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Table of Content

Volume 39 Issue 12
25 December 2023
Analysis on the Degree of Coupling Coordination between County Ecosystem Services and Rural Revitalization in the Priority Areas for Biodiversity Conservation in Southeastern Himalayas: A Case Study of Dingjie County
WANG Nan, YAO Guo-hui, MA Wei-bo, LI Hai-dong
2023, 39(12):  1515-1524.  doi:10.19741/j.issn.1673-4831.2023.0245
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Clarifying the coupling coordination relationship between rural revitalization and ecosystem services is not only an objective requirement for consolidating and expanding poverty alleviation achievements, but also has certain practical implications for implementing the concept of "Lucid Waters and Lush Mountains are Invaluable Assets" and promoting the realization of ecological product value. Taking Dingjie County in the Tibet Autonomous Region, which is located in a priority area for biodiversity conservation in southeastern Himalayas, as an example, this paper constructs a research framework for the coupling coordination degree of rural revitalization-ecosystem services from the three dimensions of industrial revitalization, ecological beauty, and people's prosperity, and analyzes the coupling relationship between the rural revitalization index and ecosystem service value of 10 townships in Dingjie County from 2000 to 2020. The results show that: (1) the rural revitalization index of four townships in Dingjie County is higher than the county average, and the rural revitalization index in 2010-2020 has increased significantly compared with 2000-2010. (2) The ecosystem service value (ESV) was higher in Chentang Township, Duobuza Township, and Qiongzi Township, and the decreasing trend of ecosystem service value in Dingjie County during 2010-2020 was significantly slower than that in 2000-2010. (3) In 2020, the coupling coordination degree of 5 townships in Dingjie County was higher than the county average, with the spatial distribution of coupling coordination degree being low in the center of the county and high in the north and south. Finally, countermeasures and suggestions were proposed from the perspectives of industry guidance, ecological security, and classified assistance. The research results can provide technical support for promoting regional ecological economic development and rural revitalization.
Temporal and Spatial Evolution of Habitat Quality and Its Topographic Gradient Effect in Xinzhou City Based on InVEST Model from 1985 to 2020
SU Jing, RUI Han-yi, ZHU Qin-yuan, ZHANG Wei-dong, WU Qiu-ju, LI Shi-mei, LIU Guo-qiang, ZHU Lin
2023, 39(12):  1525-1533.  doi:10.19741/j.issn.1673-4831.2023.0530
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The ecological response of habitat quality to land use change and topographical factors has become a prominent subject of research in ecology. In view of the unclear response status of habitat quality in Xinzhou City, Shanxi Province, the InVEST model was used to assess its habitat quality from 1985 to 2020, and the terrain factor was used to study its terrain gradient effect. The results show that the land use change in Xinzhou City during the period of 1985 to 2020 mainly involved the mutual conversion of cultivated land and grassland, as well as the conversion of forest land and cultivated land to construction land. The average habitat quality index in Xinzhou City exhibited a slight decline followed by a significant upward trend, with the lowest being 0.739 1 in 1990 and the highest being 0.787 4 in 2020. The area occupied by higher-quality habitats with the habitat quality index ≥0.8 gradually increased, mainly distributed in mountainous and loess gully areas. The area of lower-quality habitats with the habitat quality index ranges from 0.2 to 0.4 gradually decreased, mainly distributed in basin areas. The low level habitats with the habitat quality index below 0.2 also gradually increased. The change in habitat quality from 1985 to 2020 demonstrated clear spatial differentiation: significant gains in 8 counties in the west, notable losses in Xinfu District and Dingxiang County in the southeast. Meanwhile, there is a significant topographic gradient effect, and the habitat quality in basin areas with low terrain gradients has degraded in certain extent. The improvement in habitat quality is greatest in the loess gully area with medium terrain gradient. The habitat quality is highest in mountainous areas with high terrain gradients. The research results can provide decision-making references for improving regional ecological quality and optimizing ecological land use.
