As a kind of biological fertilizer sources, green manure can improve soil fertility and the quality of agricultural products. This paper introduced the germplasm resource of green manures in the major provinces in Chi...As a kind of biological fertilizer sources, green manure can improve soil fertility and the quality of agricultural products. This paper introduced the germplasm resource of green manures in the major provinces in China, mainly summarized the characteristics of decomposition and nutrients release of returning green manures to soils, as well as the influence on soil fertility and succeeding crops, with the aim to provide references for rational utilization of green manures and the scientific management of farmland nutrients.展开更多
This study was intended to estimate production of major livestock and poultry manure and contaminant content,and find out current situation of manure pollution,so as to provide reference for pollution control of lives...This study was intended to estimate production of major livestock and poultry manure and contaminant content,and find out current situation of manure pollution,so as to provide reference for pollution control of livestock and poultry breeding industry in Guangxi.Based on the related statistic data in 2010 and the excretion coefficient of different livestock and poultry,the manure and its contaminant production amount of main livestock and poultry in Guangxi were estimated.Then the annual livestock and poultry manure load of farmland and the loss of contaminant were also calculated to analyze the ecological pressure resulted from livestock and poultry breeding in Guangxi.Following results were obtained:in 2010,the production amount of the livestock and poultry manure in Guangxi was 9141.30×104tons,including nutrient TN42.07×104tons and TP 13.62×104tons;the annual livestock and poultry manure and N,P pure nutrient load of farmland was 21t/hm2,98kg/hm2,and 32 kg/hm2respectively;the production amount of manure contaminants was BOD5383.43×104tons,COD Cr435.42×104tons,and NH3-N 42.08×104tons;according to 30%loss rate,the loss amount of COD Cr and NH3-N was higher than the sum of industrial and life waste water.It was concluded that the livestock and poultry breeding industry had little impact on soil environment,but posed a grave threat to water environment.展开更多
Inland culture of shrimp integrated with irrigation could be one of the most feasible livelihood options for many households nearby saline land.Compared with seawater and most of reported brackish water used for shrim...Inland culture of shrimp integrated with irrigation could be one of the most feasible livelihood options for many households nearby saline land.Compared with seawater and most of reported brackish water used for shrimp culture,the sulfate content was higher in both surface and ground water in the central Asia.We evaluated the effects of salinity,the SO_(4)^(2-)/Cl^(-)ratio and their interaction on the growth,oxygen consumption,Na+/K+-ATPase activity,total antioxidant capacity(T-AOC),and hepatopancreas histology of Litopenaeus vannamei reared in artificial seawater.The experiment lasted for 30 d,two salinity levels(20 and 10)and four SO_(4)^(2-)/Cl^(-)ratios(0.14,0.577,1.127,and 2.225 mg/mg)of waters were set.Results show no significant differences in survival among groups.Salinity and its interaction effects with SO_(4)^(2-)/Cl^(-)ratio did not significantly affect the final body weight,weight gain,and specific growth rate of shrimps,whereas the SO_(4)^(2-)/Cl^(-)ratio did(P<0.05).Shrimp mean weight gain and specific growth rate at water SO_(4)^(2-)/Cl^(-)ratio of 2.225 were significantly lower than at ratio of 0.14.At salinity 20,the shrimp final body weight at water SO_(4)^(2-)/Cl^(-)ratio of 2.225 was significantly lower than at other ratios(P<0.05),whereas there was no significant difference in final body weight among treatments at salinity 10(P>0.05).Oxygen consumption,Na^(+)/K^(+)-ATPase activity,and T-AOC increased with increasing SO_(4)^(2-)/Cl^(-)ratio at both salinities.L.vannamei exposed to water SO_(4)^(2-)/Cl^(-)ratio of 2.225 at salinity 20 showed severe histopathological changes.This study indicated that L.vannamei has strong tolerance to sulfate in brackish water environment.The shrimp is more adaptable to SO_(4)^(2-)/Cl^(-)ratios below 2.225 at lower salinity,and the optimal SO_(4)^(2-)/Cl^(-)range for the growth is 0.14–0.577(mg/mg)regardless of salinity level.展开更多
Marine biological activity has long been recognized to impact the atmospheric chemistry of coastal areas.In this work,we monitored the seasonal variation of carbonyl compounds in the coastal city of Qingdao,located in...Marine biological activity has long been recognized to impact the atmospheric chemistry of coastal areas.In this work,we monitored the seasonal variation of carbonyl compounds in the coastal city of Qingdao,located in the north of China’s coastline and the south of Jiaodong Peninsula,with the vast hinterland in the west.The mean total concentration of the 15 carbonyls varied significantly between seasons,with the highest observed in autumn(10.2±6.2 ppbv),followed by spring(9.0±3.0 ppbv),winter(6.4±4.0 ppbv)and summer(3.4±1.4 ppbv).Using bivariate analysis,the agricultural emissions from inland areas were responsible for the high levels of carbonyls in the autumn.In summer,clean and humid sea winds helped reduce the concentration of carbonyls,but they also brought air masses from vegetation,and marine organisms,which contributed to high levels of carbonyls in the spring of coastal areas.The observation-based chemistry box model found that the forma-tion of formaldehyde and acetaldehyde was primarily controlled by the RO+O2 reaction,and alkenes oxidation was the main contributing factor.Based on the OH radical loss rate(LOH)and ozone formation potential(OFP)calculation,we found that autumn and spring seasons have significantly higher values of LOH and OFP than winter and summer due to the presence of high concentrations of carbonyl compounds.Therefore,it is believed that these carbonyl compounds primarily originate from agricultural activities,and marine air influences the atmospheric chemistry of the coastal areas.展开更多
With weathering crust Ion-Absorbed Type Rare Earth （IATRE） ores in southern Jiangxi as an example, rare earth percolation leaching and leaching solution precipitation process research were carried out under conditio...With weathering crust Ion-Absorbed Type Rare Earth （IATRE） ores in southern Jiangxi as an example, rare earth percolation leaching and leaching solution precipitation process research were carried out under conditions of magnetic field. The effect on the rare earth leaching process such as magnetic field strength, magnetization time, magnetization manner, and other factors were discussed. The effect on the mother rare earth liquor sedimentation rate, purity, and crystallization behavior such as magnetic field strength, magnetization time, and magnetization manner were investigated. Leaching and precipitation mechanism of magnetization on IATRE were analyzed. The results showed that the magnetic treatment can improve leaching rate of weathering crust IATRE and the sedimentation rate, and reduce consumption of reagents.展开更多
