Table of Content

Volume 38 Issue 7
25 July 2022
Visual Analysis of Hot Spots and Trends in Ecological Restoration Evaluation Based on China National Knowledge Infrastructure
YUAN Jing-fang, LIU Xiao-man, ZHANG Wen-guo, ZHANG Yi-fan
2022, 38(7):  817-826.  doi:10.19741/j.issn.1673-4831.2021.0624
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Bibliometric methods and knowledge graph were used to clearly understand the current status of ecological restoration evaluation in China. The 1 523 papers collected in CNKI database in past 30 years were used as the data source to analyze the relevant literature of ecological restoration evaluation. The results show that:(1)The discipline communication intensity of ecological restoration evaluation research is low, the overall volume of authors' publications is not high, and the authors' cooperative groups are small. Among the research institutions, Beijing Forestry University, Lanzhou University and Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences are the highest contributors; (2)The research hotspots of ecological restoration evaluation mainly focus on three parts:ecological restoration evaluation types, evaluation indexes of different functional types and restoration effectiveness; (3)The research hotspots of ecological restoration evaluation have gone through three stages, and all stages presented their distinct characteristics of the time. The research hotspots of each stage are deepened compared with the previous stage. In the early stage, some specific ecosystem restoration is evaluated mainly combined with the actual needs. In the later stage, with the progress of various ecological restoration work, different ecological restoration evaluation systems appeared. In recent years, the focus of research has shifted to policy-oriented and technology integration as the support of evaluation. The research results can provide reference for the further strengthening of ecological restoration evaluation research.
Research Progress on Reducing Cadmium and Arsenic Accumulation in Rice Grains
ZHANG Hui-juan, SU Qi-qian, DING Hao-jie, LI Xiao-feng, XU Qi-jing, Rensing Christopher, LIU Xue
2022, 38(7):  827-838.  doi:10.19741/j.issn.1673-4831.2021.0244
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Heavy metals pollution in farmland soils induced by mining, waste discharge and sewage irrigation can be concentrated and transported via the food chain, thereby posing great risks to human health. Rice is an important staple food, which however, is readily to uptake and accumulate cadmium (Cd) and arsenic (As) from contaminated soils, rendering it to be a main dietary source of As and Cd of humans. Therefore, exploring strategies to reduce Cd and As content in rice grains has practical importance to ensure food safety and human health. Ways and strategies to reduce Cd and As in rice grains are reviewed, including:(1) Passivate Cd and As by adding biochar, iron salts and fertilizer in paddy soils, decrease their bioavailability and thus the uptake by rice; (2) Eliminate membrane lipid peroxidation stress and promote the formation of non-protein thiol in rice via external application of sulfur (S), fix Cd in vacuoles of rice tissues and reduce its transport to grains, thus reduce Cd accumulation in grains; (3) External application of silicon (Si) to compete with arsenite (As3+) for rice uptake of As; (4) Manipulate redox state in rhizosphere by changing water content in rice field, thereby affect the uptake and accumulation of Cd and As in rice. Root oxygen secretion can promote the formation of iron film on rice root surface, facilitate As oxidation into arsenate (As5+) by changing soil redox state, thereby enhance the adsorption and fixation of As5+ on root surface to reduce its uptake by rice; (5) Regulate the expression of transporters, i. e., knock out Mn transporter[STBX]OsNRAMP5 or stem/leaf cytoplasmic transporter OsLCT1, silence Si efflux transporter Lsi2, and overexpress OsHMA3n, OsHMA2, and ScAcr3p[STBZ] transporters can reduce Cd and As accumulation in rice grains by promoting root As3+ efflux and reducing Cd/As3+ translocation to xylem and grain; (6) Screen and cultivate low Cd/As accumulation species. Through the combination of agronomic measures, genetic engineering, and germplasm resource screening, rice species with low Cd/As accumulation and high yield can be selected. Besides, reasonable planning of planting patterns can help to decrease Cd/As uptake and accumulation in rice. The information provide supports for safe production of rice in slight-moderate contaminated soils.