Analysis of Cyanobacterial Response to Nutrient Changes in Dianchi Lake By Using AEM3D Model
DU Cheng-dong, PAN Ji-zheng, ZHANG Guo-zheng, LI Yong, LUO Chun-liang, LI Qing-zhuo, HUA Yue-zhou
2023, 39(12):  1534-1546.  doi:10.19741/j.issn.1673-4831.2022.0458
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In order to understand the spatial and temporal distribution patterns of cyanobacterial outbreaks and the effect of exogenous nutrient regulation on cyanobacterial outbreaks in Dianchi Lake, the 3-Dimensional coupled Hydrodynamic-Aquatic Ecosystem Model (AEM3D) from HydroNumerics, Australia was used to simulate the spatial and temporal distribution characteristics of TN, TP and cyanobacteria, and to investigate the response relationship of cyanobacteria under different exogenous nutrient concentrations by regulating the values of exogenous nutrients. The results show that the concentration of TP was higher in spring, which acted as an important nutrient factor in algal growth. The concentration of TN was higher in autumn, which played a key role in algal growth. When simulating single-factor exogenous nutrient reduction at different rates, it was found that total exogenous phosphorus had a greater effect on cyanobacteria than total exogenous nitrogen, while the changes in exogenous nitrogen in spring had a greater effect on cyanobacteria. When only TP was controlled, a 25% reduction was effective in reducing Chl-a concentration in the lake, and when only TN was controlled, a 50% nitrogen reduction was more reasonable. Compared to the reduction of a single nutrient, the effect on control of Chl-a concentration was superior when nitrogen and phosphorus nutrients were both reduced by 10% or above 50% at the same time.
Characteristics and Pollution Assessment of Nitrogen and Phosphorus Fractions in River Sediments in Urumqi and Surrounding Areas
SU Wen-hao, ZHU Xin-ping, WANG Ling, LEI Rong-rong, HAN Tian-lun, WANG Long-mian, KONG Ming
2023, 39(12):  1547-1558.  doi:10.19741/j.issn.1673-4831.2023.0607
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In Urumqi and surrounding areas, 5 typical river channels were selected, with 3 sampling points (a total of 15 sampling points) set up for each channel to collect sediment samples. By measuring the physical and chemical properties, nitrogen and phosphorus content, and fractions of river sediments, and evaluating the ecological risk of nitrogen and phosphorus pollution levels in river sediment, so as to reveal the distribution characteristics of nitrogen and phosphorus content and fractions in river sediments and their potential ecological risks. The results show that the total nitrogen contents of the sediments were between 1 699.23 and 3 702.93 mg·kg-1 (the average content was 2 799.40 mg·kg-1), and the total phosphorus contents were between 596.65 to 1 729.53 mg·kg-1 (the average content was 994.82 mg·kg-1). The main fractions of transformable nitrogen (TTN) in the sediment were strong oxidant leachable nitrogen (SOEF-N) and weak acid leachable nitrogen (WAEF-N), accounting for 43.94% and 40.42% of TTN, respectively. The main phosphorus fractions of inorganic phosphorus in the sediments were calcium-bound phosphorus (HCl-P) and residual phosphorus (Res-P), accounting for 58.94% and 14.94% of total phosphorus (TP), respectively. The average content of bioavailable phosphorus (BAP) was 134.92 mg·kg-1, accounting for 12.48% of TP. The main fractions of organic phosphorus in the sediment were fulvic acid-bound organic phosphorus (Fulvic-OP) and hydrochloric acid-leachable organic phosphorus (HCl-OP), accounting for 34.38% and 32.95% of organic phosphorus, respectively. According to Redundancy analysis, TP content, pH, and Fe2O3 content were the main factors affecting the distribution characteristics of nitrogen and phosphorus fractions in river sediments. The comprehensive pollution index method evaluation show that the comprehensive pollution degrees of TP and TN in the river sediments were moderate or severe. The results can provide basic data and scientific basis for urban river water environment management and river administration in the northwest arid region of China.
