环境科学最新文献

{"title":"[Characterization of Microbial Community Structure in Long-term Polycyclic Aromatic Hydrocarbon-contaminated Soil].","authors":"Yang-Yang Jiao, Ting Wu, Rui Li, Gao-Peng Bian, Hai-Hua Jiao, Zhi-Hui Bai","doi":"10.13227/j.hjkx.202401153","DOIUrl":"https://doi.org/10.13227/j.hjkx.202401153","url":null,"abstract":"<p><p>Characterizing the structure of soil microbial communities in natural habitats chronically contaminated with polycyclic aromatic hydrocarbons （PAHs） contributes to the understanding of potential risks and changes in ecological functions of contaminated soils. Microorganisms are facilitators of material cycling and functional stability in soil ecosystems. Few studies are available on the microbial community structure of soil contaminated with long-term high concentrations of PAHs. In this study, we investigated the effects of PAHs on soil microbial community structure in natural habitats using field surveys and high-throughput sequencing analysis of 16S rRNA genes in agricultural soils contaminated with PAHs around a coking plant in Shanxi. The results showed that soil microorganisms were diverse （40 phyla, 769 genera, and 1610 species）. Proteobacteria, Actinobacteria, Chloroflexi, Acidobacteria, and Gemmatimonadetes were the dominant taxa, with a total abundance of 79.8%. No obvious dominant taxa was observed at the genus and species levels. Electrical conductivity （EC）； pH； total organic matter （TOC）； total potassium （TK）； fast-acting potassium （AK）； and Dibenzo（a,h）anthracene （DaA）, Benzo（a）anthracene （BaA）, and Anthracene （Ant） were the first drivers of the microbial community （<i>R</i>²≥ 0.10）. Soluble phosphorus （AP）； fast-acting nitrogen （AN）； and Acenaphthylene （Acy）, Benzo（b）fluoranthene （BbF）, Fluoranthene （Fla）, and Pyrene （Pyr） were the second drivers （0.05 ≤ <i>R</i>² &lt; 0.10）. Total nitrogen （TN）； total phosphorus （TP）； and Phenanthrene （Phe）, Benzo（a）pyrene （BaP）, Chrysene （Chry）, Benzo（k）fluoranthene （BkF）, and Indeno（1,2,3-cd）pyrene （InP） were the third driving factors （<i>R</i>² &lt; 0.05）. The study will provide some theoretical basis for the research of ecological risk management and microbial remediation technology of PAHs-contaminated soil.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1885-1896"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Effects of Organic Materials Applied to Saline Soil on Crop Growth and Soil Saline-alkali Index].","authors":"Xiao-Juan Yang, Hao He, Li-Yang Cheng, Xiang-Jie Chang, Shuai Li, Meng-Meng Yu, Bin-Quan Wang, Jun-Hua Li","doi":"10.13227/j.hjkx.202403269","DOIUrl":"https://doi.org/10.13227/j.hjkx.202403269","url":null,"abstract":"<p><p>To provide a theoretical basis for the scientific application of organic materials in salinized soil and the improvement of soil quality and to explore the response phenotype of an organic material-salinized soil-plant system, the salinized soil in Xinjiang was considered as the research object, and cotton, rape, and oil sunflower were considered as the test crops. Six treatments, including the control group, microbial agent, humic acid, organic fertilizer, biochar, and straw, were set up for indoor culture experiments. The effects of different organic materials on the growth of cotton, oil sunflower, and rape crops and soil saline-alkali indexes under moderate salinization soil conditions were analyzed, and the combinations with certain improvement effects were screened out. This provided a certain experimental basis for the application and promotion of organic materials in Xinjiang. The results showed that, compared with that under the control treatment, the application of the microbial inoculant, organic fertilizer, and biochar had a significant effect on crop growth. At 60 d of emergence, the dry weight of cotton after the application of the microbial inoculant, organic fertilizer, and biochar increased by 41%, 43%, and 25%, respectively. The dry weight of oil sunflower increased by 5%, 13%, and 27%, respectively. The dry weight of rape increased by 113%, 104%, and 83%, respectively. After the application of organic fertilizer and biochar, the emergence rate of cotton and rape increased by 14.3% and 10.2%, respectively, and 26.50% and 20.82%, respectively. Taking the results of the soil salt-alkali index analysis at 60 d after seedling emergence as an example, the application of the microbial agent and straw had no significant effect on the total amount of water-soluble salt in the soil, whereas the application of humic acid, organic fertilizer, and biochar