Mudflat vegetation plays a crucial role in the ecological function of wetland environment,and obtaining its fine spatial distri-bution is of great significance for wetland protection and management.Remote sensing tech...Mudflat vegetation plays a crucial role in the ecological function of wetland environment,and obtaining its fine spatial distri-bution is of great significance for wetland protection and management.Remote sensing techniques can realize the rapid extraction of wetland vegetation over a large area.However,the imaging of optical sensors is easily restricted by weather conditions,and the backs-cattered information reflected by Synthetic Aperture Radar(SAR)images is easily disturbed by many factors.Although both data sources have been applied in wetland vegetation classification,there is a lack of comparative study on how the selection of data sources affects the classification effect.This study takes the vegetation of the tidal flat wetland in Chongming Island,Shanghai,China,in 2019,as the research subject.A total of 22 optical feature parameters and 11 SAR feature parameters were extracted from the optical data source(Sentinel-2)and SAR data source(Sentinel-1),respectively.The performance of optical and SAR data and their feature paramet-ers in wetland vegetation classification was quantitatively compared and analyzed by different feature combinations.Furthermore,by simulating the scenario of missing optical images,the impact of optical image missing on vegetation classification accuracy and the compensatory effect of integrating SAR data were revealed.Results show that:1)under the same classification algorithm,the Overall Accuracy(OA)of the combined use of optical and SAR images was the highest,reaching 95.50%.The OA of using only optical images was slightly lower,while using only SAR images yields the lowest accuracy,but still achieved 86.48%.2)Compared to using the spec-tral reflectance of optical data and the backscattering coefficient of SAR data directly,the constructed optical and SAR feature paramet-ers contributed to improving classification accuracy.The inclusion of optical(vegetation index,spatial texture,and phenology features)and SAR feature parameters(SAR index and SAR texture features)in the classification algorithm resulted in an OA improvement of 4.56%and 9.47%,respectively.SAR backscatter,SAR index,optical phenological features,and vegetation index were identified as the top-ranking important features.3)When the optical data were missing continuously for six months,the OA dropped to a minimum of 41.56%.However,when combined with SAR data,the OA could be improved to 71.62%.This indicates that the incorporation of SAR features can effectively compensate for the loss of accuracy caused by optical image missing,especially in regions with long-term cloud cover.展开更多
Variable and unpredictable food resources at stopover sites bring severe challenges to migrating shorebirds. Opportunistic foraging strategies, referring to shorebirds consuming prey in proportion to their availabilit...Variable and unpredictable food resources at stopover sites bring severe challenges to migrating shorebirds. Opportunistic foraging strategies, referring to shorebirds consuming prey in proportion to their availability, allow shorebirds to replenish fuel and nutrient reserves efficiently for continuing their migration. Chongming Dongtan, located in the Yangtze River estuary of eastern China, is the first major stopover site of shorebirds on the Chinese mainland during their northward migration. We investigated the diet of Great Knots (Calidris tenuirostris) at Chongming Dongtan during the spring stopovers of 2009 and 2010 through benthos sampling and dropping analysis. The benthos samples were categorized into gastropods, bivalves, polychaetes, crustaceans and insect larvae. Dropping analysis indicated that gastropods and bivalves constituted more than 70% of the diet of the Great Knot, with Assiminea violacea and Corbicula fluminea being the most frequently consumed. Chi-square tests indicated that for each prey category, there was no significant difference between the frequency of its occurrence in the benthos samples and dropping samples during the early stopover periods of 2009 and 2010 and during the late stopover periods of 2010. Although there was a statistically significant difference between the frequency of occurrence of prey in the total macrobenthos and in the droppings of the Great Knots during the late stopover period in 2009, the more abundant prey were more frequently consumed by the Great Knots. This suggests that Great Knots adopted an opportunistic foraging strategy during their stopover at Chongming Dongtan.展开更多
We measured organic carbon input and content of soil in two wetland areas of Chongming Dongtan （Yangtze River Estuary） to evaluate variability in organic carbon accumulation capability in different wetland soils. Ob...We measured organic carbon input and content of soil in two wetland areas of Chongming Dongtan （Yangtze River Estuary） to evaluate variability in organic carbon accumulation capability in different wetland soils. Observed differences were investigated based on the microbial activity and environmental factors of the soil at the two sites. Results showed that the organic carbon content of wetland soil vegetated with Phragmites australis （site A） was markedly lower than that with P. australis and Spartina alterniflora （site B）. Sites differences were due to higher microbial activity at site A, which led to higher soil respiration intensity and greater carbon outputs. This indicated that the capability of organic carbon accumulation of the site B soils was greater than at site A. In addition, petroleum pollution and soil salinity were different in the two wetland soils. After bio-remediation, the soil petroleum pollution at site B was reduced to a similar level of site A. However, the culturable microbial biomass and enzyme activity in the remediated soils were also lower than at site A. These results indicated that greater petroleum pollution at site B did not markedly inhibit soil microbial activity. Therefore, differences in vegetation type and soil salinity were the primary factors responsible for the variation in microbial activity, organic carbon output and organic carbon accumulation capability between site A and site B.展开更多
The environmental quality of heavy metals （Pb, Cd, Cr, As, Hg） in agricultural surface soil of Chongming Island was assessed by national, local and professional standards based on a large scale investigation, in whi...The environmental quality of heavy metals （Pb, Cd, Cr, As, Hg） in agricultural surface soil of Chongming Island was assessed by national, local and professional standards based on a large scale investigation, in which 28 samples from vegetable plots, 65 samples from paddy fields and 9 samples from watermelon fields were collected from whole island area. Results showed that the average concentration of Pb, Cd, Cr, As and Hg was 21.6 mg.kg^-l,0.176 mg.kg^-1, 69.4 mg.kg^-1, 9.209 mg.kg^-1 and 0.128 mg.kg^-1, respectively. Compared with the background value of Shanghai City soil, except for Pb and Cr, all the other heavy metals average concentrations in Chongming Island agricultural surface soil exceeded their corresponding natural-background values. The concentrations of Cd, As and Hg were 33.0%, 1.2% and 26.3% higher than the background value of Shanghai City, respectively. In addition, inverse distance interpolation （IDW） tool of GIS was also applied to study the spatial variation of heavy metals. The results indicated that most of agricultural soil quality was good, and the ratio of ecological, good soil, certified soil and disqualified soil were 1.26%, 97.1%, 1.47% and 0.12%, respectively. About 10.1%, 85.7%, 27.0%, 55.4% and 55.2% soil samples exceeded the Pb, Cd, Cr, As and Hg background value of Shanghai City, respectively. Among these three land use type soils, vegetable soil was most seriously polluted by heavy metals, which is probably related to the over-application of pesticides. The annual deposition fluxes of Pb, Cd, As and Hg were 7736μg·m^-2·a^-1, 208μg·m^-2·a^-1, 2238μg·m^-2·a^-1 and 52.8 μg·m^-2·a^-1 respectively. Crop straw burning was the important source of heavy metals of atmospheric deposition, and atmospheric deposition contributed a lot to heavy metals in agricultural soil in Chongming Island.展开更多
The investigations on the organic carbon （OC） of core sediments were carried out in Chongming east tidal fiat （CM） during Scirpus mariqueter growing stage （from April to December 2004） in Yangtze Estuary. The Ya...The investigations on the organic carbon （OC） of core sediments were carried out in Chongming east tidal fiat （CM） during Scirpus mariqueter growing stage （from April to December 2004） in Yangtze Estuary. The Yangtze River annually transports a runoff discharge of 30,000 m^3/s, carrying about 480 million tons of sediments to the estuarine and coastal area, which formed a great OC pool. In the sampling spots, seven quadrats of 50 cm × 50 cm and five sediments cores of 20 cm deep （40 cm deep in December） were randomly established in order to collect vegetations and core sediments samples during the low tide each month except November. After pretreatment, the core sediments were sieved and their OC contents were measured according to the potassium dichromate method. The results show that the higher surface sediment OC content in summer comes from allochthonous terrigenous particle settlements on the Chongming east middle tidal fiat S. mariqueter zone. In autumn and winter, the decomposing of the defoliated S. mariqueter increases the surface sediments OC content. Settling velocity, sediment temperature and S. mariqueter growth are the main factors that can control the sediment carbon content. Summer is the “carbon losing” period of the tidal fiat sediments, while from September, it changes into the “carbon accumulating” period of sediment OC pool because of the decomposing of dead S. mariqueter community in the sediments. From this alternation of “carbon losing” period and “carbon accumulating” period, we conclude that carbon in the OC pool of the middle tidal fiat S. mariqueter zone sediments mainly comes from the atmospheric carbon rooted by S. mariqueter photosynthesis.展开更多