Multi-scale Measurement of Trade-offs and Synergies of Ecosystem Services in the Taolai River Basin
ZHAO Ting, PAN Jing-hu
2022, 38(7):  839-850.  doi:10.19741/j.issn.1673-4831.2021.0703
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The ecological environment of arid inland river basins is extremely sensitive and delicate. Clarifying the relationships between different ecosystem services in inland river basins from various spatial scales can offer scientific references for ecological restoration and socio-economic sustainable development of river basins. Considering the Taolai River basin as an example, seven typical ecosystem services, including climate regulation services, biodiversity maintenance services, soil conservation services, water resource supply services, availability of aesthetic landscape services, wind prevention and sand fixation services, and food supply services during 2000-2018 were analyzed. The trade-offs and synergies between watershed ecosystem services were assessed from grid-scale, watershed scale, administrative area scale, and service cluster scale, and their spatial distribution characteristics were discussed. Spatial superposition method, superposition analysis method, and Pearson correlation coefficient method as well as self-organizing feature mapping (SOFM) neural network method were employed to assess the trade-offs and synergies between watershed ecosystem services from grid-scale, watershed scale, and administrative district scale, and service cluster scale. Furthermore, their spatial distribution characteristics were explored. The following are the conclusions of this study. (1) On grid-scale, the ecosystem services of most grid units in the research area switched from synergies to trade-off relationships from 2000 to 2018. (2) At the watershed scale, the relationships among the seven ecosystem services are primarily synergistic, whereas the relationship between soil conservation system service, and both the water resource supply service, and the wind prevention and sand fixation service are primarily trade-offs. (3) At the administrative district scale, the ecosystem services of the counties and districts primarily had various degrees of synergies. The highest synergistic relationship was found between climate regulation service and food supply service. (4) At the service cluster scale, the supply capacity of the seven ecosystem services had been substantially improved. The relationships among most of the ecosystem services in the cluster switched from trade-offs to synergies. This study can offer a scientific foundation for decision-makers to develop suitable ecological-economic coordinated development techniques at various spatial scales.
Simulation and Optimization of Spatial Land Use of Tropical Forest Ecological Protection in Southern Border of Yunnan Based on “Wild Wisdom”
2022, 38(7):  851-859.  doi:10.19741/j.issn.1673-4831.2021.0516
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The tropical forest in the southern border of Yunnan Province is identified as a hotspot of ecological diversity and an important ecological barrier. It is of great ecological significance to optimize the land use layout in such region. The thought of wilderness protection coincides with the traditional ecological wisdom philosophy conforming to nature. In this study the thought of wilderness protection and traditional ecological wisdom were combined into proposing the concept of "wilderness wisdom", and to construct the optimization model of land use under wilderness protection. To archieve this goal, GeoSOS (geographical simulation and optimization systems)-FLUS model was used. A variety of development driving factors were set as the constraints of human expansion, and the degree of wilderness was taken as the constraint variable. Multi-scenario simulation of land use change in tropical forest region in the southern border of Yunnan Province was carried out and compared, followed by an analysis of the difference of artificial space expansion between inertia mode and wilderness protection mode. The optimal layout plan that coordinates the artificial space and wilderness space was then put forward. The results show that the spatial layout based on the integrated development inertia and wilderness protection could better meet the needs of ecological space protection than the one from the development inertia alone. The proposed framework of artificial space and wilderness space can provide quantitative decision support for the optimization of land use planning and layout in similar regions, and provide a new perspective for the study of ecological wisdom.
