes were quantified for cyanobacterial colonies (primarily Microcystis colonies) and their contribution to N removal was estimated for a large, shallow eutrophic lake in China, Lake Taihu. Various N cycling processes were determined via stable 15N isotope, together with 16S rRNA gene sequencing and quantitative microbial element cycling (QMEC) chip. Denitrification was found to be the most prominent process, estimated to be 36.63, 9.85, 3.35, and 3.15 times higher than dissimilatory nitrate reduction to ammonium (DNRA), nitrification, ammonium (NH4+) uptake and nitrate (NO3−) uptake rates, respectively. Denitrifiers accounted for a large part of the bacterial taxa (35.50 ± 24.65%), and the nirS gene was the most abundant among N cycling-related genes, with (2.54 ± 0.51) × 109 copies g−1Microcystis colonies. A field investigation revealed a positive correlation between the potential denitrification rate and the Chl-a concentration (mostly derived from Microcystis colonies). Based on a multiple stepwise regression model and historical data from 2007 to 2015 for Lake Taihu, the total amount of N removed via denitrification by Microcystis colonies was estimated at 171.72 ± 49.74 t yr−1; this suggests that Microcystis colonies have played an important role in N removal in Lake Taihu since the drinking water crisis in 2007. Overall, this study revealed the importance of denitrification within Microcystis colonies for N removal in eutrophic lakes, like Lake Taihu.