Salt marshes are research hotspots of the carbon cycle in coastal zones because large amounts of atmospheric carbon dioxide is fi xed by salt marshes vegetation and stored in its biomass and soil.Dissolved organic car...Salt marshes are research hotspots of the carbon cycle in coastal zones because large amounts of atmospheric carbon dioxide is fi xed by salt marshes vegetation and stored in its biomass and soil.Dissolved organic carbon(DOC)in submarine groundwater(well water and pore water)in salt marshes plays an important role in advective exchange between the salt marshes and coastal waters.However,the molecular characteristics of DOC in salt marsh groundwater are poorly understood because of the complex DOC structures and hydrodynamic process.In this study,fl uorescent components and refractory DOC(RDOC)in submarine groundwater from a salt marsh(Chongming Island,China)and adjacent coastal water were characterized by fl uorescence spectroscopy and nuclear magnetic resonance spectroscopy.The fl uorescent components identifi ed by parallel factor analysis indicated that humic-like substances dominated the chromophoric dissolved organic matter in the submarine groundwater.The chromophoric dissolved organic matter and dissolved organic matter in the submarine groundwater had non-conservative behaviors because of additions from terrestrial humic substances.The nuclear magnetic resonance spectra indicated that bioactive substances(carbohydrates)contributed only 13.2%-14.8%of the dissolved organic matter in the submarine groundwater but carboxyl-rich alicyclic molecules(CRAMs),the main components of RDOC,contributed 64.5%of the dissolved organic matter.Carbohydrates and CRAMs contributed 16.4%and 61.7%of the dissolved organic matter in the coastal water,similar to the contributions for submarine groundwater.The DOC concentration in submarine groundwater was 386±294μmol/L,which was signifi cantly higher than that in coastal water(91±19μmol/L).The high DOC concentrations and>60%relative RDOC content suggested that submarine groundwater may be an important source of RDOC to coastal seawater.This information will be helpful for estimating the climate eff ects of salt marsh blue carbon.展开更多
The analysis of vegetation-environment relationships has always been a study hotspot in ecology. A number of biotic, hydrologic and edaphic factors have great influence on the distribution of macrophytes within salt m...The analysis of vegetation-environment relationships has always been a study hotspot in ecology. A number of biotic, hydrologic and edaphic factors have great influence on the distribution of macrophytes within salt marsh.Since the exotic species Spartina alterniflora（S. alterniflora） was introduced in 1995, a rapid expansion has occurred at Chongming Dongtan Nature Reserve（CDNR） in the Changjiang（Yangtze） River Estuary, China.Several important vegetation-environment factors including soil elevation, tidal channels density（TCD）,vegetation classification and fractional vegetation cover（FVC） were extracted by remote sensing method combined with field measurement. To ignore the details in interaction between biological and physical process,the relationship between them was discussed at a large scale of the whole saltmarsh. The results showed that Scirpus mariqueter（S. mariqueter） can endure the greatest elevation variance with 0.33 m throughout the marsh in CDNR. But it is dominant in the area less than 2.5 m with the occurrence frequency reaching 98%. S. alterniflora has usually been found on the most elevated soils higher than 3.5 m but has a narrow spatial distribution. The rapid decrease of S. mariqueter can be explained by stronger competitive capacity of S. alterniflora on the high tidal flat. FVC increases with elevation which shows significant correlation with elevation（r=0.30, p〈0.001）. But the frequency distribution of FVC indicates that vegetation is not well developed on both elevated banks near tidal channels from the whole scale mainly due to tidal channel lateral swing and human activities. The significant negative correlation（r=–0.20, p〈0.001） was found between FVC and TCD, which shows vegetation is restricted to grow in higher TCD area corresponding to lower elevation mainly occupied by S. mariqueter communities. The maximum occurrence frequency of this species reaches to 97% at the salt marsh with TCD more than 8 m/m2.展开更多
With climate change and rising sea levels,the coastal zone’s flood risk is deteriorating.Previous researches have shown a gradually degrading capacity of traditional hard engineering structures(e.g.,seawall,dikes)on ...With climate change and rising sea levels,the coastal zone’s flood risk is deteriorating.Previous researches have shown a gradually degrading capacity of traditional hard engineering structures(e.g.,seawall,dikes)on flood mitigation due to problems such as land subsidence and insufficient maintenance.To remedy the defects,the"building with nature concept"for coastal protection with saltmarshes was examined by combining field measurements and numerical simulations.The advantages of saltmarsh over traditional seawall on flood protection was demonstrated from the perspective of both flood area mitigation and economic gain,based on scenario simulations.Results show that tidal wetlands are essential in mitigating significant wave heights(Hs)and current velocities even during storm conditions.The storm wave and current velocity reduction ratio(RRw and RRc)by saltmarshes on Chongming Dongtan Shoal(CMDS)during Typhoon 9711 is approximately 11%and 51%,respectively.The wave and current mitigation by Scirpus mariqueter are more efficient than Spartina alterniflora and Phragmites australis during measurements in 2010,which were approximately 0.3 m and 0.2 m/s,0.125 m and 0.155 m/s,0.086 m and 0.128 m/s per kilometer width,respectively.The summer saltmarsh area 54.2 km2 on CMDS protects approximately 32 km^(2)land area behind the seawall from being flooded,equivalent to the seawall heightening of approximately 0.42 m on equivalent flood mitigation.The performance of cost-and-benefit analysis shows a relatively higher(by 3%–7%)net present value(NPV)and a higher(by 1.5 times)benefit-cost ratio(BC)of nature-based solution(i.e.,saltmarsh restoration)compared with traditional hard engineering solution(i.e.,seawall construction).Thus,building seawall with nature,such as a hybrid flood protection measure,should be implemented in the future coastal redesign and maintenance.展开更多
Haemaphysalis ticks are pathogenic vectors that threaten human and animal health and were identified in Chongming,the third largest island in China.To understand the distribution of these ticks and determine their pot...Haemaphysalis ticks are pathogenic vectors that threaten human and animal health and were identified in Chongming,the third largest island in China.To understand the distribution of these ticks and determine their potential invasion risk,this study aimed to identify the habitat suitability of the dominant tick H.flava based on natural environmental factors.Geographic information system(GIS)images were combined with sample points from tick investigations to map the spatial distribution of H.flava.Data on 19 bioclimatic variables,environmental variables,and satellite-based landscapes of Chongming Island were retrieved to create a landcover map related to natural environmental determinants of H.flava.These data included 38 sites associated with the vectors to construct species distribution models with MaxEnt,a model based on the maximum entropy principle,and to predict habitat suitability for H.flava on Chongming Island in 2050 and 2070 under different climate scenarios.The model performed well in predicting the H.flava distribution,with a training area under the curve of 0.84 and a test area under the curve of 0.73.A habitat suitability map of the whole study area was created for H.flava.The resulting map and natural environment analysis highlighted the importance of the normalized difference vegetation index and precipitation in the driest month for the bioecology of H.flava,with 141.61 km^(2)(11.77%),282.94 km^(2)(23.35%),and 405.30 km^(2)(33.69%)of highly,moderately,and poorly suitable habitats,respectively.The distribution decreased by 135.55 km^(2) and 138.82 km^(2) in 2050 and 2070,respectively,under the shared socioeconomic pathway(SSP)1.2.6 climate change scenario.However,under SSP 5.8.5,the total area will decrease by 128.5 km^(2) in 2050 and increase by 151.64 km^(2) in 2070.From a One Health perspective,this study provides good knowledge that will guide tick control efforts to prevent the spread of Haemaphysalis ticks or transmission risk of Haemaphysalis-borne infections at the human-animal-environment interface on the island.展开更多