Phytoremediation technology is a newly-developed way of soil heavy metal pollution repair with high efficiency and good ecological comprehensive benefit. This paper briefly introduces the soil heavy metal pollution st...Phytoremediation technology is a newly-developed way of soil heavy metal pollution repair with high efficiency and good ecological comprehensive benefit. This paper briefly introduces the soil heavy metal pollution status at home and abroad,and focuses on the analysis of harm,sources and current situation of soil heavy metal pollution at home and abroad as well as mechanism and application of phytoremediation.Finally it discusses the key problems in phytoremediation technology that need to resolve in the future.展开更多
The distribution of hexachloroeyclohexanes （HCHs） and dichlorodiphenyltrichloroethanes （DDTs） in the surface sea- water and sediment of Jincheng Bay mariculture area were investigated in the present study. The con...The distribution of hexachloroeyclohexanes （HCHs） and dichlorodiphenyltrichloroethanes （DDTs） in the surface sea- water and sediment of Jincheng Bay mariculture area were investigated in the present study. The concentration of total HCHs and DDTs ranged from 2.98 to 14.87ngL-l and were〈0.032ngL-1, respectively, in surface seawater, and ranged from 5.52 to 9.43 and from 4.11 to 6.72 ng g-l, respectively, in surface sediment. It was deduced from the composition profile of HCH isomers and DDT congeners that HCH residues derived from a mixture of technical-grade HCH and lindane whereas the DDT residues derived from technical-grade DDT and dicofol. Moreover, both HCH and DDT residues may mainly originate from historical inputs. The hazard quotient of α-HCH, β-HCH, γ-HCH and δ-HCH to marine species was 0.030, 0.157, 3.008 and 0.008, respectively. It was estimated that the overall probability of adverse biological effect from HCHs was less than 5%, indicating that its risk to seawater column spe- cies was low. The threshold effect concentration exceeding frequency of γ-HCH, p,p＇-DDD, p,p＇-DDE and p,p＇-DDT in sediment ranged from 8.3% to 100%, and the relative concentration of the HCH and DDT mixture exceeded their probable effect level in sediment. These findings indicated that the risk to marine benthos was high and potentially detrimental to the safety of aquatic prod- ucts, e.g., sea cucumber and benthic shellfish.展开更多
Bio-embankment is an important soil and water conservation measure in the purple hilly area in China,which can effectively improve the ability of cultivated soil layers to resist rainfall erosion and runoff scour.In c...Bio-embankment is an important soil and water conservation measure in the purple hilly area in China,which can effectively improve the ability of cultivated soil layers to resist rainfall erosion and runoff scour.In contrast,the ecological effect of bioembankment depends on the stability of the earth bank.Taking the natural grass bank as a control(CK),the root distribution,root tensile properties and shear resistance of root-soil composites for 3 typical soil and water conservation bio-embankments,namely,Morus alba Linn(Morns),Zanthoxylum bungeanum Maxim(Zanthoxylum)and Medicago sativa(Medicago)were analysed.The results included the following:(1)The root system of the bio-embankments generally decreased in extent with the soil depth;fine roots in the o-io cm depth were most prevalent and significantly higher than those at the other depths,and coarse roots were mainly distributed in the o-30cm layer.(2)The stress-strain curves of the roots of each bio-embankment were single-peak curves without clear strain softening phenomena.The smaller the root diameters were,the smoother the stress-strain curves,and the lower the capability of the earth bank to resist collapse.The larger the root diameters were,the lower the tensile strength.The average root tensile force was highest for Zanthoxylum(73.91 N),followed by Medicago(68.07N)and Morus(61.88 N),and the average root tensile strength showed the same trend,16.52 MPa for Zanthoxylum,16.08 MPa for Medicago and 13.02MPa for Morus.(3)The bio-embankment measures significantly improved the soil shear resistance,especially under vertical loads of 1oo kPa and 200kPa.The soil internal friction angle showed a significant log-positive correlation with root morphological parameters of root length density(RLD),root surface area density(RSAD) and rootweight density(RWD),while the soil cohesion force showed a positive linear correlation with these parameters.The results provide effective parameters supporting for the design of bio-embankments and promoting the use of soil reinforcement with suitable species selection in protective earth banks for stability in the purple hilly area.展开更多
The feasibility of using ultrasound to enhance the performance of de-sulphurization and de-ashing during slime flotation was investigated. The Setararn C80 calorimeter, the contact angle gauge DCAT21 and an electropho...The feasibility of using ultrasound to enhance the performance of de-sulphurization and de-ashing during slime flotation was investigated. The Setararn C80 calorimeter, the contact angle gauge DCAT21 and an electrophoresis apparatus were used to study the surface nature of coal, pyrite and refuse before and after ultrasonic conditioning. The yield, ash and sulfur contents of equally sized coal slimes were also measured before and after ultrasonic conditioning. The results show that ultrasonic conditioning can drive the separation of pyrite and refuse from coal. After ultrasonic conditioning the hydrophobicity of coal and hydrophilicity of pyrite and refuse increase. The perfect index of flotation, the perfect index of de-sulphurization and the percentage of de-sulphurization increase by 22.51%, 25.36% and 2.49%, respectively. This study shows that ultrasonic conditioning can enhance the performance of de-sulphurization and de-ashing of coal flotation methods.展开更多
The Qaidam Basin, located in the northern margin of the Qinghai-Tibet Plateau, is a large Mesozoic-Cenozoic basin, and bears huge thick Cenozoic strata. The geologic events of the Indian- Eurasian plate-plate collisio...The Qaidam Basin, located in the northern margin of the Qinghai-Tibet Plateau, is a large Mesozoic-Cenozoic basin, and bears huge thick Cenozoic strata. The geologic events of the Indian- Eurasian plate-plate collision since -55 Ma have been well recorded. Based on the latest progress in high-resolution stratigraphy, a technique of balanced section was applied to six pieces of northeast- southwest geologic seismic profiles in the central and eastern of the Qaidam Basin to reconstruct the crustal shortening deformation history during the Cenozoic collision. The results show that the Qaidam Basin began to shorten deformation nearly synchronous to the early collision, manifesting as a weak compression, the deformation increased significantly during the Middle and Late Eocene, and then weakened slightly and began to accelerate rapidly since the Late Miocene, especially since the Quaternary, reflecting this powerful compressional deformation and rapid uplift of the northern Tibetan Plateau around the Qaidam Basin.展开更多