increased the total amount of water-soluble salt in the soil. The application of the microbial agent and straw could reduce soil pH, and the application of humic acid and biochar could increase soil pH. Soil electrical conductivity of all organic materials increased and humic acid treatment increased the most significantly. The effect of the microbial agent and straw treatment on soil alkalinity was the best, whereas the other treatments showed no significant difference. Straw could reduce soil sodium adsorption ratio, and humic acid and organic fertilizer could increase the soil sodium adsorption ratio. In summary, it is recommended to apply microbial agents, organic fertilizers, and biochar to saline soil for the purpose of promoting crop growth, and to apply a microbial agent and straw to saline soil for the purpose of improving soil quality.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1751-1761"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Impacts of Online Measurements of Organic Molecular Markers as Input Species for PM_2.5 Source Apportionments: A Case Study in Hangzhou During the 19^th Asian Games].","authors":"Shu-Hui Zhu, Cong-Yan Huang, Yong Lai, Yu-Hang Wu, Ren-Chang Yan, Jian-Dong Shen, Jun-Jie Tian, Ya-Qin Gao, Ying-Ge Ma","doi":"10.13227/j.hjkx.202404043","DOIUrl":"https://doi.org/10.13227/j.hjkx.202404043","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Positive matrix factorization （PMF） is one of the most widely used receptor models for PM&lt;sub&gt;2.5&lt;/sub&gt; source apportionment. The traditional PMF method generally uses inorganic （such as nitrate, sulfate, and EC） measurement data as input species to apportion PM&lt;sub&gt;2.5&lt;/sub&gt; sources. These species have ambiguous source origins； thus quantifying PM&lt;sub&gt;2.5&lt;/sub&gt; sources with high source sectors is difficult. In this study, online measurements of major chemical components, elemental tracers, as well as organic molecular markers were applied in a PMF model to investigate the differences between the major chemical components-based PMF （MCC） and organic molecular markers-based PMF （OMM） methods in terms of source identification, source separation, and source quantification. The results showed that with the input of organic molecular markers （such as polycyclic aromatic hydrocarbons, fatty acids, dicarboxylic acids, hydroxyl-dicarboxylic acids, C&lt;sub&gt;9&lt;/sub&gt; acids, and phthalic acid）, the OMM method greatly enlarged the number of source factors identified. Further, industry emission, shipping emission, dust, vehicle emission, biomass burning, secondary nitrate, and secondary sulfate； two primary source factors （coal combustion and cooking emission）； and four secondary organic aerosol （SOA） source factors were also resolved in the OMM method. Comparing with the source profiles resolved by the MCC method, we found that OC/EC mass ratios in OMM-resolved source profiles of industry emission, vehicle emission, biomass burning, and coal combustion were closer to those obtained from emission inventories. In terms of source quantification, the mass contributions of vehicle emission and biomass burning resolved by the MCC method were notably higher than those resolved by the OMM method, especially under high O&lt;sub&gt;3&lt;/sub&gt; concentrations （&gt; 120 μg·m&lt;sup&gt;-3&lt;/sup&gt;）. This suggests that without the input of specific organic molecular markers, the MCC method was inclined to apportion parts of secondary source contributions into primary sources （such as vehicle emission and biomass burning）. We further quantified and compared PM&lt;sub&gt;2.5&lt;/sub&gt; source contributions in Hangzhou before, during, and after the 19&lt;sup&gt;th&lt;/sup&gt; Asian Games with the application of the OMM method. Our results showed that the percentage contributions of vehicle emission, industry emission, and dust dropped by 65%, 24%, and 24%, respectively, during the Games. Anthropogenic SOA and aged SOA also displayed significant decreases in mass contributions during the Games by 35% and 49%, respectively, due to the emission reduction of volatile organic compounds （VOCs）. These results imply that PM&lt;sub&gt;2.5&lt;/sub&gt; pollution can be effectively controlled with the implementation of emission reduction measures. Our study also revealed that online measurements of organic molecular markers are important for improving PM&lt;sub&gt;2.5&lt;/sub&gt; source apportionment results and formulating pollution control