Analysis of Spatial and Temporal Distribution and Meteorological Driving Factors of PM2.5 in Hubei Province from 2001 to 2020
ZHOU Jing-cheng, YAO Heng, CAO Yan-xiao, ZHU Xi, CHEN Ning
2023, 39(12):  1559-1567.  doi:10.19741/j.issn.1673-4831.2022.1357
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Grasping the spatial and temporal evolution of PM2.5 pollution is the basis and prerequisite for its targeted management. The annual average PM2.5 concentration data of each prefecture-level city in Hubei Province from 2001-2020 were extracted from the raster data of PM2.5 earth surface concentration, and spatial autocorrelation and kernel density estimation methods and Geodetector were used to study the spatial and temporal distribution characteristics of PM2.5 and the characteristics of meteorological driving factors. The main results of the study are as follows: The rate of compliance with the secondary standard for PM2.5 concentration in major cities across Hubei Province appears to be increasing. The average annual PM2.5 concentration in each city gradually increased from 42.47 to 62.94 from 2001 to 2013, and decreased from 62.94 to 32.85 from 2013 to 2020. The kernel density estimation shows that the annual average PM2.5 concentrations in the cities were gradually dispersed before 2013, while the annual average PM2.5 concentrations in the cities after 2013 were gradually concentrated in the lower concentration intervals. Taking Wuhan and other central cities as the dividing line, there is a gradient of high to low PM2.5 concentrations in Hubei Province in both east and west directions, and the concentration in the west is lower than that in the east. The dispersion effect in areas of higher concentrations diminishes gradually after 2013. There was a significant positive aggregation effect in the spatial distribution of PM2.5, Qianjiang, Xiantao and Tianmen basically showed high-high aggregation characteristics, while Enshi Tujia and Miao Autonomous Prefecture and Shennongjia Forest Area all showed low-low aggregation characteristics. Very few cities showed high-low or low-high aggregation characteristics. Geodetector shows that the meteorological factors had a significant effect on the PM2.5 concentration. The average explanatory degree of various meteorological factors on PM2.5 concentration is ranked as follows: wind speed (0.798) > temperature (0.752) > humidity (0.727) > sunshine (0.694) > precipitation (0.639). The dominant driving factors were different in different years, and temperature was the dominant driving factor before 2010, while wind speed was the dominant driving factor after 2010.
Impacts of Urbanization and Natural Background on Ecosystem Service Tradeoffs: A Case Study of Luoyang City
DING Hong-hao, HE Hong-bin, LI Jia-lei, SUN Ran-hao
2023, 39(12):  1568-1579.  doi:10.19741/j.issn.1673-4831.2022.0546
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The structure and function of urban ecosystem and its internal relationship are constantly changing under the interaction of human and nature. The scientific nature of development planning and the waste of resources are the essential and difficult points of current urban ecological management. Clarifying the status and internal relationship of urban ecosystem services and its influencing factors is of great significance for optimizing urban ecological management and implementing green sustainable development. In this study, the temporal and spatial variation characteristics and trade-off synergy of six types of ecosystem services of Luoyang City in 2010 and 2019 were quantitatively evaluated, the influencing factors of spatial differentiation of service and trade-off intensity were analyzed, and the spatial distribution of comprehensive cold and hot spots of ecosystem services was identified. The results show that: (1) The spatial distribution of ecosystem services in Luoyang City was highly coupled with the landscape pattern. Soil conservation and water production changed significantly, and the change area was concentrated in the southern forest land. (2) There was a synergistic relationship among carbon storage, habitat quality, aesthetic landscape and soil conservation services, and the trade-off relationship exists between grain yield, water yield and the rest services. (3) The trade-off intensity of ecosystem services in Luoyang City was high in south and low in north. The high-intensity areas were dominated by woodland landscape. Slop, NDVI, altitude, GDP and precipitation had relatively high explanations for the spatial heterogeneity of trade-off intensity. (4) The cold and hot spots of ecosystem services were mainly distributed in the northwest and southeast of the city, respectively. Service types in overlapping service areas were mainly carbon storage, soil conservation and habitat quality. Systematic quantitative research on urban ecosystem services was helpful to the clarification of the advantages and disadvantages of urban ecological base, and to the optimization of the allocation of environmental resources and to provide scientific basis for maximizing ecological benefits.