The coastal plain region usually shows the agricultural dominated industry mode, so more and more attention is paid to non-point pollutants discharge. In this study, the method for assessing the influence of non-point...The coastal plain region usually shows the agricultural dominated industry mode, so more and more attention is paid to non-point pollutants discharge. In this study, the method for assessing the influence of non-point pollutants discharge on river water quality is probed which is concluded as follows： （1） Considering the costal plain island is characterized as nearly even elevation, the conventional gravitational runoff confluence method based on eight-point gravitational flowing directions （DS） is unable to compute the runoff confluence received by the surrounding rivers, so a new method of triangular confluence based on three-points of grid center and the river segments is presented. Further the equations of non-point pollutants loads estimation and non-point pollutants confluence on rivers are presented. （2） The integration mode of non-point pollutants model and river water quality model is presented so as to further assess the non-point pollutants contribution to river water quality. （3） With the Chongming Island, the third largest island in China, as an example, the above-mentioned equations are specified. For this island, the non-point pollutants loads are estimated and linked to the developed water quality model of the river network in the island, and further the non-point pollution evolution in river network is simulated. In this scenario, the non-point pollution contribution to river water quality over the whole island is clearly displayed, and the area where the river water quality is seriously influenced by non-point pollutants discharge is distinctly depicted. This scenario also shows the water quality contribution ratio of non-point pollution to point pollution can be in the range of 55.5% to 44.5% which proves the importance of non-point pollution control in costal plain islands.展开更多
Background:Antimicrobial resistance(AMR)is one of the greatest threats to animal and public health.Here,we conducted a dynamic surveillance of Escherichia coli on Chongming Island in Shanghai during 2009-2021 to ident...Background:Antimicrobial resistance(AMR)is one of the greatest threats to animal and public health.Here,we conducted a dynamic surveillance of Escherichia coli on Chongming Island in Shanghai during 2009-2021 to identify the characteristics and trends of Chongming’s AMR pandemic.Methods:Rectal(cloaca)swabs from four poultry and nine swine farms(Chongming Island,2009-2021)were collected for E.coli strains acquisition.The micro-broth dilution method was used to test antimicrobial susceptibility of E.coli isolates against 10 antimicrobial classes including 15 antimicrobials.Utilizing generalized linear mixed models(GLMMs)and co-occurrence analyses,we further explored the multiple-drug-resistance(MDR)combinations and dynamic patterns of E.coli over 10 years in two food animals.Results:Total of 863 MDR isolates were found among 945 collected E.coli isolates,337 from poultry and 608 from swine.Both isolates exhibited high resistant rates(>70%)to tetracyclines,phenicols,sulfonamides,penicillins,and aminoglycosides(only in swine).The resistant rates of swine isolates to penicillins,aminoglycosides,tetracyclines,phenicols,and polymyxins were significantly higher than those of poultry isolates,whereas resistance to fluoroquinolones was reversed.Resistance to polymyxins decreased similarly in swine(42.4%in 2009 to 0.0%in 2021)and poultry isolates(from 16.5%to 0.0%).However,resistance to other seven antimicrobial classes(excluding carbapenems and penicillins)declined dramatically in swine isolates,particularly fluoroquinolones(from 80.5%to 14.4%),and tendencies of resistance to the seven classes showed markedly divergent patterns in poultry isolates.Using Poisson GLMMs,the AMR carriage since 2016 was significantly lower than that of 2009(odds ratio<1),indicating a decline in the risk of MDR emergence.Furthermore,despite the highly diverse MDR profiles,co-occurrence analysis identified two prominent MDR clusters of penicillins-phenicols-fluoroquinolones in poultry and aminoglycosides-tetracyclines-sulfonamides-phenicols in swine.Conclusions:Our study uncovered vastly distinct AMR patterns and dynamic tendencies of poultry and swine E.coli isolates from Chongming.Meanwhile,Chongming’s AMR status has ameliorated,as indicated by the decline in antimicrobials prevalence(particularly in swine),lower likelihood of MDR emergence and low carbapenem-,cephalosporin-,and polymyxin resistance.Importantly,this surveillance results are the vital basis for future policy development in Chongming and Shanghai.展开更多
The spectral reflectance of recently formed salt marshes at the mouth of the Yangtze River,which are undergoing invasion by Spartina alterniflora,were assessed to determine the potential utility of remotely sensed dat...The spectral reflectance of recently formed salt marshes at the mouth of the Yangtze River,which are undergoing invasion by Spartina alterniflora,were assessed to determine the potential utility of remotely sensed data in assessing future invasion and changes in species composition.Following a review of published research on remote sensing of salt marshes,53 locations along three transects were sampled for paired data on plant species composition and spectral reflectance using a FieldSpecTM Pro JR Field Portable Spectroradiometer.Spectral data were processed concerning reflectance,and the averaged reflectance values for each sample were reanalysed to correspond to a 12-waveband bandset of the Compact Airborne Spectral Imager.The spectral data were summarised using principal components analysis(PCA)and the relationships between the vegetation composition,and the PCA axes of spectral data were examined.The first PCA axis of the reflectance data showed a strong correlation with variability in near infrared reflectance and‘brightness’,while the second axis was correlated with visible reflectance and‘greenness’.Total vegetation cover,vegetation height,and mudflat cover were all significantly related to the first axis.The implications of this in terms of the ability of remote sensing to distinguish the various salt marsh species and in particular the invasive species S.alterniflora were discussed.Major differences in species with various physiognomies could be recognised but problems occurred in separating early colonising S.alterniflora from other species at that stage.Further work using multi-seasonal hyperspectral data might assist in solving these problems.展开更多
Thebackground,concept,connotation,principles,andmethodsofeco-planningforanEco-Demonstration Park(EDP)and sustainability were examined based on a case study of the Luhua EDP in the Chongming Island of Shanghai,China,wh...Thebackground,concept,connotation,principles,andmethodsofeco-planningforanEco-Demonstration Park(EDP)and sustainability were examined based on a case study of the Luhua EDP in the Chongming Island of Shanghai,China,which is an important part of Shanghai Eco-city planning and construction in the 21st century.By analyzing natural,social and economic conditions,calculating population using the land capacity eco-model,eco-function zoning,and eco-construction,an innovative eco-industrial structure and technical chain were formulated.A comprehensive eco-planning scheme for the EDP was proposed,including planning and management strategies for subsystems of efficient industry,good quality human settlement,high standard eco-construction and eco-tourism as well as effective environmental protection and attractive landscape.The EDP should be an area with coordinated and sustainable economic,social and environmental subsystems.Eco-planning for the EDP should be a very important part of eco-city planning and sustainability.The paper aims to set up a theoretical framework and practical basis for eco-planning and promoting harmony between human and nature.展开更多
Soil health assessment is an important step toward understanding the potential effects of agricultural practices on crop yield, quality and human health. The objectives of this study were to select a minimum data set ...Soil health assessment is an important step toward understanding the potential effects of agricultural practices on crop yield, quality and human health. The objectives of this study were to select a minimum data set for soil health evaluation from the physical, chemical and biological properties and environmental pollution characteristics of agricultural soil and to develop a soil health diagnosis model for determining the soil health status under different planting patterns and soil types in Chongming Island of Shanghai, China. The results showed that the majority of the farmland soils in Chongming Island were in poor soil health condition, accounting for 48.9% of the survey samples, followed by the medium healthy soil, accounting for 32.2% of the survey samples and mainly distributed in the central and mid-eastern regions of the island. The indicators of pH, total organic carbon, microbial biomass carbon and Cd exerted less influence on soil health, while the soil salinization and nitrate accumulation under a greenhouse cropping pattern and phosphate fertilizer shortage in the paddy field had limited the development of soil health. Dichlorodiphenyltrichloroethanes, hexachlorocyclohexanes and Hg contributed less to soil health index (SHI) and showed no significant difference among paddy field, greenhouse and open-air vegetable/watermelon fields. The difference of the SHI of the three soil types was significant at P = 0.05. The paddy soil had the highest SHI values, followed by the gray alluvial soil, and the coastal saline soil was in a poor soil health condition, indicating a need to plant some salt-tolerant crops to effectively improve soil quality.展开更多