Remote Sensing Evaluation and Influence Factor Analysis of Ecological Environment Quality in the Fenghe River Watershed
FENG Rong-rong, ZHANG Kai-li, HAN Jia-ning, LI Ying-hui, LIU Qi-qi, LIU Kang
2022, 38(7):  860-871.  doi:10.19741/j.issn.1673-4831.2022.0043
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It is essential to accurately assess the quality of ecological environment through remote sensing data, which is of great importance to decision-making guidance for regional ecological environmental protection and sustainable development. Taking the Fenghe River watershed as the research object, the indicators of greenness, humidity, dryness, and heat were extracted from the Landsat remote sensing images and coupled into the remote sensing ecological index (RSEI) to analyze the spatio-temporal variation characteristics of the ecological environment in the Fenghe River watershed over the past 20 years. Then, the spatial clustering distribution pattern of the ecological environment quality in the study area was analyzed through spatial autocorrelation analysis. At the same time, geographic detector was used to explore the dominant and interactive factors affecting the regional ecological environment. The results show the following, (1) The mean RSEI values of the Fenghe River watershed in 2001, 2005, 2011, 2015, and 2021 were 0.543, 0.600, 0.634, 0.668, and 0.649, respectively, indicating that the ecological environment in the study area improved during 2001-2015 and slightly degraded during 2015-2021. (2) The value of global Moran's I ranged from 0.767 to 0.887, showing that the spatial distribution of the ecological environmental quality in the Fenghe River watershed had a significant positive correlation. In addition, the high-high value (H-H) agglomerations were distributed in the southern part of the study area such as Luanzhen subdistrict, while the low-low value (L-L) agglomerations were mainly distributed in Wangsi subdistrict and other northern areas with high urbanization levels. Over the past 20 years, the area of the L-L agglomerations decreased obviously at first and then increased slightly. (3) The ecological environment quality of the Fenghe River watershed was not the result of the action of a single factor, but the result of enhancement after the interaction of multiple factors. For enample, the synergistic effect was significantly strengthened after the dryness indicator interacted with other factors in 2015, suggesting that the bare soil and building area had the greatest impact on the ecological environment in the Fenghe River watershed. In future development, land-use should be rationally planned to realize the coordinated development of the river watershed economy and the natural environment in the Fenghe River watershed.
The Influence of Heat Island Effect on Vegetation Phenology in Major Urban Clusters in the Tianshan Northslope Economic Belt of Xinjiang
2022, 38(7):  872-881.  doi:10.19741/j.issn.1673-4831.2021.0675
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With the accelerating of urbanization, the impact of urban heat island effect on vegetation phenology is receiving more attention. MODIS data and products (MOD11A2, MCD12Q2, MOD13Q1) were used in combination with other related data to analyze the urban heat island effect and spatial and temporal distribution characteristics of vegetation phenology in the Urumqi-Changji, Shihezi-Manas, and Wusu-Kramay-Kuidun regions. In addition, the major urban clusters of the Tianshan Northslope Economic Belt and the relationship between them were analyzed. The results of the study show that the urban heat island intensity (UHII) was most pronounced in the Urumqi-Changji region among the three major urban agglomerations, with a range of 0.39-2.49℃. The overall performance show that the heat island intensity at night was higher than that during the day. The vegetation phenology distribution along the urban-rural gradient direction showed obvious differences. Start of growing season (SOS) was earlier, end of growing season (EOS) was later, and the vegetation growth season (GSL) was longer in urban than in suburban and rural areas. Among them, the vegetation in the Urumqi-Changji region had the earliest SOS, the latest EOS, and the longest GSL. The vegetation distribution phenology along the urban-rural gradient was significantly correlated with UHII, which showed a significant negative correlation with △SOS and a high positive correlation with △EOS and △GSL. The effect of UHII on vegetation phenology was more obvious at night. The results of this study are helpful in understanding the influence of vegetation phenology on urban heat island effect along the urban-rural gradient in the Tianshan Northslope Economic Belt and can also provide a theoretical basis and reference for improving the ecological environment of urban clusters in this economic zone.