Ecological Environment Monitoring and Driving Factors Analysis of Mining Area Based on Improved Remote Sensing Ecological Index
MA Peng-fei, ZHANG An-bing, WANG He-feng, XIN Hui-chao, LIU Fen-fen
2023, 39(12):  1580-1590.  doi:10.19741/j.issn.1673-4831.2022.0534
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A new remote sensing ecological index (NRSEI) was built to monitor and analyze the driving factors of the mining ecological environment of Feng-Feng Coal Mine in Handan of Hebei Province from 2001 to 2020 on the basis of the remote sensing ecological index (RSEI) by adding PM2.5 concentration index to greenness, humidity, dryness and heat indexes. The results prove that: (1) The NRSEI model can more truly reflect the ecological environment of the research area. In the past 20 years, the quality of the ecological environment in the study area fluctuated and changed with a slightly decrease before 2009, and then showed a trend of improvement. Overall, the NRSEI grade was mainly medium or relatively good, and the ecological environment tended to be stable. (2) The ecological degradation areas were mostly distributed in the central and eastern parts of the study area, mainly due to the expansion of cities and towns. The improvement area was mainly distributed in the western part of the study area, mainly due to less human interference and the ecological priority policies implemented by the government, which had stabilized and improved the ecological environment of the area. (3) A separate analysis of the water bodies in the study area found that the ecological environment level of the water bodies and land change areas was above medium, and the overall ecological environment was good. (4) The changes in the quality of the ecological environment in the mining area were affected by the combined action of driving factors such as rainfall, temperature, slope and human activities. The government's measurements to control and protect the ecological environment had achieved positive results.
Seasonal Variation of Culturable Bacterial Diversity and Its Physicochemical Factors in Coastal Area of Namco Lake on Tibetan Plateau
ZHENG Yan-yan, HE Kai, MENGHUA Dan-shang, DE Ji, GUO Xiao-fang
2023, 39(12):  1591-1600.  doi:10.19741/j.issn.1673-4831.2022.1349
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In order to carry out the study on seasonal changes in the diversity of culturable bacterial communities in water bodies of Namco Lake, water samples were collected in summer 2020, spring 2021 and autumn 2021, respectively. The isolation and purification of bacteria were performed by spread plate method and plate four zone streaking method, respectively. Strains were identified by 16S rDNA gene sequencing technology combined with classical taxonomy method, and the data were processed and analyzed by using relevant statistical softwares. A total of 1877 culturable bacteria strains were isolated from water samples of Namco Lake collected in three seasons, which belong to 87 species, 34 genera, 26 families, 15 orders, 7 classes and 4 phyla. The total bacterial abundance was highest in summer and lowest in autumn, while the 3 community diversity indices were highest in autumn and lowest in summer. The results of PCoA and other analyses collectively show that bacterial community structure similarity was high between spring and summer, while it was low between spring and autumn, summer and autumn. The result of the CCA indicates that total dissolved solids was the most influential physicochemical parameter on the distribution of bacterial community in different seasons. The result of the Mantel test indicates that the differences of total dissolved solids, temperature, chemical oxygen demand, and turbidity in different seasons were significantly (P<0.001) correlated with the differences of bacterial community structure. This study initially investigated the seasonal changes in the diversity of culturable bacterial communities in the water body of Namco Lake, which is of great significance for the conservation of lake ecosystems on the Tibetan Plateau and the exploitation and utilization of bacterial resources among them.