The spatial and seasonal pattern of macrozoobenthic structure and its relationship with environmental factors were studied from July 2006 to April 2008 in Mingzhu Lake,Chongming Island,Shanghai at the Changjiang River...The spatial and seasonal pattern of macrozoobenthic structure and its relationship with environmental factors were studied from July 2006 to April 2008 in Mingzhu Lake,Chongming Island,Shanghai at the Changjiang River mouth.The congruences in water quality bioassessment based on diversity and biotic indices and using different taxonomic categories were also explored to find the best assessment method of water quality for the lake.All major structural characteristics of macrozoobenthic community,including species composition,abundance,biomass and four biomass-based diversity indices(Shannon's diversity,Simpson's diversity,Pielou's evenness and Simpson's evenness index) fluctuated significantly in season but in space.The above four abundance-based diversity indices plus abundance-based Margalef's richness index did not display significant spatial variations;and significant seasonal differences were found in three indices only.Water temperature was the key environmental factor responsible for macrozoobenthic spatio-temporal distribution patterns.Water quality assessed by Shannon's index(H_a') and biological pollution index(BPI) rather than the other four biotic indices were consistent with those by trophic state index(TSI).Results from chironomids and oligochaetes did not always agree to those from the whole community when H_a' or Hilsenhoff biotic index was applied to bioassessment.Therefore,combining multiple indices and avoiding a single taxonomic category to assess water quality are strongly recommended and in Mingzhu Lake using a mixture of H_a' and BPI will ensure the most effective investigation of water quality.Our results also show that the main structural characteristics of macrozoobenthic communities in the small lake may display consistent spatial patterns.展开更多
Aims Although many studies have reported net gains of soil organic carbon(SOC)after afforestation on croplands,this is uncertain for Chinese paddy rice croplands.Here,we aimed to evaluate the effects of affores-tation...Aims Although many studies have reported net gains of soil organic carbon(SOC)after afforestation on croplands,this is uncertain for Chinese paddy rice croplands.Here,we aimed to evaluate the effects of affores-tation of paddy rice croplands on SOC sequestration and soil respiration(R).Such knowledge would improve our understanding of the efctive-ness of various land use options on greenhouse gas mitigation in China.Methods The investigation was conducted on the Chongming Island,north subtropical China.Field sites were reclaimed from coastal salt marshes in the 1960s,and soils were homogeneous with simple land use:histories.SOC stocks and R,levels were monitored over one year in a paddy rice cropland,an evergreen and a deciduous broad-leaved plantation established on previous paddy fields and a reference fal-low land site never cultivated.Laboratory incubation of soil under fast-changing temperatures was used to compare the temperature sensitivity(Q10)of SOC decomposition across land uses.Important Findings After 15-20 years of afforestation on paddy fields,SOC concentra-tion only slightly increased at the depth of 0--5 cm but decreased in deeper layers,which resulted in a net loss of SOC stock in the top 40cm.Seasonal increase of sOC was observed during the rice-growing period in croplands but not in afforested soils,suggest-ing a stronger SOC sequestration by paddy rice cropping.However,SOC sequestered under cropping was more labile,as indicated by its higher contents of dissolved organic carbon and microbial bio-mass.Also,paddy soils had higher annual R,than afforested soils;R,abruptly increased after paddy fields were drained and plowed and remained distinctively high throughout the dry farming period.Laboratory incubation revealed that paddy soils had a much higher Q10 of SOC decomposition than afforested soils.Given that tem-perature was the primary controller of R,in this region,it was con-cluded that despite the stronger SOC sequestration by paddy rice cropping,its SOC was less stable than in afforested systems and might be more easily released into the atmosphere under global warming.展开更多
The assessment of river ecosystem health is crucial for improving river resilience,achieving ecological protection and rational utilization in the Yangtze Estuary region where there is high utilization of rivers and a...The assessment of river ecosystem health is crucial for improving river resilience,achieving ecological protection and rational utilization in the Yangtze Estuary region where there is high utilization of rivers and a high demand for quality rivers by Shanghai,the world’s largest modern city.To assess the ecological health status of Yangtze Estuary rivers,this study established a river health assessment model consisting of five dimensions:water quality,river landscape,aquatic organisms,river hydrology,and human interference,and a total of ten indicators based on the ecological survey results in the summer and autumn of six river channels in Chongming Island in the Yangtze Estuary.The evaluation results reveal that the health status of rural rivers in the northwest and east of Chongming Island(S2,S3)is the best,reaching an excellent level,while the small river in the central part of Chongming Island(S6)is the worst,reaching a somewhat inferior level.Compared with rural rivers,the comprehensive evaluation results of urban rivers are good or ordinary level.The high proportion of building area on both sides of the river and the low vegetation cover are the main factors that restrict their scoring results.In contrast,rural rivers need to focus on the area of buffer zones such as forests and vegetation on both sides of the river,river connectivity,appropriate widening of narrow rivers,regular cleaning and dredging of rivers,as well as reducing human interference with the rivers.Regarding seasonal changes,the health assessment results of Chongming Island rivers in summer are better than those in autumn,and the differences between sites in summer are slightly greater than those in autumn.The seasonal differences between sites are mainly due to changes in indicators of the diversity of zooplankton,phytoplankton,and macrobenthos.To further improve the ecological health of rivers,measures of ecological restoration could be adjusted based on regular health assessment and health weakness analysis.展开更多
基金Under the auspices of the National Key Research and Development Program of China(No.2023YFC3208500)Shanghai Municipal Natural Science Foundation(No.22ZR1421500)+3 种基金National Natural Science Foundation of China(No.U2243207)National Science and Technology Basic Resources Survey Project(No.2023FY01001)Open Research Fund of State Key Laboratory of Estuarine and Coastal Research(No.SKLEC-KF202406)Project from Science and Technology Commission of Shanghai Municipality(No.22DZ1202700)。
文摘Mudflat vegetation plays a crucial role in the ecological function of wetland environment,and obtaining its fine spatial distri-bution is of great significance for wetland protection and management.Remote sensing techniques can realize the rapid extraction of wetland vegetation over a large area.However,the imaging of optical sensors is easily restricted by weather conditions,and the backs-cattered information reflected by Synthetic Aperture Radar(SAR)images is easily disturbed by many factors.Although both data sources have been applied in wetland vegetation classification,there is a lack of comparative study on how the selection of data sources affects the classification effect.This study takes the vegetation of the tidal flat wetland in Chongming Island,Shanghai,China,in 2019,as the research subject.A total of 22 optical feature parameters and 11 SAR feature parameters were extracted from the optical data source(Sentinel-2)and SAR data source(Sentinel-1),respectively.The performance of optical and SAR data and their feature paramet-ers in wetland vegetation classification was quantitatively compared and analyzed by different feature combinations.Furthermore,by simulating the scenario of missing optical images,the impact of optical image missing on vegetation classification accuracy and the compensatory effect of integrating SAR data were revealed.Results show that:1)under the same classification algorithm,the Overall Accuracy(OA)of the combined use of optical and SAR images was the highest,reaching 95.50%.The OA of using only optical images was slightly lower,while using only SAR images yields the lowest accuracy,but still achieved 86.48%.2)Compared to using the spec-tral reflectance of optical data and the backscattering coefficient of SAR data directly,the constructed optical and SAR feature paramet-ers contributed to improving classification accuracy.The inclusion of optical(vegetation index,spatial texture,and phenology features)and SAR feature parameters(SAR index and SAR texture features)in the classification algorithm resulted in an OA improvement of 4.56%and 9.47%,respectively.SAR backscatter,SAR index,optical phenological features,and vegetation index were identified as the top-ranking important features.3)When the optical data were missing continuously for six months,the OA dropped to a minimum of 41.56%.However,when combined with SAR data,the OA could be improved to 71.62%.This indicates that the incorporation of SAR features can effectively compensate for the loss of accuracy caused by optical image missing,especially in regions with long-term cloud cover.