Polycyclic aromatic hydrocarbons(PAHs),as persistent toxic substances(PTS),have been widely monitored in coastal environment,including seawater and sediment.However,scientific monitoring methods,like ecological risk a...Polycyclic aromatic hydrocarbons(PAHs),as persistent toxic substances(PTS),have been widely monitored in coastal environment,including seawater and sediment.However,scientific monitoring methods,like ecological risk assessment and integrated biomarker response,still need massive researches to verify their availabilities.This study was performed in March,May,August and October of 2018 at eight sites,Yellow River estuary(S1),Guangli Port(S2),Xiaying(S3),Laizhou(S4),Inner Bay(S5),Outer Bay(S6),Hongdao(S7)and Hongshiya(S8)of Shandong Peninsula,China.The contents of 16 priority PAHs in local seawater and sediment were determined,by which ecological risk assessment risk quotient(RQ)for seawater and sediment quality guidelines(SQGs)were calculated to characterize the PAHs pollution.Meanwhile,multiple biomarkers in the digestive gland of clam Ruditapes philippinarum were measured to represent different biological endpoints,including ethoxyresorufin-O-deethylase(EROD),glutathione S-transferase(GST),sulfotransferase(SULT),superoxide dismutase(SOD)and lipid peroxidation(LPO),by which integrated biomarker response(IBR)was calculated to provide a comprehensive assessment of environmental quality.Taken together,these results revealed the heaviest pollution at S2 as both PAHs concentrations and biomarkers responses reflected,and supported the integrated biomarker response as a useful tool for marine environmental monitoring,through its integration with SQGs.展开更多
The fly ash from Jixi power plant was treated with various surface modifiers. The surface properties of the modified fly ash,including active index wetting angle,were measured in this paper. The modified fly ash was f...The fly ash from Jixi power plant was treated with various surface modifiers. The surface properties of the modified fly ash,including active index wetting angle,were measured in this paper. The modified fly ash was filled into rubber to improve the rubber properties. The results of rubber tests indicate that the type of the surface modifiers has a great influence on the rubber reinforcing properties. The fly ash modified by titanate coupling agents exhibits the best performance in respect to rubber reinforcing properties. The test results show that the fly ash can take place of some decomposition material so that the dosage of decomposition in rubber can be reduced,resulting in the low producing cost of rubber and the low pollution of fly ash.展开更多
Study on morphological changes of a bay can help to identify the effects of anthropogenic activities on coastal environ-ment and guide the exploration of marine resources.In this paper,morphological data including coa...Study on morphological changes of a bay can help to identify the effects of anthropogenic activities on coastal environ-ment and guide the exploration of marine resources.In this paper,morphological data including coastline and water areas in five discrete years between 1968 and 2015 were selected and extracted from the remote sensing images and historical marine charts to study the morphological changes in Laizhou Bay(LZB),one of the bays in the southwest of the Bohai Sea.A systematic analysis on spatial variations of the coastline and the surface areas of different types of waters in LZB was conducted.The results showed that the surface area of LZB was decreased by 1253.2km^(2)in the last half century,which is 17.4%of the total in the 1970s.The areas of the natural wetland and the intertidal zone were decreased by 17.2%and 56.1%,respectively,and the average water depth varied from 9.05 m to 8.16m at low tide level from 1968 to 2015.The coastline and shape variations of the bay turned to be complex after the 1980s,and the shape index of LZB showed an increasing trend in more recent years.The centroid of the bay generally migrated to the northeast direction,i.e.,the direction of the center of the Bohai Sea,and the shrinking direction of the bay was consistent with the migration direction of the coastline.The reclamation area during 1968-2015 in LZB was 1201.7km^(2),and 94.1%was in the inter-tidal zone.The overall morphological change of the bay during the last half century was mainly controlled by the coastal reclamation activities,and the Yellow River runoff including the river course change and sediment load variation was also an important control-ling factor.展开更多
Semicarbazide has become an important pollutant in the environment,but there was no comprehensive literature on its advances.In this review,the source,biotoxicity and detection methods are summarized.Among the sources...Semicarbazide has become an important pollutant in the environment,but there was no comprehensive literature on its advances.In this review,the source,biotoxicity and detection methods are summarized.Among the sources is the material of chemical reaction,a metabolite of nitrofurazone,food processing(production by azobisformamide and hypochlorite treatment),endogenous substances,etc.Semicarbazide is demonstrated to be accumulative and reproductive toxicity,mutagenicity and genotoxicity,endocrine disruptors,and neurotoxicity.There are still many controversies on the effect of genotoxicity and no clear result on the carcinogenic mechanism.HPLC-MS/MS is the mainstream of the detection methods.Other methods,including HPLC,immunoassay method,biosensor method,electrochemical detection,capillary electrophoresis technique,and spectral techniques mainly,have become less and less in recent years.On all these counts,to reduce the content of semicarbazide in the environment,the key is to control the use of nitrofurazone as the banned drug effectively.Meanwhile the toxicity data should be supplemented to reveal its toxic mechanism.展开更多
Currently,sustainable agricultural development in China is facing some big challenges of how to promote the present developing pattern,to lengthen material transformation chain,to increase the utilization rate of mate...Currently,sustainable agricultural development in China is facing some big challenges of how to promote the present developing pattern,to lengthen material transformation chain,to increase the utilization rate of material and energy in agricultural system and to form a healthy agricultural ecological circulation system.China is a major country producing crops and straws.Both high-efficient utilizing pattern of straw and technological system are needed urgently.According to the field survey,we point out the status of straw utilization and the main recycling pattern in typical farming areas in Sichuan,China through the literature review and data collection.Based on the statistical analysis,the economic,environmental and social benefits of each utilization way are analyzed,and the methods and measures are proposed in order to promote recycling utilization of the straw in Sichuan farming area,and to offer theoretical guidance for energy saving,food safety,and pollution control.展开更多
