Ecological Environmental Factors Research Articles

Fish community dynamics following the low-head dam removal and newly installed fish passage in a headstream tributary of Jinsha River, Southwest China

Low-head dams and small hydropower developments are widely distributed in global rivers because of their high cost-efficiency and smooth implementation. However, these installations have great ecological impacts on native fish communities due to the loss of longitudinal river connectivity. Although dam removal and fishway construction are effective measures to mitigate river fragmentation, research on their effects on fish communities remains limited to date. In this study, we investigated fish community dynamics in a mountainous tributary of the Jinsha River–Heishui River following dam removal, fishway construction, and fishway renovation. Our fish sampling data from 2018 to 2023 yielded 6137 fish belonging to 25 species, 12 families, and 3 orders. The native fish community predominantly represented the typical fish fauna of the Qinghai-Tibetan Plateau, primarily including the genus Schizothorax and the families Sisoridae and Nemacheilidae. Representative fish species in the Heishui River demonstrate notable adaptations to cold water, high altitude, and rapid flow environments. After removing the Laomuhe Dam, upstream fish abundance increased sharply, but species richness slightly decreased in the short term. Fishway construction significantly enhanced species richness and abundance and reduced the difference between the upstream and downstream fish communities from the Songxin Dam. However, the subsequent fishway renovation altered the dominance of fish species, with marginal changes in community structure and abundance. Variations in fish community dynamics in the river channel and fishway structure can be attributed to differences in ecological guilds (e.g., flow preference and thermal regime) and environmental factors (e.g., flow discharge, water temperature, and water depth). The present study provides insight into the significance of mitigation measures for the impact of dams on mountainous rivers in southwest China through ecological assessment and guides for decision-making in the conservation and restoration of specific fish communities.

Environmental Assessment and Restoration of the Hunjiang River Basin Based on the DPSIR Framework

The Hunjiang River, a vital water system in northeastern China, has suffered severe ecological damage due to overexploitation. This study analyzes the basin’s environmental conditions from 2016 to 2020, identifies key restoration factors, and examines practical restoration projects. Investigating five major pollutants (permanganate index, chemical oxygen demand (COD), biochemical oxygen demand, ammonia nitrogen, total phosphorus) in eight sections, the study finds the Xicun section most polluted, mainly from Baishan City’s industrial and domestic discharges. The ammonia nitrogen concentration at the Zian section also shows deterioration. Using a DPSIR (Driving forces, Pressures, State, Impacts, Responses) framework, the study elucidates the relationship between environmental and socio-economic issues. Results indicate that population changes, industrial development, and water resource management have complex ecological impacts. Evaluating the urban water resource carrying capacity with the entropy weight method and correlation coefficient weighting method, the study finds that increasing forest coverage, improving wastewater treatment efficiency, and reducing COD emissions are crucial. Quantitative assessment of integrated protection and restoration projects involving mountains, rivers, forests, farmlands, lakes, and grasslands demonstrates their positive impact. This research reveals the interplay between the ecological environment and social factors, proposes practical restoration measures, and clarifies project effects, providing reliable decision-making schemes for policymakers.

Influence factors of ecological environment in Wanjiang River Basin based on RSEI and CASA models

Influence factors of ecological environment in Wanjiang River Basin based on RSEI and CASA models

Machine learning-driven source identification and ecological risk prediction of heavy metal pollution in cultivated soils

To overcome challenges in assessing the impact of environmental factors on heavy metal accumulation in soil due to limited comprehensive data, our study in Yangxin County, Hubei Province, China, analyzed 577 soil samples in combination with extensive big data. We used machine learning techniques, the potential ecological risk index, and the bivariate local Moran’s index (BLMI) to predict Cr, Pb, Cd, As, and Hg concentrations in cultivated soil to assess ecological risks and identify pollution sources. The random forest model was selected for its superior performance among various machine learning models, and results indicated that heavy metal accumulation was substantially influenced by environmental factors such as climate, elevation, industrial activities, soil properties, railways, and population. Our ecological risk assessment highlighted areas of concern, where Cd and Hg were identified as the primary threats. BLMI was used to analyze spatial clustering and autocorrelation patterns between ecological risk and environmental factors, pinpointing areas that require targeted interventions. Additionally, redundancy analysis revealed the dynamics of heavy metal transfer to crops. This detailed approach mapped the spatial distribution of heavy metals, highlighted the ecological risks, identified their sources, and provided essential data for effective land management and pollution mitigation.