基金supported by the National Natural Science Foundation of China(Grant No.30670269,31071939)
文摘Variable and unpredictable food resources at stopover sites bring severe challenges to migrating shorebirds. Opportunistic foraging strategies, referring to shorebirds consuming prey in proportion to their availability, allow shorebirds to replenish fuel and nutrient reserves efficiently for continuing their migration. Chongming Dongtan, located in the Yangtze River estuary of eastern China, is the first major stopover site of shorebirds on the Chinese mainland during their northward migration. We investigated the diet of Great Knots (Calidris tenuirostris) at Chongming Dongtan during the spring stopovers of 2009 and 2010 through benthos sampling and dropping analysis. The benthos samples were categorized into gastropods, bivalves, polychaetes, crustaceans and insect larvae. Dropping analysis indicated that gastropods and bivalves constituted more than 70% of the diet of the Great Knot, with Assiminea violacea and Corbicula fluminea being the most frequently consumed. Chi-square tests indicated that for each prey category, there was no significant difference between the frequency of its occurrence in the benthos samples and dropping samples during the early stopover periods of 2009 and 2010 and during the late stopover periods of 2010. Although there was a statistically significant difference between the frequency of occurrence of prey in the total macrobenthos and in the droppings of the Great Knots during the late stopover period in 2009, the more abundant prey were more frequently consumed by the Great Knots. This suggests that Great Knots adopted an opportunistic foraging strategy during their stopover at Chongming Dongtan.
基金supported by the National Key Scientific and Technological Project (No.2006BAC01A14)the Shanghai Key Scientific and Technological Project (No.06DZ12302)
文摘We measured organic carbon input and content of soil in two wetland areas of Chongming Dongtan （Yangtze River Estuary） to evaluate variability in organic carbon accumulation capability in different wetland soils. Observed differences were investigated based on the microbial activity and environmental factors of the soil at the two sites. Results showed that the organic carbon content of wetland soil vegetated with Phragmites australis （site A） was markedly lower than that with P. australis and Spartina alterniflora （site B）. Sites differences were due to higher microbial activity at site A, which led to higher soil respiration intensity and greater carbon outputs. This indicated that the capability of organic carbon accumulation of the site B soils was greater than at site A. In addition, petroleum pollution and soil salinity were different in the two wetland soils. After bio-remediation, the soil petroleum pollution at site B was reduced to a similar level of site A. However, the culturable microbial biomass and enzyme activity in the remediated soils were also lower than at site A. These results indicated that greater petroleum pollution at site B did not markedly inhibit soil microbial activity. Therefore, differences in vegetation type and soil salinity were the primary factors responsible for the variation in microbial activity, organic carbon output and organic carbon accumulation capability between site A and site B.
基金National Natural Science Foundation of China, No.40701164, No.40730526 Public Project of Ministry of Environmental Protection of China, No.WFLY-2009-1-SK-06-03 National Key Water Program during the 1 lth Five-Year Plan Period, No.2009ZX07317-006
文摘The environmental quality of heavy metals （Pb, Cd, Cr, As, Hg） in agricultural surface soil of Chongming Island was assessed by national, local and professional standards based on a large scale investigation, in which 28 samples from vegetable plots, 65 samples from paddy fields and 9 samples from watermelon fields were collected from whole island area. Results showed that the average concentration of Pb, Cd, Cr, As and Hg was 21.6 mg.kg^-l,0.176 mg.kg^-1, 69.4 mg.kg^-1, 9.209 mg.kg^-1 and 0.128 mg.kg^-1, respectively. Compared with the background value of Shanghai City soil, except for Pb and Cr, all the other heavy metals average concentrations in Chongming Island agricultural surface soil exceeded their corresponding natural-background values. The concentrations of Cd, As and Hg were 33.0%, 1.2% and 26.3% higher than the background value of Shanghai City, respectively. In addition, inverse distance interpolation （IDW） tool of GIS was also applied to study the spatial variation of heavy metals. The results indicated that most of agricultural soil quality was good, and the ratio of ecological, good soil, certified soil and disqualified soil were 1.26%, 97.1%, 1.47% and 0.12%, respectively. About 10.1%, 85.7%, 27.0%, 55.4% and 55.2% soil samples exceeded the Pb, Cd, Cr, As and Hg background value of Shanghai City, respectively. Among these three land use type soils, vegetable soil was most seriously polluted by heavy metals, which is probably related to the over-application of pesticides. The annual deposition fluxes of Pb, Cd, As and Hg were 7736μg·m^-2·a^-1, 208μg·m^-2·a^-1, 2238μg·m^-2·a^-1 and 52.8 μg·m^-2·a^-1 respectively. Crop straw burning was the important source of heavy metals of atmospheric deposition, and atmospheric deposition contributed a lot to heavy metals in agricultural soil in Chongming Island.
基金NationalNaturalScience Foundation ofChina,No.40173030No.40131020+3 种基金ExcellentYoung TeacherProgram ofthe M inistry ofEducationKey Program ofShanghaiScience Foundation,No.02DJ14029Science & TechnologyDepartment of Shanghai, No.04DZ19301 Project
文摘The investigations on the organic carbon （OC） of core sediments were carried out in Chongming east tidal fiat （CM） during Scirpus mariqueter growing stage （from April to December 2004） in Yangtze Estuary. The Yangtze River annually transports a runoff discharge of 30,000 m^3/s, carrying about 480 million tons of sediments to the estuarine and coastal area, which formed a great OC pool. In the sampling spots, seven quadrats of 50 cm × 50 cm and five sediments cores of 20 cm deep （40 cm deep in December） were randomly established in order to collect vegetations and core sediments samples during the low tide each month except November. After pretreatment, the core sediments were sieved and their OC contents were measured according to the potassium dichromate method. The results show that the higher surface sediment OC content in summer comes from allochthonous terrigenous particle settlements on the Chongming east middle tidal fiat S. mariqueter zone. In autumn and winter, the decomposing of the defoliated S. mariqueter increases the surface sediments OC content. Settling velocity, sediment temperature and S. mariqueter growth are the main factors that can control the sediment carbon content. Summer is the “carbon losing” period of the tidal fiat sediments, while from September, it changes into the “carbon accumulating” period of sediment OC pool because of the decomposing of dead S. mariqueter community in the sediments. From this alternation of “carbon losing” period and “carbon accumulating” period, we conclude that carbon in the OC pool of the middle tidal fiat S. mariqueter zone sediments mainly comes from the atmospheric carbon rooted by S. mariqueter photosynthesis.