The effects of putrescine on improving rice growth under aluminum(Al)toxicity conditions have been previously demonstrated,however,the underlying mechanism remains unclear.In this study,treatment with 50 pmol/L Al sig...The effects of putrescine on improving rice growth under aluminum(Al)toxicity conditions have been previously demonstrated,however,the underlying mechanism remains unclear.In this study,treatment with 50 pmol/L Al significantly decreased rice root growth and whole rice dry weight,inhibited Ca2+uptake,decreased ATP syn thesis,and in creased Al,H2O2 and malon dialdehyde(MDA)con tents,whereas the application of putrescine mitigated these negative effects.Putrescine increased root growth and total dry weight of rice,reduced total Al content,decreased H2O2 and MDA contents by increasing antioxidant enzyme(superoxide dismutase,peroxidase,catalase and glutathione S・transferase)activities,increased Ca2+uptake and energy product!oru Proteomic analyses using data-independent acquisition successfully identified 7934 proteins,and 59 representative proteins exhibiting fold-change values higher than 1.5 were randomly selected.From the results of the proteomic and biochemical analyses,we found that putrescine significantly inhibited ethylene biosynthesis and phosphorus uptake in rice roots,increased pectin methylation,decreased pectin content and apoplastic Al deposit!on in rice roots.Putrescine also alleviated Al toxicity by repairing damaged DNA and increasing the proteins involved in maintaining plasma membra ne integrity and normal cell proliferation.These fin dings improve our understanding of how putrescine affects the rice response to Al toxicity,which will facilitate further studies on environmental protection,crop safety,in novations in rice performance and real-world producti on.展开更多
The chlorophyll a(Chl a)is an important indicator of marine ecosystems.The spatiotemporal variation of the Chl a greatly aff ects the mariculture and marine ranching in coastal waters of the Shandong Peninsula.In the ...The chlorophyll a(Chl a)is an important indicator of marine ecosystems.The spatiotemporal variation of the Chl a greatly aff ects the mariculture and marine ranching in coastal waters of the Shandong Peninsula.In the current study,the climatology and seasonal variability of surface Chl-a concentration around the Shandong Peninsula are investigated based on 16 years(December 2002-November 2018)of satellite observations.The results indicate that the annual mean Chl-a concentration is greater in the Bohai Sea than in the Yellow Sea and decreases from coastal waters to off shore waters.The highest Chl-a concentrations are found in Laizhou Bay(4.2-8.0 mg/m^(3)),Haizhou Bay(4.2-5.9 mg/m^(3))and the northeast coast of the Shandong Peninsula(4.4-5.0 mg/m^(3)),resulting from the combined eff ects of the intense riverine input and long residence time caused by the concave shape of the coastline.The seasonal Chl-a concentration shows a significant spatial variation.The Chl-a concentrations in these three subregions generally exhibit an annual maximum in August/September,due to the combined eff ects of sea surface temperature,river discharge and sea surface wind.In the southeast coast region,however,the Chl-a concentration is lowest throughout the year and reaches a maximum in February with a minimum in July,forced by the seasonal evolution of the Yellow Sea Cold Water and monsoon winds.The interannual Chl-a concentration trends vary among regions and seasons.There are significant increasing trends over a large area around Haizhou Bay from winter to summer,which are mainly caused by the rising sea surface temperature and eutrophication.In other coastal areas,the Chl-a concentration shows decreasing trends,which are clearest in summer and induced by the weakening land rainfall.This study highlights the differences in the Chl-a dynamics among regions around the Shandong Peninsula and is helpful for further studies of coupled physical-ecological-human interactions at multiple scales.展开更多
1 Introduction Ostracodes are good materials for studying palaeoenvironmental evolution because of their sensitive response to environment changes.At present,the environmental implications of ostracodes are mainly based
The present trial was conducted with starry flounder Platichthys stellatus broodstock to evaluate the effects of dietary vitamin A, ascorbic acid, and a-tocopherol on the gonadal development and reproductive performan...The present trial was conducted with starry flounder Platichthys stellatus broodstock to evaluate the effects of dietary vitamin A, ascorbic acid, and a-tocopherol on the gonadal development and reproductive performance. 8 000 IU/kg diet vitaminA （VA group）, 500 mg/kg diet ascorbic acid （Vcpp group）, or 250 mg/kg diet a-tocopherol （a-TA group） was added into basal diet to create 3 vitamin experimental diets, respectively. Each diet was fed to 450 starry flounder broodstock for 104 days. Samples were collected weekly. The gonadosomatic index （GSI） of 3 vitamin experimental groups first decreased and then increased. Maximum GSI of Vcpp group was higher than that of ct-TA group but lower than that of VA group. The spawning periods of 3 vitamin experimental groups lasted 49, 56, and 45 days, respectively. No mature eggs were observed in the control group during the trial. The absolute fecundity （AF） and relative fecundity （RF） of a-TA group was higher than that of Vcpp group but lower than that of VA group. The results suggest that different vitamins play different roles in the fish reproductive process. Vitamin A stimulated the maturation of the ovary, ascorbic acid prolonged the spawning period, and a-tocopherol affected the development of the eggs.展开更多
Spartina alterniflora as an alien invasive plant,poses a serious threat to the ecological functions of the coastal wetland of the Jiaozhou Bay.As of 2019,the distribution area of S.alterniflora in the Jiaozhou Bay has...Spartina alterniflora as an alien invasive plant,poses a serious threat to the ecological functions of the coastal wetland of the Jiaozhou Bay.As of 2019,the distribution area of S.alterniflora in the Jiaozhou Bay has reached more than 500 hm^(2).For this reason,combined with field surveys,remote sensing monitoring of the invasion S.alterniflora in the Jiaozhou Bay has been carried out.To accurately identify S.alterniflora within the Jiaozhou Bay coastal wetland,we used a new method which is an implement of deep convolutional neural network,and by which we got a higher accuracy than the traditional method.Based on distribution of S.alterniflora extracted by the proposed method,the temporal and spatial distribution characteristics of S.alterniflora were analyzed.And then combined with environmental factors,the invasion mechanism of S.alterniflora in the Jiaozhou Bay was analyzed in detail.From the monitoring results,it can be seen that S.alterniflora in Jiaozhou Bay is mainly distributed in the beaches near the Yanghe River Estuary and its southern side,the Dagu River Estuary and the Nügukou.Spartina alterniflora first broke out near the Yanghe River Estuary and gradually spread to the tidal flats near the Nügukou.The Dagu River Estuary is dominated by S.anglica,whose area has not changed much over the years,and a small amount of S.alterniflora has invaded later.展开更多
基金Supported by the Natural Science Foundation of Guangxi(2017GXNSFBA198204)the Key Science and Technology Project of Guangxi(Guike AA17204059-9&AA172040459-10)+1 种基金the Planning Project for Scientific Research and Technological Development of Xixiangtang District,Nanning City(2017-2-10309)the Special Fund for the Fundamental Research of Guangxi Academy of Agricultural Sciences(Guinongke 2018YT07&2018YM28)
文摘As a kind of biological fertilizer sources, green manure can improve soil fertility and the quality of agricultural products. This paper introduced the germplasm resource of green manures in the major provinces in China, mainly summarized the characteristics of decomposition and nutrients release of returning green manures to soils, as well as the influence on soil fertility and succeeding crops, with the aim to provide references for rational utilization of green manures and the scientific management of farmland nutrients.