Precocity of fruiting in Pinus yunnanensis revealed by common garden experiment and association analysis with molecular markers

Shortening the growth cycle and maintaining high yields are the goals pursued by all breeders. Under the distinct ecological conditions of tropical and rainy and dry seasons, many plants experience the phenomenon of early flowering and fruiting under adverse conditions. However, there is still no clear conclusion as to whether early flowering and fruiting will affect the vegetative growth of plants. In this study, the vegetative and reproductive growth traits of 270 families of Pinus yunnanensis of 6 years old in common garden were analyzed. There were significant differences in phenotypic traits of different populations, indicating that the trait differences were genetically stable. The variation of vegetative growth traits mainly comes from within populations, and the variation of reproductive growth traits mainly comes among populations. The average coefficient of variation of reproductive growth traits was significantly higher than that of vegetative growth traits. There was a positive correlation between vegetative growth traits and precocity of fruiting. Ecological environment factors have impact on phenotypic variation, among which the temperature of the wettest season has the greatest impact. According to cluster analysis, the nine populations could be divided into three categories. These cluster results were not due to geographic distances, indicating the discontinuity of phenotypic variation. By association analysis, 9 and 3 SSR loci were found to be significantly associated with the trait of precocity of fruiting, respectively. Among them, PK840 locus had the highest interpretation rate for the trait of precocity of fruiting. There were 10 and 7 unique haplotypes in precocity and non-precocity of fruiting individuals, with 179 bp and 183 bp bands, respectively. According to the breeding goal of high productivity and precocity of fruiting, 54 superior families and 200 superior individuals were selected. This study explored the adaptation strategies of tree growth traits to environmental changes.

Karyological analyses in several Algerian populations of six species of the genus Vicia L. (Fabaceae)

As part of the evaluation and valorization of plant genetic resources of fodder and pastoral interest in Algeria, seventeen (17) natural populations belonging to six (06) species of the genus Vicia (Vicia sativa, Vicia disperma, Vicia monardii, Vicia ohchroleuca, Vicia onobrychioides and Vicia lutea), originated from different ecological regions in the North-Eastern of the country, were considered. The populations have been the subject of mitotic and meiotic studies. Haploid and diploid numbers and chromosome measurements were determined. Original results were observed for the first time in some species. In fact, chromosome counts have revealed some new chromosome numbers. The first number (2n=14, n=7) was observed in the endemic subspecies of Algeria, V. ochroleuca subsp. atlantica and in the species Vicia onobrychioides. The second number (n=6) was observed in the species Vicia disperma. Within Vicia monardii, the three new chromosome numbers, previously observed only in mitosis by our research team, were confirmed for the first time through the present meiosis study (n=6, 7 and 8), indicating that they are A type chromosomes. The base number x=7 is the most frequently observed number in the six Vicia species. The observed chromosome numbers would be related to some ecological factors (altitude, rainfall) of the origin environment of the populations. Chromosome measurements and established karyotypes were determined for the first time in V. monardii, V. onobrychioides and V. ochroleuca subsp. atlantica. Chromosome size and karyotype formula are variable among the studied species and subspecies. Karyotypes vary from symmetrical to asymmetrical and the intrachromosomal asymmetry is higher than interchromosomal one. The new cytogenetic data would contribute to a better understanding of the evolution mechanism of the species in the genus Vicia L.