基金Supported by the Natural Science Foundation of Shanghai(No.19ZR1415300)the Zhejiang Provincial Natural Science Foundation of China(No.LQ21D060005)the China Postdoctoral Science Foundation(No.2020M681931)。
文摘Salt marshes are research hotspots of the carbon cycle in coastal zones because large amounts of atmospheric carbon dioxide is fi xed by salt marshes vegetation and stored in its biomass and soil.Dissolved organic carbon(DOC)in submarine groundwater(well water and pore water)in salt marshes plays an important role in advective exchange between the salt marshes and coastal waters.However,the molecular characteristics of DOC in salt marsh groundwater are poorly understood because of the complex DOC structures and hydrodynamic process.In this study,fl uorescent components and refractory DOC(RDOC)in submarine groundwater from a salt marsh(Chongming Island,China)and adjacent coastal water were characterized by fl uorescence spectroscopy and nuclear magnetic resonance spectroscopy.The fl uorescent components identifi ed by parallel factor analysis indicated that humic-like substances dominated the chromophoric dissolved organic matter in the submarine groundwater.The chromophoric dissolved organic matter and dissolved organic matter in the submarine groundwater had non-conservative behaviors because of additions from terrestrial humic substances.The nuclear magnetic resonance spectra indicated that bioactive substances(carbohydrates)contributed only 13.2%-14.8%of the dissolved organic matter in the submarine groundwater but carboxyl-rich alicyclic molecules(CRAMs),the main components of RDOC,contributed 64.5%of the dissolved organic matter.Carbohydrates and CRAMs contributed 16.4%and 61.7%of the dissolved organic matter in the coastal water,similar to the contributions for submarine groundwater.The DOC concentration in submarine groundwater was 386±294μmol/L,which was signifi cantly higher than that in coastal water(91±19μmol/L).The high DOC concentrations and>60%relative RDOC content suggested that submarine groundwater may be an important source of RDOC to coastal seawater.This information will be helpful for estimating the climate eff ects of salt marsh blue carbon.
基金Program Strategic Scientific Alliances between China and the Netherlands under contract No.2008DFB90240Open Research Fund Program for State Key Laboratory of Estuarine and Coastal Research under contract No.SKLEC201207Open Research Fund Program for Shandong Province Key Laboratory of Marine Ecology Environment and Disaster Prevention under contract No.2012011
文摘The analysis of vegetation-environment relationships has always been a study hotspot in ecology. A number of biotic, hydrologic and edaphic factors have great influence on the distribution of macrophytes within salt marsh.Since the exotic species Spartina alterniflora（S. alterniflora） was introduced in 1995, a rapid expansion has occurred at Chongming Dongtan Nature Reserve（CDNR） in the Changjiang（Yangtze） River Estuary, China.Several important vegetation-environment factors including soil elevation, tidal channels density（TCD）,vegetation classification and fractional vegetation cover（FVC） were extracted by remote sensing method combined with field measurement. To ignore the details in interaction between biological and physical process,the relationship between them was discussed at a large scale of the whole saltmarsh. The results showed that Scirpus mariqueter（S. mariqueter） can endure the greatest elevation variance with 0.33 m throughout the marsh in CDNR. But it is dominant in the area less than 2.5 m with the occurrence frequency reaching 98%. S. alterniflora has usually been found on the most elevated soils higher than 3.5 m but has a narrow spatial distribution. The rapid decrease of S. mariqueter can be explained by stronger competitive capacity of S. alterniflora on the high tidal flat. FVC increases with elevation which shows significant correlation with elevation（r=0.30, p〈0.001）. But the frequency distribution of FVC indicates that vegetation is not well developed on both elevated banks near tidal channels from the whole scale mainly due to tidal channel lateral swing and human activities. The significant negative correlation（r=–0.20, p〈0.001） was found between FVC and TCD, which shows vegetation is restricted to grow in higher TCD area corresponding to lower elevation mainly occupied by S. mariqueter communities. The maximum occurrence frequency of this species reaches to 97% at the salt marsh with TCD more than 8 m/m2.
基金The National Natural Science Foundation of China under contract Nos 51761135024,42171282 and 41701001the Key Projects of Intergovernmental Science and Technology Innovation Cooperation of the Ministry of Science and Technology in China under contract No.2018YFE0109900+1 种基金the International Science&Technology Cooperation s of Shanghai Science and Technology Commission under contract No.19230712400the China Postdoctoral Science Foundation under contract No.2018M630414。
文摘With climate change and rising sea levels,the coastal zone’s flood risk is deteriorating.Previous researches have shown a gradually degrading capacity of traditional hard engineering structures(e.g.,seawall,dikes)on flood mitigation due to problems such as land subsidence and insufficient maintenance.To remedy the defects,the"building with nature concept"for coastal protection with saltmarshes was examined by combining field measurements and numerical simulations.The advantages of saltmarsh over traditional seawall on flood protection was demonstrated from the perspective of both flood area mitigation and economic gain,based on scenario simulations.Results show that tidal wetlands are essential in mitigating significant wave heights(Hs)and current velocities even during storm conditions.The storm wave and current velocity reduction ratio(RRw and RRc)by saltmarshes on Chongming Dongtan Shoal(CMDS)during Typhoon 9711 is approximately 11%and 51%,respectively.The wave and current mitigation by Scirpus mariqueter are more efficient than Spartina alterniflora and Phragmites australis during measurements in 2010,which were approximately 0.3 m and 0.2 m/s,0.125 m and 0.155 m/s,0.086 m and 0.128 m/s per kilometer width,respectively.The summer saltmarsh area 54.2 km2 on CMDS protects approximately 32 km^(2)land area behind the seawall from being flooded,equivalent to the seawall heightening of approximately 0.42 m on equivalent flood mitigation.The performance of cost-and-benefit analysis shows a relatively higher(by 3%–7%)net present value(NPV)and a higher(by 1.5 times)benefit-cost ratio(BC)of nature-based solution(i.e.,saltmarsh restoration)compared with traditional hard engineering solution(i.e.,seawall construction).Thus,building seawall with nature,such as a hybrid flood protection measure,should be implemented in the future coastal redesign and maintenance.
基金supported in part by The International Joint Laboratory on Tropical Diseases Control in the Greater Mekong Subregion fund(21410750200)the Science and Technology Commission of Shanghai,China and The Science and Technology Innovation Project fund of the School of Global Health,Shanghai Jiao Tong University School of Medicine(SGHKJCX2021-05,SGHKJCX2021-04),China.