基金Supported by Special Basic Scientific Research Project of Guangxi Academy of Agricultural Sciences[201020(Basic)]Scientific Development Fund Project of Guangxi Academy of Agricultural Sciences(GXAAS 2012JM10)
文摘This study was intended to estimate production of major livestock and poultry manure and contaminant content,and find out current situation of manure pollution,so as to provide reference for pollution control of livestock and poultry breeding industry in Guangxi.Based on the related statistic data in 2010 and the excretion coefficient of different livestock and poultry,the manure and its contaminant production amount of main livestock and poultry in Guangxi were estimated.Then the annual livestock and poultry manure load of farmland and the loss of contaminant were also calculated to analyze the ecological pressure resulted from livestock and poultry breeding in Guangxi.Following results were obtained:in 2010,the production amount of the livestock and poultry manure in Guangxi was 9141.30×104tons,including nutrient TN42.07×104tons and TP 13.62×104tons;the annual livestock and poultry manure and N,P pure nutrient load of farmland was 21t/hm2,98kg/hm2,and 32 kg/hm2respectively;the production amount of manure contaminants was BOD5383.43×104tons,COD Cr435.42×104tons,and NH3-N 42.08×104tons;according to 30%loss rate,the loss amount of COD Cr and NH3-N was higher than the sum of industrial and life waste water.It was concluded that the livestock and poultry breeding industry had little impact on soil environment,but posed a grave threat to water environment.
基金Supported by the Science and Technology Program of Jungar Banner 2021“Demonstration and Promotion of Shrimp Farming Technology in Saline-alkali Land of Jungar Banner”,Science and Technology Program of Hangjin Banner 2023,Shandong Key Laboratory of Marine Ecological Restoration(No.201917)the Central Public-interest Scientific Institution Basal Research Fund,CAFS(No.2023 TD 58)。
文摘Inland culture of shrimp integrated with irrigation could be one of the most feasible livelihood options for many households nearby saline land.Compared with seawater and most of reported brackish water used for shrimp culture,the sulfate content was higher in both surface and ground water in the central Asia.We evaluated the effects of salinity,the SO_(4)^(2-)/Cl^(-)ratio and their interaction on the growth,oxygen consumption,Na+/K+-ATPase activity,total antioxidant capacity(T-AOC),and hepatopancreas histology of Litopenaeus vannamei reared in artificial seawater.The experiment lasted for 30 d,two salinity levels(20 and 10)and four SO_(4)^(2-)/Cl^(-)ratios(0.14,0.577,1.127,and 2.225 mg/mg)of waters were set.Results show no significant differences in survival among groups.Salinity and its interaction effects with SO_(4)^(2-)/Cl^(-)ratio did not significantly affect the final body weight,weight gain,and specific growth rate of shrimps,whereas the SO_(4)^(2-)/Cl^(-)ratio did(P<0.05).Shrimp mean weight gain and specific growth rate at water SO_(4)^(2-)/Cl^(-)ratio of 2.225 were significantly lower than at ratio of 0.14.At salinity 20,the shrimp final body weight at water SO_(4)^(2-)/Cl^(-)ratio of 2.225 was significantly lower than at other ratios(P<0.05),whereas there was no significant difference in final body weight among treatments at salinity 10(P>0.05).Oxygen consumption,Na^(+)/K^(+)-ATPase activity,and T-AOC increased with increasing SO_(4)^(2-)/Cl^(-)ratio at both salinities.L.vannamei exposed to water SO_(4)^(2-)/Cl^(-)ratio of 2.225 at salinity 20 showed severe histopathological changes.This study indicated that L.vannamei has strong tolerance to sulfate in brackish water environment.The shrimp is more adaptable to SO_(4)^(2-)/Cl^(-)ratios below 2.225 at lower salinity,and the optimal SO_(4)^(2-)/Cl^(-)range for the growth is 0.14–0.577(mg/mg)regardless of salinity level.
基金supported by the National Natural Science Foundation of China(Nos.21976106,42005092,and 42105111)the Natural Science Foundation of Shandong Province(Nos.ZR2020QD058 and ZR2021QD144)+1 种基金the Introduction and Cultivation Plan for Young Innovative Talents of Colleges and Universities by the Education Department of Shandong Province(No.142,2019)。
文摘Marine biological activity has long been recognized to impact the atmospheric chemistry of coastal areas.In this work,we monitored the seasonal variation of carbonyl compounds in the coastal city of Qingdao,located in the north of China’s coastline and the south of Jiaodong Peninsula,with the vast hinterland in the west.The mean total concentration of the 15 carbonyls varied significantly between seasons,with the highest observed in autumn(10.2±6.2 ppbv),followed by spring(9.0±3.0 ppbv),winter(6.4±4.0 ppbv)and summer(3.4±1.4 ppbv).Using bivariate analysis,the agricultural emissions from inland areas were responsible for the high levels of carbonyls in the autumn.In summer,clean and humid sea winds helped reduce the concentration of carbonyls,but they also brought air masses from vegetation,and marine organisms,which contributed to high levels of carbonyls in the spring of coastal areas.The observation-based chemistry box model found that the forma-tion of formaldehyde and acetaldehyde was primarily controlled by the RO+O2 reaction,and alkenes oxidation was the main contributing factor.Based on the OH radical loss rate(LOH)and ozone formation potential(OFP)calculation,we found that autumn and spring seasons have significantly higher values of LOH and OFP than winter and summer due to the presence of high concentrations of carbonyl compounds.Therefore,it is believed that these carbonyl compounds primarily originate from agricultural activities,and marine air influences the atmospheric chemistry of the coastal areas.
基金the Natural Science Foundation of Jiangxi Province (0050009)
文摘With weathering crust Ion-Absorbed Type Rare Earth （IATRE） ores in southern Jiangxi as an example, rare earth percolation leaching and leaching solution precipitation process research were carried out under conditions of magnetic field. The effect on the rare earth leaching process such as magnetic field strength, magnetization time, magnetization manner, and other factors were discussed. The effect on the mother rare earth liquor sedimentation rate, purity, and crystallization behavior such as magnetic field strength, magnetization time, and magnetization manner were investigated. Leaching and precipitation mechanism of magnetization on IATRE were analyzed. The results showed that the magnetic treatment can improve leaching rate of weathering crust IATRE and the sedimentation rate, and reduce consumption of reagents.