Investigating the Ecological Range Distribution and Environmental Factors Affecting the Distribution of Woody Species in the Zagros Forests of Ilam Province

Investigating the Ecological Range Distribution and Environmental Factors Affecting the Distribution of Woody Species in the Zagros Forests of Ilam Province

Spatio-Temporal Evaluation of Water Resources System Resilience and Identification of Its Driving Factors in the Yellow River Basin

Water resources are crucial for the development of ecosystems and humanity. The Yellow River Basin (YRB), as an important ecological area in China, is facing significant challenges in ecological protection and high-quality development due to global climate change and intense human activities. In order to alleviate the water resources crisis in the YRB, it is necessary to calculate the resilience of the water resources system and identify the main influencing factors. This paper considered the factors of water resources, social economy, and ecological environment, then constructed an evaluation framework of the water resources system resilience (WRSR) from three aspects: resistance, restoration, and adaptability. Taking nine provinces along the YRB as a case study, the WRSR was measured by using the entropy weight TOPSIS model, and its driving factors were analyzed with Geographical Detectors (GD). The results showed that: (1) From 2010 to 2022, the WRSR in the Yellow River Basin and various provinces was showing a fluctuating increasing trend, in which Ningxia had the highest average WRSR (0.646), while Shanxi had the lowest (0.168). (2) From three dimensions, the development trends of resistance, restoration, and adaptability in the YRB and various provinces from 2010 to 2022 were relatively stable. Shandong’s resistance level far exceeded that of other provinces, having the highest average resistance value (0.692), and Ningxia had the highest average value of restoration (0.827) and adaptability (0.711). However, Gansu had the lowest average value of resistance (0.119), Sichuan had the lowest average value of restoration (0.097), and Shandong had the lowest average value of adaptability (0.110). (3) In terms of impact factors, the development and utilization rate of water resources (C13) and the development and utilization rate of surface water resources (C14) in the restoration subsystem consistently ranked in the top two of influencing factors. Similarly, the water consumption per 10,000 yuan of GDP (C26) in the adaptability subsystem consistently ranked within the top ten. On the other hand, the natural population growth rate (C6) in the resistance subsystem, as well as the impact of ammonia nitrogen emissions (C9) and total precipitation (C2) in wastewater, exhibited an upward trend. Based on these, this paper provides relevant suggestions for improving the WRSR in the YRB.

ПРОБЛЕМИ МОДЕРНІЗАЦІЇ ТРАНСПОРТНОГО ЗАБЕЗПЕЧЕННЯ ПІДПРИЄМСТВ В АГРАРНОМУ СЕКТОРІ ЕКОНОМІКИ

The article addresses the critical issue of modernization of transport support for the effective functioning of the agricultural sector of the economy. It is proven that today the material and technical support of the agricultural sector is experiencing a crisis and urgently requires modernization. Reforms in agriculture are changing the needs and creating market foundations for farms, procurement organizations, and processing enterprises, necessitating a reevaluation of the entire logistics and transportation infrastructure. The current state of the fleet of agricultural enterprises leads to significant difficulties in farming operations and ensuring the quality of agricultural products. Many agricultural enterprises face challenges with outdated and inefficient transport equipment, which increases operational costs and decreases productivity. It is noted that the evolving needs of agricultural enterprises in trucks, tractors, and other mechanisms are becoming increasingly objective and critical, underscoring the necessity for a modern, reliable transport infrastructure. Problems with the physical wear and tear of the material and technical base of agricultural enterprises are compounded by the increasing competition among transport enterprises and the complexity of transport maintenance. These challenges demand a review of scientific approaches and innovative management solutions. A holistic strategy is essential to address these issues, considering the interplay between ecological sustainability, economic viability, and social responsibility. For the effective operation of the agricultural sector, it is necessary to modernize the transport system to align with contemporary market conditions. This modernization should integrate ecological, economic, and social factors of the external environment, ensuring that transport solutions are sustainable and efficient. A comprehensive approach is required, involving the adoption of advanced technologies, the development of integrated transport networks, and the enhancement of logistical coordination. Key initiatives include the procurement of new transport units and equipment, the establishment of a unified electronic transport system, and the modernization of the infrastructure of auto transport enterprises and farms. Implementing these initiatives will lead to significant improvements in the efficiency and reliability of transport services, reducing downtime and operational costs. Moreover, the development of new management methods based on mutual benefits between motor transport companies and customers of services in the agricultural sector is crucial. These methods should focus on creating synergies through collaboration and shared goals, enhancing the overall efficiency and productivity of the agricultural sector. Addressing the modernization of transport support in the agricultural sector involves a multi-faceted approach that considers the dynamic needs of modern agriculture. By focusing on technological advancements, infrastructure improvements, and innovative management practices, the agricultural sector can overcome current challenges and achieve sustainable growth and development.