Spatial Distribution and Environmental Interpretation of Casuarina equisetifolia Communities on Nanji Island
KONG Jing, JI Xin-yue, WANG Peng-cheng, YANG Guo-dong, YU Yuan-chun
2022, 38(7):  882-889.  doi:10.19741/j.issn.1673-4831.2021.0603
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Casuarina equisetifolia is one of the main protective species in Nanji Island, this study aims to prove the planning for the construction of the shelter forest in Nanji Island and understand the impact of different environmental factors on the Casuarina equisetifolia community. Methods:24 community quadrats were established. Multivariate regression trees(MRT) and self-organizing feature mapping(SOM) were used in this study to classify the surviving communities of Casuarina equisetifolia. Results show that:(1) The 24 selected quadrats could be divided into 4 community groups associations and the results obtained using various research methodologies were highly consistent. (2) The relationship between the survival condition of Casuarina equisetifolia and water content and the organic matter in the soil indicates that being one of the windbreak plants, Casuarina equisetifolia plays an important role in the conservation of soil and water, wind prevention and sand fixation, as well as the improvement of the soil structure. (3) The combination of SOM and MRT can be used as a comprehensive analytical method in future researches on the relationship between plant species and environmental factors.
Camera-trapping Survey of the Diversity of Mammals and Birds in Qiyunshan National Nature Reserve
QIAN Lei, LI Yan-kuo, LI Jia-qi, WAN Ya-qiong, LUO Hui-tan, WU Zhi-ming, LU Jian, WANG Zhen-yu, DING Hong-xiu, ZHONG Yi-feng, SHAO Rui-qing, SHEN Jin, TA Qi, LI An-mei
2022, 38(7):  890-896.  doi:10.19741/j.issn.1673-4831.2021.0459
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To further understand the biodiversity status of the Qiyunshan National Nature Reserve in Jiangxi Province, the diversity of mammal and bird species was investigated by using camera-trapping technology from February 2017 to November 2019. The reserve and surrounding region were divided into 1 km×1 km grids using a Geographic Information System (GIS). Sixty grids were selected as monitoring plots, with one camera per grid. In the survey area, the cameras operated for 29 809 working days. 16 wild mammal species belonging to 11 families and 4 orders, and 49 wild bird species belonging to 19 families 9 orders were identified in 8 167 independent photos. Among the detected species, 2 were listed as first-class Nationally Protected Wildlife, and 13 as second-class. Three species were identified to be Vulnerable (VU), and two as Near Threatened (NT) under the IUCN Red List criterion. The 5 mammal species ranked most common by the relative abundance index (RAI) were Muntiacus reevesi, Melogale moschata, Dremomys pyrrhomerus, Sus scrofa and Paguma larvata. Further, the 5 bird species ranked most common were Lophura nycthemera, Myophonus caeruleus, Bambusicola thoracicus, Erythrogenys swinhoei and Garrulax pectoralis. 11 species, including Dremomys pyrrhomerus, Chalcophaps indica, and Hierococcyx varius, etc. were first recorded for the Qiyunshan National Nature Reserve. These species were mainly distributed within the altitudes of >700-1 000 and >1 000-1 300 m (48 and 48 species, respectively). Species were most abundant in evergreen broad-leaved forest, and deciduous broad-leaved forest (55 and 49 species, respectively). The results of this survey has enhanced the baseline data for wildlife resources in the Qiyunshan National Nature Reserve, laying foundation for further research and protection management.