policie","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1314-1325"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Soil Carbon Restoration and Its Influencing Factors in Coal Mining Areas of Yellow River Basin: A Meta-analysis].","authors":"Hong-Wei Sun, Mei-Fang Yan","doi":"10.13227/j.hjkx.202401155","DOIUrl":"https://doi.org/10.13227/j.hjkx.202401155","url":null,"abstract":"<p><p>Coal mining has caused notable disturbance and destruction to the ecosystem, leading to intensified regional carbon emissions. Ecological restoration of abandoned coal mines can improve the physical and chemical properties of damaged soil and increase soil carbon storage. Therefore, ecological restoration of coal mine areas is crucial for improving regional carbon sink levels and environments. Currently, most studies on ecological restoration in Chinese coal mining areas are scattered across the major coal-producing provinces in the Yellow River Basin. Its effect on soil carbon sequestration at a basin scale must be crucially elucidated. In this study, we focused on changes in soil physicochemical properties and enzyme activities after vegetation restoration using an integrated analysis method, combined with climate and soil characteristics in the Yellow River Basin's coal mining areas to reveal the major factors affecting soil carbon restoration. Our results showed that： ① Soil physicochemical properties and enzyme activities were improved significantly after ecological restoration； however, some differences were present among different soil layers. ② Soil organic carbon （SOC）, total nitrogen, and alkali-hydrolyzed nitrogen increased by 62.2%, 40.5%, and 36.0%, respectively, showing an overall increasing trend with increasing restoration years. From the perspective of vegetation type, mixed forest had the largest increment in SOC. ③ The increase in nitrogen and phosphorus content improved soil fertility and helped to increase soil carbon input from vegetation litter, thus promoting the restoration of the soil organic carbon pool. In addition, average annual temperature and precipitation along with soil type also played important roles affecting soil C restoration. In the future, based on climate and soil characteristics of specific mining areas, suitable vegetation types should be selected from a perspective of C sequestration to enhance C sink of the whole basin.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1690-1702"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Evolution and Simulation of Ecological Vulnerability in Qinghai-Xizang Plateau Nature Reserve].","authors":"Xiao-Feng Wang, Yuan-Yuan Zheng, Ze-Chong Sun, Ji-Tao Zhou, Xiao-Xue Wang, Meng-Na Zhu","doi":"10.13227/j.hjkx.202403096","DOIUrl":"https://doi.org/10.13227/j.hjkx.202403096","url":null,"abstract":"<p><p>The Qinghai-Xizang Plateau is the largest ecologically fragile and sensitive area in China and clarifying the spatial and temporal characteristics of ecological vulnerability of the Qinghai-Xizang Plateau Nature Reserve is important to promote the synergistic enhancement of the ecological security barrier and green development. Taking the Qinghai-Xizang Plateau Nature Reserve as a case study, we constructed a system of evaluation indicators and quantitatively evaluated the spatial and temporal characteristics based on the three dimensions of sensitivity-importance-resilience （SIR）. We also simulated the scenarios of ecological vulnerability under different decision-making preferences by using AHP-OWA. The results showed that： ① From 2000 to 2020, the ecological vulnerability index （EVI） of the Qinghai-Xizang Plateau decreased from 0.79 to 0.74, and the ecological vulnerability pattern of the nature reserves showed a trend of improvement； however, the higher vulnerability areas were still dominant. ② The spatial pattern of ecological vulnerability showed a general pattern of \"high in the northwest and low in the southeast,\" with the high values mainly concentrated in the northwest and low values in the southeast. The high values were mainly concentrated in Qiangtang, Cocozily, Zhongkunlun, and Arjinshan, and the low values were located in the southeast of Yarlung Zangbo River and Ruoergai Wetland Nature Reserve. ③ Based on the OWA method, three scenarios were set up, from the sustainability-oriented to the economy-priority oriented, and the scope of the highly fragile area was expanding, with the Qiangtang and Arjinshan regions being more obvious, and the changes in the low fragile area being lesser. This study assessed the ecological vulnerability of the Qinghai-Xizang Plateau Nature Reserve and simulated the future scenarios of vulnerability under different development conditions through the OWA method, which can provide theoretical references for the construction of regional sustainable development and vulnerability risk early warning mechanisms.