Contribution to ecological environmental factors and the occurrence of haemosporidians in birds in Zhongar Alatau National Park, Kazakhstan

In addition to the presence of a suitable host and vector, the prevalence of haemosporidians is influenced by several important factors, including the environmental conditions of the habitat, which depend on broader geographic characteristics. The aim of this study is to perform a preliminarily assessment of the distribution of blood parasites in birds from the mountainous area of Zhongar Alatau NP and to find potential new sites for research on their ecology in Kazakhstan. The results of this research constitute the first report on the occurrence of blood parasites from this area. A total of 58 birds, from the order Passeriformes and one individual from the order Caprimulgiformes, were examined during the study. The overall prevalence of infections caused by haemosporidian parasites (Haemoproteus, Leucocytozoon) was 18.6%. Neither the genus Plasmodium nor the presence of trypanosomes and microfilariae was detected in the birds examined. Three birds (5.1% prevalence) were infected with parasites of the genus Haemoproteus, in all eleven positive birds the analyses showed the presence of parasites of the genus Leucocytozoon (18.6% prevalence). The presence of parasites genus Haemoproteus was detected only in birds that were also infected with Leucocytozoon parasites. More infections with parasites of the genus Leucocytozoon are predicted due to the higher altitude and ecological factors at the capture sites, which are more favourable for the development of vectors of this genus. The species Haemoproteus majoris was detected in the host Emberiza cioides and species Haemoproteus minutus in host Turdus merula. Other species of this genus in the hosts Cyanistes cyanus and Turdus atrogularis were not determined. The species Leucocytozoon fringilinarum was detected in the hosts Cyanistes cyanus and Parus major, Leucocytozoon dubreuili was detected in Turdus atrogularis and Turdus merula. In the other host species Aegithalos caudatus, Emberiza cioides and Periparus aterus, it was not possible to dermine the species of the genus Leucocytozoon.

Transformation of soil and plant pastures cover of light chestnut soils in to sandy soils of kochubey biosphere station

The transformation of the vegetation cover of pasture landscapes is the result of the interaction of climatic, ecological, physiological and anthropogenic environmental factors. The result of the dependence of the conservation of species in the vegetation cover, especially forage plants, on the influence of these factors and the determination of their variability and stability in pasture ecosystem communities is relevant for production and science. As a result of a long-term study (more than 10 years) of the soil and vegetation cover of pasture landscapes on different soils and sands of the Kochubey Biosphere Station (KBS), especially under the conditions of anthropogenic impact, it was revealed that weeds adapt well to new conditions, stable populations of non-forage plants are created, causing deflation and degradation. The floristic composition and ecological and coenotic characteristics of the dominant plant species were studied on light chestnut sandy loamy soils and sands. The rapid change of indigenous species of plant communities formed in the conditions of a continental climate indicates a high mobility of vegetation. The species diversity and occurrence of plant species characterize the qualitative difference between the compared soils (light chestnut, sandy loam and sand). The described syntaxa reflect the directions of natural and anthropogenic transformation of the vegetation of light chestnut soils and sandy massifs of the KBS, which are characterized by a change in the composition of the prevailing life forms, a decrease in the role of valuable forage plant species and an increase in the diversity of annual non-forage species, without changing their species diversity. The landscape dynamics of the KBS territory is expressed in the transformation of the relief and vegetation cover under the influence of eolian processes with an increase in the projective cover and overgrowth of mobile landforms of sand massifs.