Effects of Hetian-chicken Grazing in Artificial Grass under Forest on Soil Physico-chemical Properties and Microbial Flora
GAO Cheng-fang, CHEN Dong-jin, XIN Qing-wu, YING Zhao-yang
2023, 39(12):  1601-1609.  doi:10.19741/j.issn.1673-4831.2022.1186
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The local poultry breed-Hetian chicken has been grazing mainly under forest for a long time in Changting County. However, the traditional high-density and continuous grazing model under the forest causes damage to the ecological environment. In this paper, the influence of grazing time and grazing model on soil physic-chemical properties and bacterial colonies in forest was studied, and the appropriate grazing time and model of Hetian chicken have been found out. The regular chemical analysis and 16S rDNA sequencing were used to determine the chemical characteristics and microbial diversity of grazing on natural grass (group A) and artificial grass (group B) in the forest land during 3 different grazing time periods. The results show that the soil chemical traits were significantly influenced by grazing methods. The soil SOM, TN, AP, AK, NO3-N and NH4+-N contents in group B were extreme significantly higher than those in group A. The soil SOM and AK contents in group A and B were gradually increasing. AP contents increased firstly and then decreased, reached the highest point at 60 d, while NO3-N and NH4+-N contents showed a decreasing trend with the grazing time. Soil microbial diversity indexes Chao1, Shannon and Simpson in group A were greatly influenced by grazing time, while the changes in group B was not obvious. The dominant bacterial colonies of group A were Actinobacteria, Bacteroidetes, Chloroflexi, and Firmicutes, and those of group B were Gemmatimonadetes, Proteobacteria, and Acidobacteria. The results show that grazing on artificial grass under forest for 60 d, the chemical contents are relatively high and the microbial diversity is relatively rich, and the dominant bacterial colonies were Gemmatimonadetes, Proteobacteria and Acidibacteria. The results of this study could provide reference for sustainably maintaining and protecting the soil ecological environment.
Effects of Organic Fertilization on Soil Phosphorus Transformation in Paddy Field by Using Microbial Stoichiometry
ZHANG Ling-yu, CHEN Guang-lei, ZHAO Hong-meng, WU Li-wu, CHEN Hao, YU Yun-fei, YE Wen-ling, WANG Yu
2023, 39(12):  1610-1618.  doi:10.19741/j.issn.1673-4831.2022.0430
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Organic fertilizers significantly increases soil phosphorus (P) pools in paddy soils. Microbial stoichiometry can play an important role in the process of reflecting soil P transformation. Based on 100% replacement of chemical fertilizers with organic fertilizers at different nitrogen application rates, including 0 (N0), 75 (N75), 150 (N150), 225 (N225) and 300 kg·hm-2 (N300), this study analyzed the effect of organic fertilizers on soil P pools in paddy fields and the effect of microbial stoichiometry on soil P transformation in different rice-growing stages. The results show that in the third year, compared with no fertilizer treatment, all organic fertilizer treatments increased the concentration of soil Olsen-P by 12.9%-153% and TP by 5.80%-40.6%), respectively, at rice seedling stage and harvest stage. Further analysis of the soil P components changes showed that the available P(Resin-P, NaHCO3-Pi, NaHCO3-Po), secondary-P(NaOH-Pi, NaOH-Po), and organic P (Po)(Labile Organic P, Moderately Labile Organic P, Stable Organic P) increased by 37.3%-142%, 7.50%-41.3% and 3.41%-32.2%, respectively. With the further increase of organic fertilizer application (N225 and N300), soil labile P (including Olsen-P and available P) did not increase. Through Redundancy Analysis and Pearson Correlation Analysis, it was found that soil MBC and MBN were significantly negatively correlated with soil Olsen-P, available P, secondary-P and labile organic P (LPo), indicating that the increase of microbial biomass decreased the soil labile P concentration. However, MBP was significantly positively correlated with soil Olsen-P and soil inorganic P (Pi) components at harvest stage, because rice roots changed the rhizosphere environment, which in turn affected soil microbial biomass and soil Pi. During the growth period of rice seedling season, the microbial stoichiometric ratio (MBC/MBP and MBN/MBP) was significantly negatively correlated with soil LPo, while in the rice harvest stage, the microbial stoichiometric ratio (MBC/MBP and MBN/MBP) was significantly negatively correlated with soil Olsen-P and Pi. It showed that microbial stoichiometry significantly affected soil labile P and Po, and promoted the conversion of soil Po to labile P. This study aims to provide a theoretical basis for guiding the application of organic fertilizers to promote P in paddy soil and increase its efficiency.