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1633-1644"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Analysis the Source and Spatiotemporal Variation of Dissolved Organic Matter in the Chaohe River Watershed].","authors":"Zhuo-Ni Ma, Chun-Zi Guo, Hao Zhang, Shuang Song, Yao-Qi Gong, Chen-Yang Shou, Fu-Jun Yue","doi":"10.13227/j.hjkx.202404106","DOIUrl":"https://doi.org/10.13227/j.hjkx.202404106","url":null,"abstract":"<p><p>Dissolved organic matter （DOM） is widespread in aquatic environments and plays a crucial role in various biogeochemistry processes. Urbanization and anthropogenic activities have significantly altered the source and characteristics of DOM in rivers. Therefore, analyzing the spatial and temporal variation of DOM on a watershed scale to trace its source for effective water quality management is important. In this study, the composition characteristics of DOM in the Chaohe River watershed, which is the source of drinking water in northern China, were analyzed using the EEM-PARAFAC method. Furthermore, the source of DOM was further identified by analyzing the relationships among optical parameters. The results revealed the four components in DOM： component 1 resembled fulvic acid, while component 2 and component 4 exhibited characteristics similar to those of humic compounds. Component 3 displayed tryptophan-like acidity, with the highest intensity observed during both high and low flow periods. Temporal and spatial variation in fluorescence parameters further indicated a distinct source of DOM across the three water periods. Notably, non-point source pollution was prominent during the low water period, whereas soil-related characteristics dominated during the flood season. Spatial analysis revealed that under natural vegetation cover, terrestrial detritus significantly influenced DOM originating from the source area. However, urbanization-induced anthropogenic pollution had become more pronounced in the middle reaches. Additionally, the downstream area with extensive aquatic vegetation coverage experienced notable impacts from phytoplankton proliferation. Correlation analysis demonstrated varying degrees of association between water environmental parameters, nitrogen and phosphorus content, optical parameters, and DOM across three hydrological periods. These findings revealed that water environment dynamics and nutrient sources govern the temporal and spatial distribution patterns of DOM.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1395-1405"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Effect of Low-density Polyethylene Microplastics on Soybean-soil-microbial System].","authors":"Yu-Fei Jia, Jia-Wen Wang, Rui-Kun Wang, Tian-Qi Wang, Xue-Hui Xu","doi":"10.13227/j.hjkx.202403213","DOIUrl":"https://doi.org/10.13227/j.hjkx.202403213","url":null,"abstract":"<p><p>The widespread use of plastics has led to the prevalence of microplastics in the soil environment, which, as an emerging pollutant, affects plant growth, soil physicochemical properties, and microbial community structure. The effects of different contents of low-density polyethylene microplastics （LDPE-MPs） on soybean growth, soil physicochemical properties, soil enzyme activities, and microbial activities were investigated through pot culture experiments to explore the toxic effects of microplastics on soybean-soil-microbial systems. The results showed that compared with that in the control, microplastics inhibited soybean emergence （14.1%-25.0%）, whereas plant height, biomass, and pod weight were inhibited by low concentration and promoted by high concentration, and SPAD of soybean was significantly reduced by high concentrations of microplastics stress. Microplastics affected the quality of soybeans, with s-sugars, s-proteins, and cellulose increased by 117.7%-258.8%, 3.7%-61.6%, and 47.8%-83.4%, respectively, compared with those in the control. Microplastic addition also affected soybean nutrient uptake, as evidenced by the promotion of N （95.1%-144.4%） and P （4.1%-20.4%） uptake in the above-ground portion of soybeans and N （11.4%-19.4%） and P （8.5%-42.6%） uptake in the below-ground portion of soybeans, and inhibited K （2.2%-15.3%） uptake in the aboveground portion of the plant and K （3.9%-9.4%） uptake in the below-ground portion