A Study on Habitat Suitability and Ecological Threshold of Waterbird Guilds in Yancheng Coastal Wetlands:Implications for Habitat Structure Restoration
WANG Cheng, LIU Hong-yu, LI Yu-feng, WANG Gang, DONG Bin, CHEN Hao, ZHANG Ya-nan, ZHAO Yong-qiang
2022, 38(7):  897-908.  doi:10.19741/j.issn.1673-4831.2021.0370
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Yancheng coastal wetland is a new world natural heritage site, which mainly focuses on waterbird habitat conservation. The current status and potential problems of waterbird habitat conservation have attracted much attention from scholars. In this study, five major waterbirds habitat sites in Yancheng coastal wetland were selected. Based on the data of three waterbirds guilds, environmental variables and habitat types obtained from field survey, GIS technology, random forest (RF) and threshold indicator taxa analysis (TITAN) were used to identify the suitable habitat of the three guilds and analyze the response threshold of environmental variables. The results show that the shorebirds were mainly distributed in eastern edge of Tiaozini habitat site and Core habitat site, anatidae was mainly distributed in farmland and reed marshes of Tiaozini and Core area, and herons were mainly distributed in aquaculture ponds and reed marshes of each habitat site. The area proportion of suitable areas of antidae in the five habitat sites was smaller than that of shorebirds and herons. T_hab, D_wat, P_fvc, D_ree, D_swa and D_far were the main environmental variables affecting the distribution of the three guilds in suitable areas, covering environmental indicators, such as habitat type, vegetation coverage and distance indicators. There were differences in the number of species in the positive and negative response thresholds of the main environmental variables in three guilds, and the response thresholds of the waterbird guilds to the environmental variables were also different. Finally, some suggestions and schemes for waterbirds diversity maintenance and habitat landscape structure restoration in Yancheng coastal wetland were proposed.
Diversity and Distribution of Birds in Zhaojue County, Sichuan Province
WANG Yan, CHENG Yu-wen, DONG Zhe-han, ZHANG Shang-ming-yu, HE Xing-cheng, ZHONG Yu-hua, WU Yong-jie
2022, 38(7):  909-914.  doi:10.19741/j.issn.1673-4831.2021.0457
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In January, May, August and October of 2020, a field survey of bird diversity in Zhaojue County was conducted by using the fixed transect line method. A total of 107 species of birds from 38 families, 11 orders were recorded in Zhaojue County. There are 69 species of Oriental origin, 28 species of Palearctic origin and 10 species are widespread. The birds include 76 residential species, 24 summer visitor species, 3 winter visitor species and 4 passage migrants. There are 6 Class-2 nationally protected birds distributed in this region. Four species belong to CITES appendix Ⅱ and four species are endemic to China. Based on the result of seasonal analysis, it was found that the bird species richness was the highest in summer, the abundance of bird species was the highest in autumn, and species richness and abundance were the lowest in winter. There were obvious dominant species in each season and the dominant species in summer is the most similar to autumn. Among the 9 habitats in this region, birds in the coniferous forest had the highest species diversity, and birds in the bush had the most abundance. There were dominant species in all habitats except for coniferous forest. Coniferous forest and evergreen broad-leaved forest have the highest similarity of birds. The elevational pattern of species richness indicate that the peak of bird species richness and abundance appeared at the elevations of 2 100-2 400 m, and the minimum species richness appeared at the elevations of 3 300-3 600 m. The species at 2 100-2 400 m are most similar to those at 2 400-2 700 m. This study firstly reports on the bird resources in Zhaojue County and provides primary bird diversity data for the Liangshan Mountains, which will be helpful for the protection of bird diversity in this area.
Characteristics of Microbial Structure of Typical Plant Communities in South Dongting Lake Poplar Clearing Area
DENG Nan, TIAN Yu-xin, SONG Qing-an, TIAN Fei, MA Feng-feng, LUO Xue-wei, LI De-xian, YAN Jing-fen
2022, 38(7):  915-924.  doi:10.19741/j.issn.1673-4831.2021.0488
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As one of the most important lake wetland ecosystems in China, Dongting Lake plays a key role in maintaining regional ecological security. Due to the early economic development and other factors, large-scale planting of poplar has posed a serious threat to the biodiversity protection and wetland ecosystem security of Dongting Lake area. Therefore, ecological restoration project has been carried out to resolve this problem. In this research, the phyllosphere microorganism from five primary and natural regeneration plant communities in South Dongting Lake restoration area were analysed by using Illumina HiSeq sequencing platform. The results show that the Shannon index and β diversity of poplar bacteria community was higher than others, but the α and β diversity of poplar fungus community was lower than some herbaceous communities. Poplar had the most specific bacterial species and the native Phragmites communis community had the most specific fungal species. Gammaproteobacteria, Bacilli and Erysipelotrichia were the most abundant bacteria in all plant communities. Dothideomycetes and Sordariomycetes were the most abundant fungi in all plant communities. This study has explored the differences of microbial community structure in the main plant communities after ecological restoration in South Dongting Lake area, and provides theoretical support for ecological restoration of poplar clearing slashes in Dongting Lake area.
