环境科学最新文献

Jiangxi Province， as one of the first national ecological civilization pilot zones in China， holds a significant responsibility in ecological protection and sustainable development. Ecological vulnerability assessment is of great guiding value for ecological protection and restoration in Jiangxi Province. Based on the sub-watershed and raster evaluation units， combined with remote sensing image data， land use data， soil data， meteorological data， socio-economic data， etc.， an ecological vulnerability assessment framework was established using the ecological sensitivity-resilience-pressure （SRP） model to evaluate the spatiotemporal dynamics of ecological vulnerability in Jiangxi Province from 2000 to 2020， and the driving factors of ecological vulnerability changes were revealed using an interpretable machine learning model （XGBoost-SHAP）. The results indicate that： ① The areas with relatively low ecological vulnerability of Jiangxi Province were primarily distributed in the northeastern， northwestern， and southern mountainous regions， while areas with higher vulnerability were concentrated in the plains and riverbanks where human activities are intensive， such as the Poyang Lake plain area. The overall distribution was primarily characterized by mild and light vulnerability. ② In the years 2000， 2010， and 2020， the average ecological vulnerability index values were 0.224， 0.219， and 0.206， respectively， indicating a downward trend in the ecological vulnerability index. Among these， the areas where the ecological vulnerability index decreased accounted for 75.75% of the total area. ③ The changes in soil erosion intensity， FVC， percentage of soil erosion above moderate， and land use were key factors driving ecological vulnerability changes， with relative importance weights of 34.66%， 25.99%， 10.83%， and 10.63%， respectively. Moreover， the contributions of these factors exhibited significant spatial variation. The research findings can provide theoretical support for ecological environment protection in Jiangxi Province， while also offering important references and insights for the application of machine learning methods in the study of ecological vulnerability.

In order to investigate whether the addition of organic fertilizers could reduce the uptake and accumulation of polystyrene nanoplastics （PS-NPs） in the roots and stalks of cotton plants， a pot experiment was conducted using different amounts of organic fertilizers （0 g·kg^-1 and 10 g·kg^-1） combined with a fixed amount of PS-NPs （100 mg·kg^-1）. Fluorescently labeled PS-NPs with a particle size of 200 nm were used as tracers. The results demonstrated that cotton roots absorbed PS-NPs and transferred them to the stalks. Quantitative analysis revealed that most of the particles were retained in the roots under the treatment of nanoplastics + organic fertilizer （MOF₁）， with the fluorescence intensity of PS-NPs transferred to the stalks accounting for only 60.08% of that in the roots. Compared to those in the blank control （CK）， the SPAD value， stem dry matter mass， and leaf dry matter mass of cotton plants in the nanoplastic-only （MOF₀） treatment were significantly reduced by 6.94%， 37.29%， and 22.36%， respectively. In contrast， the leaf area in the MOF₁ treatment increased significantly by 10.12%. Additionally， plant height， stem thickness， leaf area， SPAD value， root dry matter mass， and leaf dry matter mass in the MOF₁ treatment were all significantly higher than those in the MOF₀ treatment， increasing by 9.28%， 13.99%， 10.12%， 7.82%， 21.05%， and 21.47%， respectively. Furthermore， compared to those in the CK treatment， the activities of superoxide dismutase （SOD）， peroxidase （POD）， and catalase （CAT） in the roots of MOF₀-treated plants were significantly elevated by 30.91%， 11.61%， and 40.00%， respectively， while malondialdehyde （MDA） mass molar concentration decreased by 12.24%. For MOF₁-treated plants， the activities of SOD and CAT in the roots were significantly increased by 44.51% and 100%， respectively， and MDA mass molar concentration was reduced by 26.43%. In conclusion， organic fertilizer effectively reduced the accumulation of PS-NPs in cotton plant stalks by 43.78%. It also significantly mitigated the transfer of PS-NPs from roots to stalks， thereby reducing the overall accumulation of PS-NPs in cotton plants.

Confronted with the intertwined challenges of agricultural non-point source pollution and carbon emissions， the synergistic reduction of both is crucial for the comprehensive green transformation of agricultural development. Based on measurements of the agricultural digitization level in each province， this study empirically examines the impact of digital transformation on the synergy between pollution and carbon reduction， as well as its underlying mechanisms， using provincial panel data from 2005 to 2022. The study concluded that agricultural digital transformation had a significant synergistic effect of reducing pollution and carbon emissions， and it could simultaneously and significantly reduce the emissions of agricultural non-point source pollutants and carbon emissions. After conducting robustness tests， such as controlling for endogeneity， replacing the explained variables and core explanatory variables， adjusting the research window， and using the system GMM estimation， this conclusion still holds. Mechanism analysis revealed that green technology innovation and improvements in resource allocation efficiency were two key channels through which digital promotion could facilitate the synergistic development of pollution and carbon reduction in agriculture. Heterogeneity analysis indicated that the benefits of agricultural digital transformation in achieving pollution and carbon reduction synergies were more pronounced in the eastern region， areas with high levels of digitization， regions with advanced digital infrastructure， and locales with abundant human capital.