of the plan, respectively. The addition of microplastics had little effect on soil pH； however, it significantly increased CEC （65.1%-74.7%） and SOM （22.6%）. With the increase in the addition content, the content of NO₃^--N, AP, AK, and UE activities were significantly reduced； the content of NO₃^--N, AP, and AK was reduced by 57.7%, 22.0%, and 18.8% compared with that in the control at 3% addition, respectively； and UE activity was inhibited by 13.98%. Further, 16S rRNA sequencing analysis showed that microplastic stress increased the abundance of the Proteobacter group and reduced the abundance of the Acidobacter group in the soil, decreasing the diversity of the community, which in turn destabilized the microbial community and made the entire system less stable. In summary, microplastic stress affects the stability of soybean-soil-microbial systems.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1831-1840"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Seasonal and Spatial Variation Characteristics of Surface Water Quality and Its Influencing Factors in Baiyangdian Lake].","authors":"Rong-Zhen Xu, Yu-Shan Wang, De-Chao Yin, Xu-Qing Wang","doi":"10.13227/j.hjkx.202401138","DOIUrl":"https://doi.org/10.13227/j.hjkx.202401138","url":null,"abstract":"<p><p>Baiyangdian Lake is the major ecological function area of Xiongan New Area. To reveal the surface water quality and its changing trends, seasonal changing trends, spatial changing characteristics, and influencing factors of the important indicators of the surface water,statistical description,ion diagrams,factor analysis, and other methods were comprehensively used to systematically study the surface water quality of Baiyangdian Lake. The results showed that the surface water quality of Baiyangdian Lake was gradually improving,and the water quality was mainly Class IV by 2020. COD,permanganate index,total nitrogen, and total phosphorus were key indicators that affected the water quality of Baiyangdian Lake. The spatial and temporal variation characteristics of these four key indicators were analyzed. The study of spatial change characteristics revealed that the content of oxygen-consuming substances that were difficult to be oxidized in the surface water was high,and the substances carried by the river entering Baiyangdian Lake directly affected the water quality near the entrance of the lake. The time variation characteristics indicated that under the background of ecological water replenishment,the concentration level of pollutants in surface water had significantly decreased, and the water quality had been significantly improved. The hydrochemical type of the surface water was mainly HCO₃-Na type. TDS and the main ion concentrations were higher in the south and lower in the north. The constant ion components mainly originated from the weathering and dissolution of silicate rocks；the trace water chemical components were affected by natural and man-made factors. The natural source was rock weathering. The man-made factors included atmospheric deposition,agricultural and industrial sources,and the superimposed impact of organic pollution. The research results can provide scientific support for the protection and restoration of Baiyangdian Lake ecology.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1382-1394"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Spatial and Temporal Variation of Dissolved Organic Matter and Its Biodegradability in Typical Algal Bay].","authors":"Yuan-Qiang Wu, Wei Jin, Ke Hua, Zi-Chen Cang, Xin Liu","doi":"10.13227/j.hjkx.202402012","DOIUrl":"https://doi.org/10.13227/j.hjkx.202402012","url":null,"abstract":"<p><p>The biodegradability of dissolved organic matter （DOM） is a crucial factor in assessing the carbon balance and ecosystem equilibrium of freshwater lakes. It is closely linked to regional hydrological characteristics and biochemical processes. Taking cyanobacterial bloom-dominated bays in Lake Taihu as the research object, combined with characterization by ultraviolet absorption, three-dimensional fluorescence spectroscopy, and bioassay experiments, this study analyzed the temporal and spatial variations of DOM concentration, structural composition, and biodegradable dissolved organic carbon （BDOC） during the rainy and bloom season and the dry and post-bloom season. The results showed that during the bloom season, the release of cyanobacterial-derived organic matter led to a significant increase in DOM concentration in Meiliang Bay and Gonghu Bay, which was mainly composed of protein