Efficiency and Gas Emission Assessment of Various Solid-liquid Separation Technologies for Animal Slurry: A Meta Analysis
ZHANG Xin-xing, WANG Shan-shan, LIANG Wen-xu, WEN Li-qing, ZHANG Wei-tao, GAO Zhi-ling
2023, 39(12):  1619-1628.  doi:10.19741/j.issn.1673-4831.2022.0665
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Solid-liquid separation technology is widely used in animal farms to manage slurry. To evaluate the distribution of components in slurry under the application of different solid-liquid separation technologies, 36 published articles were screened for comprehensive meta-analysis. The results of data analysis show that the separation efficiency (EX-SF) of slurry was positively correlated with dry matter content of raw slurry. Centrifuge and screw press are the two most widely used separation technologies in practical production. With the same dry matter content of raw slurry, the EX-SF of centrifuge is higher than that of screw press. The efficiencies of different separation technologies are classified according to the removal efficiency and separation efficiency. The EX-SF of FM, DM, VS, TN, TAN, TP and TK in solids of the high efficiency group are 2.5, 1.9, 1.6, 3.1, 5.2, 2.3 and 3.1 times as high as that of the low efficiency group, respectively. After solid-liquid separation, the CH4 and GHG emissions of the slurry were significantly reduced by 34.4%-67.9% and 38.9%-60.7%, respectively. The high efficiency group has higher potential of gas emission reduction than the low efficiency group. This study also provides theoretical basis for the prediction of the efficiency and environmental impact of different liquid and solid components separation technologies in storage and field application, which has important reference value for the accurate evaluation and safe utilization of separated slurry in China.
Effects of Reduction in Nitrogen Fertilizer in Combination with Iron Powder on Reactive Nitrogen Loss in Rice-wheat Rotation Farmland
LONG Ya-ou, QIU Zi-jian, HU Ming-cheng, ZHAO Li-jia, LI Tian-ling, GAO Nan, SENOO Keishi, SHEN Wei-shou
2023, 39(12):  1629-1636.  doi:10.19741/j.issn.1673-4831.2022.0552
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Rice-wheat rotation cropland is an important source of ammonia volatilization, nitrous oxide (N2O) emissions and nitrate leaching in China's Yangtze River Base. Although reducing the amount of nitrogen fertilizer can reduce the adverse environmental consequences brought on by irrational nitrogen fertilization, it may result in the risk of crop yield reduction. Application of iron powder can stimulate the growth of iron-reducing bacteria in flooded paddy soil and enhance their nitrogen-fixing activity. In this study, the conventional nitrogen fertilization rate (100%N), 80% of the conventional nitrogen fertilization rate (80%N), 80%N in combination with iron powder (80%N + Fe), 60% of the conventional nitrogen fertilization rate (60%N), 60%N in combination with iron powder (60%N + Fe), no nitrogen application (0%N), 0%N in combination with iron powder (0%N + Fe), yielding a total of 7 treatments. Each treatment has four replicates (plots). The effects of reduction in nitrogen fertilizer in combination with iron powder on crop yields, ammonia volatilization, N2O emission and mineral nitrogen leaching were investigated by in situ field experiments. The results show that the wheat yield was increased by 9.7% in 80%N + Fe treatment compared with 80%N in 2021. The rice yields were comparative between 80%N + Fe treatment and the conventional nitrogen fertilization rate. The 80%N + Fe treatment could ensure both wheat and rice yields relative to the conventional N fertilization rate. Ammonia volatilization in paddy fields decreased significantly with the reduction in nitrogen fertilization rate (P<0.05); 80%N + Fe treatment further decreased the cumulative ammonia volatilization amount and ammonia volatilization intensity by 50.99% and 47.41%, respectively (P<0.05). The cumulative N2O emission in the 80%N + Fe treatment decreased by 78.16% in the wheat season of 2021 compared with the 80%N treatment (P<0.05). It decreased by 18.27% compared with the conventional nitrogen fertilization rate in the rice season. Meanwhile, 80%N + Fe treatment decreased the leaching of nitrate nitrogen in deep soil leachate. Therefore, 80%N in combination iron powder could maintain stable crop yields while reducing the nitrogen losses in the rice-wheat rotation cropland, probably because iron powder enhances the nitrogen-fixing activity of iron-reducing bacteria in flooded paddy fields. The 20% reduction in nitrogen fertilizer input mainly resulted in lower nitrogen losses including volatilization, N2O emissions and nitrate leaching. Yet the corresponding soil microbial mechanism deserves further exploration.