基金Supported by Fundamental Research Funds for the GXAAS(2015JZ292015JZ302015YT32)
文摘Phytoremediation technology is a newly-developed way of soil heavy metal pollution repair with high efficiency and good ecological comprehensive benefit. This paper briefly introduces the soil heavy metal pollution status at home and abroad,and focuses on the analysis of harm,sources and current situation of soil heavy metal pollution at home and abroad as well as mechanism and application of phytoremediation.Finally it discusses the key problems in phytoremediation technology that need to resolve in the future.
基金supported by the Marine Special Scientific Fund for the Non-profit Public Industry of China (200805031)Fund of Key Laboratory of Fishery Ecology and Environment, Guangdong Province (LFE-20144)Scientific Research Foundation for the Third Institute of Oceanography, State Oceanic Administration (No. 2013031)
文摘The distribution of hexachloroeyclohexanes （HCHs） and dichlorodiphenyltrichloroethanes （DDTs） in the surface sea- water and sediment of Jincheng Bay mariculture area were investigated in the present study. The concentration of total HCHs and DDTs ranged from 2.98 to 14.87ngL-l and were〈0.032ngL-1, respectively, in surface seawater, and ranged from 5.52 to 9.43 and from 4.11 to 6.72 ng g-l, respectively, in surface sediment. It was deduced from the composition profile of HCH isomers and DDT congeners that HCH residues derived from a mixture of technical-grade HCH and lindane whereas the DDT residues derived from technical-grade DDT and dicofol. Moreover, both HCH and DDT residues may mainly originate from historical inputs. The hazard quotient of α-HCH, β-HCH, γ-HCH and δ-HCH to marine species was 0.030, 0.157, 3.008 and 0.008, respectively. It was estimated that the overall probability of adverse biological effect from HCHs was less than 5%, indicating that its risk to seawater column spe- cies was low. The threshold effect concentration exceeding frequency of γ-HCH, p,p＇-DDD, p,p＇-DDE and p,p＇-DDT in sediment ranged from 8.3% to 100%, and the relative concentration of the HCH and DDT mixture exceeded their probable effect level in sediment. These findings indicated that the risk to marine benthos was high and potentially detrimental to the safety of aquatic prod- ucts, e.g., sea cucumber and benthic shellfish.
基金funded by the Natural Science Foundation of China (Grants No. 41771310)the Public welfare industry (agriculture) special research project (Grants No. 201503119-01-01).
文摘Bio-embankment is an important soil and water conservation measure in the purple hilly area in China,which can effectively improve the ability of cultivated soil layers to resist rainfall erosion and runoff scour.In contrast,the ecological effect of bioembankment depends on the stability of the earth bank.Taking the natural grass bank as a control(CK),the root distribution,root tensile properties and shear resistance of root-soil composites for 3 typical soil and water conservation bio-embankments,namely,Morus alba Linn(Morns),Zanthoxylum bungeanum Maxim(Zanthoxylum)and Medicago sativa(Medicago)were analysed.The results included the following:(1)The root system of the bio-embankments generally decreased in extent with the soil depth;fine roots in the o-io cm depth were most prevalent and significantly higher than those at the other depths,and coarse roots were mainly distributed in the o-30cm layer.(2)The stress-strain curves of the roots of each bio-embankment were single-peak curves without clear strain softening phenomena.The smaller the root diameters were,the smoother the stress-strain curves,and the lower the capability of the earth bank to resist collapse.The larger the root diameters were,the lower the tensile strength.The average root tensile force was highest for Zanthoxylum(73.91 N),followed by Medicago(68.07N)and Morus(61.88 N),and the average root tensile strength showed the same trend,16.52 MPa for Zanthoxylum,16.08 MPa for Medicago and 13.02MPa for Morus.(3)The bio-embankment measures significantly improved the soil shear resistance,especially under vertical loads of 1oo kPa and 200kPa.The soil internal friction angle showed a significant log-positive correlation with root morphological parameters of root length density(RLD),root surface area density(RSAD) and rootweight density(RWD),while the soil cohesion force showed a positive linear correlation with these parameters.The results provide effective parameters supporting for the design of bio-embankments and promoting the use of soil reinforcement with suitable species selection in protective earth banks for stability in the purple hilly area.
基金Projects 50274036 supported by the National Natural Science Foundation of China1055G039 by the Mainstay Teacher Originality Innovation Plan Foundation of the Education Department of Heilongjiang Province.
文摘The feasibility of using ultrasound to enhance the performance of de-sulphurization and de-ashing during slime flotation was investigated. The Setararn C80 calorimeter, the contact angle gauge DCAT21 and an electrophoresis apparatus were used to study the surface nature of coal, pyrite and refuse before and after ultrasonic conditioning. The yield, ash and sulfur contents of equally sized coal slimes were also measured before and after ultrasonic conditioning. The results show that ultrasonic conditioning can drive the separation of pyrite and refuse from coal. After ultrasonic conditioning the hydrophobicity of coal and hydrophilicity of pyrite and refuse increase. The perfect index of flotation, the perfect index of de-sulphurization and the percentage of de-sulphurization increase by 22.51%, 25.36% and 2.49%, respectively. This study shows that ultrasonic conditioning can enhance the performance of de-sulphurization and de-ashing of coal flotation methods.
基金co-supported by the President Fund and Innovation Program of Chinese Academy of Sciences(no.:kzcx2-yw-104)the Chinese National Science Foundation grants(no.:40334038)the Science and Technology Key Project of Ministry of Education of China(no.:306016).
文摘The Qaidam Basin, located in the northern margin of the Qinghai-Tibet Plateau, is a large Mesozoic-Cenozoic basin, and bears huge thick Cenozoic strata. The geologic events of the Indian- Eurasian plate-plate collision since -55 Ma have been well recorded. Based on the latest progress in high-resolution stratigraphy, a technique of balanced section was applied to six pieces of northeast- southwest geologic seismic profiles in the central and eastern of the Qaidam Basin to reconstruct the crustal shortening deformation history during the Cenozoic collision. The results show that the Qaidam Basin began to shorten deformation nearly synchronous to the early collision, manifesting as a weak compression, the deformation increased significantly during the Middle and Late Eocene, and then weakened slightly and began to accelerate rapidly since the Late Miocene, especially since the Quaternary, reflecting this powerful compressional deformation and rapid uplift of the northern Tibetan Plateau around the Qaidam Basin.