文摘Haemaphysalis ticks are pathogenic vectors that threaten human and animal health and were identified in Chongming,the third largest island in China.To understand the distribution of these ticks and determine their potential invasion risk,this study aimed to identify the habitat suitability of the dominant tick H.flava based on natural environmental factors.Geographic information system(GIS)images were combined with sample points from tick investigations to map the spatial distribution of H.flava.Data on 19 bioclimatic variables,environmental variables,and satellite-based landscapes of Chongming Island were retrieved to create a landcover map related to natural environmental determinants of H.flava.These data included 38 sites associated with the vectors to construct species distribution models with MaxEnt,a model based on the maximum entropy principle,and to predict habitat suitability for H.flava on Chongming Island in 2050 and 2070 under different climate scenarios.The model performed well in predicting the H.flava distribution,with a training area under the curve of 0.84 and a test area under the curve of 0.73.A habitat suitability map of the whole study area was created for H.flava.The resulting map and natural environment analysis highlighted the importance of the normalized difference vegetation index and precipitation in the driest month for the bioecology of H.flava,with 141.61 km^(2)(11.77%),282.94 km^(2)(23.35%),and 405.30 km^(2)(33.69%)of highly,moderately,and poorly suitable habitats,respectively.The distribution decreased by 135.55 km^(2) and 138.82 km^(2) in 2050 and 2070,respectively,under the shared socioeconomic pathway(SSP)1.2.6 climate change scenario.However,under SSP 5.8.5,the total area will decrease by 128.5 km^(2) in 2050 and increase by 151.64 km^(2) in 2070.From a One Health perspective,this study provides good knowledge that will guide tick control efforts to prevent the spread of Haemaphysalis ticks or transmission risk of Haemaphysalis-borne infections at the human-animal-environment interface on the island.
基金supported by the Scientific Research Project of Chongming Island of Shanghai Science and Technology Commision(Grant No. 06dz12037)
文摘The coastal plain region usually shows the agricultural dominated industry mode, so more and more attention is paid to non-point pollutants discharge. In this study, the method for assessing the influence of non-point pollutants discharge on river water quality is probed which is concluded as follows： （1） Considering the costal plain island is characterized as nearly even elevation, the conventional gravitational runoff confluence method based on eight-point gravitational flowing directions （DS） is unable to compute the runoff confluence received by the surrounding rivers, so a new method of triangular confluence based on three-points of grid center and the river segments is presented. Further the equations of non-point pollutants loads estimation and non-point pollutants confluence on rivers are presented. （2） The integration mode of non-point pollutants model and river water quality model is presented so as to further assess the non-point pollutants contribution to river water quality. （3） With the Chongming Island, the third largest island in China, as an example, the above-mentioned equations are specified. For this island, the non-point pollutants loads are estimated and linked to the developed water quality model of the river network in the island, and further the non-point pollution evolution in river network is simulated. In this scenario, the non-point pollution contribution to river water quality over the whole island is clearly displayed, and the area where the river water quality is seriously influenced by non-point pollutants discharge is distinctly depicted. This scenario also shows the water quality contribution ratio of non-point pollution to point pollution can be in the range of 55.5% to 44.5% which proves the importance of non-point pollution control in costal plain islands.
基金This study was supported by the National Natural Science Foundation of China(Grant No.32170141)China Medical Board(No.20-365)Shanghai Jiao Tong University Integrated Innovation Fund(no.2020-01)。
文摘Background:Antimicrobial resistance(AMR)is one of the greatest threats to animal and public health.Here,we conducted a dynamic surveillance of Escherichia coli on Chongming Island in Shanghai during 2009-2021 to identify the characteristics and trends of Chongming’s AMR pandemic.Methods:Rectal(cloaca)swabs from four poultry and nine swine farms(Chongming Island,2009-2021)were collected for E.coli strains acquisition.The micro-broth dilution method was used to test antimicrobial susceptibility of E.coli isolates against 10 antimicrobial classes including 15 antimicrobials.Utilizing generalized linear mixed models(GLMMs)and co-occurrence analyses,we further explored the multiple-drug-resistance(MDR)combinations and dynamic patterns of E.coli over 10 years in two food animals.Results:Total of 863 MDR isolates were found among 945 collected E.coli isolates,337 from poultry and 608 from swine.Both isolates exhibited high resistant rates(>70%)to tetracyclines,phenicols,sulfonamides,penicillins,and aminoglycosides(only in swine).The resistant rates of swine isolates to penicillins,aminoglycosides,tetracyclines,phenicols,and polymyxins were significantly higher than those of poultry isolates,whereas resistance to fluoroquinolones was reversed.Resistance to polymyxins decreased similarly in swine(42.4%in 2009 to 0.0%in 2021)and poultry isolates(from 16.5%to 0.0%).However,resistance to other seven antimicrobial classes(excluding carbapenems and penicillins)declined dramatically in swine isolates,particularly fluoroquinolones(from 80.5%to 14.4%),and tendencies of resistance to the seven classes showed markedly divergent patterns in poultry isolates.Using Poisson GLMMs,the AMR carriage since 2016 was significantly lower than that of 2009(odds ratio<1),indicating a decline in the risk of MDR emergence.Furthermore,despite the highly diverse MDR profiles,co-occurrence analysis identified two prominent MDR clusters of penicillins-phenicols-fluoroquinolones in poultry and aminoglycosides-tetracyclines-sulfonamides-phenicols in swine.Conclusions:Our study uncovered vastly distinct AMR patterns and dynamic tendencies of poultry and swine E.coli isolates from Chongming.Meanwhile,Chongming’s AMR status has ameliorated,as indicated by the decline in antimicrobials prevalence(particularly in swine),lower likelihood of MDR emergence and low carbapenem-,cephalosporin-,and polymyxin resistance.Importantly,this surveillance results are the vital basis for future policy development in Chongming and Shanghai.
基金This research was funded by the Key Project of the Shanghai Science and Technology Committee(Grant No.06DZ12302)National Basic Research Program of China(Grant No.2004CB720505).
文摘The spectral reflectance of recently formed salt marshes at the mouth of the Yangtze River,which are undergoing invasion by Spartina alterniflora,were assessed to determine the potential utility of remotely sensed data in assessing future invasion and changes in species composition.Following a review of published research on remote sensing of salt marshes,53 locations along three transects were sampled for paired data on plant species composition and spectral reflectance using a FieldSpecTM Pro JR Field Portable Spectroradiometer.Spectral data were processed concerning reflectance,and the averaged reflectance values for each sample were reanalysed to correspond to a 12-waveband bandset of the Compact Airborne Spectral Imager.The spectral data were summarised using principal components analysis(PCA)and the relationships between the vegetation composition,and the PCA axes of spectral data were examined.The first PCA axis of the reflectance data showed a strong correlation with variability in near infrared reflectance and‘brightness’,while the second axis was correlated with visible reflectance and‘greenness’.Total vegetation cover,vegetation height,and mudflat cover were all significantly related to the first axis.The implications of this in terms of the ability of remote sensing to distinguish the various salt marsh species and in particular the invasive species S.alterniflora were discussed.Major differences in species with various physiognomies could be recognised but problems occurred in separating early colonising S.alterniflora from other species at that stage.Further work using multi-seasonal hyperspectral data might assist in solving these problems.
基金This work was supported by the National Social Science Key Foundation of China(Grant No.06&ZD024)the National Natural Science Foundation of China(Grant No.39930040)the Funding of Department of Science and Technology of Shanghai,China(No.06dz12304).
文摘Thebackground,concept,connotation,principles,andmethodsofeco-planningforanEco-Demonstration Park(EDP)and sustainability were examined based on a case study of the Luhua EDP in the Chongming Island of Shanghai,China,which is an important part of Shanghai Eco-city planning and construction in the 21st century.By analyzing natural,social and economic conditions,calculating population using the land capacity eco-model,eco-function zoning,and eco-construction,an innovative eco-industrial structure and technical chain were formulated.A comprehensive eco-planning scheme for the EDP was proposed,including planning and management strategies for subsystems of efficient industry,good quality human settlement,high standard eco-construction and eco-tourism as well as effective environmental protection and attractive landscape.The EDP should be an area with coordinated and sustainable economic,social and environmental subsystems.Eco-planning for the EDP should be a very important part of eco-city planning and sustainability.The paper aims to set up a theoretical framework and practical basis for eco-planning and promoting harmony between human and nature.