Effects of Different Electrolytes on Adsorption-desorption of Fulvic Acid onto Dairy Manure Biochar
HUANG Hui-qun, ZENG He-ping, LIU Xi-yuan
2023, 39(12):  1637-1645.  doi:10.19741/j.issn.1673-4831.2022.0506
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In order to reduce the loss of fulvic acid and to improve its utilization, the effect of dairy manure biochar on fulvic acid adsorption-desorption was investigated by using indoor experiment. The Langmuir and Freundlich equations, pseudo-first-order model, pseudo-second-order model and intra-particle diffusion equation were used to study the effects of dairy manure biochar on the adsorption and desorption of fulvic acid by the three kinds of electrolytes (NaCl, Na2SO4 and Na3PO4). The results show that the isothermal adsorption process of dairy manure biochar on FA was in accordance with the Langmuir equation, and the kinetic equation was in accordance with the pseudo-second-order equation. It was significantly different for the dairy manure biochar on the isothermal adsorption and desorption processes of FA with the three kinds of electrolytes, the order of adsorption capacity and adsorption rates were NaCl>Na2SO4>Na3PO4, the order of desorption capacity and desorption rates were Na3PO4>Na2SO4>NaCl, the adsorption intensity and desorption intensity of MBC also reacted to this rule. It was significantly different with the three kinds of electrolytes on adsorption and desorption kinetics of FA by dairy manure biochar, and the order of adsorption capacity and adsorption rates were NaCl>Na2SO4>Na3PO4, the order of desorption capacity and desorption rates were Na3PO4>Na2SO4>NaCl. The results from the Intra-particle diffusion equation also showed the simultaneous control of the external diffusion and the diffusion of inter-particle. In summary, NaCl has the strongest effect on the adsorption of FA by the dairy manure biochar, which is beneficial for the enhancement of soil fertility, the improvement of the organic pollutants adsorption capacity, and the improvement of the ecological environment.
Transcriptome Sequencing and Sequence Analysis of Key Genes in the Insulin Signaling Pathway of Chironomus tentans
ZHANG Cheng-lin, GU Wen, WANG Zhen, SHI Li-li, WANG Lei, YANG Jia-xin
2023, 39(12):  1646-1656.  doi:10.19741/j.issn.1673-4831.2023.0132
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To explore the endocrine disrupting gene markers of invertebrates based on the insulin signal pathway, this study selected Chironomus tentans as the model organism, identified the key genes in the insulin signal pathway on the basis of transcriptome sequencing, and carried out the full-length amplification of cDNA and the multi-species comparison of amino acid sequences for the upstream genes such as InR, Pdk, Akt and FoxO. Based on the cDNA full-length sequence, the InR, Pdk, Akt and FoxO genes of Chironomus tentans can encode protein sequences containing 1 436, 522, 520 and 470 amino acids, respectively. The sequence homology comparison and phylogenetic tree analysis results verified its evolutionary conservatism. The qRT-PCR results of the relative expression of genes in Ⅰ-Ⅳ instar larvae, pupae, female adults and male adults show that the expression trend of InR, Pdk, Akt and FoxO in C. tentans was similar. The peaks of gene expression in I and IV instar indicate that insulin signaling induces faster growth and development rates in I and IV instar larvae. The expression of InR, Pdk, Akt, and FoxO in female adults was significantly higher than that in males, which may be related to the involvement of insulin signaling in the development of the female reproductive system.