Using Medium-Resolution Remote Sensing Satellite Images to Evaluate Recent Changes and Future Development Trends of Mangrove Forests on Hainan Island, China

Mangroves are endemic forest communities in tropical and subtropical coastal zones. China’s Hainan Island is very rich in mangrove plant species. In recent years, due to climate change and human disturbance, the living environment of many mangrove distribution areas has been seriously threatened. This study used land satellite series remote sensing images from 1990 to 2020 to monitor the coverage and area changes of mangroves on Hainan Island. The spatial distribution pattern and change trend of mangroves were explored using the standard deviation ellipse method, and the CA–Markov model was used to predict the possible changes of mangroves in the study area in 2025 and 2030. The development trend of mangroves in the future and the driving factors affecting the evolution of mangroves were also analyzed. Over the past 30 years, the area of mangroves has witnessed fluctuations. It decreased from 4578 hectares in 1990 to its lowest at 3870 hectares in 2005 and then rebounded to 4474 hectares by 2020, indicating an initial decline followed by a gradual increase. Although conservation and restoration efforts have yielded success, specific areas have witnessed a decline in mangrove coverage. From 1990 to 2020, mangrove areas in Huiwen decreased from 1055 hectares to 904 hectares, areas in Guannan decreased from 227 hectares to 167 hectares, areas in Xinyinggang decreased from 328 hectares to 298 hectares, areas in Yangpugang decreased from 747 hectares to 682 hectares, areas in Huachangwan decreased from 355 hectares to 327 hectares, and areas in Puqian decreased from 170 hectares to 141 hectares. In particular, the growth in the Eastern and Mayao port areas is especially significant. Additionally, data analysis has revealed the spatial distribution characteristics of mangroves in different regions, such as the mangrove area in Dongzhaigang, which remained relatively stable from 1990 to 2020, while in other areas like Huiwen and Guannan, the mangrove area decreased during these 20 years. By calculating the standard deviation ellipse, we observed that the overall change of mangroves on Hainan Island from 1990 to 2020 was relatively slow, mainly distributed along the northern coastal area of Hainan Island. Furthermore, the standard deviation ellipse and SDE center point of each mangrove growth area have visualized the growth trends of the mangroves. The Markov chain simulation results show that future changes in mangroves will mainly be concentrated in the marginal areas of the mangroves. These areas may be affected by rising sea levels, climate change, soil salinity, and human activities. In the future, mangrove areas are expected to display a dynamic equilibrium, experiencing periods of expansion and reduction, ultimately moving towards a more consistent state. To protect and restore mangroves, it is necessary to strengthen the monitoring and management of their ecological environment and socio-economic factors and improve their stability and diversity.

State of the Art and Contribution to the Documentation on Fishing, Aquaculture and on the Microbiological Profile of Clarias Gariepinus and Oreochromis Niloticus Two Species of Fish Reared in the Whedos of the Upper Ouémé Delta in the Republic of Benin

Fish is an important source of animal protein in Africa and is used in the composition of several national dishes. This literature review examines fishing, aquaculture and fish reared in the whèdos of the upper Ouémé delta in Benin. It addresses socio-economic aspects, nutritional importance and traditional fish preservation technology. The sources of information used are publications, books, reports of dissertations and theses and technical notes. It was found that Clarias gariepinus and Oreochromis niloticus, among others, are two species of fish most often raised in the whèdos of the Ouémé River in Benin. These fish adapt to large variations of ecological factors of the aquatic environment found everywhere in Africa and reproduce easily in captivity, which favors their breeding in ponds. These species present multiple fish farming qualities: resistance to high densities, resistance to diseases and low oxygen levels, easy adaptation to artificial feeding and high growth. Microbiological contamination of fish flesh occurs only after capture and can be endogenous or exogenous contamination. Generally, several processes are used to overcome this problem of contamination of fish. Hot smoking and drying are very often used. The lack of hygiene in the traditional technology of smoking fish sometimes favor a considerable microbial contamination of the obtained products. Thus, contaminated fish can be the cause of foodborne diseases such as food poisoning. Most of the pathogenic strains responsible for these diseases are resistant to certain antibiotics.

Stronger effects of simultaneous warming and precipitation increase than the individual factor on soil bacterial community composition and assembly processes in an alpine grassland.