基金supported by Shandong Provincial Department of Agriculture and Rural Affairs(No.20180163)the National Natural Science Foundation of China-Shandong Joint Fund for Marine Science Research Centers(No.20180165)。
文摘Polycyclic aromatic hydrocarbons(PAHs),as persistent toxic substances(PTS),have been widely monitored in coastal environment,including seawater and sediment.However,scientific monitoring methods,like ecological risk assessment and integrated biomarker response,still need massive researches to verify their availabilities.This study was performed in March,May,August and October of 2018 at eight sites,Yellow River estuary(S1),Guangli Port(S2),Xiaying(S3),Laizhou(S4),Inner Bay(S5),Outer Bay(S6),Hongdao(S7)and Hongshiya(S8)of Shandong Peninsula,China.The contents of 16 priority PAHs in local seawater and sediment were determined,by which ecological risk assessment risk quotient(RQ)for seawater and sediment quality guidelines(SQGs)were calculated to characterize the PAHs pollution.Meanwhile,multiple biomarkers in the digestive gland of clam Ruditapes philippinarum were measured to represent different biological endpoints,including ethoxyresorufin-O-deethylase(EROD),glutathione S-transferase(GST),sulfotransferase(SULT),superoxide dismutase(SOD)and lipid peroxidation(LPO),by which integrated biomarker response(IBR)was calculated to provide a comprehensive assessment of environmental quality.Taken together,these results revealed the heaviest pollution at S2 as both PAHs concentrations and biomarkers responses reflected,and supported the integrated biomarker response as a useful tool for marine environmental monitoring,through its integration with SQGs.
基金Project 2003AA4CS131 supported by the Key Projects for Tackling Scientific and Technological Problems of Harbin
文摘The fly ash from Jixi power plant was treated with various surface modifiers. The surface properties of the modified fly ash,including active index wetting angle,were measured in this paper. The modified fly ash was filled into rubber to improve the rubber properties. The results of rubber tests indicate that the type of the surface modifiers has a great influence on the rubber reinforcing properties. The fly ash modified by titanate coupling agents exhibits the best performance in respect to rubber reinforcing properties. The test results show that the fly ash can take place of some decomposition material so that the dosage of decomposition in rubber can be reduced,resulting in the low producing cost of rubber and the low pollution of fly ash.
基金This study was financially supported by the National Science Foundation of China(NSFC)-Shandong Joint Funds(Nos.U1606404,U1906215)the Ocean Spe-cial Funds for Scientific Research on Public Causes(No.201205001).
文摘Study on morphological changes of a bay can help to identify the effects of anthropogenic activities on coastal environ-ment and guide the exploration of marine resources.In this paper,morphological data including coastline and water areas in five discrete years between 1968 and 2015 were selected and extracted from the remote sensing images and historical marine charts to study the morphological changes in Laizhou Bay(LZB),one of the bays in the southwest of the Bohai Sea.A systematic analysis on spatial variations of the coastline and the surface areas of different types of waters in LZB was conducted.The results showed that the surface area of LZB was decreased by 1253.2km^(2)in the last half century,which is 17.4%of the total in the 1970s.The areas of the natural wetland and the intertidal zone were decreased by 17.2%and 56.1%,respectively,and the average water depth varied from 9.05 m to 8.16m at low tide level from 1968 to 2015.The coastline and shape variations of the bay turned to be complex after the 1980s,and the shape index of LZB showed an increasing trend in more recent years.The centroid of the bay generally migrated to the northeast direction,i.e.,the direction of the center of the Bohai Sea,and the shrinking direction of the bay was consistent with the migration direction of the coastline.The reclamation area during 1968-2015 in LZB was 1201.7km^(2),and 94.1%was in the inter-tidal zone.The overall morphological change of the bay during the last half century was mainly controlled by the coastal reclamation activities,and the Yellow River runoff including the river course change and sediment load variation was also an important control-ling factor.
基金The work was supported by the National Key R&D Program of China(No.2017YFC1600702)the Key Lab of Marine Bioactive Substance and Modern Analytical Technique,SOA(No.MBSMAT-2019-04)+1 种基金the Modern Agro-Industry Technology Research System in Shandong Pro-vince(No.SDAIT-26-05)the National Natural Science Foundation of China(No.31901787).
文摘Semicarbazide has become an important pollutant in the environment,but there was no comprehensive literature on its advances.In this review,the source,biotoxicity and detection methods are summarized.Among the sources is the material of chemical reaction,a metabolite of nitrofurazone,food processing(production by azobisformamide and hypochlorite treatment),endogenous substances,etc.Semicarbazide is demonstrated to be accumulative and reproductive toxicity,mutagenicity and genotoxicity,endocrine disruptors,and neurotoxicity.There are still many controversies on the effect of genotoxicity and no clear result on the carcinogenic mechanism.HPLC-MS/MS is the mainstream of the detection methods.Other methods,including HPLC,immunoassay method,biosensor method,electrochemical detection,capillary electrophoresis technique,and spectral techniques mainly,have become less and less in recent years.On all these counts,to reduce the content of semicarbazide in the environment,the key is to control the use of nitrofurazone as the banned drug effectively.Meanwhile the toxicity data should be supplemented to reveal its toxic mechanism.
基金Supported by the National Key Technology R & D Program(2007B-AD89B15)
文摘Currently,sustainable agricultural development in China is facing some big challenges of how to promote the present developing pattern,to lengthen material transformation chain,to increase the utilization rate of material and energy in agricultural system and to form a healthy agricultural ecological circulation system.China is a major country producing crops and straws.Both high-efficient utilizing pattern of straw and technological system are needed urgently.According to the field survey,we point out the status of straw utilization and the main recycling pattern in typical farming areas in Sichuan,China through the literature review and data collection.Based on the statistical analysis,the economic,environmental and social benefits of each utilization way are analyzed,and the methods and measures are proposed in order to promote recycling utilization of the straw in Sichuan farming area,and to offer theoretical guidance for energy saving,food safety,and pollution control.
基金supported by the Zhejiang Provincial Natural Science Foundation of China(Grant No.LQ19C020007)the National Natural Science Foundation of China(Grant Nos.31901452,31771733,32001104 and 31872857)+2 种基金the Key Research and Development Program of Zhejiang Province,China(Grant No.2021C02002)the Open Project of State Key Laboratory of Rice Biology of China(Grant No.20190402)the Basic Research Foundation of National Commonweal Research Institute of China(Grant No.2017RG004-2).