In the context of the challenge posed by climate change and the pursuit of the "dual carbon" goals， accurately assessing the efficiency of forest carbon sinks in various regions， identifying the reasons behind efficiency differences， and accordingly proposing effective resource allocation pathways are of great significance for promoting coordinated regional development， improving resource utilization efficiency， and achieving carbon sequestration and emission reduction. Based on provincial data from China spanning from 2004 to 2021， a three-stage DEA model was constructed to measure the forest carbon sink efficiency of 30 provinces and municipalities， and a regional difference analysis was conducted. Simultaneously， a prediction model based on GAN and KOA-CNN-BiLSTM-Attention was established to forecast the total carbon sink targets that each region intends to achieve by 2030， and scenarios were set up to enhance the accuracy of the model. Based on the three-stage theory， further improvements were made to the inverse DEA model to discuss the resource allocation path planning schemes for various regions to achieve their predicted carbon sink targets. In particular， feedback was provided on the current input redundancies and deficiencies in each region. The results showed that： ① Although China's forest carbon sink efficiency showed a trend of growth， it was still at a moderately low level overall. Moreover， there were significant regional differences. Regions with higher efficiency levels were mainly distributed in the southwest and northeast， while those in North China had lower levels and require attention. The remaining regions fell in between and still had room for development. ② The core reasons for the differences in forest carbon sink efficiency among regions were natural resource endowments （including forest resources and natural conditions） and the degree of concern for forestry （including policy support and resource allocation preferences）. Scientific management and operation played a reinforcing role in enhancing the forest carbon sink capacity of the regions. ③ The northeast and southwest regions have made significant contributions in terms of total forest carbon sink. Nationally， the total forest carbon sink is expected to increase by 7% to 30% by 2030， and the forest carbon sink will continue to play a crucial role in carbon emission reduction and sequestration. ④ Each region needs to make incremental improvements in at least one input area. Land input will be the main challenge in achieving future carbon sink targets and is also a key limiting factor for the current level of forest carbon sink efficiency. In the long run， Heilongjiang and Inner Mongolia have the best prospects for forest carbon sink development. The research can provide decision-making references for governments and related industries in pursuing the "dual carbon" goals and help enhance carbon sequestration efficiency and resource allocation efficiency.

The Hetao Irrigation Area is an important commodity grain base in China. The irrigated area has already had a history of large-scale agricultural film use for more than 30 years， resulting in microplastic pollution that has aroused wide concern. This study collected surface water samples in the all-drainage channel and main drainage channel and groundwater samples in Wuyuan County， Bayannaoer City， Inner Mongolia Autonomous Region to investigate the pollution characteristics， sources， and risks of microplastics in surface water and groundwater in the Hetao Irrigation Area. The concentration of five types of microplastics， including polyvinyl chloride （PVC）， polyethylene （PE）， polyethylene terephthalate （PET）， polypropylene （PP）， and polystyrene （PS）， were determined by the tube furnace pyrolysis-thermal desorption-gas chromatography-mass spectrometry （Py-TD GC/MS） method. The results of the study showed that the concentration of microplastics in drained surface water ranged from ND to 317.1 μg·L^-1， showing the concentration trend of PVC>PE>PET>PP>PS， of which PVC and PE were the dominant microplastic species， with concentrations significantly higher than those of PP and PS （P<0.05）. The concentration of microplastics in groundwater ranged from ND to 44.8 μg·L^-1， showing a concentration trend of PE>PVC>PET>PP>PS， and the concentration of microplastics in drained surface water was significantly higher than that in groundwater （P<0.05）. Hierarchical clustering and Spearman's correlation coefficient methods were used to analyze the sources of microplastics in drained surface water and groundwater. The results showed that agricultural films were the main source of microplastics in water samples from the study area and that infiltration of microplastics carried by water flow from surface water was a potential source of microplastics in groundwater. The pollution load index （PLI） was used to evaluate the pollution level of microplastics， and the polymer hazard index （PHI） was used to evaluate the potential risk of microplastics in the water environment of the Hetao Irrigation Area. The PLI value indicated that the microplastics in the surface and groundwater in the study area were at a low level of contamination and that the increase in the amount of water discharged from the study area in the autumn irrigation period due to the flooding of the area diluted the microplastics in surface and groundwater. The PHI value indicated that PVC was the most potentially hazardous. The PHI value indicated that PVC had the highest potential risk. The results of this study can provide a research basis for the prevention， control， and management of microplastics in the Hetao Irrigation Area.