Identification of Influencing Factors of Nitrogen and Phosphorus Removal from Aquaculture Wastewater by Constructed Wetlands
LI Fei-xiang, YUE Chen, ZHANG Chao-yue, ZHANG Rui-rui, YANG Li-yang, MU Jing-li, HUANG Ya-ling
2022, 38(7):  925-932.  doi:10.19741/j.issn.1673-4831.2021.0640
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This study investigated various factors affecting the removal of nitrogen and phosphorus from aquaculture wastewater. Specifically, how hydraulic retention time (HRT), herbaceous halophyte(Sesuvium portulacastrum), biomass carbon, water flow pattern, seasonal and environmental factors affecting the removal of total phosphorus (TP), total nitrogen (TN), and ammonia nitrogen (NH4+-N) in 12 constructed wetland systems. The results show that by setting up the HRT in the range of 0 to 3 days, the removal rates of nitrogen and phosphorus increased with the increase of HRT, meanwhile the conductivity and pH of effluent increased gradually. When the HRT was 3 days, S. portulacastrum plants could improve the removal rates of TN, TP, and NH4+-N to a certain extent. Adding biomass carbon into zeolite-based system could significantly improve the removal rates of TN and NH4+-N, however, the biomass carbon played a negative role in the removal of TP in the system. Among the four water flow patterns used in this study, the upward vertical-flow wetland systems resulted in the best removal rates of nitrogen and phosphorus. Conductivity, dissolved oxygen, and pH were significantly and positively correlated with the removal rate of TN and TP, while pH was significantly and positively correlated with the removal of NH4+-N. The removal efficiencies of TN and TP were the highest in summer, and the efficiency for removal of NH4+-N was the highest in spring. The water temperature was positively correlated with the removal of TN, TP and NH4+-N.
Dynamic Non-target Analysis and Occurrence of Herbicides Residues in Rice-crayfish and Rice-crab Co-culture Systems in Jiangsu Province
LIU Chong-wan, ZHU Xiao-hua, XU Zhi-hua, REN Di, MENG Yong, LIU Yi, TANG Jian-qing
2022, 38(7):  933-943.  doi:10.19741/j.issn.1673-4831.2021.0749
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To evaluate the herbicides residues in rice-crayfish and rice-crab systems in Jiangsu Province, 3 typical breeding bases were selected in these two systems. The dynamic non-target analysis was performed and the occurrence of herbicides residues was tested in biological samples (crayfish and crab) and the environmental samples (field water and field sediment) with ultra-high performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry (UPLC-Q-TOF MS) during the culture cycle. Accurate screening and ecological risk assessment of 21 herbicides were conducted through a quantitative analysis with high detection frequency and exposure risk. The results show that 12 and 11 herbicides were detected in the rice-crayfish and rice-crab system, respectively with monuron and cyanazine both detected in the two systems. The main residual herbicides in the rice-crayfish system were quinmerac[the frequency deducted was all relatively high in the crayfish, field water and field sediment samples, with the highest value reached to (12.1±0.17) μg·kg-1, (22.5±2.47) μg·L-1 and (21.6±1.91) μg·kg-1, respectively], diuron[the highest value reached to (11.5±1.10) μg·kg-1, (16.7±1.65) μg·L-1 and (19.7±0.97) μg·kg-1, respectively], cyanazine[the highest values reached to (11.2±0.36) μg·kg-1,(22.5±3.01) μg·L-1 and (29.5±3.20) μg·kg-1, respectively], chlorotoluron[the frequency of detection was only relatively high in the field sediment samples and the highest value reached to (20.1±2.99) μg·kg-1] and nicosulfur[the highest value reached to (15.8±1.05) μg·kg-1]. The main residual herbicides in the rice-crab system were benzeneacetamide[the frequency of detection was only relatively high in the field sediment samples and the highest value reached to (20.2±2.05) μg·kg-1], thiobencarb[the frequency of detection were all relatively high in the