Composition and traits of soil microbial communities that closely related to their ecological functions received extensive attention in the context of climate changes. We investigated the responses of soil bacterial community structure, traits, and functional genes to the individual warming, precipitation increases, and the combination of warming and precipitation increases in an alpine grassland in the Qinghai-Tibet Plateau that is experiencing warming and wetting climate change. Soil properties, plant diversity and biomass were measured, and the ecological processes and environmental factors driving bacterial community changes were further explored. Results indicated that the Shannon diversity of soil bacterial communities decreased significantly only under the combination treatment, which might due to the decreased plant diversity. Soil bacterial community composition was significantly correlated with soil pH, and was affected obviously by the combination treatment. At the taxonomic classification, the relative abundance of Xanthobacteraceae and Beijerinckiaceae increased 127.67 and 107.62%, while the relative abundance of Rubrobacteriaceae and Micromonosporaceae decreased 78.29 and 54.72% under the combination treatment. Functional genes related to nitrogen and phosphorus transformation were enhanced in the combination treatment. Furthermore, weighted mean ribosomal operon copy numbers that positively correlated with plant aboveground biomass increased remarkably in the combination treatment, indicating a trend of life-history strategies shift from oligotrophic to copiotrophic. Stochastic processes dominated soil bacterial community, and the proportion of stochasticity increased under the combination treatment. Our study highlights the significant effects of simultaneous warming and precipitation increase on soil bacterial community.

Comprehensive assessment of river ecological environment in nature reserve based on TOPSIS combined with grey correlation method.

The main driving factors of river ecological environment were analyzed to reveal the response mechanism of river ecosystem to ecological environmental factors. The results showed that the driving factors of river water quality were resistivity, COD and reoxidation potential, the driving factors of soil environment along river banks were total phosphorus, total nitrogen and pH, and the driving factors of plant nutrition along river banks were total potassium and total nitrogen. The contribution rates of water quality, soil and plant to river ecological environment health were 43, 51 and 70%, respectively. The comprehensive ecological environment of Menghuo River, Gongyihai, Arulendi River, Yiniu River, Dahonggou River and Nanya River is superior to each other, with the comprehensive proximity index of 0.6258, 0.5908, 0.5524, 0.5265, 0.5195 and 0.3889, respectively. Each detection index can accurately and truly invert the ecological environment health status of rivers in the protected areas.

Machine learning-based digital mapping of soil organic carbon and texture in the mid-Himalayan terrain.

Mountain soils have received significant attention due to their profound influence on ecological processes and environmental factors. However, mapping these soils in digital soil mapping technique encounters several challenges, including high local variability, non-linear relationships between environmental covariates and soil properties, limited accessibility in complex topographical settings, and the absence of universally applicable covariates for soil formation. To address these issues, this study integrates soil-forming factors of the scorpan model to map soil organic carbon (SOC) and soil texture in the mid-Himalayas. By considering over 100 environmental covariates, with a focus on terrain parameters relevant to mountainous environments, the study aims to enhance the accuracy of ML regression models through augmentation techniques that overcome data insufficiency. Using augmented soil observations and covariates, a non-parametric random forest regression model is trained and applied to predict soil variables across the study area, generating a continuous fine-resolution map. The model's performance, evaluated against an unknown dataset, was significant with an R-square of 0.80, 0.79, 0.72, and 0.84 for clay, sand, silt, and SOC, respectively. Furthermore, a sensitivity analysis of the environmental covariates and their impact on the model revealed that all the soil-forming factors make a significant contribution to the model's effectiveness. The insights gained from this research contribute to a better understanding of mountain soils and facilitate the development of effective conservation and sustainable management strategies for mountainous regions.

An urban waterlogging footprint accounting based on emergy: A case study of Beijing

The waterlogging disaster has become a major threat to the resilient development of cities, which needs a unified and systematic accounting framework to estimate potential waterlogging effects in terms of forming disaster prevention strategies. In this paper, we developed an emergy-based waterlogging footprint accounting framework applying depth-damage functions, input–output (IO) analysis and ecological footprint, considering both economic and environmental factors. Taking the old town Beijing as a case study, we simulated the urban waterlogging distribution with a hydrodynamic model (InfoWorks ICM) over different return periods (1, 2, 3, 5, 10, 20, and 50 years) at high resolution. This study first considered the economic impact caused by urban waterlogging to evaluate the direct economic loss and indirect economic loss by using the depth-damage function and IO model, respectively. The environmental loss was assessed with an ecological footprint and was unified by emergy with economic loss. Then, four emergy-based indicators were established to quantify the specific impacts of waterlogging on urban resilience. The results show that the waterlogging footprints grew constantly by 284.57% from 1 year to 50 years. The waterlogging footprints driven by environmental loss, which were overlooked, accounted for 13.02% of the total. The waterlogging footprint density and waterlogging resilience index showed high spatial heterogeneity, indicating that the sensitivity of subdistricts to waterlogging varies greatly. Our study provides a useful energy-based tool for assessing urban waterlogging losses and supports decision-making for waterlogging disaster mitigation and risk zoning management.