文摘The effects of putrescine on improving rice growth under aluminum(Al)toxicity conditions have been previously demonstrated,however,the underlying mechanism remains unclear.In this study,treatment with 50 pmol/L Al significantly decreased rice root growth and whole rice dry weight,inhibited Ca2+uptake,decreased ATP syn thesis,and in creased Al,H2O2 and malon dialdehyde(MDA)con tents,whereas the application of putrescine mitigated these negative effects.Putrescine increased root growth and total dry weight of rice,reduced total Al content,decreased H2O2 and MDA contents by increasing antioxidant enzyme(superoxide dismutase,peroxidase,catalase and glutathione S・transferase)activities,increased Ca2+uptake and energy product!oru Proteomic analyses using data-independent acquisition successfully identified 7934 proteins,and 59 representative proteins exhibiting fold-change values higher than 1.5 were randomly selected.From the results of the proteomic and biochemical analyses,we found that putrescine significantly inhibited ethylene biosynthesis and phosphorus uptake in rice roots,increased pectin methylation,decreased pectin content and apoplastic Al deposit!on in rice roots.Putrescine also alleviated Al toxicity by repairing damaged DNA and increasing the proteins involved in maintaining plasma membra ne integrity and normal cell proliferation.These fin dings improve our understanding of how putrescine affects the rice response to Al toxicity,which will facilitate further studies on environmental protection,crop safety,in novations in rice performance and real-world producti on.
基金Supported by the National Natural Science Foundation of China(Nos.41776012,41606107,41576082)the National Key Research and Development Program of China(Nos.2019YFD0901305,2018YFC1407605)+4 种基金the Science and Technology Development Plan Project of Shandong Province(No.2016ZDJS09A02)the Key Research and Development Project of Zhejiang Province(No.2020C03012)the Key Research and Development Project of Guangdong Province(No.2020B1111030002)the Major Science and Technology Project of Sanya YZBSTC(No.YZ2019ZD0X)the Shandong Provincial Natural Science Foundation(No.ZR201911060280)。
文摘The chlorophyll a(Chl a)is an important indicator of marine ecosystems.The spatiotemporal variation of the Chl a greatly aff ects the mariculture and marine ranching in coastal waters of the Shandong Peninsula.In the current study,the climatology and seasonal variability of surface Chl-a concentration around the Shandong Peninsula are investigated based on 16 years(December 2002-November 2018)of satellite observations.The results indicate that the annual mean Chl-a concentration is greater in the Bohai Sea than in the Yellow Sea and decreases from coastal waters to off shore waters.The highest Chl-a concentrations are found in Laizhou Bay(4.2-8.0 mg/m^(3)),Haizhou Bay(4.2-5.9 mg/m^(3))and the northeast coast of the Shandong Peninsula(4.4-5.0 mg/m^(3)),resulting from the combined eff ects of the intense riverine input and long residence time caused by the concave shape of the coastline.The seasonal Chl-a concentration shows a significant spatial variation.The Chl-a concentrations in these three subregions generally exhibit an annual maximum in August/September,due to the combined eff ects of sea surface temperature,river discharge and sea surface wind.In the southeast coast region,however,the Chl-a concentration is lowest throughout the year and reaches a maximum in February with a minimum in July,forced by the seasonal evolution of the Yellow Sea Cold Water and monsoon winds.The interannual Chl-a concentration trends vary among regions and seasons.There are significant increasing trends over a large area around Haizhou Bay from winter to summer,which are mainly caused by the rising sea surface temperature and eutrophication.In other coastal areas,the Chl-a concentration shows decreasing trends,which are clearest in summer and induced by the weakening land rainfall.This study highlights the differences in the Chl-a dynamics among regions around the Shandong Peninsula and is helpful for further studies of coupled physical-ecological-human interactions at multiple scales.
基金supported by the National Natural Science Foundation of China (41372179)the Special Funds for Public Welfare Land and Resources Scientific Project (201311140)
文摘1 Introduction Ostracodes are good materials for studying palaeoenvironmental evolution because of their sensitive response to environment changes.At present,the environmental implications of ostracodes are mainly based
基金Supported by the Public Science and Technology Research Funds Projects of Ocean(No.201205025)the Platform of Aquatic Nutrition and Feed(No.201304001)the Taishan Scholar Fellowship of Shandong Province
文摘The present trial was conducted with starry flounder Platichthys stellatus broodstock to evaluate the effects of dietary vitamin A, ascorbic acid, and a-tocopherol on the gonadal development and reproductive performance. 8 000 IU/kg diet vitaminA （VA group）, 500 mg/kg diet ascorbic acid （Vcpp group）, or 250 mg/kg diet a-tocopherol （a-TA group） was added into basal diet to create 3 vitamin experimental diets, respectively. Each diet was fed to 450 starry flounder broodstock for 104 days. Samples were collected weekly. The gonadosomatic index （GSI） of 3 vitamin experimental groups first decreased and then increased. Maximum GSI of Vcpp group was higher than that of ct-TA group but lower than that of VA group. The spawning periods of 3 vitamin experimental groups lasted 49, 56, and 45 days, respectively. No mature eggs were observed in the control group during the trial. The absolute fecundity （AF） and relative fecundity （RF） of a-TA group was higher than that of Vcpp group but lower than that of VA group. The results suggest that different vitamins play different roles in the fish reproductive process. Vitamin A stimulated the maturation of the ovary, ascorbic acid prolonged the spawning period, and a-tocopherol affected the development of the eggs.
基金The National Natural Science Foundation of China under contract Nos 42076189,41206172 and 61601133the Natural Science Foundation of Beijing under contract No.JQ20021the Remote Sensing Monitoring Project of Geographical Elements in Shandong Yellow River Delta National Nature Reserve—the Remote Sensing Monitoring Technology Project of Spartina alterniflora in Shandong Province in 2020。
文摘Spartina alterniflora as an alien invasive plant,poses a serious threat to the ecological functions of the coastal wetland of the Jiaozhou Bay.As of 2019,the distribution area of S.alterniflora in the Jiaozhou Bay has reached more than 500 hm^(2).For this reason,combined with field surveys,remote sensing monitoring of the invasion S.alterniflora in the Jiaozhou Bay has been carried out.To accurately identify S.alterniflora within the Jiaozhou Bay coastal wetland,we used a new method which is an implement of deep convolutional neural network,and by which we got a higher accuracy than the traditional method.Based on distribution of S.alterniflora extracted by the proposed method,the temporal and spatial distribution characteristics of S.alterniflora were analyzed.And then combined with environmental factors,the invasion mechanism of S.alterniflora in the Jiaozhou Bay was analyzed in detail.From the monitoring results,it can be seen that S.alterniflora in Jiaozhou Bay is mainly distributed in the beaches near the Yanghe River Estuary and its southern side,the Dagu River Estuary and the Nügukou.Spartina alterniflora first broke out near the Yanghe River Estuary and gradually spread to the tidal flats near the Nügukou.The Dagu River Estuary is dominated by S.anglica,whose area has not changed much over the years,and a small amount of S.alterniflora has invaded later.