field water and field sediment samples and the highest values reached to (11.2±1.01) μg·L-1 and (20.1±3.28) μg·kg-1, respectively], bensulfuron methyl[the highest value reached to (26.4±3.17) μg·kg-1], monuron[the highest values reached to (11.7±2.03) μg·L-1 and (20.1±2.64) μg·kg-1, respectively], 2,4-D-butyl ester[the highest value reached to (19.5±2.43) μg·kg-1] and atrazine[as with the benzeneacetamide and the highest value reached to (24.7±1.98) μg·kg-1]. Herbicide residues were mainly detected in environmental samples, especially in field sediment, less in crayfish and crab, and the residues were mainly concentrated in the early stage of aquaculture, and the frequency and value were controllable during the harvest time. The results of this study show that the comprehensive ecological risk of herbicides in crayfish and crab was at medium level, while the risk of field water and field sediment were both at high level, in particular, 10 of the 11 herbicides detected in field sediment were in high risk. In this study, it was evident that the herbicides pollution in rice-crayfish and rice-crab systems in Jiangsu Province were in the order of field sediment > field water > aquatic product (crayfish and crab). The results indicate that herbicide residues in field sediment have a potential risk to the aquatic environment, and the risk of herbicide residues pollution to aquatic product (crayfish and crab) is at controllable level during the harvest period.
Effect of Hyperthermophilic Pretreatment on Water Distribution and the Subsequent Composting Decomposition of Livestock and Poultry Manure
HUANG Ying, CHEN Yue-hong, LIN Jiu-jun, HUANG Hong-ying, CHANG Zhi-zhou, XU Yue-ding, CAO Yun
2022, 38(7):  944-952.  doi:10.19741/j.issn.1673-4831.2021.0302
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In order to explore the relationship between the water characteristics of livestock manure after hyperthermophlic pretreatment and the subsequent composting ripening cycle, the water characteristics of chicken manure and pig manure were determined by using the drying method, and the dehydration rate and the maturity period were also detected. The following four treatments were conducted:traditional composting (CK); hyperthermophilic pretreatment composting (HPC) with pretreatment time of 2, 4 and 6 h, respectively. Results show that after hyperthermophilic pretreatment, the content of bound water (capillary water + adsorbed water + internal bound water) in pig manure and chicken manure was significantly lower than that in the control (P<0.05). Among them, the proportion of capillary water in the pig manure and chicken manure after high temperature pretreatment for 4 h was 72.0% and 68.0%, respectively, significantly higher than that of the control, while the proportion of adsorbed water in the pig manure and chicken manure was 25.9% and 30.9% respectively, significantly (P<0.05) lower than that of the control. Compared with the control, the hyperthermophilic pretreatment for 4 h can make the subsequent composting process heat up in advance, increase the temperature and prolong the high temperature period, eventually the seed germination index reached to 80.1%. In addition, the dehydration rate of pig manure and chicken manure after hyperthermophilic pretreatment was significantly higher than that of the control (P<0.05) in the subsequent composting process. And, the correlation analysis show that there was a significant (P<0.01) positive correlation between dehydration rate and seed germination index. Therefore, the hyperthermophilic pretreatment changes the water distribution of livestock and poultry manure and promotes the transformation of water in the form of high binding energy to low binding energy, which helps to promote the dehydration efficiency of subsequent composting process. To some extent, it is beneficial to shorten the decomposition time and reduce the cost of composting, and provide new methods and ideas for future research on dehydration technology of livestock and poultry manure.