components, such as tyrosine and tryptophan （&gt;70%） with a lower aromaticity （SUVA₂₅₄）, molecular weight, and humification degree （HIX）. In comparison, the DOM samples in Zhushan Bay had higher absorbance （SUVA₃₅₀）, SUVA₂₅₄, HIX, relative molecular mass, and content of humic substances, which was associated with stronger input of terrestrial humic substances during the rainy season. As a result, the average BDOC in Zhushan Bay was lower （31.6%） compared to those in the other two bays （38.8%）. With the decline of cyanobacterial bloom and the decrease of terrestrial input in the dry and post-bloom season, in-situ degradation significantly increased SUVA₂₅₄ and humic-like components while decreasing protein-like components in DOM. This resulted in a decrease in average BDOC to 28.1%. Partial least squares analysis further revealed that DOM optical indices could effectively predict BDOC （<i>R</i>²=0.81）, with fluorescence peaks T/C and <i>S</i>_R indices being the most effective positive predictive factors and SUVA₂₅₄ being the most effective negative predictive factor. These findings suggest that cyanobacterial blooms and in-situ degradation are crucial processes that affect the biodegradability of DOM in freshwater lakes and propose an alternative method for assessing BDOC.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1406-1416"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Temporal and Spatial Heterogeneity and Its Influencing Factors of Carbon Surplus and Deficit at County-Level Areas in Shaanxi Province].","authors":"Yi-Meng Ding, Ling Han, Xin Huang","doi":"10.13227/j.hjkx.202401161","DOIUrl":"https://doi.org/10.13227/j.hjkx.202401161","url":null,"abstract":"<p><p>Carbon source and sink monitoring is an important prerequisite for realizing the dual-carbon target and the evolution of its spatial-temporal pattern and the spatial-temporal heterogeneity of the driving factors are the scientific basis for the implementation of the emission reduction and sink enhancement policy according to the local conditions, which is of great importance for the sustainable development of the region. Based on the carbon balance of payment relationship, the carbon surplus and deficit of Shaanxi Province counties were calculated in 2000, 2010, and 2020 from land use, and a series of exploratory spatial and temporal analysis methods （ESTDA）, including spatial autocorrelation, cold and hot spot analysis, standard deviation ellipse, and LISA-time pathway, were used to study the dynamics of carbon surplus and deficit in Shaanxi Province at different spatial-temporal scales. From the 21 indicators, six types of major driving factors were selected by principal component analysis, and the geographical spatio-temporal weighted regression model （GTWR） was used to identify their spatio-temporal heterogeneity to construct a comprehensive system of indicators to analyze the carbon deficit and its spatio-temporal heterogeneity in Shaanxi Province. The results showed that： ① A carbon surplus of 8.56 million tons in 2000, a carbon deficit of 3 296 tons in 2010, and a deficit of 33.34 million tons occurred in 2020 in Shaanxi Province, and the growth rate of carbon emissions was much larger than that of carbon sinks, which indicates that it was gradually moving towards carbon peaks in Shaanxi Province； however, there is a long way to go to achieve the goal of carbon neutrality. ② The geographical distribution of the \"north deficit and south surplus\" phenomenon was visually represented. A carbon deficit was concentrated in the wind and sand area along the Great Wall and Guanzhong plain. The spatial-temporal leap characteristics were more stable. In conclusion, efforts aimed at emission reduction and carbon sink enhancement were strategically directed towards the northern Shaanxi Region. ③ Among various indicator systems including urban construction, natural resources, anthropogenic activities, energy consumption, industrial development, and ecological protection indicator systems, only ecological protection positively drove carbon profit and deficit. Notably, natural resources had the strongest spatial and temporal heterogeneity in their impact on carbon deficit, and energy consumption was positively driven in some areas of Shaanxi Province. The results will provide accurate policy directions for the development of carbon neutral strategies in Shaanxi Province.</p>","PeriodicalId":35937,"journal":{"name":"环境科学","volume":"46 3","pages":"1502-1516"},"PeriodicalIF":0.0,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}