In order to ensure the safe production of rice in the Cd-polluted farmland in southeast Chongqing， field experiments of low accumulation variety （D）， soil conditioner （T）， leaf surface barrier agent （Y）， low accumulation variety combined with soil conditioner （DT）， low accumulation variety combined with leaf surface barrier agent （DY）， and low accumulation variety combined with soil conditioner and leaf surface barrier agent （DTY） were carried out in typical acidic yellow soil in southeast Chongqing. The effects of different safe utilization techniques on Cd content in rice were compared. The results showed that all the safe utilization techniques could reduce the content of Cd in rice seeds to varying degrees， but only D， T， or Y safe utilization measures existed in the test plot. Planting rice varieties with low accumulation combined with soil conditioner or leaf barrier agent （DT， DY， and DTY） could reduce the Cd content of rice seeds below the food safety limit specified in GB 2762-2022. In the treatment groups （T， DT， and DTY） treated with calcium soil conditioner， the soil pH value was significantly increased， and the content of available Cd in the soil was decreased， which effectively inhibited the migration of Cd from soil to roots， stems， and leaves of rice. The amount of TF seed/stem and leaf in the treatment group （Y， DY， and DTY） was significantly lower than that in the CK treatment group （P <0.05）， indicating that the leaf and leaf blocking agent improved the fixation of Cd in the stem and leaf and thus reduced the transfer of Cd from the stem and leaf to the seed. The difference of rice varieties with low accumulation was mainly manifested in the difference of Cd transport from roots to stems and leaves. Compared with that in CK， all treatment groups showed different degrees of yield increase， among which the DY treatment group with low accumulation variety combined with leaf barrier agent had the highest yield. Under the premise of ensuring the safety of rice seed Cd， the integrated technology of low accumulation varieties combined with leaf surface barrier is the best combination measure to ensure the safe utilization of acidic yellow soil in the high geological background area of southeast Chongqing， taking into account the factors of rice yield， economic cost， and the acceptance of farmers.

Pinus massoniana forests are the predominant vegetation in the Three Gorges Reservoir Area. The stability of its soil carbon pool plays an important role in regulating the regional carbon balance. In order to analyze the characterization of different soil organic carbon fractions and their influencing factors by P. massoniana forests in the main urban area of Chongqing， this study analyzed characteristics of soil organic carbon fractions and their drivers in 22 representative P. massoniana forest plots in the area. Surface soil （0-10 cm）， particulate organic carbon （POC）， and mineral-associated organic carbon （MAOC） contents were measured， with forest stand characteristics and soil physicochemical properties examined to identify driving mechanisms. The results showed that surface soil organic carbon content ranged from 9.0 to 18.6 g·kg^-1， exhibiting low overall levels and significant spatial variability. Soil organic carbon primarily existed in stable mineral-associated forms （MAOC averaged 75.2%）， while POC displayed a significantly higher C/N ratio than MAOC （P<0.01）. Covariance analysis revealed positive correlations between POC and MAOC （P<0.05） and between both fractions and total soil organic carbon （P<0.01）， with their contributions to total soil organic carbon variations being nearly equivalent. General linear regression and redundancy analysis demonstrated that stand age （P<0.05） and total soil nitrogen （P<0.01） positively influenced MAOC content， indicating their critical roles in stable soil organic carbon accumulation. Variation partitioning highlighted stronger effects of soil physicochemical properties （notably total nitrogen and C/N ratio） on soil organic carbon fractions compared to stand characteristics. These findings suggest that stand age and soil nitrogen availability were key determinants of stable soil organic carbon sequestration in P. massoniana forests， with soil nitrogen dynamics dominating soil organic carbon fraction patterns.

Tire wear particles （TWP）， a major source of microplastics （MPs）， are persistent environmental pollutants with notable toxicity. Although TWP pollution in soils has garnered increasing attention， most research has concentrated on aquatic environments， leaving gaps in understanding its effects on plants and co-occurring soil pollutants. This study examined the impact of TWP on plant growth and soil pollutants， specifically antibiotic resistance genes （ARGs）， using the kidney bean （Phaseolus vulgaris L.） as a model. The findings should enhance predictions and develop mitigation strategies for soil TWP risks. Pot experiments and qPCR analysis were conducted to assess the effects of TWP at concentrations of 0.1% and 1% on kidney bean growth and soil ARGs abundance， while evaluating the role of soil properties in regulating these interactions. TWP exposure impaired seedling growth， reducing root development by 31.35%-49.03% and fresh weight by 31.40%-48.33%. At 0.1% TWP， ARGs abundance in rhizosphere and non-rhizosphere soils increased significantly by 13.58% and 14.83%， respectively. At 1% TWP， the enhancement of ARGs abundance weakened， and ARGs in non-rhizosphere soil significantly decreased compared to that in the control. However， higher TWP concentrations led to a significant increase in high-risk genes such as aadE and tetO， indicating that TWP pollution intensified the ARGs risk in soil. Correlation and redundancy analyses revealed that TWP inhibited plant growth and increased the pollution level and health risks of soil ARGs by increasing soil conductivity and depleting nutrients like dissolved organic carbon. This study provides critical insights into the effects of TWP residues on plant growth and soil ARGs. This study's findings aim to offer a scientific basis for the assessment of ecological risks posed by the combined contamination of TWP and ARGs in agricultural soils.