Toward ecological environmental risk for spoil ground group management in mega projects

PurposeThe numerous spoil grounds brought about by mega transportation infrastructure projects which can be influenced by the ecological environment. To achieve better management of spoil grounds, this paper aims to assess their comprehensive risk levels and categorize them into different categories based on ecological environmental risks.Design/methodology/approachBased on analysis of the environmental characteristics of spoil grounds, this paper first comprehensively identified the ecological environmental risk factors and developed a risk assessment index system to quantitatively describe the comprehensive risk levels. Second, this paper proposed a comprehensive model to determine the risk assessment and categorization of spoil ground group in mega projects integrating improved projection pursuit clustering (PPC) method and K-means clustering algorithm. Finally, a case study of a spoil ground group (includes 50 spoil grounds) in a mega infrastructure project in western China is presented to demonstrate and validate the proposed method.FindingsThe results show that our proposed comprehensive model can efficiently assess and categorize the spoil grounds in the group based on their comprehensive ecological environmental risk. In addition, during the process of risk assessment and categorization of spoil grounds, it is necessary to distinguish between sensitive factors and nonsensitive factors. The differences between different categories of spoil grounds can be recognized based on nonsensitive factors, and high-risk spoil grounds which need to be focused more on can be identified according to sensitive factors.Originality/valueThis paper develops a comprehensive model of risk assessment and categorization of a group of spoil grounds based on their ecological environmental risks, which can provide a reference for the management of spoil grounds in mega projects.

Toward the carbon neutrality: Forest carbon sinks and its spatial spillover effect in China

Developing forest carbon sinks is very important for China to achieve carbon neutrality. However, the forest resource distribution is spatially dependent, and forest carbon sinks cannot be sufficiently developed in an isolated pattern. Therefore, based on the spatial panel data of 30 provinces in China from 2003 to 2019, this study establishes a spatial econometric model and identifies transregional spillover effects of forest carbon sinks. The results show that the forest carbon sinks do have transregional spatial correlation characteristics. In addition to similar ecological environment factors in adjacent regions, the forest carbon sinks are closely related to the economic development structure and related policies. The proportion of the forest area and urbanization level are positively correlated with the forest carbon sinks in the region and neighboring regions, but the amount of deforestation and transport infrastructure level has a negative effect. Implementing carbon trading pilot programs in one region can promote the development of its local forest carbon sinks, but it has a negative spillover effect on the other regions. Furthermore, environmental regulation has a positive spillover effect on neighboring regions, whereas forestry production efficiency has a negative spillover effect. Some policy implications are proposed according to the results and China's realistic characteristics.

Research on Early Childhood Bilingual Education in China from the Perspective of Cognitive Neuroscience

With the rapid development of globalization and the world economy, English, as the universal language, plays a pivotal role in the international political, economic and cultural fields. English non-native speakers are paying more and more attention to popularizing English education as an important part of basic education, and English learning is also showing a trend of becoming younger and younger. However, the early childhood language acquisition process is influenced and controlled by various complex factors, including acquisition age, acquisition methods, family ecological environment and socio-cultural factors. At present, the early childhood bilingual education in China is booming, but due to the mentality of most parents and the immaturity and incompleteness of various conditions, combined with the lack of scientific theoretical basis and empirical research on early childhood bilingual learning, the bilingual education in early childhood There have been many problems in the development process. In recent years, the development of brain development in the field of cognitive neuroscience has made important progress, prompting people to continuously explore how to more effectively promote early childhood language development and bilingual ability. Starting from the concept of bilingual education, this paper expounds the latest research results of early childhood bilingual ability development and brain development, the current situation, existing problems and development path of bilingual education for preschool children in China, and provides a large number of parents, educators and educational decision-making departments. Useful lessons are learned from experience.