基金Supported by the Major National Science and Technology Project of Water Pollution Control and Treatment,China(No.2009ZX07317-006)the National Natural Science Foundation of China(No.40971259)the Shanghai Excellent Academic Leaders Plan,China(No.10XD1401600)
文摘Soil health assessment is an important step toward understanding the potential effects of agricultural practices on crop yield, quality and human health. The objectives of this study were to select a minimum data set for soil health evaluation from the physical, chemical and biological properties and environmental pollution characteristics of agricultural soil and to develop a soil health diagnosis model for determining the soil health status under different planting patterns and soil types in Chongming Island of Shanghai, China. The results showed that the majority of the farmland soils in Chongming Island were in poor soil health condition, accounting for 48.9% of the survey samples, followed by the medium healthy soil, accounting for 32.2% of the survey samples and mainly distributed in the central and mid-eastern regions of the island. The indicators of pH, total organic carbon, microbial biomass carbon and Cd exerted less influence on soil health, while the soil salinization and nitrate accumulation under a greenhouse cropping pattern and phosphate fertilizer shortage in the paddy field had limited the development of soil health. Dichlorodiphenyltrichloroethanes, hexachlorocyclohexanes and Hg contributed less to soil health index (SHI) and showed no significant difference among paddy field, greenhouse and open-air vegetable/watermelon fields. The difference of the SHI of the three soil types was significant at P = 0.05. The paddy soil had the highest SHI values, followed by the gray alluvial soil, and the coastal saline soil was in a poor soil health condition, indicating a need to plant some salt-tolerant crops to effectively improve soil quality.
基金Supported by the Promotion Project of Developing Agriculture through Science and Technology of Shanghai Municipality(No.3-4 in 2006)the Open Project of Key Laboratory of Freshwater Biodiversity Conservation and Utilization,Certificated by Ministry of Agriculturethe Shanghai University Knowledge Service Platform,Shanghai Ocean University Aquatic Animal Breeding Center(No.ZF1206)
文摘The spatial and seasonal pattern of macrozoobenthic structure and its relationship with environmental factors were studied from July 2006 to April 2008 in Mingzhu Lake,Chongming Island,Shanghai at the Changjiang River mouth.The congruences in water quality bioassessment based on diversity and biotic indices and using different taxonomic categories were also explored to find the best assessment method of water quality for the lake.All major structural characteristics of macrozoobenthic community,including species composition,abundance,biomass and four biomass-based diversity indices(Shannon's diversity,Simpson's diversity,Pielou's evenness and Simpson's evenness index) fluctuated significantly in season but in space.The above four abundance-based diversity indices plus abundance-based Margalef's richness index did not display significant spatial variations;and significant seasonal differences were found in three indices only.Water temperature was the key environmental factor responsible for macrozoobenthic spatio-temporal distribution patterns.Water quality assessed by Shannon's index(H_a') and biological pollution index(BPI) rather than the other four biotic indices were consistent with those by trophic state index(TSI).Results from chironomids and oligochaetes did not always agree to those from the whole community when H_a' or Hilsenhoff biotic index was applied to bioassessment.Therefore,combining multiple indices and avoiding a single taxonomic category to assess water quality are strongly recommended and in Mingzhu Lake using a mixture of H_a' and BPI will ensure the most effective investigation of water quality.Our results also show that the main structural characteristics of macrozoobenthic communities in the small lake may display consistent spatial patterns.
基金Ministry of Science and Technology of China(2010CB950604)National Major Scientific and Technological Project in China(2010BAK69B14)+2 种基金National Natural Science Foundation of China(30970556,31170386)Doctoral Program of Higher Education of China(20093227110004)Key Project of the Shanghai Scientific and Technological Committee(10DZ1200700).
文摘Aims Although many studies have reported net gains of soil organic carbon(SOC)after afforestation on croplands,this is uncertain for Chinese paddy rice croplands.Here,we aimed to evaluate the effects of affores-tation of paddy rice croplands on SOC sequestration and soil respiration(R).Such knowledge would improve our understanding of the efctive-ness of various land use options on greenhouse gas mitigation in China.Methods The investigation was conducted on the Chongming Island,north subtropical China.Field sites were reclaimed from coastal salt marshes in the 1960s,and soils were homogeneous with simple land use:histories.SOC stocks and R,levels were monitored over one year in a paddy rice cropland,an evergreen and a deciduous broad-leaved plantation established on previous paddy fields and a reference fal-low land site never cultivated.Laboratory incubation of soil under fast-changing temperatures was used to compare the temperature sensitivity(Q10)of SOC decomposition across land uses.Important Findings After 15-20 years of afforestation on paddy fields,SOC concentra-tion only slightly increased at the depth of 0--5 cm but decreased in deeper layers,which resulted in a net loss of SOC stock in the top 40cm.Seasonal increase of sOC was observed during the rice-growing period in croplands but not in afforested soils,suggest-ing a stronger SOC sequestration by paddy rice cropping.However,SOC sequestered under cropping was more labile,as indicated by its higher contents of dissolved organic carbon and microbial bio-mass.Also,paddy soils had higher annual R,than afforested soils;R,abruptly increased after paddy fields were drained and plowed and remained distinctively high throughout the dry farming period.Laboratory incubation revealed that paddy soils had a much higher Q10 of SOC decomposition than afforested soils.Given that tem-perature was the primary controller of R,in this region,it was con-cluded that despite the stronger SOC sequestration by paddy rice cropping,its SOC was less stable than in afforested systems and might be more easily released into the atmosphere under global warming.
基金financially supported by the Innovation Program of Shanghai Municipal Education Commission(2019-01-07-00-05-E00027)the National Natural Science Foundation of China(U2240220)+4 种基金the Open Research Fund of Key Laboratory of Ocean Space Resource Management Technology(KF-2022-105)China Postdoctoral Science Foundation(2021M691023)Innovation Program of Shanghai Municipal Education Commission,2019-01-07-00-05-E00027,Ya Ping WangNational Natural Science Foundation of China,U2240220,Ya Ping WangKey Laboratory of Ocean Space Resource Management Technology,MNR,KF-2022-105,Benwei Shi。
文摘The assessment of river ecosystem health is crucial for improving river resilience,achieving ecological protection and rational utilization in the Yangtze Estuary region where there is high utilization of rivers and a high demand for quality rivers by Shanghai,the world’s largest modern city.To assess the ecological health status of Yangtze Estuary rivers,this study established a river health assessment model consisting of five dimensions:water quality,river landscape,aquatic organisms,river hydrology,and human interference,and a total of ten indicators based on the ecological survey results in the summer and autumn of six river channels in Chongming Island in the Yangtze Estuary.The evaluation results reveal that the health status of rural rivers in the northwest and east of Chongming Island(S2,S3)is the best,reaching an excellent level,while the small river in the central part of Chongming Island(S6)is the worst,reaching a somewhat inferior level.Compared with rural rivers,the comprehensive evaluation results of urban rivers are good or ordinary level.The high proportion of building area on both sides of the river and the low vegetation cover are the main factors that restrict their scoring results.In contrast,rural rivers need to focus on the area of buffer zones such as forests and vegetation on both sides of the river,river connectivity,appropriate widening of narrow rivers,regular cleaning and dredging of rivers,as well as reducing human interference with the rivers.Regarding seasonal changes,the health assessment results of Chongming Island rivers in summer are better than those in autumn,and the differences between sites in summer are slightly greater than those in autumn.The seasonal differences between sites are mainly due to changes in indicators of the diversity of zooplankton,phytoplankton,and macrobenthos.To further improve the ecological health of rivers,measures of ecological restoration could be adjusted based on regular health assessment and health weakness analysis.