The Yellow River Basin is an important water source in China， and heavy metal contamination in groundwater of the Yellew River Basin has achieved significant attention. This study analyzed the spatiotemporal variations， pollution levels， and sources of six heavy metals （Fe， Mn， As， Cu， Zn， and Pb） in 152 groundwater drinking water sources in the Yellow River Basin from 2018 to 2022 and assessed human health risks，which provided a scientific basis for groundwater pollution management and health risk management. The results showed that the over-standard rates of Fe， Mn， As， Cl^-， ammonia nitrogen， and F^- were 0.62%， 2.17%， 0.17%， 0.56%， 0.06%， 0.16%， and 0.33%， respectively. The average concentrations of Fe and Mn generally decreased from upstream to downstream； As peaked in the midstream； while Cu， Zn， and Pb were highest downstream. The heavy metal pollution index （HPI） indicated that 91.89% and 4.20% of the monitored data were at low and moderate pollution levels， respectively. Principal component analysis showed that Fe， Mn， and As in groundwater in the Yellow River Basin were mainly affected by natural factors， such as mineral oxidation and water-rock interaction， followed by human activities. Cu， Zn， and Pb were mainly affected by human factors， such as industrial， transportation， and agricultural activities. Correlation analysis showed that hydrochemical parameters ammonia nitrogen and Cl^- were associated with the migration and transformation of Mn， Fe， and As. The health risk assessment results showed that heavy metals had no significant potential non-carcinogenic risk or carcinogenic risk to human body， but under extreme conditions， both the non-carcinogenic risk value （HQ） and carcinogenic risk value （CR） of As exceeded the standard values in different age groups， and As contributed more than 84% to total CR in three age groups. Therefore， it is recommended to improve the quality of groundwater drinking water sources by strengthening the source control measures and preventive measures and to strengthen the risk prevention and control of As to reduce its risk to human health.

Henan Province is one of the major grain producing areas in China， and the irrational application of pesticides and chemical fertilizers during the grain production process has led to the continual accentuation of the problem of agricultural non-point source pollution. Agricultural non-point source pollution is the major source of pollutants in China's water bodies， which has become one of the main factors threatening the water environment and water ecological security. Inventory analysis was used to estimate the pollution load of chemical oxygen demand （COD）， total nitrogen （TN）， and total phosphorus （TP） from agricultural non-point source in Henan Province from 2001 to 2021. The study elucidated the spatial and temporal distribution characteristics of these pollution loads and their emission intensities. It also identified the main sources contributing to the pollution load. The results indicated that： ① In terms of temporal variation， from 2001 to 2021， the pollution load and emission intensity of COD and TN from agricultural non-point source in Henan Province showed a decreasing trend， while the pollution load and emission intensity of TP showed an increasing trend. ② The spatial distribution of COD， TN， and TP pollution loads exhibited spatial clustering characteristics， and the high value areas were mainly distributed in the southern part （Nanyang， Zhumadian， and Xinyang） and eastern part （Shangqiu and Zhoukou） of Henan Province. Nevertheless， there were substantial regional disparities in the spatial distribution of emission intensity. Generally， the eastern region had higher values than the western region， and the northern region had higher values than the southern region. Notably， the spatial distribution patterns of high value areas of pollution load and emission intensity revealed significant differences. ③ The main source of COD pollution load was livestock and poultry farming， and the main sources of TN and TP pollution loads were chemical fertilizer and livestock and poultry farming. The main contributing areas for COD， TN， and TP pollution loads were Nanyang， Zhumadian， and Zhoukou. In general， the agricultural non-point source pollution in Henan Province had staged changes in time and significant differences in spatial distribution. Dual control strategies of "load control-intensity constraint" should be implemented in pollution risk prevention and control， and pollution reduction paths such as fertilizer reduction and efficiency increase， manure organic fertilizer utilization， and straw resource utilization should be promoted.